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Objective Methods Results Interpretation Rehabilitation is thought to reduce ataxia severity in individuals with hereditary cerebellar ataxia (HCA). This multicenter, randomized controlled superiority trial aimed to examine the efficacy of a 30‐week goal‐directed rehabilitation program compared with 30 weeks of standard care on function, ataxia, health‐related quality of life, and balance in individuals with an HCA.Individuals with an autosomal dominant or recessive ataxia (aged ≥15 years) were enrolled at 5 sites in Australia. Participants were randomized (1:1) to receive rehabilitation (6 weeks of outpatient physiotherapy followed by a 24‐week home exercise program) (n = 39) or continued their usual activity (n = 37). The primary outcome measure was the motor domain of the Functional Independence Measure (mFIM) at 7 weeks. Secondary outcomes included the Scale for the Assessment and Rating of Ataxia (SARA) and the SF‐36v2, assessed at 7, 18, and 30 weeks. Outcome assessors were blinded to treatment allocation.Seventy‐one participants (rehabilitation, 37; standard‐care, 34) were included in the intention‐to‐treat analysis. At 7 weeks, mFIM (mean difference 2.26, 95% confidence interval [CI]: 0.26 to 4.26, p = 0.028) and SARA (−1.21, 95% CI: −2.32 to −0.11, p = 0.032) scores improved after rehabilitation compared with standard care. Compared with standard care, rehabilitation improved SARA scores at 30 weeks (mean difference −1.51, 95% CI: −2.76 to −0.27, p = 0.017), but not mFIM scores (1.74, 95% CI: −0.32 to 3.81, p = 0.098). Frequent adverse events in both groups were fatigue, pain, and falls.Goal‐directed rehabilitation improved function at 7 weeks, with improvement in ataxia and health‐related quality of life maintained at 30 weeks in individuals with HCA, beyond that of standard care. ANN NEUROL 2024 [ABSTRACT FROM AUTHOR]

Spinocerebellar ataxia type 6 (SCA6) is a polyglutamine disorder caused by the expansion of CAG repeats in the gene encoding voltage‐gated calcium channel subunit alpha1 A (CACNA1A). The clinical features of SCA6 include slowly progressive cerebellar ataxia and downbeat positioning nystagmus. The clinical significance of 19 CAG repeats is unclear. We report a case with 19/11 CAG repeats in CACNA1A determined by direct sequencing. The case presented with DPN, which is one of the most important symptoms of SCA6, but did not present with ataxia. [ABSTRACT FROM AUTHOR]

Background: Spinocerebellar ataxia type 21 (SCA21) is a rare inherited neurological disorder characterized by motor, cognitive, and behavioral disturbances, caused by autosomal dominant TMEM240 variants. Objectives: To identify the genetic cause of a dystonic tremor with autosomal dominant inheritance. Methods: Six subjects of a multi‐generational French family affected by tremor and dystonia were studied. Each patient underwent a comprehensive clinical assessment and a whole‐exome sequencing analysis. Results: All six subjects presented with early‐onset prominent hand dystonic tremor and multifocal/generalized dystonia, secondarily developing mild cerebellar ataxia. The younger generation showed more pronounced cognitive and behavioral impairment. The known pathogenic TMEM240 c.509C>T (p.P170L) variant was found in heterozygosis in all subjects. Conclusions: Dystonic tremor can represent the core clinical feature of SCA21, even in absence of overt cerebellar ataxia. Therefore, TMEM240 pathogenic variants should be considered disease‐causing in subjects displaying dystonic tremor, variably associated with ataxia, parkinsonism, neurodevelopmental disorders, and cognitive impairment. [ABSTRACT FROM AUTHOR]

Background: This systematic review and meta‐analysis aimed to assess the effectiveness of non‐invasive brain stimulation (NIBS), including repetitive transcranial magnetic stimulation (rTMS) and transcranial electrical stimulation (tES), as a neurological intervention for degenerative cerebellar ataxia (DCA) based on preregistration (PROSPERO: CRD42023379192). Objective: We aimed to explore clinical outcomes and examine the parameters associated with NIBS efficacy in DCA patients. Methods: The PubMed, Cochrane Library, CHINAL, and PEDro databases were searched for relevant randomized controlled trials (RCTs). Data extraction, quality assessment, and heterogeneity analyses were conducted; the Grading, Recommendations, Assessment, Development, and Evaluation was used to assess the quality of evidence and a meta‐analysis was performed. Results: Seventeen RCTs that included 661 patients on the scale for assessment and rating of ataxia (SARA) and 606 patients on the International Cooperative Ataxia Rating Scale (ICARS) were included. These RCTs showed a serious risk of bias (RoB) and low certainty of evidence for both outcomes. NIBS significantly reduced SARA (MD = −2.49, [95% confidence interval: −3.34, −1.64]) and ICARS (−5.27 [−7.06, −3.47]); the subgroup analysis showed significant effects: rTMS and tES reduced both outcomes. However, there were no significant differences in the effects of rTMS and tES. Additional subgroup analysis indicated the impact of rTMS frequency and the total number of tES sessions on ataxia. Conclusion: Non‐invasive brain stimulation may reduce ataxia in DCA patients, but the estimated effect size may change in future studies because the RoB was serious and the certainty of evidence was low, and the heterogeneity was high. To establish evidence for selecting NIBS methods and parameters, continued high‐quality RCTs are required. [ABSTRACT FROM AUTHOR]

Background: Strokes in young individuals often stem from unusual causes. Posterior circulation ischemic stroke caused by vertebral artery insufficiency due to atlantoaxial instability or dislocation is rare. We present a case of posterior circulation ischemic stroke due to an unstable os odontoideum and review the current literature. The clinical features and imaging manifestations are described to promote awareness of etiology, early diagnosis, and assessment. Case Presentation: A 24‐year‐old male presented with recurrent right‐sided limb numbness and weakness and cerebellar ataxia due to posterior circulation ischemic stroke. The work‐up revealed thrombosis reformation in the tortuous left vertebral artery. It is noteworthy that the patient developed compression and chronic damage of the vertebral artery secondary to atlantoaxial instability and lateral dislocation due to an os odontoideum. He underwent antiplatelet and anticoagulant therapy, cervical traction, and posterior atlantoaxial screw fixation and fusion with iliac crest autograft. The postoperative course was uneventful. At 6‐month follow‐up, the patient had a solid fusion mass and rigid stability of the atlantoaxial joint without neurologic deficits or ischemic sequelae. Conclusions: For unexplained posterior circulation ischemic stroke, it is important to consider unstable os odontoideum as a potential etiology, especially in pediatric and young adult male patients. Atlantoaxial instability and dislocation with os odontoideum, especially when occurring laterally, may cause insufficiency of the vertebral artery and subsequent posterior circulation ischemic strokes. The significance of lateral atlantoaxial dislocation in the genesis of vertebral artery injury and the necessity for specific positional imaging are emphasized. [ABSTRACT FROM AUTHOR]

Cerebellar ataxia, neuropathy, and vestibular areflexia syndrome (CANVAS) is caused by biallelic pathogenic expansions, or compound heterozygosity with other pathogenic variants in the RFC1 gene. CANVAS is estimated to be underdiagnosed, both because of the lack of formal diagnostic criteria and molecular challenges that translate to lesser access and high cost of routine testing. Our aim was to address the need for making CANVAS genetic testing routine, by designing a streamlined two‐step PCR consisting of a short‐allele screening PCR and a confirmatory PCR with fragment capillary electrophoresis detection. Exome sequencing of RFC1 was additionally foreseen to resolve potential compound heterozygosity cases. Specificity of our approach was evaluated using ataxia patients with known non‐CANVAS diagnoses, and optimized using Southern blot confirmed CANVAS patients. We evaluated our approach by testing patients consecutively referred for clinically suspected CANVAS using first the two‐step PCR, followed by exome sequencing. Our approach was able to accurately identify negative and confirm positive cases in prospectively collected suspected CANVAS patients presenting with at least three typical clinical signs. The proposed testing approach provides an alternative method able to clearly distinguish between CANVAS negative and positive cases and can be easily incorporated into the genetic diagnostic laboratory workflow. [ABSTRACT FROM AUTHOR]

Objective Methods Results Interpretation Patients with ovarian cancer (OC) may develop anti‐Yo‐associated paraneoplastic cerebellar degeneration (PCD)—a cerebellar ataxia associated with tumor‐induced autoimmunity against CDR2 and CDR2L proteins. Dysregulation of circulating exosomal microRNAs (miRNAs) occur in OC. Here, we investigated whether PCD is associated with changes in the exosomal miRNA profiles of OC patients.Serum exosomes were isolated from patients with OC (n = 15), patients with OC and anti‐Yo‐associated PCD (n = 14) and healthy controls (HC, n = 15). Small RNA sequencing was used to identify differentially expressed miRNAs. Receiver operating characteristic curves were used to evaluate biomarker sensitivity and specificity, and miRNA target prediction analysis was employed to elucidate gene targets.OC patients with PCD exhibited a distinct exosomal miRNA expression profile. We detected 103 differentially expressed exosomal miRNAs in PCD patients compared to OC patients without PCD and 139 differentially expressed exosomal miRNAs compared to controls. Particularly miR‐486‐5p, miR‐4732‐5p, miR‐98‐5p and miR‐21‐5p exhibited notable sensitivity and specificity for discriminating PCD patients from both OC patients without PCD and healthy controls. miRNA target prediction showed that several of the differentially expressed miRNAs in PCD patients targeted the CDR2 and CDR2L genes.Our results demonstrate that OC patients with anti‐Yo‐associated PCD exhibit a distinct exosomal miRNA profile compared to OC patients without PCD. Several of the differentially expressed exosomal miRNAs in PCD patients showed diagnostic potential and may hold relevance for understanding the pathogenesis of PCD. [ABSTRACT FROM AUTHOR]

This article discusses the natural history of dystonia in patients with SYNE1 ataxia, a late-onset autosomal recessive cerebellar syndrome. The study focuses on a Brazilian cohort of seven patients who were evaluated over a five-year period. The researchers found that dystonia in SYNE1 ataxia is rare but can manifest as focal hand dystonia or upper extremity dystonia. The article provides detailed clinical and demographic features of the patients and discusses the progression of dystonia symptoms over time. Additionally, the article explores the relationship between the use of trihexyphenidyl and muscle activity in patients with ATX-SYNE1, a form of autosomal recessive cerebellar ataxia. It presents neuroimaging results, neurophysiological findings, blood work, and genetic tests related to the condition. The article suggests that cerebellar abnormalities may contribute to the development of dystonic symptoms in ATX-SYNE1 patients and concludes that dystonia should be considered as part of the multisystemic phenotype of ATX-SYNE1. [Extracted from the article]

Background: POLIII‐related leukodystrophies are a group of recently recognized hereditary white matter diseases with a similar clinical and radiological phenotype. No Tunisian studies have been published about POLIII‐related leukodystrophy due to POLR3A variants. The aim of this study was to contribute to the clinical, radiological, and genetic characterization of POLR3A‐related leukodystrophy in a Tunisian cohort. Methods: We report six cases of genetically confirmed POLR3A‐related leukodystrophy belonging to six unrelated Tunisian families, along with a review of previously published pediatric cases. Results: All patients were born to consanguineous marriages and originated from the North or the Center of Tunisia. Age at onset varied between 15 months and 6 years. The clinical phenotype was similar in all patients with cerebellar ataxia, tremor, and nystagmus being the key features. Brain imaging showed diffuse hypomyelination in all patients with progressive cerebellar atrophy in three patients. Molecular analysis identified the same bi‐allelic NM_007055.4:c.2011T>C; p.(Trp671Arg) variant in the POLR3A gene in all patients. Conclusion: We hypothesize a founder effect for the identified variant given its recurrence in six unrelated individuals with a similar clinical phenotype. Given the apparent genetic homogeneity of Tunisian POLR3A patients, the recurrent variant should be directly targeted. This should facilitate diagnosis in index patients, and genetic counseling. [ABSTRACT FROM AUTHOR]

Aim: To investigate the current status of chewing ability and analyze the risk factors among Chinese community‐dwelling older adults. Methods: In this cross‐sectional study, color‐changeable gum and a color difference meter were used to assess chewing ability in the population. The statistical analysis employed multivariate logistic regression models to identify and quantify the factors influencing chewing ability. Results: A total of 373 community‐dwelling adults aged 65 and older in Chengdu, in the west of China, were included in this study; 64 individuals (17.2%) exhibited signs of poor chewing ability. Female (odds ratio [OR]: 0.124, 95% CI: 0.057–0.268, p <.001), education level with college degree and above (OR: 0.114, 95% CI: 0.030–0.434, p =.001), number of teeth less than 20 (OR: 5.401, 95% CI: 2.509–11.626, p <.001), and decreased oral diadochokinesis (OR: 4.445, 95% CI: 1.775–11.132, p =.001) were significant factors in chewing ability in this study, after adjustment for potential variables. Conclusions: The prevalence of decreased chewing ability among Chinese community‐dwelling older adults was 17.2% and decreased chewing ability was associated with men, lower education level, less than 20 teeth and decreased oral diadochokinesis. [ABSTRACT FROM AUTHOR]

Background and Aims Methods Results Interpretation Ultrasound nerve cross‐sectional area (CSA) of patients affected with axonal neuropathy usually shows normal value. Cerebellar ataxia, neuropathy and vestibular areflexia syndrome (CANVAS) seems to represent an exception, showing smaller CSA, but previous reports did not test for biallelic RFC1 gene repeat expansions.We compared nerve CSA from CANVAS patients (tested positive for biallelic RFC1 gene repeat expansions) with the CSA from a group of patients with chronic idiopathic axonal polyneuropathy (CIAP) who tested negative for RFC1 gene repeat expansions, hereditary axonal neuropathy (Charcot‐Marie‐Tooth type 2, CMT2), and Friedreich ataxia (FRDA).We enrolled 15 CANVAS patients (eight men, mean age 66.3 ± 11.5 years, mean disease duration 9.3 ± 4.1 years), affected with sensory axonal neuronopathy. Controls consisted of 13 CIAP (mean age 68.5 ± 12.8 years, seven men), seven CMT2 (mean age 47.9 ± 18.1 years, four men), 12 FRDA (mean age 33.7 ± 8.8, five men). Nerve ultrasound was performed at median, ulnar, sciatic, sural, and tibial nerves and brachial plexus, bilaterally. The nerve CSA from CANVAS patients was significantly smaller than the one from the other cohorts at several sites with significant and high accuracy at Receiver‐operating characteristic (ROC) curve analyses. RFC1 AAGGG pentanucleotide expansion, disease duration, and disability did not correlate with CSA at any site, after Bonferroni correction.Decreased sonographic nerve sizes, in arms and legs, in patients with sensory neuropathy and normal motor conduction studies could point to CANVAS‐spectrum disease and help guide appropriate genetic testing. [ABSTRACT FROM AUTHOR]

We report an autopsy case of a 70‐year‐old man who was clinically diagnosed with atypical progressive supranuclear palsy (PSP). He initially presented with gait ataxia and then showed vertical gaze palsy, rigidity, akinesia, dysphagia, and mild cognitive impairment, followed by prominent upper motor signs later in the course of the disease. Cranial magnetic resonance imaging revealed tegmental atrophy of the midbrain. Autopsy revealed severe neuronal loss and gliosis in the motor cortex and corticospinal degeneration and mild to moderate neuronal loss and gliosis in the basal ganglia, substantia nigra, midbrain, and pons. Tufted astrocytes were primarily found in the motor cortex and basal ganglia. Globose‐type neurofibrillary tangles were observed in the locus coeruleus and nucleus olivaris inferior. In the cerebellar cortex, mild Purkinje cell loss and scattered axonal torpedoes were observed with tau‐positive Purkinje cells. The dentate nucleus displayed severe neuronal loss and gliosis. The present case showed characteristics of both PSP with prominent cerebellar ataxia (PSP‐C) and PSP‐primary lateral sclerosis (PSP‐PLS). [ABSTRACT FROM AUTHOR]

Background Objective Methods Results Conclusions There are more than 30 immunoglobulin G (IgG) autoantibody biomarkers of autoimmune cerebellar ataxia reported.To describe a novel IgG biomarker targeting neurobeachin, a scaffolding protein integral to synapse formation and function.Clinical and laboratory‐based assessment was used for a novel diagnostic biomarker of autoimmune ataxia.A 46‐year‐old woman had ataxia onset followed by bilateral knee pain, attributable to rheumatoid arthritis. She was negative for standard neural antibodies. Her ataxia stabilized and tremor initially improved after corticosteroid treatment, but she progressed to wheelchair‐dependence (on methotrexate and then rituximab) over 4 years, in keeping with the trajectory encountered by many with autoimmune ataxia. In contrast, her inflammatory arthritis remitted with immunotherapy. Neurobeachin‐IgG was unmasked in serum and cerebrospinal fluid using protein arrays and confirmed using neurobeachin‐specific confocal immunofluorescence and Western blot.Neurobeachin‐IgG is a new neural antibody biomarker of cerebellar ataxia among a growing antibody repertoire, collectively common but often individually rare. © 2024 International Parkinson and Movement Disorder Society. [ABSTRACT FROM AUTHOR]

Background: Biallelic variants in the major facilitator superfamily domain containing 8 gene (MFSD8) are associated with distinct clinical presentations that range from typical late‐infantile neuronal ceroid lipofuscinosis type 7 (CLN7 disease) to isolated adult‐onset retinal dystrophy. Classic late‐infantile CLN7 disease is a severe, rare neurological disorder with an age of onset typically between 2 and 6 years, presenting with seizures and/or cognitive regression. Its clinical course is progressive, leading to premature death, and often includes visual loss due to severe retinal dystrophy. In rare cases, pathogenic variants in MFSD8 can be associated with isolated non‐syndromic macular dystrophy with variable age at onset, in which the disease process predominantly or exclusively affects the cones of the macula and where there are no neurological or neuropsychiatric manifestations. Methods: Here we present longitudinal studies on four adult‐onset patients who were biallelic for four MFSD8 variants. Results: Two unrelated patients who presented with adult‐onset ataxia and had macular dystrophy on examination were homozygous for a novel variant in MFSD8 NM_152778.4: c.935T>C p.(Ile312Thr). Two other patients presented in adulthood with visual symptoms, and one of these developed mild to moderate cerebellar ataxia years after the onset of visual symptoms. Conclusions: Our observations expand the knowledge on biallelic pathogenic MFSD8 variants and confirm that these are associated with a spectrum of more heterogeneous clinical phenotypes. In MFSD8‐related disease, adult‐onset recessive ataxia can be the presenting manifestation or may occur in combination with retinal dystrophy. [ABSTRACT FROM AUTHOR]

Objective: Transcranial sonography (TCS) is a noninvasive neuroimaging technique, visualizing deep brain structures and the ventricular system. Although widely employed in diagnosing various movement disorders, such as Parkinson's disease and dystonia, by detecting disease‐specific abnormalities, the specific characteristics of the TCS in cerebellar ataxia remain inconclusive. We aimed to assess the potential value of TCS in patients with cerebellar ataxias for disease diagnosis and severity assessment. Methods: TCS on patients with genetic and acquired cerebellar ataxia, including 94 with spinocerebellar ataxias (SCAs) containing 10 asymptomatic carriers, 95 with cerebellar subtype of multiple system atrophy (MSA‐C), and 100 healthy controls (HC), was conducted. Assessments included third ventricle width, substantia nigra (SN) and lentiform nucleus (LN) echogenicity, along with comprehensive clinical evaluations and genetic testing. Results: The study revealed significant TCS abnormalities in patients with cerebellar ataxia, such as enlarged third ventricle widths and elevated rates of hyperechogenic SN and LN. TCS showed high accuracy in distinguishing patients with SCA or MSA‐C from HC, with an AUC of 0.870 and 0.931, respectively. TCS abnormalities aided in identifying asymptomatic SCA carriers, effectively differentiating them from HC, with an AUC of 0.725. Furthermore, third ventricle width was significantly correlated with SARA and ICARS scores in patients with SCA3 and SCOPA‐AUT scores in patients with MSA‐C. The SN area and SARA or ICARS scores in patients with SCA3 were also positively correlated. Interpretation: Our findings illustrate remarkable TCS abnormalities in patients with cerebellar ataxia, serving as potential biomarkers for clinical diagnosis and progression assessment. [ABSTRACT FROM AUTHOR]

Granuloprival degeneration is an uncommon form of cerebellar cortical degeneration (CCD). A 3‐month‐old Yorkshire Terrier and a 7‐month‐old Lagotto Romagnolo dog were presented with a history of progressive cerebellar dysfunction including wide‐based stance, cerebellar ataxia, intention tremors, and loss of menace response despite normal vision. Magnetic resonance imaging of the brain identified marked diffuse decrease of the cerebellum size. Euthanasia was performed in both cases because of progression of clinical signs. Histopathological examination identified marked diffuse thinning of the granular cell layer with almost complete loss of the granular cell neurons, providing a definitive diagnosis of granuloprival CCD. Granuloprival CCD should be considered as a differential diagnosis in Yorkshire Terrier and Lagotto Romagnolo dogs with post‐natal progressive clinical signs of cerebellar dysfunction. [ABSTRACT FROM AUTHOR]

Background: Autosomal recessive spastic ataxia ofCharlevoix–Saguenay (ARSACS) is a rare neurodegenerative disorder characterizedby early‐onset cerebellar ataxia, peripheral sensorimotor neuropathy, and lowerlimb spasticity. We present clinical andgenetic data of the first Bulgarian patients diagnosed with ARSACS by wholeexome sequencing (WES). Methods: Variant filtering was performed usinglocally established pipeline and the selected variants were analysed by Sangersequencing. All patients underwent clinical examination and testingincluding the standard rating scales for spastic paraplegia and ataxia. Results: Five different SACS gene variants, three of which novel, have been identified inpatients from three different ethnic groups. In addition to the classicalclinical triad, brain MRI revealed cerebellar atrophy, linear pontineT2‐hypointensities, and hyperintense rim lateral tothalamus combined with retinal nerve fiber layer thickening on opticcoherence tomography (OCT). Conclusion: We expand the mutation, geographic, and phenotypic spectrum of ARSACS, adding Bulgaria to the world map of the disease, and drawing attention to the fact that it is still misdiagnosed. We demonstrated that brain MRI and OCT are necessary clinical tests for ARSACS diagnosis, even if one of the cardinal clinical features is lacking [ABSTRACT FROM AUTHOR]

Key Clinical Message: This case report highlights the challenges of diagnosing MSA‐C in resource‐limited settings. MRI findings like the "hot cross bun" sign can be supportive, but the unavailability of advanced tools like seed amplification assay may delay diagnosis. Early diagnosis is crucial for proper symptom management. Multiple system atrophy is a rare neurodegenerative disorder affecting the pyramidal, autonomic, nigrostriatal, and cerebellar tracts. Multisystem atrophy should be considered in adults with progressive motor or autonomic dysfunctions. Clinical manifestations vary depending on the system, including bradykinesia, tremor, rigidity, cerebellar ataxia, and autonomic failure. Depending on the initial predominant manifestation, multisystem atrophy is classified as Parkinsonian (MSA‐P) and cerebellar (MSA‐C). Our patient presented with progressive loss of balance, rigidity, slurred speech, choking episodes, and loss of morning tumescence for 4 years, suggesting autonomic and cerebellar involvement. He was diagnosed with MSA after 4 years of initial presentation with combinations of magnetic resonant imaging findings and clinical manifestations. Diagnosing multiple system atrophy in such resource‐limited areas is challenging. The unavailability of seed application tests and biomarkers significantly affected the delayed diagnosis. [ABSTRACT FROM AUTHOR]

Objective: Biallelic mutations in PRDX3 have been linked to autosomal recessive spinocerebellar ataxia type 32. In this study, which aims to contribute to the growing body of knowledge on this rare disease, we identified two unrelated patients with mutations in PRDX3. We explored the impact of PRDX3 mutation in patient skin fibroblasts and the role of the gene in neurodevelopment. Methods: We performed trio exome sequencing that identified mutations in PRDX3 in two unrelated patients. We also performed functional studies in patient skin fibroblasts and generated a "crispant" zebrafish (Danio rerio) model to investigate the role of the gene during nervous system development. Results: Our study reports two additional patients. Patient 1 is a 19‐year‐old male who showed a novel homozygous c.525_535delGTTAGAAGGTT (p. Leu176TrpfsTer11) mutation as the genetic cause of cerebellar ataxia. Patient 2 is a 20‐year‐old male who was found to present the known c.425C>G/p. Ala142Gly variant in compound heterozygosity with the p. Leu176TrpfsTer11 one. While the fibroblast model failed to recapitulate the pathological features associated with PRDX3 loss of function, our functional characterization of the prdx3 zebrafish model revealed motor defects, increased susceptibility to reactive oxygen species‐triggered apoptosis, and an impaired oxygen consumption rate. Conclusions: We identified a new variant, thereby expanding the genetic spectrum of PRDX3‐related disease. We developed a novel zebrafish model to investigate the consequences of prdx3 depletion on neurodevelopment and thus offered a potential new tool for identifying new treatment opportunities. [ABSTRACT FROM AUTHOR]

Background: Spinocerebellar ataxia 29 (SCA29) is a rare genetic disorder characterized by early‐onset ataxia, gross motor delay, and infantile hypotonia, and is primarily associated with variants in the ITPR1 gene. Cases of SCA29 in Asia are rarely reported, limiting our understanding of this disease. Methods: A female Korean infant, demonstrating clinical features of SCA29, underwent evaluation and rehabilitation at our outpatient clinic from the age of 3 months to the current age of 4 years. Trio‐based genome sequencing tests were performed on the patient and her biological parents. Results: The infant initially presented with macrocephaly, hypotonia, and nystagmus, with nonspecific findings on initial neuroimaging. Subsequent follow‐up revealed gross motor delay, early onset ataxia, strabismus, and cognitive impairment. Further neuroimaging revealed atrophy of the cerebellum and vermis, and genetic analysis revealed a de novo pathogenic heterozygous c.800C>T, p.Thr267Met missense mutation in the ITPR1 gene (NM_001378452.1). Conclusion: This is the first reported case of SCA29 in a Korean patient, expanding the genetic and phenotypic spectrum of ITPR1‐related ataxias. Our case highlights the importance of recognizing early‐onset ataxic symptoms, central hypotonia, and gross motor delays with poor ocular fixation, cognitive deficits, and isolated cerebellar atrophy as crucial clinical indicators of SCA29. [ABSTRACT FROM AUTHOR]

Background and purpose: Paraneoplastic neurological autoimmunity is well described with small‐cell lung cancer, but information is limited for other neuroendocrine neoplasms (NENs). Methods: Adult patients with histopathologically confirmed non‐pulmonary NENs, neurological autoimmunity within 5 years of NEN diagnosis, and neural antibody testing performed at the Mayo Clinic Neuroimmunology Laboratory (January 2008 to March 2023) were retrospectively identified. Control sera were available from patients with NENs without neurological autoimmunity (116). Results: Thirty‐four patients were identified (median age 68 years, range 31–87). The most common primary tumor sites were pancreas (nine), skin (Merkel cell, eight), small bowel/duodenum (seven), and unknown (seven). Five patients received immune checkpoint inhibitor (ICI) therapy before symptom onset; symptoms preceded cancer diagnosis in 62.1% of non‐ICI‐treated patients. The most frequent neurological phenotypes (non‐ICI‐treated) were movement disorders (12; cerebellar ataxia in 10), dysautonomia (six), peripheral neuropathy (eight), encephalitis (four), and neuromuscular junction disorders (four). Neural antibodies were detected in 55.9% of patients studied (most common specificities: P/Q‐type voltage‐gated calcium channel [seven], muscle‐type acetylcholine receptor [three], anti‐neuronal nuclear antibody type 1 [three], and neuronal intermediate filaments [two]), but in only 6.9% of controls. Amongst patients receiving cancer or immunosuppressive therapy, 51.6% had partial or complete recovery. Outcomes were unfavorable in 48.3% (non‐ICI‐treated) and neural autoantibody positivity was associated with poor neurological outcome. Discussion: Neurological autoimmunity associated with non‐pulmonary NENs is often multifocal and can be treatment responsive, underscoring the importance of rapid recognition and early treatment. [ABSTRACT FROM AUTHOR]

Background: Core stability exercises (CSE) have been shown to be effective in improving trunk function in several neurological diseases, but the evidence is scarce on Hereditary Ataxias (HA). Objective: To evaluate the effectiveness of a 5‐week home‐based CSE program in terms of ataxia severity, trunk function, balance confidence, gait speed, lower limb motor function, quality of life, health status and falls rate in HA individuals at short‐ and long‐term. Methods: This is an assessor‐blind randomized controlled clinical trial parallel group 1:1. The individuals were divided in experimental group (EG) performed standard care in addition to CSE, and control group (CG) performed standard care alone. The CSE home‐program was conducted 1‐h/day, 5‐day/week for 5‐week. The assessment was performed at baseline, endpoint (5‐week), and follow‐up (10‐week). The primary outcomes were ataxia severity assessed by the Scale for the Assessment and Rating of Ataxia and trunk function assessed by Spanish‐version of Trunk Impairment Scale 2.0. The secondary outcomes were balance confidence assessed by Activities‐specific Balance Confidence (ABC), gait speed by 4‐meter walk test (4‐MWT), the lower limb motor function by 30‐s sit‐to‐stand, quality of life by EuroQol 5‐dimension 5‐level (EQ‐5D‐5L), health‐status by EQ‐5D and falls rate. Results: Twenty‐three HA individuals were recruited (51.8 ± 11.10 years). Statistically significant group‐time interaction was shown in ABC (F:5.539; P = 0.007), EQ‐5D‐5L Total (F:4.836; P = 0.013), EQ 5D (F:7.207; P = 0.006). Conclusions: No statistical differences between groups for ataxia severity and trunk function were observed. However, were differences for balance confidence, gait speed, quality of life, and falls rate in HA individuals. [ABSTRACT FROM AUTHOR]

Background: The newly discovered intronic repeat expansions in the genes encoding replication factor C subunit 1 (RFC1) and fibroblast growth factor 14 (FGF14) frequently cause late‐onset cerebellar ataxia. Objectives: To investigate the presence of RFC1 and FGF14 pathogenic repeat expansions in Serbian patients with adult‐onset cerebellar ataxia. Methods: The study included 167 unrelated patients with sporadic or familial cerebellar ataxia. The RFC1 repeat expansion analysis was performed by duplex PCR and Sanger sequencing, while the FGF14 repeat expansion was tested for by long‐range PCR, repeat‐primed PCR, and Sanger sequencing. Results: We identified pathogenic repeat expansions in RFC1 in seven patients (7/167; 4.2%) with late‐onset sporadic ataxia with neuropathy and chronic cough. Two patients also had bilateral vestibulopathy. Repeat expansions in FGF14 were found in nine unrelated patients (9/167; 5.4%) with ataxia, less than half of whom presented with neuropathy and two‐thirds with global brain atrophy. Tremor and episodic features were the most frequent additional characteristics in carriers of uninterrupted FGF14 repeat expansions. Among the 122 sporadic cases, 12 (9.8%) carried an expansion in either RFC1 or FGF14, comparable to 4/45 (8.9%) among the patients with a positive family history. Conclusions: Pathogenic repeat expansions in RFC1 and FGF14 are relatively frequent causes of adult‐onset cerebellar ataxia, especially among sporadic patients, indicating that family history should not be considered when prioritizing ataxia patients for testing of RFC1 or FGF14 repeat expansions. [ABSTRACT FROM AUTHOR]

This article presents a case study of a patient with autoimmune cerebellar ataxia caused by antibodies attacking septin-5, a neural protein involved in neurotransmitter exocytosis. The patient initially experienced COVID-19 pneumonia followed by symptoms of ataxia, diplopia, and dysarthria. The article discusses the patient's medical history, laboratory findings, and treatment course, highlighting the use of immunotherapy. The study suggests that autoimmune cerebellar ataxia may have a prolonged inflammatory course and may respond to a serially escalating course of immunosuppressive treatments. [Extracted from the article]

Spinocerebellar ataxia 27 B (SCA27B) is caused by the expansion of GAA repeats in the intron of the fibroblast growth factor 14 (FGF14) on chromosome 13 and is inherited dominantly. An 80‐year‐old male visited the hospital complaining of ataxic gait and harboring 229 pure GAA repeat units in the FGF14. Almost all the clinical features were similar to that of SCA27B. However, the patient initially presented with episodic grip myotonia, which has not been previously reported. [ABSTRACT FROM AUTHOR]

The article discusses the case of a 58-year-old woman with Spinocerebellar Ataxia Type 12 (SCA12) who underwent bilateral deep brain stimulation of the posterior subthalamic area (PSA) to alleviate intractable action tremors. The patient's tremors significantly improved post-surgery, leading to better quality of life and reduced tremor amplitudes. The study highlights the effectiveness of deep brain stimulation in treating medication-resistant tremors in patients with SCA12, emphasizing the need for continued monitoring to assess long-term outcomes. [Extracted from the article]

The article discusses a case study of a 20-year-old male patient with genetically proven Salih ataxia due to a novel truncating variant in the RUBCN gene. The patient presented with seizures, intellectual disability, and tremulousness of both upper limbs, among other symptoms. The study expands the phenotypic and genotypic spectrum of SCAR15, a rare disorder characterized by early-onset ataxia, cognitive impairment, and dysarthria. The identified variant in the RUBCN gene is classified as likely pathogenic, leading to endolysosomal machinery defects and impacting autophagy and lipid metabolism. The article highlights the importance of considering RUBCN-related ataxia in patients with childhood-onset ataxia, dystonia, epilepsy, and intellectual disability, especially when cerebellar atrophy is absent. [Extracted from the article]

This article, titled "Neurosarcoidosis: A good reason for a brainstorm," discusses the case of a 46-year-old woman who presented with symptoms of unsteady gait, spastic right lower limb paresis, cerebellar ataxia, and vesicosphincter dysfunction. Brain and spinal MRI revealed multiple leptomeningeal nodules, predominantly in the insular regions and posterior fossa, along with associated white matter hyperintensities. The patient was diagnosed with sarcoidosis based on biopsy results and was treated with immunosuppression, which resulted in significant clinical and radiologic improvement. The article emphasizes the importance of appropriate investigations and prompt treatment for neurosarcoidosis. [Extracted from the article]

Several review articles on voltage‐gated calcium channels (VGCCs) classify VGCCs into five electrophysiological types and 10 genotypes. Each VGCC is distributed in different organs and specialized cells, and various organ‐specific human genetic diseases have been reported. Most of the human diseases caused by abnormalities in the VGCCs are genetic diseases. To the best of our knowledge, Lambert–Eaton myasthenic syndrome (LEMS) appears to be the only autoimmune disease for VGCCs. Approximately 90% of LEMS patients are positive for autoantibodies against P/Q‐VGCCs in the active zone of nerve endings. On the other hand, about 50% of LEMS patients a tumor‐associated neurological syndrome with small cell lung cancer. Neurological symptoms in LEMS patients include weakness of proximal limb muscles, reduced tendon reflexes, autonomic neuropathy, and in 9%–14% of patients, cerebellar ataxia, and paraneoplastic cerebellar degeneration. In the second half of this manuscript, we provide a clinical review with reference to the recently published Practical Guideline for Myasthenia gravis and LEMS 2022 in Japan. [ABSTRACT FROM AUTHOR]

Background: Fatigue is a prevalent and debilitating symptom in neurological disorders, including spinocerebellar ataxias (SCAs). However, the risk factors of fatigue in the SCAs as well as its impact have not been well investigated. Objectives: To study the prevalence of fatigue in SCAs, the factors contributing to fatigue, and the influence of fatigue on quality of life. Methods: Fatigue was assessed in 418 participants with SCA1, SCA2, SCA3, and SCA6 from the Clinical Research Consortium for the Study of Cerebellar Ataxia using the Fatigue Severity Scale. We conducted multi‐variable linear regression models to examine the factors contributing to fatigue as well as the association between fatigue and quality of life. Results: Fatigue was most prevalent in SCA3 (52.6%), followed by SCA1 (36.7%), SCA6 (35.7%), and SCA2 (35.6%). SCA cases with fatigue had more severe ataxia and worse depressive symptoms. In SCA3, those with fatigue had a longer disease duration and longer pathological CAG repeat numbers. In multi‐variable models, depressive symptoms, but not ataxia severity, were associated with more severe fatigue. Fatigue, independent of ataxia and depression, contributed to worse quality of life in SCA3 and SCA6 at baseline, and fatigue continued affecting quality of life throughout the disease course in all types of SCA. Conclusions: Fatigue is a common symptom in SCAs and is closely related to depression. Fatigue significantly impacts patients' quality of life. Therefore, screening for fatigue should be considered a part of standard clinical care for SCAs. [ABSTRACT FROM AUTHOR]

A pathogenic GAA repeat expansion in the first intron of the fibroblast growth factor 14 gene (FGF14) has been recently identified as the cause of spinocerebellar ataxia 27B (SCA27B). We herein screened 160 Greek index cases with late‐onset cerebellar ataxia (LOCA) for FGF14 repeat expansions using a combination of long‐range PCR and bidirectional repeat‐primed PCRs. We identified 19 index cases (12%) carrying a pathogenic FGF14 GAA expansion, a diagnostic yield higher than that of previously screened repeat‐expansion ataxias in Greek LOCA patients. The age at onset of SCA27B patients was 60.5 ± 12.3 years (range, 34–80). Episodic onset (37%), downbeat nystagmus (32%) and vertigo (26%) were significantly more frequent in FGF14 expansion‐positive cases compared to expansion‐negative cases. Beyond typical cerebellar signs, SCA27B patients often displayed hyperreflexia (47%) and reduced vibration sense in the lower extremities (42%). The frequency and phenotypic profile of SCA27B in Greek patients was similar to most other previously studied populations. We conclude that FGF14 GAA repeat expansions are the commonest known genetic cause of LOCA in the Greek population and recommend prioritizing testing for FGF14 expansions in the diagnostic algorithm of patients with LOCA. [ABSTRACT FROM AUTHOR]

Background: Genetic prion diseases, including Gerstmann‐Sträussler‐Scheinker disease (GSS), are extremely rare, fatal neurodegenerative disorders, often associated with progressive ataxia and cognitive/neuropsychiatric symptoms. GSS typically presents as a rapidly progressive cerebellar ataxia, associated with cognitive decline. Late‐onset cases are rare. Objective: To compare a novel GSS phenotype with six other cases and present pathological findings from a single case. Methods: Case series of seven GSS patients, one proceeding to autopsy. Results: Case 1 developed slowly progressive gait difficulties at age 71, mimicking a spinocerebellar ataxia, with a family history of balance problems in old age. Genome sequencing revealed a heterozygous c.392G > A (p.G131E) pathogenic variant and a c.395A > G resulting in p.129 M/V polymorphism in the PRNP gene. Probability analyses considering family history, phenotype, and a similar previously reported point mutation (p.G131V) suggest p.G131E as a new pathogenic variant. Clinical features and imaging of this case are compared with those six additional cases harboring p.P102L mutations. Autopsy findings of a case are described and were consistent with the prion pathology of GSS. Conclusions: We describe a patient with GSS with a novel p.G131E mutation in the PRNP gene, presenting with a late‐onset, slowly progressive phenotype, mimicking a spinocerebellar ataxia, and six additional cases with the typical P102L mutation. [ABSTRACT FROM AUTHOR]

Cerebellar ataxia, neuropathy, vestibular areflexia syndrome (CANVAS) is a late‐onset, autosomal recessive neurodegenerative disorder caused by biallelic AAGGG/ACAGG repeat expansion (AAGGG‐exp/ACAGG‐exp) in RFC1. The recent identification of patients with CANVAS exhibiting compound heterozygosity for AAGGG‐exp and truncating variants supports the loss‐of‐function of RFC1 in CANVAS patients. We investigated the pathological changes in 2 autopsied patients with CANVAS harboring biallelic ACAGG‐exp and AAGGG‐exp. RNA fluorescence in situ hybridization of the 2 patients revealed CCTGT‐ and CCCTT‐containing RNA foci, respectively, in neuronal nuclei of tissues with neuronal loss. Our findings suggest that RNA toxicity may be involved in the pathogenesis of CANVAS. ANN NEUROL 2024;95:607–613 [ABSTRACT FROM AUTHOR]

Background: We aimed to investigate the prognostic factors associated with clinical outcomes in CV2/Collapsin response‐mediator protein 5 (CRMP5)‐IgG paraneoplastic neurologic disorders (PND). Methods: This is a retrospective study of patients with CV2/CRMP5‐IgG PND evaluated between 2002–2022. We examined the association of clinical variables (including age, clinical phenotype [autoimmune encephalopathy, myelopathy, polyneuropathy/radiculopathy, MG, cerebellar ataxia, chorea, optic neuropathy], cancer) with three clinical outcomes (wheelchair dependence, modified Rankin Scale [mRS], mortality) using univariate logistic regression and Cox proportional hazards modeling. Kaplan–Meier estimates were used to determine the probability of survival. Results: Twenty‐seven patients (56% female) with CV2/CRMP5‐IgG PND were identified with a median follow‐up of 54 months (IQR = 11–102). An underlying tumor was identified in 15 patients (56%) including small cell lung cancer (SCLC) (8, [53%]), thymoma (4, [27%]), and other histologies (3, [20%]). At last follow‐up, 10 patients (37%) needed a wheelchair for mobility and this outcome was associated with myelopathy (HR = 7.57, 95% CI = 1.87–30.64, P = 0.005). Moderate–severe mRS = 3–5 was associated with CNS involvement (encephalopathy, myelopathy, or cerebellar ataxia) (OR = 7.00, 95% CI = 1.18–41.36, P = 0.032). The probability of survival 4 years after symptom onset was 66%. Among cancer subtypes, SCLC (HR = 18.18, 95% CI = 3.55–93.04, P < 0.001) was significantly associated with mortality, while thymoma was not. Interpretation: In this retrospective longitudinal study of CV2/CRMP5‐IgG PND, patients with CNS involvement, particularly myelopathy, had higher probability of disability. SCLC was the main determinant of survival in this population. [ABSTRACT FROM AUTHOR]

Aims: The open‐loop nature of conventional deep brain stimulation (DBS) produces continuous and excessive stimulation to patients which contributes largely to increased prevalence of adverse side effects. Cerebellar ataxia is characterized by abnormal Purkinje cells (PCs) dendritic arborization, loss of PCs and motor coordination, and muscle weakness with no effective treatment. We aim to develop a real‐time field‐programmable gate array (FPGA) prototype targeting the deep cerebellar nuclei (DCN) to close the loop for ataxia using conditional double knockout mice with deletion of PC‐specific LIM homeobox (Lhx)1 and Lhx5, resulting in abnormal dendritic arborization and motor deficits. Methods: We implanted multielectrode array in the DCN and muscles of ataxia mice. The beneficial effect of open‐loop DCN‐DBS or closed‐loop DCN‐DBS was compared by motor behavioral assessments, electromyography (EMG), and neural activities (neurospike and electroencephalogram) in freely moving mice. FPGA board, which performed complex real‐time computation, was used for closed‐loop DCN‐DBS system. Results: Closed‐loop DCN‐DBS was triggered only when symptomatic muscle EMG was detected in a real‐time manner, which restored motor activities, electroencephalogram activities and neurospike properties completely in ataxia mice. Closed‐loop DCN‐DBS was more effective than an open‐loop paradigm as it reduced the frequency of DBS. Conclusion: Our real‐time FPGA‐based DCN‐DBS system could be a potential clinical strategy for alleviating cerebellar ataxia and other movement disorders. [ABSTRACT FROM AUTHOR]

This article explores the pathogenicity of the SETX I1942T variant in Ataxia with Oculomotor Apraxia Type 2 (AOA2) through segregation analysis. AOA2 is a hereditary ataxia characterized by progressive cerebellar dysfunction, oculomotor apraxia, and peripheral neuropathy. The SETX gene, responsible for encoding senataxin, is found to have mutations in AOA2 patients. The article presents a case study of two siblings with AOA2 symptoms and a homozygous variant in the SETX gene. The study confirms the pathogenic nature of the variant and contributes to the understanding of genotype-phenotype correlation in AOA2. [Extracted from the article]

Using proteomic analysis, we identified anti‐NAE antibodies (autoantibodies against NH2‐terminal of alpha‐enolase) as a diagnostic marker for Hashimoto's encephalopathy (HE). As cases of HE with serum anti‐NAE antibodies accumulated, the clinical spectrum of HE with anti‐NAE antibodies became expanded. In addition, it is now known that antibodies can be detected in other diseases that differ from conventional HE. We recently reported the detection of anti‐NAE antibodies in patients with a clinical diagnosis of multiple system atrophy or corticobasal syndrome. These findings suggest that anti‐NAE antibodies indicate an immune mechanism in the pathogenesis of neurodegenerative diseases. We propose a novel disease concept for anti‐NAE antibody‐associated disorders (NAEAD). The clinical spectrum of NAEAD is not limited to HE but is a broad spectrum that partially shares several autoimmune neurological diseases, including autoimmune acute encephalopathy, autoimmune cerebellar ataxia, and autoimmune psychosis, and even extends to immune‐associated neurodegenerative diseases. [ABSTRACT FROM AUTHOR]

Pathogenic variants in PNPLA8 have been described either with congenital onset displaying congenital microcephaly, early onset epileptic encephalopathy and early lethality or childhood neurodegeneration with progressive microcephaly. Moreover, a phenotype comprising adulthood onset cerebellar ataxia and peripheral neuropathy was also reported. To our knowledge, only six patients with biallelic variants in PNPLA8 have been reported so far. Here, we report the clinical and molecular characterizations of three additional patients in whom exome sequencing identified a loss of function variant (c.1231C>T, p.Arg411Ter) in Family I and a missense variant (c.1559T>A, p.Val520Asp) in Family II in PNPLA8. Patient 1 presented with the congenital form of the disease while Patients 2 and 3 showed progressive microcephaly, infantile onset seizures, progressive cortical atrophy, white matter loss, bilateral degeneration of basal ganglia, and cystic encephalomalacia. Therefore, our results add the infantile onset as a new distinct phenotype of the disease and suggest that the site of the variant rather than its type is strongly correlated with the disease onset. In addition, these conditions demonstrate some overlapping features representing a spectrum with clinical features always aligning with different age of onset. [ABSTRACT FROM AUTHOR]

Background: Progressive external ophthalmoplegia (PEO) is a common subtype of mitochondrial encephalomyopathy. Objective: The study aimed to investigate the relationship between mitochondrial DNA (mtDNA) abnormalities, muscle pathology, and clinical manifestations in Chinese patients with single large‐scale mtDNA deletion presenting with PEO. Methods: This is a retrospective single‐center study. Patients with PEO who had a single large deletion in mitochondrial DNA were included in this study. The associations were analyzed between mtDNA deletion patterns, myopathological changes, and clinical characteristics. Results: In total, 155 patients with mitochondrial PEO carrying single large‐scale mtDNA mutations were enrolled, including 137 chronic progressive external ophthalmoplegia (CPEO) and 18 Kearns–Sayre syndrome (KSS) patients. The onset ages were 9.61 ± 4.12 in KSS and 20.15 ± 9.06 in CPEO. The mtDNA deletions ranged from 2225 bp to 9131 bp, with m.8470_13446del being the most common. The KSS group showed longer deletions than the CPEO group (p = 0.004). Additionally, a higher number of deleted genes encoding respiratory chain complex subunits (p = 0.001) and tRNA genes (p = 0.009) were also observed in the KSS group. A weak negative correlation between the mtDNA deletion size and ages of onset (p < 0.001, r = −0.369) was observed. The proportion of ragged red fibers, ragged blue fibers, and cytochrome c negative fibers did not correlate significantly with onset ages (p > 0.05). However, a higher percentage of abnormal muscle fibers corresponds to an increased prevalence of exercise intolerance, limb muscle weakness, dysphagia, and cerebellar ataxia. Conclusion: We reported a large Chinese cohort consisting of mitochondrial PEO patients with single large‐scale mtDNA deletions. Our results demonstrated that the length and locations of mtDNA deletions may influence onset ages and clinical phenotypes. The severity of muscle pathology could not only indicate diagnosis but also may be associated with clinical manifestations beyond the extraocular muscles. [ABSTRACT FROM AUTHOR]

Background and Objectives: The GAA repeat expansion within the fibroblast growth factor 14 (FGF14) gene has been found to be associated with late‐onset cerebellar ataxia. This study aimed to investigate the genetic causes of cerebellar ataxia in patients in Japan. Methods: We collected a case series of 940 index patients who presented with chronic cerebellar ataxia and remained genetically undiagnosed after our preliminary genetic screening. To investigate the FGF14 repeat locus, we employed an integrated diagnostic strategy that involved fluorescence amplicon length analysis polymerase chain reaction (PCR), repeat‐primed PCR, and long‐read sequencing. Results: Pathogenic FGF14 GAA repeat expansions were detected in 12 patients from 11 unrelated families. The median size of the pathogenic GAA repeat was 309 repeats (range: 270–316 repeats). In these patients, the mean age of onset was 66.9 ± 9.6 years, with episodic symptoms observed in 56% of patients and parkinsonism in 30% of patients. We also detected FGF14 repeat expansions in a patient with a phenotype of multiple system atrophy, including cerebellar ataxia, parkinsonism, autonomic ataxia, and bilateral vocal cord paralysis. Brain magnetic resonance imaging (MRI) showed normal to mild cerebellar atrophy, and a follow‐up study conducted after a mean period of 6 years did not reveal any significant progression. Discussion: This study highlights the importance of FGF14 GAA repeat analysis in patients with late‐onset cerebellar ataxia, particularly when they exhibit episodic symptoms, or their brain MRI shows no apparent cerebellar atrophy. Our findings contribute to a better understanding of the clinical variability of GAA‐FGF14‐related diseases. [ABSTRACT FROM AUTHOR]

Spinocerebellar ataxia 3 (SCA3) is an incurable, neurodegenerative genetic disorder that leads to progressive cerebellar ataxia and other parkinsonian‐like pathologies because of loss of cerebellar neurons. The role of an expanded polyglutamine aggregate on neural progenitor cells is unknown. Here, we show that SCA3 patient‐specific induced neural progenitor cells (iNPCs) exhibit proliferative defects. Moreover, SCA3 iNPCs have reduced autophagic expression compared to control. Furthermore, although SCA3 iNPCs continue to proliferate, they do not survive subsequent passages compared to control iNPCs, indicating the likelihood that SCA3 iNPCs undergo rapid senescence. Exposure to interleukin‐4 (IL‐4), a type 2 cytokine produced by immune cells, resulted in an observed increase in expression of autophagic programs and a reduction in the proliferation defect observed in SCA3 iNPCs. Our results indicate a previously unobserved role of SCA3 disease ontology on the neural stem cell pool and a potential therapeutic strategy using IL‐4 to ameliorate or delay disease pathology in the SCA3 neural progenitor cell population. [ABSTRACT FROM AUTHOR]

Hereditary ataxias, especially when presenting sporadically in adulthood, present a particular diagnostic challenge owing to their great clinical and genetic heterogeneity. Currently, up to 75% of such patients remain without a genetic diagnosis. In an era of emerging disease‐modifying gene‐stratified therapies, the identification of causative alleles has become increasingly important. Over the past few years, the implementation of advanced bioinformatics tools and long‐read sequencing has allowed the identification of a number of novel repeat expansion disorders, such as the recently described spinocerebellar ataxia 27B (SCA27B) caused by a (GAA)•(TTC) repeat expansion in intron 1 of the fibroblast growth factor 14 (FGF14) gene. SCA27B is rapidly gaining recognition as one of the most common forms of adult‐onset hereditary ataxia, with several studies showing that it accounts for a substantial number (9–61%) of previously undiagnosed cases from different cohorts. First natural history studies and multiple reports have already outlined the progression and core phenotype of this novel disease, which consists of a late‐onset slowly progressive pan‐cerebellar syndrome that is frequently associated with cerebellar oculomotor signs, such as downbeat nystagmus, and episodic symptoms. Furthermore, preliminary studies in patients with SCA27B have shown promising symptomatic benefits of 4‐aminopyridine, an already marketed drug. This review describes the current knowledge of the genetic and molecular basis, epidemiology, clinical features and prospective treatment strategies in SCA27B. [ABSTRACT FROM AUTHOR]

Background and purpose: Ataxia–telangiectasia (A‐T) is a rare, autosomal recessive, multisystem disorder that leads to progressive neurodegeneration with cerebellar ataxia and peripheral polyneuropathy. Cerebellar neurodegeneration is well described in A‐T. However, peripheral nervous system involvement is an underdiagnosed but important additional target for supportive and systemic therapies. The aim of this study was to conduct neurophysiological measurements to assess peripheral neurodegeneration and the development of age‐dependent neuropathy in A‐T. Methods: In this prospective study, 42 classical A‐T patients were assessed. The motor and sensory nerve conduction of the median and tibial nerves was evaluated. Data were compared to published standard values and a healthy age‐ and gender‐matched control group of 23 participants. Ataxia scores (Klockgether, Scale for the Assessment and Rating of Ataxia) were also assessed. Results: In A‐T, neurophysiological assessment revealed neuropathic changes as early as the first year of life. Subjective symptomatology of neuropathy is rarely described. In the upper extremities, motor neuropathy was predominantly that of a demyelinating type and sensory neuropathy was predominantly that of a mixed type. In the lower extremities, motor and sensory neuropathy was predominantly that of a mixed type. We found significant correlations between age and the development of motor and sensory polyneuropathy in A‐T compared with healthy controls (p < 0.001). Conclusions: In A‐T, polyneuropathy occurs mostly subclinically as early as the first year of life. The current study of a large national A‐T cohort demonstrates that development of neuropathy in A‐T differs in the upper and lower extremities. [ABSTRACT FROM AUTHOR]

Background and purpose: Dominantly inherited GAA repeat expansions in the fibroblast growth factor 14 (FGF14) gene have recently been shown to cause spinocerebellar ataxia 27B (SCA27B). We aimed to study the frequency and phenotype of SCA27B in a cohort of patients with unsolved late‐onset cerebellar ataxia (LOCA). We also assessed the frequency of SCA27B relative to other genetically defined LOCAs. Methods: We recruited a consecutive series of 107 patients with LOCA, of whom 64 remained genetically undiagnosed. We screened these 64 patients for the FGF14 GAA repeat expansion. We next analysed the frequency of SCA27B relative to other genetically defined forms of LOCA in the cohort of 107 patients. Results: Eighteen of 64 patients (28%) carried an FGF14 (GAA)≥250 expansion. The median (range) age at onset was 62.5 (39–72) years. The most common clinical features included gait ataxia (100%) and mild cerebellar dysarthria (67%). In addition, episodic symptoms and downbeat nystagmus were present in 39% (7/18) and 37% (6/16) of patients, respectively. SCA27B was the most common cause of LOCA in our cohort (17%, 18/107). Among patients with genetically defined LOCA, SCA27B was the main cause of pure ataxia, RFC1‐related disease of ataxia with neuropathy, and SPG7 of ataxia with spasticity. Conclusion: We showed that SCA27B is the most common cause of LOCA in our cohort. Our results support the use of FGF14 GAA repeat expansion screening as a first‐tier genetic test in patients with LOCA. [ABSTRACT FROM AUTHOR]

Background and purpose: Biallelic mutation/expansion of the gene RFC1 has been described in association with a spectrum of manifestations ranging from isolated sensory neuro(no)pathy to a complex presentation as cerebellar ataxia with neuropathy and vestibular areflexia syndrome (CANVAS). Our aim was to define the frequency and characteristics of small fiber neuropathy (SFN) in RFC1 disease at different stages. Methods: RFC1 cases were screened for SFN using the Neuropathic Pain Symptom Inventory and Composite Autonomic Symptom Score 31 questionnaires. Clinical data were retrospectively collected. If available, lower limb skin biopsy samples were evaluated for somatic epidermal and autonomic subepidermal structure innervation and compared to healthy controls (HCs). Results: Forty patients, median age at onset 54 years (interquartile range [IQR] 49–61) and disease duration 10 years (IQR 6–16), were enrolled. Mild‐to‐moderate positive symptoms (median Neuropathic Pain Symptom Inventory score 12.1/50, IQR 5.5–22.3) and relevant autonomic disturbances (median Composite Autonomic Symptom Score 31 37.0/100, IQR 17.7–44.3) were frequently reported and showed scarce correlation with disease duration. A non‐length‐dependent impairment in nociception was evident in both clinical and paraclinical investigations. An extreme somatic denervation was observed in all patients at both proximal (fibers/mm, RFC1 cases 0.0 vs. HCs 20.5, p < 0.0001) and distal sites (fibers/mm, RFC1 cases 0.0 vs. HCs 13.1, p < 0.0001); instead only a slight decrease was observed in cholinergic and adrenergic innervation of autonomic structures. Conclusions: RFC1 disease is characterized by a severe and widespread somatic SFN. Skin denervation may potentially represent the earliest feature and drive towards the suspicion of this disorder. [ABSTRACT FROM AUTHOR]

Multiple system atrophy (MSA) is a neurodegenerative disorder characterised by a combined symptomatology of parkinsonism, cerebellar ataxia, autonomic failure and corticospinal dysfunction. In brains of MSA patients, the hallmark lesion is the aggregation of misfolded alpha‐synuclein in oligodendrocytes. Even though the underlying pathological mechanisms remain poorly understood, the evidence suggests that alpha‐synuclein aggregation in oligodendrocytes may contribute to the neurodegeneration seen in MSA. The primary aim of this review is to summarise the published stereological data on the total number of neurons and glial cell subtypes (oligodendrocytes, astrocytes and microglia) and volumes in brains from MSA patients. Thus, we include in this review exclusively the reports of unbiased quantitative data from brain regions including the neocortex, nuclei of the cerebrum, the brainstem and the cerebellum. Furthermore, we compare and discuss the stereological results in the context of imaging findings and MSA symptomatology. In general, the stereological results agree with the common neuropathological findings of neurodegeneration and gliosis in brains from MSA patients and support a major loss of nigrostriatal neurons in MSA patients with predominant parkinsonism (MSA‐P), as well as olivopontocerebellar atrophy in MSA patients with predominant cerebellar ataxia (MSA‐C). Surprisingly, the reports indicate only a minor loss of oligodendrocytes in sub‐cortical regions of the cerebrum (glial cells not studied in the cerebellum) and negligible changes in brain volumes. In the past decades, the use of stereological methods has provided a vast amount of accurate information on cell numbers and volumes in the brains of MSA patients. Combining different techniques such as stereology and diagnostic imaging (e.g. MRI, PET and SPECT) with clinical data allows for a more detailed interdisciplinary understanding of the disease and illuminates the relationship between neuropathological changes and MSA symptomatology. [ABSTRACT FROM AUTHOR]

A 57‐year‐old man presented with progressive muscle weakness in the lower limbs, with elevated anti‐P/Q‐type voltage‐gated calcium channel antibody levels. A repetitive stimulation test showed waxing with high‐frequency stimulation. He was diagnosed with Lambert–Eaton myasthenic syndrome (LEMS) and small‐cell lung cancer. After four courses of cisplatin and etoposide, computed tomography showed a decrease in tumor size and muscle weakness improved. After 3 months, the patient presented with progressive ataxic gait and dysarthria and was admitted to our hospital. Magnetic resonance imaging revealed slight cerebellar atrophy. We diagnosed the patient with paraneoplastic cerebellar degeneration (PCD)‐LEMS. The patient received intravenous immunoglobulin therapy, steroid pulse therapy, and plasmapheresis. The patient's cerebellar ataxia then improved. This represents a rare case of PCD‐LEMS after improvement of LEMS. [ABSTRACT FROM AUTHOR]

This article discusses the use of robot-assisted gait training (RAGT) in a patient with bilateral transtibial amputation and cerebellar ataxia. The patient initially received conventional gait training with lower-limb prostheses, but after a stroke, his gait function was reduced. After 10 weeks of conventional gait training, the patient received an additional 3 weeks of RAGT using an end-effector-type device. The results showed improvements in walking function, standing balance, and activities of daily living. While this case study suggests the therapeutic effect of RAGT for patients with bilateral transtibial amputations, further research is needed to establish definitive evidence. [Extracted from the article]