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Background: Due to confusing clinicoradiological features such as amnestic symptoms and hippocampal atrophy in frontotemporal lobar degeneration (FTLD), antemortem differentiation between FTLD and Alzheimer's disease (AD) can be challenging. Although asymmetric atrophy of the cerebral peduncle is regarded as a representative imaging finding in some disorders of the FTLD spectrum, the utility of this finding has not been sufficiently evaluated for differentiating between FTLD and AD. Objective: This study aimed to explore the diagnostic performance of asymmetric cerebral peduncle atrophy on axial magnetic resonance imaging as a simple radiological discriminator between FTLD and AD. Methods: Seventeen patients with pathologically confirmed FTLD, including six with progressive supranuclear palsy, three with corticobasal degeneration, eight with TAR DNA-binding protein 43 (FTLD-TDP), and 11 with pathologically confirmed AD, were investigated. Quantitative indices representing the difference between the volumes of the bilateral cerebral peduncles (i.e., cerebral peduncular asymmetry index [CPAI]), the voxel-based specific regional analysis system for Alzheimer's disease (VSRAD) Z-score representing the degree of hippocampal atrophy, and semiquantitative visual analysis to evaluate the asymmetry of the cerebral peduncle (visual assessment of cerebral peduncular asymmetry: VACPA) were compared between the two groups. Results: Contrary to the VSRAD Z-score, the CPAI and VACPA scores demonstrated higher diagnostic performance in differentiating patients with FTLD from those with AD (areas under the receiver operating characteristic curve of 0.88, 082, and 0.60, respectively). Conclusions: Quantitative and visual analytical techniques can differentiate between FTLD and AD. These simple methods may be useful in daily clinical practice. [ABSTRACT FROM AUTHOR]

Abstract Background Kernohan-Woltman notch phenomenon (KWNP) classically occurs when a lesion causes compression of the contralateral cerebral peduncle against the tentorium, resulting in ipsilateral hemiparesis. It has been studied clinically, radiologically and electrophysiologically which all confirmed to cause false localizing motor signs. Here, we demonstrate the potential use of fluorine-18 fluorodeoxyglucose (18 F-FDG) positron emission tomography/computed tomography (PET/CT) to identify KWNP caused by an epidural hematoma. Case presentation A 29-year-old male patient post right-sided traumatic brain injury presenting with persistent ipsilateral hemiparesis. Patient underwent decompressive craniotomy and intracranial hematoma evacuation. Brain magnetic resonance imaging in the postoperative period showed a subtle lesion in the left cerebral peduncle. PET/CT was performed to exclude early brain tumor and explain his ipsilateral hemiparesis. PET/CT imaging demonstrated a focal region of intense 18 F-FDG uptake in the left cerebral peduncle. Throughout the treatment in outpatient neurorehabilitation unit, the patient exhibited a gradual recovery of his right hemiparesis. Conclusion In our case report, for the first time, PET/CT offered microstructural and functional confirmation of KWNP. Moreover, our case suggests that 18 F-FDG PET/CT may serve as an important reference for the probability of functional recovery.

ObjectiveWhite matter (WM) microstructural changes are increasingly recognized as a mechanism of age-related cognitive differences. This study examined the associations between patterns of WM microstructure and cognitive performance on the University of California, San Francisco (UCSF) Brain Health Assessment (BHA) subtests of memory (Favorites), executive functions and speed (Match), and visuospatial skills (Line Orientation) within a sample of older adults.MethodFractional anisotropy (FA) in WM tracts and BHA performance were examined in 84 older adults diagnosed as neurologically healthy (47), with mild cognitive impairment (19), or with dementia (18). The relationships between FA and subtest performances were evaluated using regression analyses. We then explored whether regional WM predicted performance after accounting for variance explained by global FA.ResultsMemory performance was associated with FA of the fornix and the superior cerebellar peduncle; and executive functions and speed, with the body of the corpus callosum. The fornix-memory association and the corpus callosum-executive association remained significant after accounting for global FA. Neither tract-based nor global FA was associated with visuospatial performance.ConclusionsMemory and executive functions are associated with different patterns of WM diffusivity. Findings add insight into WM alterations underlying age- and disease-related cognitive decline.

BACKGROUND AND PURPOSE:Patient heterogeneity reduces statistical power in clinical trials of restorative therapies. Valid predictors of treatment responsiveness are needed, and several have been studied with a focus on corticospinal tract (CST) injury. We studied performance of 4 such measures for predicting behavioral gains in response to motor training therapy. METHODS:Patients with subacute-chronic hemiparetic stroke (n=47) received standardized arm motor therapy, and change in arm Fugl-Meyer score was calculated from baseline to 1 month post-therapy. Injury measures calculated from baseline magnetic resonance imaging included (1) percent CST overlap with stroke, (2) CST-related atrophy (cerebral peduncle area), (3) CST integrity (fractional anisotropy) in the cerebral peduncle, and (4) CST integrity in the posterior limb of internal capsule. RESULTS:Percent CST overlap with stroke, CST-related atrophy, and CST integrity did not correlate with one another, indicating that these 3 measures captured independent features of CST injury. Percent injury to CST significantly predicted treatment-related behavioral gains (r=-0.41; P=0.004). The other CST injury measures did not, neither did total infarct volume nor baseline behavioral deficits. When directly comparing patients with mild versus severe injury using the percent CST injury measure, the odds ratio was 15.0 (95% confidence interval, 1.54-147; P

Background: Kernohan-Woltman notch phenomenon (KWNP) classically occurs when a lesion causes compression of the contralateral cerebral peduncle against the tentorium, resulting in ipsilateral hemiparesis. It has been studied clinically, radiologically and electrophysiologically which all confirmed to cause false localizing motor signs. Here, we demonstrate the potential use of fluorine-18 fluorodeoxyglucose (18 F-FDG) positron emission tomography/computed tomography (PET/CT) to identify KWNP caused by an epidural hematoma.Case Presentation: A 29-year-old male patient post right-sided traumatic brain injury presenting with persistent ipsilateral hemiparesis. Patient underwent decompressive craniotomy and intracranial hematoma evacuation. Brain magnetic resonance imaging in the postoperative period showed a subtle lesion in the left cerebral peduncle. PET/CT was performed to exclude early brain tumor and explain his ipsilateral hemiparesis. PET/CT imaging demonstrated a focal region of intense 18 F-FDG uptake in the left cerebral peduncle. Throughout the treatment in outpatient neurorehabilitation unit, the patient exhibited a gradual recovery of his right hemiparesis.Conclusion: In our case report, for the first time, PET/CT offered microstructural and functional confirmation of KWNP. Moreover, our case suggests that 18 F-FDG PET/CT may serve as an important reference for the probability of functional recovery. [ABSTRACT FROM AUTHOR]

Hemorrhagic mirror stroke is a rare subtype of recurrent hemorrhagic stroke, similar to a cerebral hemorrhage in mirror position of the contralateral hemisphere. Here report two cases of hemorrhagic mirror stroke in the nondominant hemisphere of a right-handed man and a left-handed woman several years after the first similar onset in the dominant one. During rehabilitation after the first-time stroke, patients showed excellent recovery despite the development of atrophy in the cerebral peduncle on the affected side and aphasia and quadriplegia after the mirror stroke in the nondominant hemisphere. These cases not only highlight some uncommon clinical symptoms or the rare stroke type but also demonstrate the association between recovery of patients with atrophic cerebral peduncle after stroke and functional reorganization in the undamaged hemisphere.

Wrist drops are usually due to a peripheral neuropathy affecting the radial nerve. Cortical wrist drops may occur, usually due to a lesion in the contralateral hand area of the motor cortex. We report a unique case of “cortical” wrist drop due to an acute infarction of the contralateral cerebral peduncle. The patient is a 70-year-old gentleman with the vascular factors of hypertension, hyperlipidaemia, and prior cerebellar strokes, who developed sudden onset of right wrist weakness without numbness. Neurological examination showed a right wrist and finger drop. Nerve conduction study of the radial nerve was normal. MRI brain revealed an acute infarct in the medial part of the left cerebral peduncle, extending slightly to the medial thalamus; there were also old medial posterior cerebellar infarcts. Time of flight MR angiography was normal, with hypoplastic right vertebral artery. Echocardiography was normal but for a dilated right atrium. Electrocardiogram was normal, and 24-hour Holter monitoring detected infrequent atrial and ventricular ectopics. X-ray wrist showed an old ulnar styloid fracture. Nerve conduction study of the radial nerve was normal. He was switched from aspirin to clopidogrel and underwent rehabilitation. The cerebral peduncle should not be forgotten when attempting to anatomically localise the site of the lesion when evaluating a patient with a wrist drop.

The Kernohan-Woltman notch phenomenon is a paradoxical neurological manifestation consisting of a motor deficit ipsilateral to a primary brain injury. It has been observed in patients with brain tumors and with supratentorial hematomas. It is considered a false localizing neurological sign. Magnetic resonance imaging (MRI) scan has been the test of choice. The recognition of this phenomenon is important to prevent a surgical procedure on the opposite side of the lesion. The present case report describes a case of chronic subdural hematoma with a probable finding of the Kernohan-Woltman phenomenon, and it discusses its pathophysiology, imaging findings, treatment, and prognosis.

Background: Hirayama disease (HD) is a motor neuron disease and occasionally is associated with lower limb hyper-reflexia. Corticospinal tract dysfunction can be evaluated by diffusion tensor imaging (DTI), but there is paucity of study in HD.Objective: We report corticospinal tract functions using DTI in the patients with HD and correlate with clinical findings.Materials and Methods: The patients with HD diagnosed on the basis of clinical and electromyography findings were included. Their age, duration of illness, side of initial involvement, and progression were noted. Presence of lower limb hyper-reflexia, and cervical spine magnetic resonance imaging (MRI) findings were noted. Cranial MRI was done and DTI findings at internal capsule, cerebral peduncle, pons, and pyramid were noted.Results: In total, 10 patients with HD and 5 matched controls were evaluated. The apparent diffusion coefficient (7.03 ± 0.27 vs 6.83 ± 0.36), fractional anisotropy (0.79 ± 0.04 vs 0.82 ± 0.05), axial diffusivity (5.08 ± 0.08 vs 5.04 ± 0.07), and radial diffusivity (3.79 ± 0.05 vs 3.76 ± 0.05) between HD patients and controls were not different in internal capsule. These values were also not significantly different in cerebral peduncle, pons, and pyramid. These values were also not significantly different between the severe and less severely affected sides. The fractional anisotropy did not correlate with lower limb hyper-reflexia (P = 1.00) and spinal cord atrophy (P = 0.60).Conclusion: DTI study in HD patients did not reveal corticospinal tract involvement in brain. [ABSTRACT FROM AUTHOR]

• Diagnosis and treatment of cerebral peduncle neurocysticercosis have always been a challenge. • This challenge is exacerbated in the context of Vietnam, a resource-restricted environment. • Total resection of the cerebral peduncle neurocysticercosis was adequate when the patient had localized neurological deficits. Diagnosis and treatment of neurocysticercosis have always been a challenge, especially in Vietnam, a resource-restricted environment. Here, we reported successful surgical management of cerebral peduncle neurocysticercosis. A 65-year-old man with no medical history complained of headache and progressive right-sided hemiparesis for one month prior to admission. On examination, his muscle strength was 3/5 (Frankel grade) with positive Hoffmann and Babinski's signs on the right side. His brain's magnetic resonance imaging suggested a cystic brain tumor (29 × 18 mm) situated in the left cerebral peduncle and hypothalamus region. Enzyme-linked immunoassays (ELISA) of serum for Cysticercus cellulosae, Echinococcus , Toxocara, and Amebiasis were negative. The operation was performed with the modified frontotemporal-orbitozygomatic approach. We extirpated both the cysts. Histopathological examination revealed the larva of Taenia solium. Postoperatively, the hemiplegia was completely recovered, and no complication was reported The most recent revised diagnostic criteria of neurocysticercosis emphasised that neuroimaging studies play the most crucial role while clinical manifestations and exposure criteria were only indirect proofs of neurocysticercosis. Neuroimaging and clinical evidence in this patient, however, were more suggestive of cystic brain tumor, which was our most likely preoperative diagnosis. Consequently, total tumor resection required for both histopathological examination and alleviating his hemiplegia. Preoperative diagnosis of neurocysticercosis has always been a challenge. Total resection of the cerebral peduncle neurocysticercosis was adequate when the patient had localized neurological deficits. [ABSTRACT FROM AUTHOR]

Lesions arising at the ventral thalamopeduncular junction are difficult to resect. In addition to being relatively inaccessible, these lesions are located in one of the most sensitive areas of the brain. A critical question is whether new approaches could be developed to allow surgeons to adequately resect these lesions with reasonable outcomes. In the present report, we describe our approach to resect lesions in this region of the brain using an eyebrow craniotomy approach with a trajectory through the supracarotid triangle. Through retrospective data collection, we present a small series of patients who had undergone an eyebrow, supracarotid triangle approach to resect lesions located at the thalamopeduncular junction. We describe our surgical technique and report patient outcomes using this approach. Three patients had undergone an eyebrow, supracarotid approach for resection of a lesion arising at the ventral thalamopeduncular junction. Two patients had presented with a cavernoma and one with a pilocytic astrocytoma. Complete resection of all 3 lesions was achieved during surgery without any intraoperative complications. No patient developed permanent contralateral weakness despite entering the peduncle during surgery. One patient developed permanent paresthesia in his left hand. Lesions arising at the ventral thalamopeduncular junction can be adequately resected with reasonable outcomes using an eyebrow, supracarotid triangle approach. This operative technique establishes another potential operative corridor by which neurosurgeons can resect lesions arising within this relatively inaccessible part of the brain. [ABSTRACT FROM AUTHOR]

Wrist drops are usually due to a peripheral neuropathy affecting the radial nerve. Cortical wrist drops may occur, usually due to a lesion in the contralateral hand area of the motor cortex. We report a unique case of "cortical" wrist drop due to an acute infarction of the contralateral cerebral peduncle. The patient is a 70-year-old gentleman with the vascular factors of hypertension, hyperlipidaemia, and prior cerebellar strokes, who developed sudden onset of right wrist weakness without numbness. Neurological examination showed a right wrist and finger drop. Nerve conduction study of the radial nerve was normal. MRI brain revealed an acute infarct in the medial part of the left cerebral peduncle, extending slightly to the medial thalamus; there were also old medial posterior cerebellar infarcts. Time of flight MR angiography was normal, with hypoplastic right vertebral artery. Echocardiography was normal but for a dilated right atrium. Electrocardiogram was normal, and 24-hour Holter monitoring detected infrequent atrial and ventricular ectopics. X-ray wrist showed an old ulnar styloid fracture. Nerve conduction study of the radial nerve was normal. He was switched from aspirin to clopidogrel and underwent rehabilitation. The cerebral peduncle should not be forgotten when attempting to anatomically localise the site of the lesion when evaluating a patient with a wrist drop. [ABSTRACT FROM AUTHOR]

• We report a rare case of intracranial lipoma located in the cerebral peduncle. • The left oculomotor nerve ran through our patient's lipoma, which caused nerve palsy. • Our patient also exhibited vascular anomalies in the posterior circulation. Intracranial lipomas are rare and often located in the midline of the brain. Intracranial lipomas are often associated with malformations of the brain such as dysgenesis of the corpus callosum, but rarely with vascular malformations. A man presented with left-sided facial pain at the age of 31. He developed left oculomotor nerve palsy at the age of 38 years and was referred to our hospital at the age of 48. Radiological findings revealed vascular anomalies of the left posterior cerebral and superior cerebellar arteries with intracranial lipoma-like lesion in the cerebral peduncle. Surgical treatment was complicated by the lesion location, so we administered conservative therapy. Despite treatment with corticosteroids, his symptoms have not improved. This unique case documents the presentation of vascular anomalies of the left posterior cerebral and superior cerebellar arteries associated with lipoma in the cerebral peduncle. [ABSTRACT FROM AUTHOR]

Background: Holmes tremor (HT) arises from disruption of the cerebellothalamocortical pathways. A lesion can interrupt the projection at any point, resulting in this tremor. We describe a case of HT due to the rare artery of Percheron infarct and its successful treatment using deep brain stimulation. Case report: A 62-year-old woman with a right medial cerebral peduncle and bilateral thalamic stroke developed HT. Ventral intermediate nucleus (Vim) zona incerta (ZI) deep brain stimulation (DBS) surgery was performed, with improvement in her tremor. Discussion: Our case supports the theory that the more caudal ZI target in combination with Vim is beneficial in treating poorly DBS-responsive tremors such as HT. [ABSTRACT FROM AUTHOR]

Ventral midbrain cavernous malformations are rare, and annual bleeding rate is higher than supratentorial lesions. Rebleeding rate is also high if surgical resection is incomplete. The ventral midbrain is deeply located and surrounded by many perforators, which make the approach to this region difficult. We experienced two cases of ventral midbrain cavernous malformations successfully removed via orbitozygomatic interpeduncular approach. In these cases, most parts of the lesions exist behind the cerebral peduncle extending interpeduncular fossa. In the first case involving a 15-year-old girl, we removed the lesion completely through an ipsilateral orbitozygomatic interpeduncular approach with minimum sacrifice of the right cerebral peduncle. However, in the second case involving a 43-year-old man, the same approach did not reach the lesion behind the ipsilateral cerebral peduncle. At the second operation, a contralateral orbitozygomatic interpeduncular approach was used to remove the residual lesion completely. Ipsilateral and contralateral orbitozygomatic interpeduncular approaches with minimum destruction of the cerebral peduncle are options for the lesions which exist in the interpeduncular fossa and behind the cerebral peduncle.

Major ozonated autohemotherapy has been shown to promote recovery of upper limb motor function in patients with acute cerebral infarction, but whether major ozonated autohemotherapy affects remote injury remains poorly understood. Here, we assumed that major ozonated autohemotherapy contributes to recovery of clinical function, possibly by reducing remote injury after acute cerebral infarction. Sixty acute cerebral infarction patients aged 30–80 years were equally and randomly allocated to ozone treatment and control groups. Patients in the ozone treatment group received medical treatment and major ozonated autohemotherapy (47 mg/L, 100 mL ozone) for 10 ± 2 days. Patients in the control group received medical treatment only. National Institutes of Health Stroke Scale score, modified Rankin scale score, and reduced degree of fractional anisotropy values of brain magnetic resonance diffusion tensor imaging were remarkably decreased, brain function improved, clinical efficiency significantly increased, and no obvious adverse reactions detected in the ozone treatment group compared with the control group. These findings suggest that major ozonated autohemotherapy promotes recovery of neurological function in acute cerebral infarction patients by reducing remote injury, and additionally, exhibits high safety.

A 72-year-old right-handed female patient was operated on for left-sided acute subdural hematoma responsible for coma. Two weeks afterward, her neurological status had improved with a Glasgow Coma Scale score of 14 and a paradoxical left-sided hemiparesis. The brain magnetic resonance imaging displayed a diffusion-restricting, hyper fluid-attenuated inversion recovery lesion of the right cerebral peduncle facing the tentorial notch, and the patient was diagnosed with Kernohan-Woltman notch phenomenon. This allowed to focus the neurological rehabiliation on the ipsilateral motor deficit as well as the hemineglect., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Introduction: We explored the relationship between secondary degeneration of white matter (WM) tracts and motor outcomes after left basal ganglia infarction and investigated alterations in the diffusion indices of WM tracts in distal areas., Methods: Clinical neurological evaluations were accomplished using the Fugl-Meyer scale (FMS). Then, the fractional anisotropy (FA) of the bilateral superior corona radiata (SCR), cerebral peduncle (CP), corticospinal tracts (CST), and corpus callosum (CC) were measured in all patients and control subjects., Results: Regional-based analysis revealed decreased FA values in the ipsilesional SCR, CP, and CST of the patients, compared to the control subjects at 5- time points. The relative FA (rFA) values of the SCR, CP, and CST decreased progressively with time, the lowest values recorded at 90 days before increasing slightly at 180 days after stroke. Compared to the contralateral areas, the FA values of the ipsilesional SCR and CST areas were significantly decreased (P=0.023), while those of the CP decreased at 180 days (P=0.008). Compared with the values at 7 days, the rFA values of the ipsilesional SCR and CP areas were significantly reduced at 14, 30, and 90 days, while those in the CST area were significantly reduced at 14, 90, and 180 days. The CP rFA value at 7 days correlated positively with the FM scores at 180 days (r=0.469, P=0.037)., Conclusion: This study provides an objective, comprehensive, and automated protocol for detecting secondary degeneration of WM, which is important in understanding rehabilitation mechanisms after stroke., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Background We aimed to evaluate the factors associated with de novo brain cavernoma formations after patients underwent gamma knife radiosurgery (GKRS) and confirmed whether developmental venous anomaly (DVA) presented with a cavernoma and whether the cavernoma was included in the GKRS target location. Methods From January 2003 to December 2008, 95 patients underwent radiosurgery for brain cavernoma at our institution. Of these, 15 with multiple cavernomas related to familial cavernoma or with a history of surgical treatment for cavernoma were excluded. A total of 80 patients (44 men and 36 women; average age, 39.4 years) with sporadic cavernoma were retrospectively analyzed by considering the patient characteristics, including sex, age, target volume, radiation dose, clinical symptoms, cavernoma location, radiosurgery complications, and morphology of DVA. Results The average target volume, mean radiation dose, and mean target percentage were 1019.2 mm3, 13.7 Gy, and 51.1%, respectively. Nineteen patients showed cavernomas associated with DVA; of these, de novo cavernoma formations were noticed in 4 patients at a median of 49.5 months after undergoing GKRS. All de novo cavernomas were related to the presence of DVA and were located near the brainstem or cerebral peduncle. De novo cavernomas occurred when DVAs were not included in the GKRS-target location. Conclusions All de novo cavernomas were located near the brainstem or cerebral peduncle, and they occurred in the presence of DVAs. The presence of DVA in the radiosurgery target location might be potentially an important factor associated with de novo cavernoma formation. Highlights • Factors associated with de novo brain cavernoma formation after GKRS were evaluated. • De novo cavernoma formations were related to DVA. • De novo cavernomas formations were located near the brainstem or cerebral peduncle. • All de novo cavernomas occurred when DVAs were not included in GKRS target location. [ABSTRACT FROM AUTHOR]

Aim: The objectives were: 1) replicate key elements of Head Up (HUP) cardiopulmonary resuscitation (CPR) physiology in a traditional swine model of ventricular fibrillation (VF), 2) compare HUP CPR physiology in pig cadavers (PC) to the VF model 3) develop a new human cadaver (HC) CPR model, and 4) assess HUP CPR in HC.Methods: Nine female pigs were intubated, and anesthetized. Venous, arterial, and intracranial access were obtained. After 6 min of VF, CPR was performed for 2 min epochs as follows: Standard (S)-CPR supine (SUP), Active compression decompression (ACD) CPR + impedance threshold device (ITD-16) CPR SUP, then ACD + ITD HUP CPR. The same sequence was performed in PC 3 h later. In 9 HC, similar vascular and intracranial access were obtained and CPR performed for 1 min epochs using the same sequence as above.Results: The mean cerebral perfusion pressure (CerPP, mmHg) was 14.5 ± 6 for ACD + ITD SUP and 28.7 ± 10 for ACD + ITD HUP (p = .007) in VF, -3.6 ± 5 for ACD + ITD SUP and 7.8 ± 9 for ACD + ITD HUP (p = .007) in PC, and 1.3 ± 4 for ACD + ITD SUP and 11.3 ± 5 for ACD + ITD HUP (p = .007) in HC. Mean systolic and diastolic intracranial pressures (ICP) (mmHg) were significantly lower in the ACD + ITD HUP group versus the ACD + ITD SUP group in all three CPR models.Conclusion: HUP CPR decreased ICP while increasing CerPP in pigs in VF as well as in PC and HC CPR models. This first-time demonstration of HUP CPR physiology in humans provides important implications for future resuscitation research and treatment. [ABSTRACT FROM AUTHOR]

Background Autism spectrum disorder (ASD) is a mental disorder that has long been considered to result from brain underconnectivity. However, volumetric analysis of structural MRI data has failed to find consistent white matter alterations in patients with ASD. The present study aims to examine whether there are consistent focal white matter alterations as measured by diffusion tensor imaging (DTI) in individuals with ASD compared with typically developing (TD) individuals. Method Coordinate-based meta-analysis was performed on 14 studies that reported fractional anisotropy (FA) alterations between individuals with ASD and TD individuals. These studies have in total 297 subjects with ASD and 302 TD subjects. Results Activation likelihood estimation (ALE) analysis identified two clusters of white matter regions that showed consistent reduction of FA in individuals with ASD compared with TD individuals: the left splenium of corpus callosum and the right cerebral peduncle. Conclusions Consistent focal white matter reductions in ASD could be identified by using FA, highlighting the cerebral peduncle which is usually overlooked in studies focusing on major white matter tracts. These focal reductions in the splenium and the cerebral peduncle may be associated with sensorimotor impairments seen in individuals with ASD. [ABSTRACT FROM AUTHOR]

Ischemically damaged brain can be accompanied by secondary degeneration of associated axonal connections e.g. Wallerian degeneration. Diffusion tensor imaging (DTI) is widely used to investigate axonal injury but the cellular correlates of many of the degenerative changes remain speculative. We investigated the relationship of DTI of directly damaged cerebral cortex and secondary axonal degeneration in the cerebral peduncle with cellular alterations in pan-axonal neurofilament staining, myelination, reactive astrocytes, activation of microglia/macrophages and neuronal cell death. DTI measures (axial, radial and mean diffusivity, and fractional anisotropy (FA)) were acquired at hyperacute (3 h), acute (1 and 2 d) and chronic (1 and 4 week) times after transient cerebral hypoxia with unilateral ischemia in neonatal rats. The tissue pathology underlying ischemic and degenerative responses had a complex relationship with DTI parameters. DTI changes at hyperacute and subacute times were smaller in magnitude and tended to be transient and/or delayed in cerebral peduncle compared to cerebral cortex. In cerebral peduncle by 1 d post-insult, there were reductions in neurofilament staining corresponding with decreases in parallel diffusivity which were more sensitive than mean diffusivity in detecting axonal changes. Ipsilesional reductions in FA within cerebral peduncle were robust in detecting both early and chronic degenerative responses. At one or four weeks post-insult, radial diffusivity was increased ipsilaterally in the cerebral peduncle corresponding to pathological evidence of a lack of ontogenic myelination in this region. The detailed differences in progression and magnitude of DTI and histological changes reported provide a reference for identifying the potential contribution of various cellular responses to FA, and, parallel, radial, and mean diffusivity.

Molecular layer interneurons (MLIs, stellate and basket cells) of the cerebellar cortex are linked together by chemical and electrical synapses and exert a potent feedforward inhibition on Purkinje cells. The functional role of MLIs during specific motor tasks is uncertain. Here, we used two-photon imaging to study the patterns of activity of neighboring individual MLIs in the Crus II region of awake female mice during two types of oromotor activity, licking and bruxing, using specific expression of the genetically encoded calcium indicator protein GCaMP6s. We found that both stellate and basket cells engaged in synchronized waves of calcium activity during licking and bruxing, with high degrees of correlation among the signals collected in individual MLIs. In contrast, no calcium activity was observed during whisking. MLI activity tended to lag behind the onset of sustained licking episodes, indicating a regulatory action of MLIs during licking. Furthermore, during licking, stellate cell activity was anisotropic: the coordination was constant along the direction of parallel fibers (PFs), but fell off with distance along the orthogonal direction. These results suggest a PF drive for Ca2+ signals during licking. In contrast, during bruxing, MLI activity was neither clearly organized spatially nor temporally correlated with oromotor activity. In conclusion, MLI activity exhibits a high degree of correlation both in licking and in bruxing, but spatiotemporal patterns of activity display significant differences for the two types of behavior. [ABSTRACT FROM AUTHOR]

Kernohan-Woltman notch phenomenon (KWNP) is an ipsilateral motor weakness due to compression of the contralateral cerebral peduncle. Most of the KWNP cases reported have been due to subdural hematomas, intracranial spaceoccupying lesions, and spontaneous bleeding of vascular malformations. In this study, we present the first pediatric case of KWNP caused by a traumatic epidural hematoma. Although subdural hematomas are the most frequent reason for KWNP, epidural hematomas may cause paradoxical ipsilateral signs not only in adults but also in pediatric patients. [ABSTRACT FROM AUTHOR]

Kernohan–Woltman notch phenomenon (KWNP) is a false localising sign which may still cause diagnostic confusion. It was first described by Kernohan and Woltman in 1929, through post-mortem studies on 297 patients following cases of false localisation. They proposed that raised intracranial pressure causes uncal herniation, which can compress the contralateral cerebral peduncle against the tough tentorium, manifesting as hemiparesis ipsilateral to the primary brain lesion. A number of case reports have been written since the original description of this phenomenon, primarily secondary to intracranial bleeds, and little has been written about long-term outcome of patients who develop KNWP. We performed a literature search of all published cases of KWNP, and reviewed its clinical, pathophysiological, imaging and neurophysiological characteristics. Furthermore, we summarise the long-term outcomes of these patients as described by case reports, with the aim to improve understanding of rehabilitation potential. Thirty-eight cases were found through a PubMed search. We also included a case from our own Trust, making the total number of cases in the analysis 39. Thirty-six cases were secondary to intracranial bleeds (22 of which were traumatic), the remainder were due to an arachnoid cyst, high grade glioma, and reabsorption bone syndrome. Additional clinical manifestations to hemibrachiocrural syndrome included third nerve palsy, mydriasis of the contralateral and ipsilateral pupils, facial nerve palsies, and parkinsonism. Twenty-six (67%) patients had improvement in motor function of varying degrees, with twelve (31%) patients attaining complete motor recovery or independence. More studies on long-term outcome of patients who develop KWNP are needed to understand rehabilitation potential. [ABSTRACT FROM PUBLISHER]

Purpose: This works comprehensively analyses a modern cohort of patients with ipsilateral hemiparesis (IH) and discusses the pathophysiological theories elaborated to explain this paradoxical neurological sign according to the findings from contemporary neuroimaging and neurophysiological techniques., Methods: A descriptive analysis of the epidemiological, clinical, neuroradiological, neurophysiological, and outcome data in a series of 102 case reports of IH published on since the introduction of CT/MRI diagnostic methods (years 1977-2021) was performed., Results: IH mostly developed acutely (75.8%) after traumatic brain injury (50%), as a consequence of the encephalic distortions exerted by an intracranial haemorrhage eventually causing contralateral peduncle compression. Sixty-one patients developed a structural lesion involving the contralateral cerebral peduncle (SLCP) demonstrated by modern imaging tools. This SLCP showed certain variability in its morphology and topography, but it seems pathologically consistent with the lesion originally described in 1929 by Kernohan & Woltman. The study of motor evoked potentials was seldom employed for the diagnosis of IH. Most patients underwent surgical decompression, and a 69.1% experienced some improvement of the motor deficit., Conclusions: Modern diagnostic methods support that most cases in the present series developed IH following the KWNP model. The SLCP is presumably the consequence of either compression or contusion of the cerebral peduncle against the tentorial border, although focal arterial ischemia may also play a contributing role. Some improvement of the motor deficit should be expected even in the presence of a SLCP, provided the axons of the CST were not completely severed., (Copyright © 2023 Elsevier Masson SAS. All rights reserved.)