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Byline: Debjyoti. Dhar, Anita. Mahadevan, A. Nagaraj, Rohan. Mahale, Chandrajit. Prasad, Athyadi. Shreedevi, Pooja. Mailankody, P. Mathuranath, Hansashree. Padmanabha Dear Sir, Neuromyelitis optica spectrum disorder (NMOSD) and Myelin oligodendrocyte glycoprotein [...]

Byline: Dhaval. Gohil, Anita. Mahadevan, A. Prabhuraj, Nupur. Pruthi Background: Knot configuration is an important but relatively neglected topic in microvascular anastomosis literature. Objective: To study the differences between end-to-end [...]

In patients with medically refractory epilepsy, resective surgery is the mainstay of therapy to achieve seizure freedom. However, ∼20-50% of cases have intractable seizures post-surgery due to the imprecise determination of epileptogenic zone. Recent intracranial studies suggest that high frequency oscillations between 80 and 200 Hz could serve as one of the consistent epileptogenicity biomarkers for localization of the epileptogenic zone. However, these high frequency oscillations are not adopted in the clinical setting because of difficult non-invasive detection. Here, we investigated non-invasive detection and localization of high frequency oscillations and its clinical utility in accurate pre-surgical assessment and post-surgical outcome prediction. We prospectively recruited 52 patients with medically refractory epilepsy who underwent standard pre-surgical workup including magnetoencephalography (MEG) followed by resective surgery after determination of the epileptogenic zone. The post-surgical outcome was assessed after 22.14 ± 10.05 months. Interictal epileptic spikes were expertly identified, and interictal epileptic oscillations across the neural activity frequency spectrum from 8 to 200 Hz were localized using adaptive spatial filtering methods. Localization results were compared with epileptogenic zone and resected cortex for congruence assessment and validated against the clinical outcome. The concordance rate of high frequency oscillations sources (80-200 Hz) with the presumed epileptogenic zone and the resected cortex were 75.0% and 78.8%, respectively, which is superior to that of other frequency bands and standard dipole fitting methods. High frequency oscillation sources corresponding with the resected cortex, had the best sensitivity of 78.0%, positive predictive value of 100% and an accuracy of 78.84% to predict the patient's surgical outcome, among all other frequency bands. If high frequency oscillation sources were spatially congruent with resected cortex, patients had an odds ratio of 5.67 and 82.4% probability of achieving a favourable surgical outcome. If high frequency oscillations sources were discordant with the epileptogenic zone or resection area, patient has an odds ratio of 0.18 and only 14.3% probability of achieving good outcome, and mostly tended to have an unfavourable outcome (χ2 = 5.22; P = 0.02; φ = -0.317). In receiver operating characteristic curve analyses, only sources of high-frequency oscillations demonstrated the best sensitivity and specificity profile in determining the patient's surgical outcome with area under the curve of 0.76, whereas other frequency bands indicate a poor predictive performance. Our study is the first non-invasive study to detect high frequency oscillations, address the efficacy of high frequency oscillations over the different neural oscillatory frequencies, localize them and clinically validate them with the post-surgical outcome in patients with medically refractory epilepsy. The evidence presented in the current study supports the fact that HFOs might significantly improve the presurgical assessment, and post-surgical outcome prediction, where it could widely be used in a clinical setting as a non-invasive biomarker.

Byline: Anu. Gupta, Roopa. Raja, Shiny. Joy, Chitrangada. Yadav, Madhavi. Tripathi, Shailesh. Gaikwad, V. Vishnu, Mamta. Singh, Rohit. Bhatia, Anita. Mahadevan, Madakasira. Padma Srivastava Dear Sir, Recent research has drawn [...]

Byline: Ragasudha. Botta, J. Kumar, Bindu. Kutty, Anita. Mahadevan, Pramod. Pal, Ravi. Yadav Introduction: Cognitive impairment is a common non-motor feature of Parkinson's Disease (PD). Diagnosis of mild cognitive impairment [...]

Byline: Sumanth. Shivaram, Manisha. Gupta, A. R. Taallapalli, Saraswati. Nashi, Anita. Mahadevan, P. Srijithesh Dear Editor, Anti-N-methyl-D-aspartate (anti-NMDA) receptor encephalitis is a potentially reversible, immune-mediated cause of encephalitis that is [...]

Byline: Ameya. Patwardhan, Joydeep. Mukherjee, Radhika. Mhatre, Vivek. Lanka, Ajay. Asranna, Ravindu. Tiwari, Neeharika. Sriram, Karthik. Kulanthaivelu, Anita. Mahadevan, Subasree. Ramakrishnan Sir, Lipid storage myopathy is a group of rare [...]

Byline: Ayush. Agarwal, Aminu. Aliyar, Shilpa. Rao, Anita. Mahadevan, Ajay. Garg, Achal. Srivastava Myelin oligodendrocyte glycoprotein-associated disorder (MOGAD) is an autoimmune oligodendrocytopathy, whereas neuromyelitis optica spectrum disorder (NMOSD) is an [...]

Byline: Shreyashi. Jha, Chandana. Nagaraj, R. Mundlamuri, Suvarna. Alladi, Saraswati. Nashi, Raghavendra. Kenchaiah, Anita. Mahadevan, Maya. Bhat, Jitender. Saini, M. Netravathi Background: Fluorodeoxyglucose-positron emission tomography (FDG-PET) in autoimmune encephalitis (AE) [...]

This letter published in the Indian Journal of Psychological Medicine discusses a case of Leucine-rich Glioma Inactivated 1 (LGI-1) Limbic Encephalitis presenting with psychotic symptoms without seizures. The patient, a 48-year-old male, initially received a misdiagnosis of schizoaffective disorder due to his atypical presentation. However, further investigations revealed LGI-1 antibodies in his serum and cerebrospinal fluid. The patient was treated with intravenous methylprednisolone and plasmapheresis, resulting in significant improvement. Subsequent relapses were managed with rituximab. The case highlights the importance of considering a neurological etiology for patients presenting with psychotic symptoms, especially when accompanied by cognitive deficits and focal neurological deficits. [Extracted from the article]

Tropical ataxic neuropathy (TAN) is characterised by ataxic polyneuropathy, degeneration of the posterior columns and pyramidal tracts, optic atrophy, and sensorineural hearing loss. It has been attributed to nutritional/toxic etiologies, but evidence for the same has been equivocal. TAN shares common clinical features with inherited neuropathies and mitochondrial disorders, it may be hypothesised that genetic abnormalities may underlie the pathophysiology of TAN. This study aimed to establish evidence for mitochondrial dysfunction by adopting an integrated biochemical and multipronged genetic analysis. Patients (n = 65) with chronic progressive ataxic neuropathy with involvement of visual and/or auditory pathways underwent deep phenotyping, genetic studies including mitochondrial DNA (mtDNA) deletion analysis, mtDNA and clinical exome sequencing (CES), and respiratory chain complex (RCC) assay. The phenotypic characteristics included dysfunction of visual (n = 14), auditory (n = 12) and visual + auditory pathways (n = 29). Reduced RCC activity was present in 13 patients. Mitochondrial DNA deletions were noted in five patients. Sequencing of mtDNA (n = 45) identified a homoplasmic variant (MT-ND6) and a heteroplasmic variant (MT-COI) in one patient each. CES (n = 45) revealed 55 variants in nuclear genes that are associated with neuropathy (n = 27), deafness (n = 7), ataxia (n = 4), and mitochondrial phenotypes (n = 5) in 36 patients. This study provides preliminary evidence that TAN is associated with a spectrum of genetic abnormalities, including those associated with mitochondrial dysfunction, which is in contradistinction from the prevailing hypothesis that TAN is related to dietary toxins. Analysing the functional relevance of these genetic variants may improve the understanding of the pathogenesis of TAN. [ABSTRACT FROM AUTHOR]

Background: Peripheral neuropathy is one of the manifestations of primary or familial amyloidosis. Published studies from India are limited. Materials and Methods: We reviewed the clinical and pathological features of amyloid neuropathy diagnosed at our Institute over the last 39 years. Results: Fifty-five cases of amyloid neuropathies were diagnosed between 1981 and 2019, constituting 0.28% of peripheral nerve biopsies (55/19,081). Age at presentation ranged from 24 to 81 years (mean--48 years) with male preponderance [M:F = 3.58:1]. Duration of symptoms at presentation varied from 3 months to 10 years (mean--2.31 years). Majority presented with small fiber neuropathy (85%). Pure sensory symptoms predominated in 23%, while 72% had sensorimotor neuropathy and 35.8% had autonomic involvement, with isolated autonomic failure in one patient. Amyloid neuropathy was clinically suspected in 22.6% of nonfamilial cases. Familial amyloid neuropathy was suspected in eight patients. Genetic testing detected ATTR and gelsolin mutation in one each of tested patients. Nerve biopsies revealed characteristic birefringent amyloid deposits stained mahogany brown by Congo red predominantly surrounding endoneurial microvessels (34.5%), also in perineurium and epineurium in 25.45% cases. Preferential loss of small diameter myelinated fibers was noted. Axonal degeneration or regeneration was conspicuously absent. Conclusion: Amyloid neuropathy is uncommon (0.28% of nerve biopsies in our series). Nerve biopsy is essential for the diagnosis. We report our experience of amyloid neuropathy and underscore the importance of making an assiduous search for amyloid deposits in the appropriate setting. Awareness of this entity is important for early diagnosis in the light of emerging therapeutic advances. [ABSTRACT FROM AUTHOR]

Byline: Sreyashi. Jha, Ajay. Asranna, Karthik. Kulanthaivelu, Bhaskar. Sanjaysingh, Subasree. Ramakrishnan, Anita. Mahadevan, Raghavendra. Kenchaiah Sir, Autoimmune encephalitis has recently emerged as a major cause of neurologic morbidity, significantly mediated [...]