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Abstract Background This research aims to study the association of genetic polymorphism in genes coding for CYP2C9 and CYP2C19 in phenytoin-induced dose-related toxicity and to assess if the presence of allele CYP2C9*3 plays a role in phenytoin-induced idiosyncratic adverse effects. Current observational case control study included 142 patients with phenytoin-induced adverse drug reactions (ADRs) and 100 controls. All these patients underwent genotyping to determine the type of CYP2C9 allele [CYP2C9*1, CYP2C9*2 or CYP2C9*3) and CYP2C19 allele (CYP2C19*1, CYP2C19*2 or CYP2C19*3] by real-time polymerase chain reaction (RT-PCR) using Applied Biosystems (ABI) 7500 Real-Time PCR System (USA). Results Presence of homozygous status for allele CYP2C9*3 was associated with significantly higher risk of phenytoin-induced dose-dependent ADRs, dose-independent ADRs, gum hyperplasia, and skin rash. Presence of heterozygous status for allele CYP2C9*3 was associated with significantly higher risk of phyenytoin-induced dose-dependent ADRs and dose-independent ADRs. Presence of either heterozygous or homozygous status for CYP2C9*2 and CYP2C19*2 did not have any bearing on dose-related side effects. None of the patients showed CYP2C19*3 allele. Conclusion Variant alleles of CYP2C9*3 are significantly overexpressed among patients with phenytoin-induced ADRs, thereby suggesting the role for CYP2C9 genotype testing to predict risk of phenytoin-related ADRs.

PurposeTo analyze the relationship between eccentric downward eye movement/eccentric downward eye-positioning (EDEM/EDEP) encountered in patients undergoing ophthalmic surgeries and its return to a centralized position under general anesthesia (GA) with the depth of anesthesia (DOA).MethodsPatients undergoing ophthalmic surgeries (6 months-12 years) under sevoflurane anesthesia without non-depolarizing muscle relaxant (NDMR) who witnessed a sudden tonic EDEM/EDEP were both retrospectively (R-group) and prospectively (P-group) enrolled (ambispective study). R-group included data-points after induction (AI) till the time surgery lasted while P-group compiled data both during induction (DI) and AI. DOA in terms of MAC (minimum alveolar concentration) at the time of EDEM/EDEP and centralization of eyeball and their timings were noted and compared for both AI and DI data-points. Also, vertical eccentric eye positions were scored and correlated with MAC.ResultsAI data included 22 (14R+8P) events and their mean MAC of EDEM/EDEP and centralization were 1.60 ± 0.25 and 1.18 ± 0.17 respectively (p = 0.000). DI data included 62 (P) cases and its mean MAC of EDEM/EDEP and centralization was 2.19 ± 0.43 and 1.39 ± 0.26 respectively (p = 0.000). Median (IQR) eye positions during down-positioning in 84 events was −3 (−3.9 to −2.5). It was preceded by an eccentric upward drift of eyes in 10/22 (6R+4P) AI cases. A strong negative correlation was seen between DOA and eccentric eye positions (r = −0.77, p = 0.000).ConclusionsTonic down-rolling of eyes is not uncommon in children seen without NDMR with higher depths of sevoflurane anesthesia compared to point of centralization and fluctuations in DOA should be avoided to circumvent inadvertent complications during ocular surgery.

Background: Leber hereditary optic neuropathy (LHON) is a maternally inherited disease resulting in irreversible visual loss usually in patients belonging to the age group of 15–35 years. Clinically, the patients present with sequential or bilateral, painless, progressive visual loss with central (or ceco-central) scotomas. Although the three mutations, namely, G11778A, T14484C, and G3460A contribute to >95% of LHON cases globally, the relative frequency of each mutation varies. Aims and Objectives: We aimed to assess the clinical and genetic profile of patients with mutation-positive LHON at a north Indian tertiary care center. Materials and Methodology: One hundred sixty-one patients (61 prospective and 100 retrospective) presenting with the clinical diagnosis of LHON were screened for the three known mitochondrial mutations (G1178A, G3460A, T14448C). Patients were assessed for detailed clinical, ophthalmological, and neurological examinations. Five milliliter of blood sample was taken to assess the three known mutations using DNA isolation and Sanger sequencing. Results and Discussion: Clinical profile of 83 patients with both positive and negative mutations was analyzed. Twenty-three out of 161 patients (14.3%) tested positive for either of the three mutations. The majority of the patients harbored G11778A mutation (56.52%) followed by T14484C (34.78%) and G3460A (8.69%). No statistical difference could be noted between the clinical profiles of mutation-negative and -positive patients.

Tolosa–Hunt syndrome (THS) remains a challenging diagnosis for many neurologists. Often believed to be a rare presentation, the classical presentation is known to involve cranial nerves and tissues surrounding the cavernous sinus. Traditionally, a diagnosis of THS is considered when all secondary conditions have been ruled out. Yet, newer findings have elaborated a complex pathogenetic process with some overlap from the IgG4 spectrum of disorders, with which it shares many phenotypic similarities. In this narrative review, we present an updated picture of the condition focusing on the latest developments in the pathogenesis, diagnosis, and clinical management of these two conditions and use illustrative examples to highlight the salient features of this rare presentation.

Myasthenia with thymoma and parathyroid adenoma is a rare presentation. Very few cases have been reported of this association without much role of plasma exchange in these patients. Here, we present our experience of plasma exchange in this rare clinical entity.

Ocular manifestations form an important clinical component of several movement disorders. Both hypokinetic and hyperkinetic movement disorders can involve the eye. Ophthalmological manifestations can arise due to dysfunction at the level of retina, optic nerves, oculomotor system, or subcortical or visual cortex. Ophthalmological findings help in differentiating various movement disorders and give a clue about their severity. These follow or may precede the diagnosis of movement disorders. Basal ganglia and its various nuclei especially substantia nigra pars reticulata play an important role in the genesis of eye movements through its connections with the superior colliculus. Eye movement abnormalities using quantitative recording techniques are now being considered as noninvasive biomarkers not only for the diagnosis but also to track the progression of disease as well as to study the effects of therapies in various movement disorders. Moreover, there is ample evidence of presence of retinal degeneration in various neurodegenerative diseases evaluated using optical coherence tomography. Various patterns of retinal thinning have been described in different movement disorders and have been found to have a correlation with the stage and severity of the disorder. In this review, we discuss ophthalmological findings of common hypokinetic and hyperkinetic movement disorders.

Purpose: Drawing differential diagnoses to a Neuro-ophthalmology clinical scenario is a difficult task for a neurology trainee. The authors conducted a study to determine if a mobile application specialized in suggesting differential diagnoses from clinical scenarios can complement clinical reasoning of a neurologist in training. Methods: A cross-sectional multicenter study was conducted to compare the accuracy of neurology residents versus a mobile medical app (Neurology Dx) in drawing a comprehensive list of differential diagnoses from Neuro-ophthalmology clinical vignettes. The differentials generated by residents and the App were compared with the Gold standard differential diagnoses adjudicated by experts. The prespecified primary outcome was the proportion of correctly identified high likely gold standard differential diagnosis by residents and App. Results: Neurology residents (n = 100) attempted 1500 Neuro-ophthalmology clinical vignettes. Frequency of correctly identified high likely differential diagnosis by residents was 19.42% versus 53.71% by the App (P < 0.0001). The first listed differential diagnosis by the residents matched with that of the first differential diagnosis adjudicated by experts (gold standard differential diagnosis) with a frequency of 26.5% versus 28.3% by the App, whereas the combined output of residents and App scored a frequency of 41.2% in identifying the first gold standard differential correctly. The residents correctly identified the first three and first five gold standard differential diagnosis with a frequency of 17.83% and 19.2%, respectively, as against 22.26% and 30.39% (P < 0.0001) by the App. Conclusion: A ruled based app in Neuro-ophthalmology has the potential to complement a neurology resident in drawing a comprehensive list of differential diagnoses.

Idiopathic intracranial hypertension (IIH) is defined as a syndrome of raised intracranial pressure with normal imaging of the brain and cerebrospinal fluid (CSF) composition. There are many controversies and myths that surround IIH. Although patients of IIH may present “typical” symptoms and signs of raised intracranial pressure, clinical scenarios often vary. A typical clinical and radiological finding poses significant problems in diagnosis and management of patients with IIH. We have tried to resolve these controversies and provide a comprehensive update on different aspects of IIH. In this article, we review the common problems encountered while dealing with patients of IIH.

Background: Although first described more than two decades ago, posterior reversible encephalopathy syndrome (PRES) continues to be enigmatic. We prospectively followed consecutive patients of PRES both clinically and radiologically for a better understanding of natural history, symptomatology, and prognosis of this not so uncommon entity. Patients and Methods: The current study included 22 consecutive patients of PRES who were followed both clinically as well as radiologically at a tertiary care institute in Northern India from December 2014 to June 2016. Results: Mean age was 30.68 ± 12.68 years. The most common symptoms included altered sensorium (77.3%), headache (72.7%), seizures (63.6%), vomiting (36.4%), and visual disturbances (22.7%). About 94.5% of patients had parieto-occipital signal changes on neuroimaging. Magnetic resonance imaging (MRI) (n = 20) revealed involvement of sites considered atypical for PRES in 95% (frontal [55%], temporal [40%], cerebellum [40%], basal ganglia [15%], deep white matter [10%] and brainstem [10%]). Diffusion restriction, haemorrhage, and contrast enhancement were seen in 30%, 22.2%, and 25% of patients. At 3 months follow-up, modified Rankin scale was 0 in 19 patients and 1 in 1 patient. Two (9.1%) patients died. Eight (36.4%) patients had eclampsia, 5 (22.7%) each had chronic kidney disease and essential hypertension whereas 2 (9.1%) each had immune-mediated disorders and drug-induced PRES. None of the clinical or imaging features predicted outcome in PRES. Conclusion: Atypical MRI presentations of PRES are common, and there is a need to keep a strong index of suspicion for the diagnosis of PRES. The prognosis of PRES is good, and most cases show excellent recovery, particularly if underlying etiology can be treated satisfactorily.

Acute nontraumatic weakness (ANTW) is defined as acute onset of weakness in any part of the body. The weakness occurs due to interruption at any point along the motor pathway. The motor pathway originates from upper motor neuron cells in the cerebral cortex and traverses through the brainstem till lower motor neurons in the spinal cord. The axon of a lower motor neuron is known as the peripheral motor nerve that synapses with muscle. ANTW is of varied etiology and presentation that may be immediately life-threatening if respiratory muscles or autonomic nervous system is involved. Involvement of respiratory muscles may be associated with respiratory failure that may require mechanical ventilation. The weakness may be localized to one limb or generalized involving several muscle groups. When bulbar muscles are involved, weakness leads to problem in swallowing and coughing that endangers the patient's airway. Similarly, the course of the disease also varies, and these patients may worsen rapidly. Hence, a comprehensive history, systematic evaluation, and a detailed neurological examination are performed to localize the disorder. There are specific clinical features peculiar to the particular location of the lesion in the body. Hence, it is possible to anatomically localize these lesions based on the clinical features. Initial laboratory tests and appropriate neuroimaging should be obtained as indicated by history and examination. The time-sensitive emergencies should be addressed immediately, as the delay in management may lead to either permanent neurological damage or may worsen the overall outcome in such conditions. The initial management should always include care of airway, breathing, and circulation (ABC). The imaging should be obtained only after initial stabilization of ABC. The definitive treatment should be done as per the etiology.

We describe an unusual case of lymphomatosis cerebri in a middle-aged lady presenting with rapid-onset dementia. The lymphomatous infiltrate, instead of forming mass lesions, percolated throughout the brain parenchyma, which is often missed on a stereotactic biopsy and hence warrants caution and awareness about this entity. The nonspecific symptoms at presentation and a variable picture at imaging make this entity diagnostically challenging.

A 15-year-old healthy boy developed acute, rapidly progressing visual loss in left eye following herpes zoster dermatitis, with a combined central retinal artery occlusion (CRAO) and central retinal vein occlusion (CRVO), along with optic perineuritis. Laboratory tests were negative. Despite an empirical, intensive antiviral treatment with systemic corticosteroids, and vision could not be restored in the affected eye. Herpes zoster dermatitis, in an immunocompetent individual, may be associated with a combined CRAO and CRVO along with optic perineuritis, leading to profound visual loss.