Utility of stimulus induced after discharges in the evaluation of peripheral nerve hyperexcitability: Old wine in a new bottle?

Limited literature is available on stimulus induced after discharges (SIAD) in patients with peripheral nerve hyperexcitability (PNH). The aim of the study was to examine the diagnostic utility of SIAD in the diagnosis and monitoring of primary PNH disorders. In this retrospective study, we studied 26 patients who were admitted with a diagnosis of primary PNH to the department of Neurology from January 2013 to April 2019. Their clinical profile, immunological characteristics were extracted from the database and nerve conduction studies were relooked for the presence of SIAD. 76% of patients in the primary PNH cohort had SIAD with 90% of them being voltage-gated potassium channel complex antibody positive; predominantly against contactin-associated protein-2 antigen and rest being paraneoplastic. There was also resolution of SIAD following treatment indicating reversible hyperexcitability. SIAD is a sensitive marker for Primary PNH syndrome with monitoring and diagnostic implications.

Sonothrombolysis for acute ischemic stroke - Break on through to the other side.

BACKGROUND: Intravenous (IV) tissue plasminogen activator (tPA) infusion combined with transcranial low-frequency ultrasound waves targeted on the occluded arterial segment (sonothrombolysis) can increase recanalization in large artery-acute ischemic stroke (LA-AIS). AIMS: To evaluate the benefits of sonothrombolysis in LA-AIS. SETTINGS AND DESIGNS: An open-labeled observational study done in a quaternary care teaching hospital. METHODOLOGY: Patients with LA-AIS within the window period (<4.5 h) with no contraindications for IV-recombinant tPA were sonothrombolysed. Recanalization was monitored and graded using the transcranial Doppler thrombolysis in brain ischemia (TIBI) flow criteria and also by time of flight magnetic resonance angiography using a modified thrombolysis in myocardial infarction score. Parenchymal changes were assessed using computed tomography (CT) or diffusion-weighted imaging-Alberta Stroke Programme Early CT Score. National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) were used to assess the outcome. RESULTS: Eighteen patients underwent sonothrombolysis and the mean onset to needle time was 138 min (range 65-256). TIBI residual flow grade of ≥2 was seen in 15 of 18 patients (83%). Immediate dramatic improvement (NIHSS score ≤3 points or improvement by ≥10 points) was seen in 6 of 18 patients (30%) and in 9 of 18 patients (50%) within the next 24 h. Two patients (one with TIBI 0, another with re-occlusion) underwent mechanical thrombectomy post-sonothrombolysis. Symptomatic hemorrhage occurred in 5.5% of the patients. At 6 months, 2 of 18 patients (11%) died and 10 of 16 patients (63%) achieved mRS ≤2. CONCLUSIONS: Sonothrombolysis appears to be a safe way to augment the effect of tPA without increasing the door to needle time with the added advantage of observing flow through the occluded artery in real time.

Host Th1/Th2 immune response to Taenia solium cyst antigens in relation to cyst burden of neurocysticercosis.

Neurocysticercosis (NCC), Taenia solium larval infection of the brain, is an important cause of acquired seizures in endemic countries, which relate to number, location and degenerating cysts in the brain. Multicyst infections are common in endemic countries although single-cyst infection prevails in India. Single-cyst infections in an endemic country suggest a role for host immunity limiting the infection. This study examined ex vivo CD4(+) T cells and in vitro Th1 and Th2 cytokine responses to T. solium cyst antigens of peripheral blood mononuclear cells of healthy subjects from endemic and nonendemic regions and of single- and multicyst-infected patients for association with cyst burden of NCC. T. solium cyst antigens elicited a Th1 cytokine response in healthy subjects of T. solium-endemic and T. solium-non-endemic regions and those with single-cyst infections and a Th2 cytokine response from subjects with multicyst neurocysticercosis. Multicyst neurocysticercosis subjects also exhibited low levels of effector memory CD4(+) T cells. Th1 cytokine response of T. solium exposure and low infectious loads may aid in limiting cyst number. Th2 cytokines and low effector T cells may enable multiple-cyst infections to establish and persist.

An unusual case of inflammatory necrotizing myopathy and neuropathy with pipestem capillaries.

Necrotizing myopathy with pipestem capillaries is a form of chronic inflammatory myopathy, with histopathology showing necrotizing myopathy, minimal cellular infiltration, and microangiopathy. A 30-year-old female presented with progressive limb weakness of 6 months, with skin pigmentation and Raynaud's phenomenon. Serum creatine phosphokinase was 3990 u/L. Muscle biopsy showed necrotic fibers, focal sparse perivascular inflammation/perifascicular atrophy, endomysial/epimysial vessel wall thickening with luminal narrowing. The features were of inflammatory necrotizing myopathy and neuropathy with pipestem capillaries/microangiopathy. She was pulsed with intravenous immunoglobulin, methylprednisolone, and cyclophosphamide and showed a good improvement. In the absence of widespread inflammatory response and classical histopathology findings, it is important to diagnose this condition as it shows a good response to aggressive and prolonged immunotherapy.

Stuck with a drowsy patient, evoke the Percheron.

BACKGROUND: Strokes caused by normal variants of the cerebral circulation can be difficult to diagnose, hence a high index of suspicion is needed. This case series discusses the clinical and radiological aspects of one such stroke caused by occlusion of the artery of Percheron (AOP). MATERIALS AND METHODS: Computerized discharge summaries, outpatient records and imaging from picture archiving and communication system (PACS, GE), of patients with AOP infarction over a period of 12-years (2002-2014) were identified and their clinical and radiological features analyzed. RESULTS: Of 3589 strokes (both ischemic and hemorrhagic), 17 (0.47%) were due to AOP infarction. Their mean age was 50 years (range: 31-72 years). Disorders of consciousness (94%) were the most common presenting symptoms followed by gaze (53%) and memory impairment (24%). At follow-up, 2/17 (12%) patients developed extrapyramidal features. All patients had bilateral paramedian thalamic infarcts on magnetic resonance imaging (MRI). Associated anterior thalamic (5/17; 30%) and mid brain (10/17; 59%) infarcts were also seen. CT scan done in 11/17 patients prior to the MRI picked up only 6/11 (55%) of these infarcts. The most common etiological factors detected using the Trial of Org 10172 in Acute Stroke Treatment (TOAST) criteria were cardio embolic (8/17; 47%) followed by small vessel occlusion (7/17; 41%). Mortality occurred in 2/17 (12%) patients. At 6 months, a modified Rankin score of 2 or less was seen in 8/17 (47%) patients. CONCLUSIONS: Artery of Percheron infarcts should be considered in the differential diagnosis of patients presenting with sudden alterations in consciousness. MRI should be the investigation of choice. An embolic etiology should be actively looked for.

"De Novo" Hypercapnic Respiratory Failure Unmasking Neuromuscular Disorders: Experiences From a Tertiary Care Center and Review of Literature.

OBJECTIVES: Neuromuscular disorders could have respiratory involvement early or late into illness. Rarely, patients may present with a hypercapnic respiratory failure (with minimal motor signs) unmasking an underlying disease. There are hardly any studies which have addressed the spectrum and challenges involved in management of this subset, especially in the real-world scenario. METHODS: A retrospective study comprising consecutive patients hospitalized with hypercapnic respiratory failure as the sole/dominant manifestation. The clinical-electrophysiological spectrum, phrenic conductions, diaphragm thickness, and outcomes were analyzed. RESULTS: Twenty-seven patients were included, the mean age was 47.29 (SD 15.22) years, and the median duration of respiratory symptoms was 2 months (interquartile range [IQR] 1-4). Orthopnea was present in 23 patients (85.2%) and encephalopathy in 8 patients (29.6%). Phrenic nerve latencies and amplitudes were abnormal in 83.3% and 95.6%, respectively. Abnormal diaphragm thickness was noted in 78.5%. Based on a comprehensive electrophysiological strategy and paraclinical tests, an etiology was established in all. Reversible etiologies were identified in 17 patients (62.9%). These included myasthenia gravis (anti-AChR and MuSK), inflammatory myopathy, riboflavin transporter deficiency neuronopathy, Pompe disease, bilateral phrenic neuritis, and thyrotoxicosis. Respiratory onset motor neuron disease was diagnosed in 8 patients (29.6%). Despite diaphragmatic involvement, a functional respiratory recovery was noted at discharge (45%) and last follow-up (60%). Predictors for good outcomes included female sex, normal nerve conductions, and recent-onset respiratory symptoms. DISCUSSION: A good functional recovery was noted in most of the patients including respiratory onset motor neuron disease. A systematic algorithmic approach helps in proper triaging, early diagnosis, and treatment. Clinical and electrodiagnostic challenges and observations from a tertiary care referral center are discussed.

Do Bone Mineral Density, Trabecular Bone Score, and Hip Structural Analysis Differ in Indian Men with Parkinson's Disease? A Case-Control Pilot Study from a Tertiary Center in Southern India.

Objective: Parkinson's disease (PD) is a neurodegenerative condition that is characterized by bradykinesia, rigidity, and gait instability. Inherent to this condition is an increased predisposition to falls and fractures. Bone health in Parkinson's disease in India has not been studied thus far. This study aimed to assess the bone mineral density (BMD), trabecular bone score (TBS), and hip structural analysis (HSA) in Indian men with PD and compare them with matched controls. Methodology: A case-control study done at a tertiary care center from southern India. Bone biochemistry, BMD, TBS, and HSA were assessed. Results: Among 40 cases and 40 age, gender, and body mass index (BMI)-matched controls, there was no significant difference in BMD between both groups. The mean (SD) TBS at the lumbar spine [1.349 (0.090)] was significantly (P = 0.019) lower in men with PD as compared to matched controls [1.401 (0.089)]. Among the parameters of HSA, the buckling ratios were significantly higher at the femoral neck [11.8 (2.2) vs 9.4 (2.2); P = 0.001] and inter-trochanteric region [9.4 (2.1) vs 7.8 (1.4); P = 0.002] among cases as compared to matched controls. Vitamin D deficiency was significantly higher in this cohort of patients as was bone turnover marker indicating bone loss and a high bone turnover state. Conclusion: A comprehensive bone health assessment comprising BMD, TBS, and HSA may be required to capture all aspects of bone strength in Indian men with PD as BMD assessment as a stand-alone tool may not suffice to obtain all information pertaining to fracture risk in these individuals.

Utility of neurophysiological criteria in Guillain Barre΄ syndrome: subtype spectrum from a tertiary referral hospital in India.

BACKGROUND: The Guillain Barre' syndrome (GBS) is a heterogeneous disease with various subtypes, the prevalence of which would depend on the geographic region. Recognition of these subtypes is of clinical importance since each subtype has an independent pathogenesis and different type of pathology and prognosis. OBJECTIVES: To study the various subtypes of GBS using the various published electrophysiological criteria. DESIGN: Retrospective descriptive study. MATERIALS AND METHODS: In a tertiary care hospital setting, the study compared the various published criteria for demyelination in GBS. The charts of 115 consecutive patients referred for electrodiagnostic evaluation to the Electromyography laboratory between July 2000 and June 2006 were reviewed. RESULTS: Of the 115 patients, 51 (44.4%) patients had axonal forms of GBS and 44 (38.2%) patients had acute inflammatory demyelinating polyradiculoneuropathy (AIDP). Applying the various published criteria, the number of patients categorized under the AIDP subtype ranged between 23.4% and 67.2%. CONCLUSION: In this study 44% patients had axonal forms of the disease, 38.2% patients had AIDP subtype and 17% remained unclassified. The most sensitive criteria to identify AIDP were the criteria proposed by Albers and colleagues and the Dutch group.

Infection-Associated Peripheral Nerve Hyperexcitability: An Under-Recognized Entity.

BACKGROUND: Peripheral nerve hyperexcitability (PNH) and neuromyotonia have been mainly attributed to antibodies against voltage-gated potassium channels (VGKC). Concurrent autoimmune disorders, malignancies, and heavy metal toxicity have also been implicated. There is scarce mention about infection as a triggering factor for PNH. There are no reports of methicillin-resistant Staphylococcus aureus (MRSA) infection being a possible precipitating factor for development of PNH. METHODS: Case series and literature review. RESULTS: Four subjects were diagnosed to have features of PNH based on clinical and electrophysiological assessment. All the subjects had concurrent evidence of cutaneous abscesses requiring surgical intervention and antibiotic therapy. The cultures in all of them revealed growth of Staphylococcus aureus with three of them being MRSA isolates. Two subjects tested positive for anti-VGKC antibodies. There was remarkable resolution in neuromyotonia after antibiotics in three subjects. One subject succumbed to fulminant MRSA septicemia. CONCLUSION: There appears to be a definitive link between staphylococcal infection (MRSA in particular) and development of PNH. The temporal evolution of PNH associated with the infection and resolution following treatment of the infection does support a causal association. The enterotoxins produced by staphylococci act as superantigens and could trigger an inflammatory cascade along with development of cross reacting antibodies against VGKC in peripheral nerves. Future studies with animal models could provide more directions in this regard.

Bone Mineral Density and Body Composition in Males with Motor Neuron Disease: A Study from Teaching Hospital in Southern Part of India.

BACKGROUND: Osteoporosis and sarcopenia are important aspects of motor neuron disease (MND). Individuals with amyotrophic lateral sclerosis (MND-ALS) have an increased risk of falls and fractures. Currently, the standard of care does not involve a routine assessment of bone mineral density (BMD) and body composition in these patients. We aimed to assess BMD, bone mineral parameters and body composition in men with MND and compared them with healthy controls. METHODS: Consecutive males between 50 and 80 years of age diagnosed as MND-ALS by revised El Escorial criteria and able to walk unassisted attending Neurology outpatient clinic were recruited into the study. Age, gender and body mass index (BMI) matched healthy controls were recruited from the local community. BMD and body composition were assessed by dual-energy x-ray absorptiometry (DXA). Bone mineral parameters and bone turnover markers (BTMs) were also assessed in them. RESULTS: A total of 30 subjects with MND-ALS and 33 controls were recruited. The mean age (years) was 59.2 in cases and 61.2 in controls. The mean BMD (g/cm2) between the two groups was similar; however, BTMs were significantly higher in the MND group (P < 0.05). Subjects with MND-ALS had significantly lower mean appendicular lean mass (ALM) (19.9 versus 22.4 kg; P = 0.007) and ALM corrected for BMI than the healthy control group (0.858 versus 0.934 kg/kg/m2; P = 0.034). Sarcopenic obesity (Percentage fat mass >27% + ALM/BMI <0.786 kg/kg/m2) was more prevalent in MND-ALS compared to controls (44.5% versus 16.7%; P = 0.03). CONCLUSION: Although BMD was not significantly different between subjects with MND-ALS and healthy controls, BTMs were significantly higher in the MND group indicating a high bone turnover state. Sarcopenia and sarcopenic obesity were also more in MND-ALS group than controls. Routine assessment for bone health parameters and body composition indices may be included in management of the patients with MND.

Patent foramen ovale closure in India; Feasibility, challenges and mid-term outcomes.

Patent foramen ovale closure (PFO) is an underutilized therapy, and our study explored the challenges and feasibility of PFO closure in the Indian setting. Eighty patients with Embolic Stroke of Undetermined Source (ESUS) were screened by transcranial Doppler (TCD) for PFO. Twenty-nine patients underwent successful closure. High-risk features of a long tunnel, inter-atrial septal aneurysm, and large defect were present in 31%, 28%, and 59%. Transcranial Doppler had a sensitivity and specificity of 78% and 53% (p = 0.02) to detect PFO. Anticoagulation was withdrawn in 85% of patients post closure. Two patients had residual shunts at follow-up of 19 (9,34) months.

Clinical Spectrum, Therapeutic Outcomes and Prognostic predictors in Paraneoplastic Neurological Syndromes - Experiences from a Tertiary Care Center in India.

BACKGROUND: Paraneoplastic Neurological Syndromes (PNSs) are a heterogeneous group of immune-mediated disorders that often precede tumor diagnosis. There are few systematic studies on the spectrum and follow-up of PNSs. OBJECTIVE: To analyze the clinical spectrum, associated tumors, antibody profile, outcomes, and prognostic predictors in a cohort of PNSs admitted in a tertiary care center. METHODS: This retrospective study included 97 patients (2008-2019). PNSs were further classified as "classical," "nonclassical," "definite," and "possible." Clinical profile, diagnostic strategies, therapeutic options, and predictors of outcomes were identified. RESULTS: The median age was 54 years (range 17-81). Thirty-nine (40.2%) had classical PNS, and 58 (59.8%) had nonclassical PNS, 74 (76.3%) had "Definite" PNS while 23 (23.7%) had "Possible" PNS. Cerebellar degeneration, peripheral neuropathy, and encephalopathy were the three most common neurological syndromes. Tumors were diagnosed in 66 (68%) patients; Lung cancer was the most common primary tumor. Antibodies were positive in 52 (53.6%). Anti-Yo antibody and anti-Ma2 antibody were the most common antibodies. The majority (57.7%) received immunotherapy in addition to definitive treatment for the tumor. A good outcome was seen in 53 (54.6%). Factors associated with good outcome were: early diagnosis, mRS <3 at presentation, absence of metastatic disease, and adjuvant immunotherapy. CONCLUSION: A high index of clinical suspicion is essential for early diagnosis and prompt management of PNS, especially the nonclassical syndromes. Multimodality diagnostic imaging techniques and antibody profiling play a crucial role in the diagnosis. A favorable prognosis can be expected with the judicious use of immunotherapy and definitive treatment of malignancy.

Clinical and Radiologic Findings of Acute Necrotizing Encephalopathy in Young Adults.

Acute necrotizing encephalopathy after an acute febrile illness, although initially described exclusively in the pediatric age group, has been recently shown to have an adult onset as well. In this study, we describe 10 patients (16 years of age or older) with acute necrotizing encephalopathy. In our study, bilateral thalamic involvement with the trilaminar pattern of diffusion restriction on MR imaging was the predominant finding seen in all of the patients reviewed. Ancillary findings of cerebral white matter, brain stem, and cerebellum involvement with sparing of the basal ganglia were also noted. A poorer outcome was observed in patients with a higher degree of thalamic involvement. The cause of an underlying infection was identified in 4 patients (dengue in 3 and influenza in 1). Overall, a sizeable portion of young adults with acute necrotizing encephalopathy have shown a poorer outcome, with dengue being an important underlying trigger in an endemic region.

Clinical Features of Four West Nile Virus Cases and Its Molecular Characterization from a South Indian Tertiary Care Hospital.

West Nile virus (WNV) is currently a significant reemerging virus of the 21st century. It belongs to the family Flaviviridae and genus Flavivirus. Although it is primarily transmitted by the Culex spp of mosquitoes, other routes of transmission are also well defined. Of eight lineages described, Lineage 1a has been reported from many parts of South India and is known to cause neuroinvasive illness. Many tests and serological techniques have been described to diagnose WNV infection such as complement fixation, neutralization, heamagglutination inhibition, ELISA, and PCR for molecular confirmation. The latter far outweighs the limitations inherent in the other tests. WNV infection is being reported from Vellore for the first time after 1968. This paper aims to describe four cases of WNV infection causing central nervous system manifestations with its molecular characterization. West Nile virus infection was diagnosed with the available molecular techniques such as PCR and sequencing, which emphasizes the need for considering West Nile virus in the differential diagnosis of acute meningoencephalitis and the wider availability of molecular diagnostic tests.

Closure of the patent foramen ovale in patients with embolic stroke of undetermined source: A clinical expert opinion and consensus statement for the Asian-Pacific region.

Recently published long-term data from randomized controlled trials have provided evidence for the prevention of recurrent embolic stroke of undetermined source by percutaneous closure of the patent foramen ovale. However, most data were obtained from Caucasian populations and evidence on patent foramen ovale closure in Asian-Pacific patients is limited. The relative paucity in clinical data from this population, as well as the fact that Asian-Pacific patients may have higher bleeding risks than Caucasians, complicates clinical decision-making. This document, resulting from a consensus meeting of Asian-Pacific clinical experts, states the consensus among these experts about how to treat Asian-Pacific patients who had an embolic stroke of undetermined source and have a patent foramen ovale, based on currently available evidence and expert opinions. In addition, uncertainties and the need for clinical data regarding patent foramen ovale closure for prevention of recurrent embolic stroke of undetermined source in general, and specifically for Asian-Pacific patients, are identified.

Cerebral Venous Thrombosis, Seasonal Trends, and Climatic Influence: A Region-SpecificStudy.

BACKGROUND AND PURPOSE: Studies looking at seasonal variation on cerebral venous thrombosis (CVT) are few with conflicting conclusions. In this region-specific study, we looked for climatic influence and seasonal trends on the incidence of CVT. METHODS: Imaging proven adult CVT cases treated over a period of 18 years from a specific geographical location with similar seasons and climatic conditions were studied. Metrological parameters prepared using 30 years of data was used. Quantum geographical information system (QGIS software) and SPSS v 22 were used for patient plotting and analysis. RESULTS: Total of 970 cases were studied. The incidence was significantly higher in summer 411 (42.3%) compared with autumn 317 (32.7%) and winter 242 (25.05); P = 0.038. This trend was consistent across all the 18 years in time series analysis. Mean age was 33.5 years (range 18-88 years). A significant majority 673 (69.4%) were below 40 years of age; P = 0.012. Females constituted 394 (40.6%) of cases. Postpartum CVT cases constituted 237 (30%). Interaction analysis showed younger age (<40 years) were more vulnerable for CVT in summer; P = 0.009. There was no seasonal influence on postpartum CVT. Apart for a weak positive correlation between rain fall (r = 0.18, P < 0.01); humidity and cloud cover was not influencing the incidence. CONCLUSIONS: Higher ambient temperatures were consistently associated with higher incidence of CVT. This is the largest region-specific study on CVT in the world. These results may be applicable to other regions with similar climatic conditions.

Clinical Spectrum and Outcome of Neurosarcoidosis: A Retrospective Cohort Study from a Teaching Hospital in India.

CONTEXT: Neurosarcoidosis (NS) is a chronic disease with a diverse clinical spectrum, therapeutic response, and outcome. There is scarce literature from our country regarding the same. AIMS: The aim of this study was to evaluate the clinical spectrum, therapeutic responses, and outcomes of NS in an Indian cohort. SETTINGS AND DESIGN: In a cross-sectional study, we included all patients with NS treated at a quaternary care teaching hospital in India from January 2007 to October 2019. SUBJECTS AND METHODS: Patients older than 18 years of age fulfilling the diagnostic criteria for NS from the Neurosarcoidosis Consortium Consensus Group were included in the study. The therapeutic response and the degree of disability at last follow-up were assessed. RESULTS: We identified 48 patients, among them 3 were categorized as having definite NS, 30 probable NS, and 15 possible NS. Cranial neuropathy was the most common presentation (47.9%), followed by myelopathy (25%). Systemic involvement was identified in 95.83% and mediastinal lymph nodes were the most common site. Clinical improvement was seen in 65.8% and disease stabilized in 28.9%, while 5.26% deteriorated. Fifty percent recovered without any residual disability, while 26.3% had minor and 23.7% had major residual sequelae. CONCLUSIONS: NS is a diverse illness, with a heterogeneous spectrum of clinical presentation, treatment response, and outcome. Cranial neuropathy is the most common presenting feature and has a good prognosis while myelopathy has an unfavorable prognosis. Meningeal and brain parenchymal disease is difficult to diagnose accurately unless systemic involvement is present. The diagnosis of NS should be clinically suspected in the appropriate clinical setting, the presence of systemic involvement should be investigated, and histologic confirmation should be attempted.

Amikacin-induced type 5 Bartter-like syndrome with severe hypocalcemia.

Aminoglycoside-induced renal toxicity is well known and may manifest with nonoliguric renal failure or renal tubular dysfunction. Aminoglycoside-induced renal tubular dysfunction could result in diffuse damage or manifest as a Fanconi-like syndrome, Bartter-like syndrome, or distal renal tubular acidosis. We discuss a patient who developed severe renal tubular dysfunction secondary to short-term therapy with Amikacin, resulting in refractory hypokalemia, hypocalcemia, hypomagnesemia, metabolic alkalosis, and polyuria. This constellation of biochemical abnormalities mimic Type 5 Bartter's syndrome, where there is activating mutation of the calcium sensing receptor in the thick ascending loop of Henle and the distal tubule. In this case this activation of the calcium sensing receptor was triggered by amikacin. This phenomenon has been described with gentamicin though never with amikacin. Recovery of the tubular dysfunction took 15 days following cessation of the offending drug, Amikacin.

Scrub Typhus-Associated Opsoclonus: Clinical Course and Longitudinal Outcomes in an Indian Cohort.

CONTEXT: Opsoclonus, a rare neurological manifestation in scrub typhus, causes significant distress and disability. There is a paucity of clinical data and outcomes in these patients. AIM: This study aims to describe the clinical and laboratory profile and longitudinal outcomes in a scrub typhus patient cohort with opsoclonus. SETTINGS AND DESIGN: This retrospective study was conducted in a 2700-bed teaching hospital in South India, in scrub typhus patients with opsoclonus over a 5-year period. PATIENTS AND METHODS: Clinical, laboratory, and radiological data and outcomes at discharge and 6- and 12-weeks postdischarge were documented. RESULTS: Of 1650 scrub typhus patients, 18 had opsoclonus. 17 had opsoclonus at presentation, while one patient developed opsoclonus on the 5th admission day, 1-day postdefervescence. Opsoclonus was first noted after a median interval of 11 (7-18) days from fever onset. It was associated with myoclonus in 94% (17/18), cerebellar dysfunction in 67% (12/18), extrapyramidal syndrome (EPS) in 33% (6/18), and aseptic meningitis in 17% (3/18) patients. Mean cerebrospinal fluid (CSF) white blood cell (WBC) count was 9 ± 2.7 cells/cumm, with mean CSF protein 118.5 ± 53.9 mg% and mean CSF glucose 97 ± 13 mg% in 1l/15 patients. Brain magnetic resonance imaging was unremarkable in 75% (9/12). Case-fatality rate was 5.5% (1/18). Complete resolution of the index neurological syndrome occurred at 12-week postdischarge. CONCLUSIONS: Opsoclonus is a rare neurological manifestation in scrub typhus, usually occurring in association with myoclonus, cerebellar dysfunction, or EPS. It appears to occur during the resolving febrile phase, with neurological deficits completely resolving at 12 weeks.