Delayed myelopathy after organophosphate intoxication: A case report

Organophosphate-induced delayed neuropathy, a central-distal axonopathy, passes through latent, progressive, static and improvement phases. During the improvement phase, the peripheral nerves regenerate unmasking the spinal cord lesion with myelopathic features. We report a case of a 16-year-old male who developed myelopathy 6 weeks following chlorpyrifos poisoning. He had a motor weakness of 4/5 in bilateral hips and 3/5 in bilateral knees and ankles. Spasticity and exaggerated reflexes with ankle clonus were present in the lower limbs. Sensory and the upper limb motor examinations were all normal. Pertinent blood, cerebrospinal fluid and nerve conduction tests were normal. Magnetic resonance imaging of the spine showed features of cord atrophy. Three months following physiotherapy, his power improved to 5/5 in bilateral knee and hip joints and 4/5 in bilateral ankles with spasticity. Organophosphate-induced delayed neuropathy can present as earlier as 6 weeks with myelopathy. Previous history of organophosphorous exposure is important in myelopathy or peripheral neuropathy.

Magnetic resonance imaging abnormalities in encephalomyelitis due to paralytic rabies: A case report

The diagnosis of rabies, a potentially fatal neuroinfectious disease, should be strongly considered in all patients who develop encephalitis following an infected animal bite even when they have received post-exposure prophylaxis. In the absence of confirmatory tests, typical magnetic resonance imaging findings help confirm the clinical diagnosis of rabies.

Round window membrane rupture following blunt force trauma

Round window rupture following barotrauma such as diving and air travel is well documented. However, we describe a case of round window rupture following a slap to the ear, which has not been described previously. A 12-year-old boy was slapped by his teacher in rural Nepal over his left ear and immediately noted hearing loss. There was no dizziness or tinnitus. He presented to our unit 21 days after the trauma and examination showed a perforation of the tympanic membrane in the anterior inferior quadrant with an otherwise normal ear examination and no nystagmus seen. Audiogram showed a left profound hearing loss, which was supported by auditory brainstem response test. Exploratory tympanotomy showed active perilymph leakage from the round window niche as demonstrated in the video attached. The round window was packed with cartilage and fascia to address the perilymph leakage. The patient was discharged the following day without any complications. This is an unusual cause for round window membrane rupture where the patient presented with hearing loss as his only symptom. Tympanotomy is recommended for patients with hearing loss following trauma with normal computed tomography imaging to exclude perilymph leak secondary to inner ear barotrauma.

Clinical Manifestations, Neuroimaging Findings, and Treatment of Idiopathic Intracranial Hypertension in a Nepalese Tertiary Centre

Introduction: Idiopathic Intracranial Hypertension is characterized by headache, visual impairment, papilledema, and increased cerebrospinal fluid opening pressure. We aim to evaluate clinical manifestations, neuroimaging findings, and treatment of Idiopathic Intracranial Hypertension in a Nepalese tertiary center. Materials and Methods: We retrospectively included patients with the diagnosis of Idiopathic Intracranial Hypertension who were admitted to the Neurology department of Tribhuvan University Teaching Hospital from 2019 June to 2021 May and presented to the Neuro-ophthalmology outpatient clinic of the hospital for follow-up. Results: Out of 16 Idiopathic Intracranial Hypertension patients, 12(75%) patients had either headache or ocular pain.  Reduced visual acuity and progressive visual loss were found in 44% of patients. Normal CSF opening pressure was found in 19%, 44% had CSF opening pressure at a range of 20-30 cm H20 and > 30 cm H20 in 37.5%. 15 Idiopathic Intracranial Hypertension patients (93.7%) were subtyped as Typical and 1 patient was diagnosed as Fulminant Idiopathic Intracranial Hypertension. Acetazolamide was used for treatment in 15 patients and 1 patient needed ventriculoperitoneal shunting. 56% Seven patients (44%) had some abnormal findings: partial empty sella (44%), and tortuous optic nerve (31%), flattened posterior eyeball (31%), and hypoplastic transverse sinus (19%). Conclusions: Idiopathic Intracranial Hypertension is an uncommon diagnosis but should be suspected in patients with chronic headaches with visual impairment. In low-resource settings, proper history along with neurological and ophthalmological examinations can even detect the early features and timely referral can save the vision and disability of Idiopathic Intracranial Hypertension patients.

Extensive bilateral intracranial calcifications and seizure in iatrogenic hypoparathyroidism: A case report

Postoperative permanent hypoparathyroidism can exhibit extensive intracranial calcifications involving basal ganglia, thalamus, cerebellum, and cerebral cortex.

Cartilaginous Choristoma of Tonsil: A hidden clinical entity

Choristoma is a tumor like mass which is an ectopic rest of normal tissue due to embryological developmental defect. The presence of choristoma in tonsil is extremely rare. On histopathological examination, mature hyaline cartilage were found surrounded by lymphoid follicles. We present a case of cartilaginous choristoma with the complaint of recurrent tonsillitis.

Cerebral venous sinus thrombosis with concomitant subdural hemorrhage and subarachnoid hemorrhages involving cerebral convexity and perimesenchephalic regions: A case report

We should suspect cerebral venous sinus thrombosis in patients with subacute onset progressive headaches with brain imaging evidence of localized cerebral edema with superimposed parenchymal, convexity subarachnoid as well as subdural hemorrhages.

Paraparetic Guillain-Barre syndrome: An uncommon diagnosis of acute flaccid paralysis of the lower limbs

Apart from the usual differentials of transverse myelitis and cord compression, paraparetic GBS should be considered when sudden, flaccid paralysis of the lower limbs occurs, as prompt diagnosis and management can minimize sequel and unnecessary procedures. We do report a case wherein we managed a similar situation without the use of an immunomodulatory therapy.

Isolated extrapontine myelinolysis with neuropsychiatric manifestation: A case report from Nepal

A referred case of a 34-year-old woman was brought to the emergency room with features of mutism and whole-body rigidity following rapid correction of hyponatremia. On presentation, she was ill looking with tremors on her both hands and legs. She was unresponsive to command and developed involuntary outbursts of laughter and crying. Based on clinical features and neuroimaging, diagnosis of isolated extrapontine myelinolysis was made. She was treated with quetiapine, vitamin B₁ and B₁₂ supplements, trihexyphenidyl, levodopa-carbidopa and physiotherapy of limbs. Due to lack of clinical trials for adequate diagnosis and management of extrapontine myelinolysis, this case report highlights the importance of extrapontine myelinolysis with neuropsychiatric manifestation in research world.

An optogenetic model reveals cell shape regulation through FAK and fascin

Cell shape regulation is important, but the mechanisms that govern shape are not fully understood, in part due to limited experimental models in which cell shape changes and underlying molecular processes can be rapidly and non-invasively monitored in real time. Here, we used an optogenetic tool to activate RhoA in the middle of mononucleated macrophages to induce contraction, resulting in a side with the nucleus that retained its shape and a non-nucleated side that was unable to maintain its shape and collapsed. In cells overexpressing focal adhesion kinase (FAK; also known as PTK2), the non-nucleated side exhibited a wide flat morphology and was similar in adhesion area to the nucleated side. In cells overexpressing fascin, an actin-bundling protein, the non-nucleated side assumed a spherical shape and was similar in height to the nucleated side. This effect of fascin was also observed in fibroblasts even without inducing furrow formation. Based on these results, we conclude that FAK and fascin work together to maintain cell shape by regulating adhesion area and height, respectively, in different cell types. This article has an associated First Person interview with the first author of the paper.

Lipid Profile and Ultrasonographic Grading in Alcoholic and Non Alcoholic Fatty Liver Patients

Background Fatty liver disease (FLD) is a common and major chronic liver disease. It has been implicated that patients have disorders of lipid metabolism and are involved in the pathogenesis of fatty liver. Hence, it was designed to observe the association between lipid profile and fatty liver disease. Objective This study was undertaken to evaluate the association of lipid profile status, hemoglobin and albumin levels with fatty liver disease patients diagnosed based on ultrasonography (USG). Method This Cross-sectional study was undertaken in the Department of Internal Medicine with the collaboration of the Department of Radiology and Department of Biochemistry, Universal College of Medical Sciences-Teaching Hospital (UCMS-TH), Bhairahawa, Nepal from March 2019 to February 2020 in a total of 100 patients diagnosed with fatty liver disease by ultrasonography. The fasting blood was collected for lipid profile and carried out in the automated analyzer following standard protocol. Result In 100 cases, the male to female ratio was 1.8:1. Fifty six percent of the total cases presented with alcoholic fatty liver disease (AFLD) while the remaining 44% with nonalcoholic fatty liver disease (NAFLD). The spectrum of lipid abnormality was observed with increased total cholesterol (TC), Low Density Lipoprotein (LDL), increased triglycerides (TG), Very Low Density Lipoprotein (VLDL) in alcoholic fatty liver disease cases as compared to nonalcoholic fatty liver disease cases. However, it has been observed that TG/HDL and Non-HDL/HDL were higher in nonalcoholic fatty liver disease as compared to alcoholic fatty liver disease. Moreover, a statistically significant difference was observed in HDL between AFLG2 and NAFLG2 (p-value: 0.012). Conclusion Dyslipidemia and decreased HDL have been implicated in fatty liver diseases. USG in conjunction with Non-HDL/HDL, TG/HDL, hemoglobin, and albumin can be useful in early screening and monitoring of dyslipidemia in fatty liver patients.

A photoswitchable GPCR-based opsin for presynaptic inhibition

Optical manipulations of genetically defined cell types have generated significant insights into the dynamics of neural circuits. While optogenetic activation has been relatively straightforward, rapid and reversible synaptic inhibition has proven more elusive. Here, we leveraged the natural ability of inhibitory presynaptic GPCRs to suppress synaptic transmission and characterize parapinopsin (PPO) as a GPCR-based opsin for terminal inhibition. PPO is a photoswitchable opsin that couples to Gi/o signaling cascades and is rapidly activated by pulsed blue light, switched off with amber light, and effective for repeated, prolonged, and reversible inhibition. PPO rapidly and reversibly inhibits glutamate, GABA, and dopamine release at presynaptic terminals. Furthermore, PPO alters reward behaviors in a time-locked and reversible manner in vivo. These results demonstrate that PPO fills a significant gap in the neuroscience toolkit for rapid and reversible synaptic inhibition and has broad utility for spatiotemporal control of inhibitory GPCR signaling cascades.

Neurobrucellosis: A differential not to be missed in patients presenting with neuropsychiatric features

When a patient presents with undulating fever and neuropsychiatric features, neurobrucellosis should be considered as a differential diagnosis. If diagnosed early, neurobrucellosis is a treatable disease with a favorable outcome.

Anti-LGI1, anti-GABABR, and Anti-CASPR2 encephalitides in Asia: A systematic review

AIM

We aim to review the literature to collate and describe features of encephalitides arising from autoantibodies against leucine-rich glioma-inactivated 1 (LGI1), gamma aminobutyric acid receptor (GABABR), and contactin-associated protein-like 2 (CASPR2) in Asian populations and compare them with findings of Western studies.

METHODS

Peer-reviewed articles published till 24 May 2020 were searched, and original, full-text studies from Asia with serum/CSF antibody-based diagnosis and at least 2 patients were selected. Twenty-four studies with 263 patients (139 anti-LGI1, 114 anti-GAGABR, and 10 anti-CASPR2) were included. Data were pooled to produce descriptive information on demographics, clinical characteristics, diagnostics, treatments, and outcome.

RESULTS

The mean age was 54.2 (anti-LGI1), 55.2 (anti-GABABR), and 47.7 years (anti-CASPR2), with an overall male predominance of 62.0%. Commonest clinical features across all types were seizures (87.5%), memory deficits (80.7%), psychiatric disturbances (75.9%), and altered consciousness (52.9%). Four anti-LGI1, 40 anti-GABABR, and 1 anti-CASPR2 patients had tumors. CSF, MRI, and EEG were abnormal in 33.3%, 54.1%, and 75% patients in anti-LGI1; 60.0%, 49.6%, and 85.7% in anti-GABABR; and 50%, 44.4%, and 100% in anti-CASPR2 patients, respectively. 95.6% patients received first-line therapy alone (steroids/IVIG/Plasma therapy), and 4.4% received second-line therapy (rituximab/cyclophosphamide). 91.7%, 63.6%, and 70% of patients had favorable outcomes (modified Rankin Score 0-2) with mortality rates at 2.5%, 23.2%, and 0% in the three types, respectively.

CONCLUSION

Our findings suggest that these disorders present in Asian patients at a relatively young age often with features of seizures, memory deficits, and psychiatric disturbances and usually demonstrate a favorable clinical outcome.

The diagnostic quandary of magnetic resonance imaging-negative Hirayama disease: a case report

Background

Magnetic resonance imaging (MRI) features are typical findings in Hirayama disease (HD) and are useful diagnostic entities but may not be present in all patients.

Case presentation

We present the case of a 22-year-old Nepalese man who presented with insidious onset of weakness of his right upper limb of more than 5 years duration. His weakness was progressive for the first 3 years, and then remained static. On examination, weakness of the interossei, thenar, hypothenar, flexor, and extensor muscles were present in his right upper limb, power was normal in his left upper and bilateral lower limbs. Minipolymyoclonus was present in both upper limbs, less prominent on the left side. Electrophysiological findings showed motor axonal neuropathy in his right upper limb, neurogenic discharges and fibrillations, and fasciculations in both upper limbs. Contrast magnetic resonance imaging (MRI) of his cervical spine in flexion was normal. Our patient was diagnosed with HD based on clinical and electrophysiological findings. Our patient was advised to use a cervical collar and regular physiotherapy and was found to have subjective benefit.

Conclusion

A normal cervical MRI does not rule out HD and the diagnosis can also be made based on clinical and electrophysiological studies. Progressive distal upper limb weakness or tremor in young patients should be evaluated for HD, because early diagnosis and intervention might halt the progression.

SRRF-Stream Imaging of Optogenetically Controlled Furrow Formation Shows Localized and Coordinated Endocytosis and Exocytosis Mediating Membrane Remodeling

Cleavage furrow formation during cytokinesis involves extensive membrane remodeling. In the absence of methods to exert dynamic control over these processes, it has been a challenge to examine the basis of this remodeling. Here we used a subcellular optogenetic approach to induce this at will and found that furrow formation is mediated by actomyosin contractility, retrograde plasma membrane flow, localized decrease in membrane tension, and endocytosis. FRAP, 4-D imaging, and inhibition or upregulation of endocytosis or exocytosis show that ARF6 and Exo70 dependent localized exocytosis supports a potential model for intercellular bridge elongation. TIRF and Super Resolution Radial Fluctuation (SRRF) stream microscopy show localized VAMP2-mediated exocytosis and incorporation of membrane lipids from vesicles into the plasma membrane at the front edge of the nascent daughter cell. Thus, spatially separated but coordinated plasma membrane depletion and addition are likely contributors to membrane remodeling during cytokinetic processes.

Traditional Fermented Indian Foods: A Treasure Hunt for Rare Lactic Acid Bacteria

The article's abstract is no available.

Physical Plasma Membrane Perturbation Using Subcellular Optogenetics Drives Integrin-Activated Cell Migration

Cells experience physical deformations to the plasma membrane that can modulate cell behaviors like migration. Understanding the molecular basis for how physical cues affect dynamic cellular responses requires new approaches that can physically perturb the plasma membrane with rapid, reversible, subcellular control. Here we present an optogenetic approach based on light-inducible dimerization that alters plasma membrane properties by recruiting cytosolic proteins at high concentrations to a target site. Surprisingly, this polarized accumulation of proteins in a cell induces directional amoeboid migration in the opposite direction. Consistent with known effects of constraining high concentrations of proteins to a membrane in vitro, there is localized curvature and tension decrease in the plasma membrane. Integrin activity, sensitive to mechanical forces, is activated in this region. Localized mechanical activation of integrin with optogenetics allowed simultaneous imaging of the molecular and cellular response, helping uncover a positive feedback loop comprising SFK- and ERK-dependent RhoA activation, actomyosin contractility, rearward membrane flow, and membrane tension decrease underlying this mode of cell migration.

Optogenetic Control of Cell Migration

Subcellular optogenetics allows specific proteins to be optically activated or inhibited at a restricted subcellular location in intact living cells. It provides unprecedented control of dynamic cell behaviors. Optically modulating the activity of signaling molecules on one side of a cell helps optically control cell polarization and directional cell migration. Combining subcellular optogenetics with live cell imaging of the induced molecular and cellular responses in real time helps decipher the spatially and temporally dynamic molecular mechanisms that control a stereotypical complex cell behavior, cell migration. Here we describe methods for optogenetic control of cell migration by targeting three classes of key signaling switches that mediate directional cellular chemotaxis-G protein coupled receptors (GPCRs), heterotrimeric G proteins, and Rho family monomeric G proteins.

Subcellular optogenetic activation of Cdc42 controls local and distal signaling to drive immune cell migration

Cdc42 is believed to play an important role in controlling the polarity of migrating cells, but it has not been possible to directly determine the effects of localized Cdc42 activity. Optogenetic activation of Cdc42 at one side of the cell was used to identify local and distal signaling responses that contribute to directed cell migration.

Migratory immune cells use intracellular signaling networks to generate and orient spatially polarized responses to extracellular cues. The monomeric G protein Cdc42 is believed to play an important role in controlling the polarized responses, but it has been difficult to determine directly the consequences of localized Cdc42 activation within an immune cell. Here we used subcellular optogenetics to determine how Cdc42 activation at one side of a cell affects both cell behavior and dynamic molecular responses throughout the cell. We found that localized Cdc42 activation is sufficient to generate polarized signaling and directional cell migration. The optically activated region becomes the leading edge of the cell, with Cdc42 activating Rac and generating membrane protrusions driven by the actin cytoskeleton. Cdc42 also exerts long-range effects that cause myosin accumulation at the opposite side of the cell and actomyosin-mediated retraction of the cell rear. This process requires the RhoA-activated kinase ROCK, suggesting that Cdc42 activation at one side of a cell triggers increased RhoA signaling at the opposite side. Our results demonstrate how dynamic, subcellular perturbation of an individual signaling protein can help to determine its role in controlling polarized cellular responses.