Guillain barre syndrome and its association with covid-19 infection – A clinical case series

A novel coronavirus (COVID-19) pandemic is caused by severe acute respiratory syndrome coronavirus 2 (SARs-CoV-2). This pandemic has been globally alarming in the current period. Several neurological manifestations are reported occurring with the infection. Guillain barre syndrome (GBS) or acute onset inflammatory polyradiculoneuropathy has been among the frequent manifestations observed among them. To know the pattern and outcome of GBS in COVID-19 affected individuals. We have taken six individuals admitted with flaccid quadriparesis in the last two months. All were affected recently by COVID 19 infection, which RT PCR of the nasopharyngeal swab confirmed. The study participants have undergone nerve conduction studies and have been diagnosed with Guillain Barre syndrome using Brighton criteria. We did cerebrospinal fluid (CSF) analysis after admission. We initiated all patients on Intravenous immunoglobulin according to body weight (2g/kg divided over five days). We used the Barthel index score to assess the outcome of the individuals. We observed a mean duration of 18.25 days between the COVID-19 infection and the onset of symptoms. Apart from motor quadriparesis and sensory symptoms being in common, we also noticed cranial nerves and autonomic involvement. We made the diagnosis using the nerve conduction studies and Brighton criteria. After initiating intravenous immunoglobulin, all patients had a good outcome, and quality of life was better after two months of follow up. Guillain Barre syndrome is one of the neurological manifestations of COVID-19 and has a dramatic response with intravenous immunoglobulin and better outcome with treatment.

Roles of N-Methyl-D-Aspartate Receptors (NMDARs) in Epilepsy

Epilepsy is one of the most common neurological disorders characterized by recurrent seizures. The mechanism of epilepsy remains unclear and previous studies suggest that N-methyl-D-aspartate receptors (NMDARs) play an important role in abnormal discharges, nerve conduction, neuron injury and inflammation, thereby they may participate in epileptogenesis. NMDARs belong to a family of ionotropic glutamate receptors that play essential roles in excitatory neurotransmission and synaptic plasticity in the mammalian CNS. Despite numerous studies focusing on the role of NMDAR in epilepsy, the relationship appeared to be elusive. In this article, we reviewed the regulation of NMDAR and possible mechanisms of NMDAR in epilepsy and in respect of onset, development, and treatment, trying to provide more evidence for future studies.

The Promising Application of a New Ulnar Nerve Compound Muscle Action Potential Measurement Montage in Amyotrophic Lateral Sclerosis

Objective Detecting peripheral nerve damage by electrophysiology examination accurately and sensitively is important for the follow-up evaluation of amyotrophic lateral sclerosis(ALS). In this study, we applied a new proximal E2 electrode in the ulnar motor nerve conduction study with E1 on abductor digiti minimi(ADM), and investigated its effect on the compound muscle action potential(CMAP) of the ulnar nerve. Methods We included 64 ALS patients and 64 age- and sex- matched controls. Patients characteristics were collected for phenotype, symptom duration and site of onset. The revised ALS Functional Rating Scale(ALSFRS-R) was evaluated at the time of administration to assess the severity of ALS. The ulnar nerve CMAP was recorded using an E1 electrode on the muscle belly and an E2 electrode on distal tendon(traditional montage, CMAP-dE2) and proximal tendon(new montage, CMAP-pE2) respectively. Results The waveform of CMAP-pE2 was steadier presenting a uniform unilobed pattern. In the controls, there were no significant differences between the amplitudes of CMAP-dE2 and CMAP-pE2(p=0.96). In ALS patients, the amplitude of CMAP-pE2 was significantly lower than that of CMAP-dE2(p<0.01), especially for patients with ADM spontaneous activity and muscular atrophy. Using the new method, the damaged axons were more likely to be stratified into more severe decreased levels. Furthermore, the decline of CMAP-pE2 was significantly correlated with ALSFRS-R(p<0.01). Conclusions The new electrode configuration in the ulnar nerve conduction test could reflect the degree of axonal injury much more sensitively after the presence of ulnar nerve degeneration and was more suitable for the evaluation of disease progression.