Study on Electrophysiological Findings of Guillain Barre Syndrome Patients Attending the Department of Neurology in BSMMU.

Abstract

Incidence and predominant subtype of Guillain Barre Syndrome (GBS) differ geographically. Electrophysiology has an important role in the early diagnosis and prediction of the prognosis. This study conducted to determine the predominant subtype of Guillain Barre Syndrome in Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh and to compare the nerve conduction study finding between the axonal and demyelinating form of GBS. To analyze the nerve conduction study findings of Guillain Barre Syndrome patients attending the department of Neurology in BSMMU. This observational, descriptive and cross sectional study was carried out in the department of Neurology, BSMMU, Dhaka from July 2014 to June 2016. Considering the inclusion and exclusion criteria, 50 patients recruited as the study population. Then after performing the nerve conduction study, patients classified into three groups: acute inflammatory demyelinating polyneuropathy (AIDP), acute motor axonal neuropathy (AMAN), acute motor and sensory axonal neuropathy (AMSAN). Among the 50 patients that are finally included in the study; about 50%, 42%, 8% had the AIDP, AMAN and AMSAN variety of GBS respectively. Out of all patients, 64% were male and 34% were female. GBS was seen in a wide range of age (18-75 years). In AIDP, maximum clustering of the cases was seen in the elderly population and in the AMAN it was seen in the younger age group. Cerebrospinal fluid (CSF) analysis did not show any significant difference between the AIDP and AMAN variant of GBS. Distal latency prolonged in at least one nerve in all patients with AIDP. In axonal form of GBS (AMAN and AMSAN), the compound muscle action potential (CMAP) amplitude was 80% of the lower limit of the normal in at least two motor nerves. Prolonged F wave latency by >80% of the upper limit of the normal was seen in 40% of the AIDP patients. According to the nerve conduction study, finding- acute inflammatory demyelinating polyneuropathy (AIDP) is the predominant subtype. Although the electrophysiology and the CSF analysis are the important tools for the diagnosis of GBS, classification should not be making based on a distinct finding alone. If all the NCS parameters in multiple nerves tested after one week and within four weeks of onset of symptoms, definite diagnosis is possible in almost all the patients of Guillain Barre Syndrome.