Early electrophysiological findings in acute inflammatory demyelinating polyradiculoneuropathy variant of Guillain-Barre syndrome in the Pakistani population - a comparison with global data.

Acute inflammatory demyelinating polyradiculoneuropathy (AIDP) and acute motor axonal neuropathy are the most common variants of Guillian-Barre syndrome documented in the Asian population. However, the variability of early neurophysiologic findings in the Asian population compared to western data has not been documented. Eighty-seven cases of AIDP were retrospectively reviewed for their demographic, clinical, electrophysiological, and laboratory data. Mean age of subjects was 31 ± 8 years with males more commonly affected. Motor symptoms (97%) at presentation predominated. Common early nerve conduction findings included low motor amplitudes (85%), recordable sural sensory responses (85%), and absent H-reflex responses (65%). Prolonged F-latencies were found most commonly in posterior tibial nerves (23%) in the lower limbs and median and ulnar nerves (18%) in the upper limbs. Blink reflex (BR) studies were performed in 57 patients and were abnormal in 80% of those with clinical facial weakness and in 17 of 52 patients (33%) with no clinical cranial nerve signs, suggesting subclinical cranial nerve involvement. Abnormal motor and sensory amplitudes are seen early. Prolonged distal latencies, temporal dispersion/conduction blocks and sural sparing pattern are other common early nerve conduction study findings of AIDP seen in the Pakistani population. There are no significant differences in abnormalities of conduction velocities and delayed reflex responses compared to published data. The BR can help in the early diagnosis of AIDP.