[Electrophysiological subtypes of Guillain-Barré syndrome in Mexican adults].

INTRODUCTION: Guillain-Barré syndrome (GBS) is an autoimmune polyradiculoneuropathy subdivided in demyelinating and axonal types. There is no established frequency about the electrophysiological subtypes in Mexico.
OBJECTIVE: to determine the frequency of electrophysiological subtypes of GBS in Mexican patients.
MATERIAL AND METHODS: The study design was descriptive and retrospective. Patients with GBS older than 15 years without coexisting major diseases were selected retrospectively from a three-year period. These patients should have met the clinical and electrophysiological criteria of GBS. Motor nerve conduction studies were made of the median, ulnar, tibial and peroneal nerves, and antidromic sensory conduction studies were performed in the median, ulnar and sural nerves. Descriptive statistics, analysis of variance and chi(2) test were used.
RESULTS: The study included fifty-one patients with median age of 45.5 years (range 16-79); 37 men and 14 women, with a ratio man-woman 2.6:1; 37% were observed in winter (p = 0.56). The electrophysiological subtypes were acute motor axonal neuropathy (AMAN) 39 %; acute inflammatory demyelinating polyneuropathy (AIDP) 23.5 %; mixed neuropathy (MN) 20%; and acute motor sensory axonal neuropathy (AMSAN) 17.5 %.
CONCLUSIONS: the most frequent electrophysiological subtype in Mexican patients was AMAN. Other frequent subtypes were MN and AMSAN. Axonal variants were the predominant types.