"Finger drop sign" in Guillain-Barré syndrome

Guillain-Barriota syndrome (GBS) is an acute neurological illness affecting the peripheral nervous system causing significant morbidity. The syndrome has been classified electrophysiologically into demyelinating and axonal forms. The clinical features of the axonal variant (acute motor axonal neuropathy--AMAN) are not well characterized, particularly in the Indian context.

To assess the incidence, clinical presentation and disease course of patients with AMAN.

This is an observational study done at a tertiary referral center in South India. The study period extended from January 2006 to July 2007. All patients with a clinical diagnosis of GBS and satisfying the electrophysiological criteria for AMAN were included.

There were 12 cases of AMAN out of a total of 84 cases of GBS. All AMAN patients showed a characteristic pattern of hand weakness predominant weakness of finger extensors with relatively normal power in finger flexors, wrist flexors and extensors. Proximal limb weakness was mild and was present in 85% cases. One patient had cranial nerve palsy and one had hyperreflexia. None of the patients progressed to respiratory failure.

AMAN is a distinct subgroup in GBS showing certain distinguishing features, the most notable being predominant weakness of finger extensors.