Hyperreflexia in Guillain-Barré syndrome: relation with acute motor axonal neuropathy and anti-GM1 antibody.

OBJECTIVES: To investigate the incidence of hyperreflexia in patients with Guillain-Barré syndrome (GBS), and its relation with electrodiagnosis of acute motor axonal neuropathy (AMAN), antiganglioside GM1 antibody, and Campylobacter jejuni infection. It was reported that patients with AMAN in northern China often had hyperreflexia in the recovery phase.
METHODS: In 54 consecutive Japanese patients with GBS, sequential findings of tendon reflexes were reviewed. By electrodiagnostic criteria, patients were classified as having AMAN or acute inflammatory demyelinating polyneuropathy (AIDP). Anti-GM1 and anti-C jejuni antibodies were measured by enzyme linked immunosorbent assays.
RESULTS: Seven (13%) patients developed hyperreflexia with the spread of the myotatic reflex to other segments in the early recovery phase, one of whom already had hyperreflexia in the acute progressive phase. Of the seven patients, six had AMAN and all seven had anti-GM1 antibodies, whereas only two had anti-C jejuni antibodies. Hyperreflexia was more often found in patients with AMAN than AIDP (6/23 v 1/18, p=0. 002), and in patients with anti-GM1 antibodies than without them (7/26 v 0/28, p=0.01). Hyperreflexic patients had milder peak disabilities than patients without hyperreflexia (p=0.03). Increased motor neuron excitability in the hyperreflexic patients was supported by increased soleus H-reflex amplitudes and the appearance of H-reflexes in the small hand or foot muscles.
CONCLUSIONS: Hyperreflexia often occurs in patients with GBS especially with AMAN, anti-GM1 antibodies, and milder disease. Increased motor neuron excitability further characterises the subgroup of patients with GBS with AMAN and anti-GM1 antibodies.