Alternating ptosis associated with asialo-GM1 and GD1b antibodies.

Miller Fisher syndrome (MFS), variant of acute inflammatory demyelinating polyradiculoneuropathy, is recognized as clinical triad (ophthalmoplegia-ataxia-areflexia). Ganglioside antibodies play an important role in the pathogenesis of acute polyradiculoneuropathy including MFS. To our knowledge, there has been no report of MFS presenting with atypical alternating ptosis or with concurrent elevation of serum GD1 and asialo-GM1 antibody titers, and negative titers of GQ1b antibody such as our patient. Our objective is to report MFS with unusual symptoms and to share our diagnostic approach. We report a rare case of MFS presenting with alternating eyelid ptosis, paresthesia, and ataxia after a respiratory infection. Initial neurological examination revealed left eyelid ptosis, hyporeflexia, positive Romberg sign, and ataxia. The ice pack test was negative. Three days later, contralateral ptosis was observed, associated with areflexia and worsened ataxia. However, there was significant improvement of the previous left eyelid ptosis. Serology revealed elevated asialo-GM1 and GD1b antibodies. Acetylcholine receptor antibodies were negative. Cerebral spinal fluid revealed elevated IgG index. Nerve conduction studies (NCS) performed four days after the onset of symptoms showed normal nerve conduction velocities and F-waves, and absent bilateral H-reflexes. Repetitive nerve stimulation (3 Hz) showed no decrement of compound muscle action potentials. Trial with a single dose of pyridostigmine showed no clinical improvement. The symptoms resolved without intervention. NCS 18 days after onset of symptoms showed mildly prolonged F-waves and absent H-reflexes. This case highlights an atypical presentation of MFS and raises the awareness of a rare autoantibody associated with it.