[A case of HTLV-I associated myelopathy with flutter-like oscillation]

We reported a 37-year-old woman showing HTLV-I associated myelopathy (HAM) with flutter-like oscillation of the eyes. She had a 15-year history of spastic paraplegia and noticed visual quaking at the age of 37 years. On neurological examination, she showed spasticity in both lower extremities, hyperreflexia in the extremities, neurogenic bladder, and transient, horizontal and pendular ocular oscillation. Anti HTLV-I antibody titers in serum and cerebrospinal fluid were significantly elevated. Brain CT scan revealed no particular abnormalities. In electrooculography, the oscillation consisted of 2 to 4 pendular cycles, having an amplitude of 3 to 10 degrees, and lasting 0.3 to 0.8 second. It occurred immediately after change of fixation at the lateral gaze. This flutter-like oscillation has been thought to result from disorders of cerebellum and its peduncles since the first description by Cogan (1954). Cerebellar signs, although infrequent, have been reported to occur in the patients with HAM. From the present study, flutter-like oscillation should be added as one of cerebellar signs which can occur in patients with HAM.