Clinical analysis of longstanding subacute myelo-optico-neuropathy: sequelae of clioquinol at 32 years after its ban

Abstract One thousand and thirty-one longstanding patients with subacute myelo-optico-neuropathy (SMON; 275 males, 756 females; mean age±S.D., 72.9±9.6 years; age at onset 37.6±9.8 years; duration of illness 35.3±4.0 years) were examined in 2002, 32 years after banning of clioquinol. At onset, 66.7% of patients were unable to walk, and 4.7% complete blindness. At present time, about 41% of patients were still difficult to walk independently, including 15.8% of completely loss of locomotion. One point six percent of patients were in complete blindness and 5.8% had severe visual impairment. The majority (95.6–97.7%) of patients exhibited sensory disturbances including superficial and vibratory sensations and dysesthesia. Dysautonomia was observed as leg hypothermia in 79.8%, urinary incontinence in 60.7%, and bowel disturbance in 95.3%. As complication, high incidence was revealed with cataract (56.2%), hypertension (40.2%), vertebral disease (35.5%), and limb articular disease (31.5%). These results indicate the serious sequelae of clioquinol intoxication, SMON.