title: [Neurotological long-term follow-up in Minamata disease in Niigata, Japan].
abstract: To determine the long-term influence of organic mercurial intoxication on audiological and equilibrium findings, we followed up 36 patients neurotologically during 1980-1987 and 1991-2000 at Kido Hospital in Niigata. Typical findings were as follows: 1. In pure-tone audiometry, 24 of 72 ears (33%) showed slight hearing deterioration and 3 (4%) showed improvement. 2. Spontaneous nystagmus had disappeared in 5 patients (14%), but appeared in new 13 patients (36%). Positional nystagmus did not improve in any patient, and deteriorated in 11 (31%). 3. In optokinetic nystagmus (OKN) tests, especially in vertical OKN test showing significant deterioration (44%). 4. The caloric nystagmus test showed marked deterioration (47%). Body-equilibrium testing showed slight deterioration in 11 patients (31%) and improvement in 5 (14%). Neurotological findings thus varied widely among patients and we were concluded that these differences were caused both by duration of methyl mercury contamination and by aging factors in patients.
authors.affiliation: Health Services Facility for the Aged Amenity Nobukiyo, Toyama.
authors.forename: Kanemasa
authors.initials: K
authors.lastname: Mizukoshi
authors.forename: Yukio
authors.initials: Y
authors.lastname: Watanabe
authors.forename: Hideo
authors.initials: H
authors.lastname: Shojaku
authors.forename: Shin
authors.initials: S
authors.lastname: Aso
authors.forename: Masatsugu
authors.initials: M
authors.lastname: Asai
authors.forename: Kenya
authors.initials: K
authors.lastname: Inukai
authors.forename: Sugata
authors.initials: S
authors.lastname: Takahashi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology; D001301:Audiometry, Pure-Tone; D005260:Female; D005500:Follow-Up Studies; D006309:Hearing; D006801:Humans; D007564:Japan; D008297:Male; D020262:Mercury Poisoning, Nervous System / Q000503:physiopathology*; D008875:Middle Aged; D017120:Nystagmus, Optokinetic; D009760:Nystagmus, Physiologic; D004856:Postural Balance; D013997:Time Factors