Positional nystagmus of the "central type" as an early sign of multiple sclerosis.

Three young, female adults complained of dizziness and nausea aggravated on lying in supine position. On examination the prominent clinical feature was positional nystagmus of the "central type". All patients finally proved to suffer from multiple sclerosis. Positional nystagmus of the "central type" has been described in patients with pathology in the area of the IV ventricle and in monkeys with experimental lesions of the vestibular nuclei. It has also been described in humans and experimental animals after ingestion of alcohol. It is concluded that presence of this type of nystagmus is a sign of pathology probably localized in the area of the vestibular nuclei. Obviously, multiple sclerosis will be one of the disease processes to be considered. However, ingestion of alcohol a few hours before examination must always be excluded.