[Vertigo in non-vascular diseases of the central nervous system].

Excluding vascular involvement, vertigo due to a central vestibular syndrome reflects a median or paramedian lesion of the brain stem or the cerebellum. Recurrent attacks of vertigo usually occur with peripheral lesions. Persistent acute vertigo with peripheral destruction can reveal ischemia of the brain stem. Central positional vertigo is rare and has symptomatology that is different from that of benign positional vertigo. Persistent instability has a symptomatology that is more difficult to analyse and is usually associated with a central vestibular syndrome when it is organic. Diagnosis of a central vestibular syndrome is based on detection of well-defined clinical or electronystagmographic signs of which abnormal nystagmus is primordial. Some of them such as inferior vertical nystagmus or dissociated nystagmus can localise the site. MRI has become the diagnostic procedure which is best adapted for identifying the most frequent aetiologies such as tumors, congenital malformations and multiple sclerosis.