[Pathogenesis of main objective neurological symptoms in Chiari malformation type I].

To study the influence of Chiari malformation (CM) size, patient's age, hydrocephaly and intracranial hypertension on the disease manifestations, 263 patients with CM type I without concomitant syringomyelia have been examined. All the patients underwent clinical neurological examination, craniography and magnetic resonance imaging of the brain and spinal cord. Five main groups of objective neurological signs were identified: oculomotor (17.1%); cochlear vestibulocerebellar (84.8%); bulbar (35.4%); conduction motor (25.9%); segmental motor sensory disturbances (9.5%). The data obtained suggest that (1) a complex of pathogenic factors determines clinical manifestations of the disease in the given patient with CM type I; (2) CM size determines significantly the incidence and extent of the main objective neurological signs; (3) with age the seventy of cochlear and vestibulocerebellar disturbances increases; (4) hydrocephaly and intracranial hypertension deteriorate cochlear, vestibulocerebellar and bulbar disturbances as well as pyramidal-tract signs.