Arnold-Chiari malformation associated with sleep apnea and central dysregulation of arterial pressure.

The natural history of symptomatic adult type I Arnold-Chiari (ACM1) malformation is variable. Patients with this condition frequently develop corticospinal and sensory deficits, together with cerebellar signs and lower cranial nerve palsies in various combinations. In the present report we describe a patient with ACM1 in whom sleep apnea together with disturbances in the central regulation of arterial pressure were a major component of the symptomatology. These paroxysmal blood pressure changes has not been previously reported. The decompression of our patient's medulla, which contains the primary respiratory centers and baroreceptors, resulted in a marked improvement and indicate that the origin may have been on a central basis.