Autonomic cardiovascular reflexes in progressive supranuclear palsy.

Assessment of possible autonomic nervous system dysfunction was performed by testing cardiovascular reflexes in nine patients with progressive supranuclear palsy (PSP). The patients were significantly different from 15 control age-matched subjects because of greater blood pressure drop on standing for 1 min, diminished rise of diastolic blood pressure during the sustained handgrip test, and lack of compensatory tachycardia measured by the 30:15 ratio on standing. The latter test abnormality was caused by a slow rise to erect posture. No differences were observed in the cold pressor test, Valsalva ratio, and heart rate response to deep breathing. The differences between patients and control subjects were usually small. Autonomic nervous system involvement in patients with PSP is minor and is caused by involvement of central brain stem sympathetic nuclei or efferent fibers.