Abnormal chemoreceptor response to hypoxia in patients with tabes dorsalis.

Nine patients with tabes dorsalis and one patient with diabetic autonomic neuropathy were subjected to hypoxia to test the integrity of their carotid chemoreceptors. Ventilation and pulse rate changes were monitored and compared with those of a group of normal subjects of comparable age and sex. Four patients had a completely negative response to hypoxia, and the changes in ventilation in the group of patients as a whole were significantly less than in the control subjects. The results indicate that some patients with autonomic denervation are unable to adjust their respiratory system in response to hypoxia.