Interictal cardiovascular autonomic responses in patients with temporal lobe epilepsy

Purpose: To measure interictal cardiovascular autonomic functions in patien ts with either refractory or well-controlled temporal lobe epilepsy (TLE). Methods: For autonomic assessment, heart rate variation during normal and d eep breathing, Valsalva maneuver, and tilting were measured in 19 patients with chronic refractory TLE, 19 patients with well-controlled TLE, and 38 a ge- and sex-matched healthy control subjects. Blood pressure responses to t ilting and isometric work also were evaluated. Results: Heart-rate (HR) variation during normal breathing (p = 0.006) and tilling(p = 0.043) was lower in patients with refractory TLE than in contro l subjects. Heart-rate response to tilting (p = 0.036) was also lower in pa tients with well-controlled TLE than in control subjects. Blood-pressure re sponses showed no differences between the patients and the control subjects . Patients taking carbamazepine (CBZ) medication had decreased KR responses to deep breathing (p = 0.046) and to tilting (p = 0.014) compared with the control subjects. Conclusions: Refractory TLE seems to be associated with dysfunction of the cardiovascular autonomic regulation, manifesting as impaired HR responses t o certain stimuli. Interictal autonomic dysfunction is seen in patients wit h well-controlled TLE as well, but it may be more evident in patients with refractory epilepsy. CBZ medication may also be associated with altered aut onomic cardiac control.