Autonomic functions in focal epilepsy: A comparison between lacosamide and carbamazepine monotherapy

Some antiepileptic drugs (AEDs), like sodium channel blockers are significantly associated with autonomic dysfunction in patients with epilepsy. Unlike other sodium-blockers AEDs, lacosamide (LCM) is a third generation AEDs which enhances the slow inactivation of voltage-gated sodium channels. So far, data about LCM on autonomic nervous system are still unknown. This study was designed to investigate cardiovascular autonomic and sudomotor function in patients affected by focal epilepsy on LCM monotherapy, compared to patients treated with carbamazepine (CBZ) monotherapy and healthy subjects.

Patients on LCM underwent autonomic function tests including head up tilt test (HUTT), Valsalva maneuver, deep breathing, hand grip, and cold face. Heart rate variability (HRV) analysis was performed in rest condition and during HUTT. Sudomotor function was assessed through Sudoscan. All results were compared with patients on carbamazepine (CBZ) monotherapy and with healthy subjects.

Fourteen patients on LCM monotherapy, 12 patients on CBZ monotherapy and 16 healthy controls were studied. At cardiovascular function tests, delta systolic blood pressure (∆SBP) at 3 min of HUTT and ∆SBP early phase II-late phase II at Valsalva maneuver were significantly lower in CBZ group compared to LCM patients. Spectral analysis of HRV showed no significant differences among LCM, CBZ and control groups. No difference in sudomotor function was found in all three groups.

In conclusion, our findings suggest that LCM and CBZ on monotherapy do not affect autonomic cardiovascular and sudomotor functions compared to controls. Nevertheless, patients on CBZ showed a lower sympathetic reactivity with respect to LCM.