Inter-ictal fatigue and antiepileptic drugs in patients with epilepsy

Fatigue is a frequently reported symptom in patients with epilepsy (PWE) while the pathophysiology, causes and effects on the disease are not yet fully understood. Fatigue may occur as a side effect of antiepileptic drugs (AEDs); however, it varies greatly depending on both the characteristics of the patients and the AEDs used. The aim of this study was to investigate the relation between fatigue, clinical features and AEDs and doses used in monotherapy in PWE. Ninety consecutive patients with the diagnosis of epilepsy, treated as monotherapy were included in the study. Demographic data, seizure type and frequency, AEDs and their doses were recorded. Fatigue severity scale (FSS) was used in the evaluation of fatigue. Cases of fatigue were defined by a FSS score ≥ 4. The mean age of the patients (57 females, 33 males) was 33 ± 12.7 years and the mean disease duration was 11.7 ± 9.1 years. Used as monotherapy, AEDs included carbamazepine (n = 29, 32.2%), valproic acid (n = 28, 31.1%), levetiracetam (n = 23, 25.6%) and lamotrigine (n = 10, 11.1%). Fatigue was reported by 52.2% of patients (FSS score ≥ 4). It was found that patients with fatigue had more seizures in the last year than those without (p = 0.031). There was no relation between fatigue and AEDs. The doses of carbamazepine and levetiracetam were significantly correlated with the scores of FSS (p = 0.042 and p = 0.023, respectively), and there was no correlation between the doses of valproic acid and lamotrigine and the scores of FSS. The results of our study showed that; approximately half of the patients with epilepsy had fatigue. Although the relation between AEDs and fatigue was not detected, it was pointed out that AED doses may play a role in the development of fatigue.