Lateralization value of peri-ictal headache in drug-resistant focal epilepsy

Objective: To examine the lateralizing value of unilateral peri-ictal and interictal headaches in patients with drug-resistant focal epilepsy (DRFE).

Methods: Four-hundred consecutive patients undergoing presurgical evaluation for DRFE were interviewed. Patients with headache were broadly divided into two groups: peri-ictal and interictal headache. The lateralizing value of unilateral headache was compared in each group between three diagnoses: temporal lobe epilepsy (TLE), extratemporal lobe epilepsy (ETLE), and temporal-plus epilepsy (TEMP+ epilepsy).

Results: Out of 400 patients, 169 (42.25%) had headaches. Peri-ictal headaches were experienced in 106 patients (26.5%) and interictal headaches were experienced in 63 (15.75%). In the peri-ictal group, unilateral headaches were present in 48 out of 60 patients (80%) with TLE; they were ipsilateral to the seizure focus in 45 out of 48 patients (93.75%). Unilateral headaches in patients with ETLE were present in 20 out of 31 patients (64.5%) and were ipsilateral to the seizure focus in 14 out of 20 patients (70%). In patients with TEMP + epilepsy, unilateral peri-ictal headaches were present in 9 out of 15 patients (60%); they were ipsilateral to the seizure focus in all 9 patients (100%). In the interictal headache group, unilateral headaches were ipsilateral the seizure focus in 9 out of 10 patients (90%) with TLE and 5 out of 6 patients (83.3%) with ETLE. None of the TEMP + epilepsy patients had a unilateral interictal headache.

Conclusion: Headache is a frequently encountered symptom in patients with DRFE. When occurring in a unilateral fashion, it has a high lateralizing value in temporal and extratemporal lobe epilepsies. This has been demonstrated to be true for both peri-ictal and interictal headaches. In the vast majority of patients with DRFE, unilateral headache occurs ipsilateral to the seizure focus.