Background: Patients with physical brain abnormalities have an increased risk of developing psychogenic nonepileptic seizures (PNES). Here we describe patients who developed PNES after intracranial neurosurgery for indications other than the control of refractory epileptic seizures and explore whether neurosurgical intervention is at risk factor for PNES.
Method: We searched the database of 372 patients diagnosed with PNES at our department over the last 10 years and identified 17 patients (4.6%) in whom PNES first started after intracranial neurosurgery. Surgical procedures included the complete or partial resection of a meningioma, AV malformation, cavernoma, plexus papilloma, neurinoma, astrocytoma, oligodendroglioma, dysontogenetic cyst, the drainage of a brain abscess and removal of a subdural hematoma. PNES were documented by ictal video-EEG, ictal EEG, or ictal observation and examination in all cases. The diagnosis of additional epileptic seizures were confirmed by ictal EEG/video-EEG, or made on the basis of a clinical assessment by an experienced epileptologist.
Findings: Five patients had purely psychogenic postoperative seizure disorders, twelve had epileptic and psychogenic attacks. Median age at neurosurgery was 32 years (range 5-54), median latency between surgery and onset of PNES was 1 year (range 0-17 years).
Interpretation: PNES may develop after intracranial neurosurgery undertaken for other indications than the control of refractory epileptic seizures. Younger patients with a history of pre-operative psychiatric problems or epileptic seizures and surgical complications may be at higher risk. A diagnosis of PNES should be considered in patients who develop refractory seizures after neurosurgery.