The value of combined ambulatory cassette-EEG and video monitoring in the differential diagnosis of intractable seizures.

OBJECTIVE: To evaluate the ability of combined ambulatory cassette-EEG and video monitoring (ACV) to establish a diagnosis in patients with attacks of unknown nature and its impact on their treatment. METHODS: We evaluated ACV in 125 consecutive patients with attacks of unknown nature. Most had intractable attacks suspected of being non-epileptic. Antiepileptic drugs (AEDs) were discontinued or reduced at the start of the procedure. The median duration of monitoring was 3 days (range 1-10). The ACV results and patient records were reviewed, and patients were called for additional follow-up when feasible. RESULTS: Attacks were recorded in 101 patients. They were epileptic in 20 patients, psychogenic in 60, both in 3, and of unknown nature in 18 (usually subjective episodes). The study resulted in AED discontinuation at discharge in 46 patients with recorded psychogenic seizures and 6 with recorded attacks of unknown nature. Three-quarters of patients followed up were free of attacks or improved. CONCLUSIONS: ACV was effective in providing a diagnosis in two-thirds of patients. If psychogenic seizures are suspected in patients on AEDs, ACV may provide the diagnosis and may help exclude epilepsy, without the need for standard EEG-CCTV, which can then be reserved for patients undergoing presurgical evaluation.