The effect of tumour associated epilepsy on performance/handicap scales used in cerebral glioma.

The sensitivity of three scales of performance and handicap to the presence and development of epilepsy in patients with brain tumours was studied. Two hypothetical cases had equivalent disability, in one case due to epilepsy and in the other to physical impairment. The second case later developed epilepsy. All consultant neurologists and neurosurgeons in Scotland were asked to grade the cases using three scales commonly used for patients with cerebral glioma. Consultants rated the patient with epilepsy alone as being less disabled and handicapped than the patient with physical impairment without seizures (sign test p < 0.003). At best 21% of clinicians (p = 0.03) were able to report a change in performance score in the second case when seizures developed. These scales do not reflect changes in handicap and performance associated with tumour associated epilepsy. Clinical trial protocols for treatments for brain tumours must state how performance and handicap related to epilepsy will be measured.