The prognosis of 560 patients with a clinical and CT diagnosis of intrinsic supratentorial brain tumour was examined retrospectively at the Department of Neurosciences, Walton Hospital, Liverpool, England. Epilepsy was the first symptom in 164 patients. Patients presenting with epilepsy had a median survival of 37 months compared to 6 months in those presenting with other symptoms; they were more likely to have a normal clinical examination, a non-enhancing low density lesion on CT scan and a low grade tumour. Significant independent variables which adversely affected prognosis were increasing age, focal neurological signs, an enhancing CT lesion at diagnosis, surgical biopsy, and male sex. Primary intracerebral tumours presenting with epilepsy were relatively benign. They were less likely to receive radiotherapy or biopsy, but more likely to undergo resective surgery. No beneficial effects from either early resective surgery or radiotherapy were demonstrated. The average duration of symptoms before CT diagnosis was 28 months (range 2 days - 232 months in those presenting with epilepsy) and 4 months (range 1 day - 175 months in those with other presentations). Seizures were refractory to anti-epileptic drugs with only 11 of 164 patients ever achieving a 1 year remission. [1]
COMMENT. Backus RE and Millichap JG analyzed the records of 291 consecutive children treated for intracranial tumor at the Mayo Clinic from 1950-1959 with particular attention to patients with seizures [2]. Seizures occurred in 17% of the total group - in 25% of patients with supratentorial tumors and in 12% of those with infratentorial tumors. They were the initial symptoms in 15% of patients with supratentorial tumors and in 1% of those with infratentorial tumors. The average age at onset was 4.9 years in the supratentorial group and 4.8 years in the infratentorial group. The diagnosis of supratentorial tumors was delayed for an average of 2 years, whereas infratentorial tumors were diagnosed within an average time of 3 months of the initial seizure. The electroencephalogram was of localizing value in 92% of tumors that involved the cerebral cortex. The histologic type of tumors was verified in 46 of the 50 patients who had seizures. Seizures were more common in patients with slowly growing astrocytomas grades 1 and 2 (67% incidence) than in those with rapidly expanding astrocytomas grades 3 and 4 (10% incidence). Symptoms of increased intracranial pressure were present at the time of the first seizure in 20% of patients with supratentorial tumors and in 79% with infratentorial tumors. A delta pattern in the EEG indicative of an expanding lesion occurred in 50% of patients and spike, sharp wave, or spike and wave seizure discharges compatible with a static lesion were recorded in 32% of patients with supratentorial tumors. [3]
With the increasing availability of neuroimaging techniques and particularly the MRI, the early diagnosis of tumor in patients with focal epilepsy will be facilitated and may lead to earlier surgical resection. The present study questions the advisability of resective surgery in patients with primary brain tumors presenting with seizures. A prospective, randomized, study of aggressive versus conservative management is required.