Seizures as a presenting symptom in neurosurgical patients: a retrospective single-institution analysis.

Background: In patients with brain lesions, the appropriate management of epileptic seizures is important because recurrent seizures have a negative effect on the clinical course and quality of life. Acute symptomatic seizures are known to be one of the risk factors to develop epilepsy that cause recurrent unprovoked seizures in the later stage. To obtain background information, we performed a retrospective study in which we investigated the incidence of seizures as one of the presenting symptoms in neurosurgical patients admitted to our department during the past 43 years.

Methods: We extracted 4537 consecutive patients from 11,675 records in our inpatient database to calculate the seizure incidence in patients with 19 most common diagnoses. We also studied whether the location of cortical lesions have relation to the seizure incidence.

Results: Among 2342 patients with brain tumors, 9 of 18 (50%) ganglioglioma-, 40 of 87 (46%) oligodendroglioma-, 69 of 207 (33%) low-grade astrocytoma-, 172 of 804 (21%) high-grade astrocytoma- or anaplastic oligodendroglioma-, 84 of 598 (14%) meningioma-, 38 of 313 (12%) metastatic brain tumor-, 7 of 67 (10%) malignant meningioma-, 7 of 79 (9%) ependymoma-, and 11 of 169 (7%) malignant lymphoma patients suffered seizures. There were 1626 patients with vascular lesions, 20 of 80 (25%) with cavernous malformation, 61 of 281 (22%) with arteriovenous malformation, 50 of 666 (8%) with subarachnoid hemorrhage, 26 of 457 (6%) with brain infarcts, and 5 of 142 (4%) with hypertensive brain hemorrhage had seizures. Of the 569 patients with traumatic brain injury, 33 of 168 (20%) with traumatic intracranial hemorrhage, 6 of 31 (19%) with brain concussion, 18 of 96 (19%) with brain contusion, 15 of 244 (6%) with chronic subdural hematoma, and 1 of 30 (3%) with minor head injury suffered seizures. We found that these seizure incidences were significantly higher when the cortical lesion was located in the frontal lobe (p<0.01, chi square test) but not in parietal, occipital, nor temporal lobes.

Conclusion: We investigated the prevalence rate of seizures at the time of admission in a large number of patients who had been treated in our institution. Our results suggest that seizures are a common feature in patients with slow-growing and frontal intra-parenchymal lesions.