Intracranial Hematomas and Head Injuries Due to Seizures

ABSTRACT & COMMENTARY
Source: Zwimpfer TJ, et al. Head injuries due to falls caused by seizures: A group at high risk for traumatic intracranial hematomas. J Neurosurg 1997;86:433-437.

Previous issues of Neurology Alert have emphasized the high overall mortality associated with medication-resistant seizure disorders (Neuro Alert 1996; 15:30-31). Zwimpfer et al now specifically report that head injuries secondary to falls during seizures are especially likely to cause intracranial hematomas.

The authors studied 582 patients admitted to their neurosurgery unit after head injuries caused by falls. They compared the 22 patients whose falls were caused by seizures with the other 560 cases. Of the 22 patients injured during seizures, 20 developed intracranial hematomas (91%), compared with 223 of 560 other cases (40%; P < 0.001). Despite the greater incidence of intracranial hematomas, the seizure patients had a mortality rate similar to the others. Seven of the 22 (32%) epilepsy cases died, while 161 of the 560 others (29%) died. Glasgow Coma Scale scores, injury severity scores, ages, and incidence of alcohol intoxication did not differ between the two groups.

COMMENTARY

The reason head injuries from seizure-related falls are likely to cause intracranial hematomas remains unclear. The suddenness of the ictal loss of consciousness and loss of postural tone, in conjunction with the absence of defensive motor responses, may contribute by increasing the force with which the skull strikes the ground. Yet, in this report by Zwimpfer et al, seizure- and non-seizure-related head injuries did not differ in mortality or severity on two clinical scales. At least one antiepileptic drug (valproate) has an antiplatelet effect, which may increase the probability of traumatic bleeding. However, valproate is not associated with increased intraoperative blood loss during neurosurgery (see Neuro Alert 1996; 14:62), and its antiplatelet properties may not be clinically significant.

Buck et al (Epilepsia 1997;38:439-444) used a questionnaire to study injuries among 344 patients with active epilepsy drawn from 31 general medical practices in the United Kingdom. During a one-year period, 70 of these 344 sustained head injuries, 48 were burned, and 28 received dental injuries (some had multiple injuries). In total for the year, 35% of these 344 had at least one seizure-related injury. Not surprisingly, injuries occurred most frequently in patients with the most severe and most frequent seizures. Women were more likely to sustain burns, probably due to more time spent cooking.

The seizure-related morbidity and mortality described by Zwimpfer et al and Buck et al indicate the danger to the patient of even one ictal event. The information provided in this article indicates that epileptics who visit the emergency room because of a head injury during seizure should have a CT scan of the head. In their offices, neurologists should aggressively attempt to eliminate all seizures, with new antiepileptic medications or epilepsy surgery, and not be satisfied with the therapy they prescribe even if only "rare" seizures occur. —drl