The Study of Seizures in 153 Head Injury Patients of the Iran-Iraq War
M. Etemadifar MD, P. Pishgahi MD, B. Kaleydari MD
Department of Neurology, Isfahan University of Medical Sciences, Isfahan, Iran
Introduction
Injury to the central nervous system constitutes one of the most common consequences of modern warfare. Seizures may develop after CNS injuries. The development of seizure is usually related to the kind of head trauma. Clinical experience gained from the Vietnam war shows that brain volume loss, early intracranial hematoma and the presence of shrapnel and projectiles in brain tissue after head injury are all associated with seizures.1,2
Other studies have revealed that up to 1/3 of patients who have suffered from bullet injuries to the head ultimately develop seizure disorders, while only 5-7% of patients with blunt head trauma experience this mishap.3,4 Subdural hematoma, cerebral contusion and loss of consciousness for more than 24 hours have been shown to be associated with an increased incidence of seizures after head injury.5
Parietal lobe involvement is usually the rule in post-traumatic seizures starting from 2 weeks or more after head injury.2 In such instances, secondary generalized seizures are prevalent in 60-70% of cases.3 The probability of late onset seizure is also correlated with the extent of brain lesion. Spike waves as well as sharp waves are characteristic EEG findings in these patients.3
During the past two decades, the impact of anti-convulsant therapy in the prophylaxis of post-traumatic seizure has been extensively studied. Although many studies claim a positive outcome after prophylactic treatment, a consensus of opinion has not been reached as to its efficacy. In fact, due to the relative paucity of cases, most of the relevant studies do not reveal conclusive results.3,5?11
The types of seizures following head trauma, its neurophysiologic mechanisms, the involved cerebral lobes, relevant neuroimaging and electrophysiological findings have not been adequately studied and further clarification is warranted. Consequently proper treatment protocols and pharmacologic interventions are still controversial.12
During the 8 year Iran-Iraq war (1980-1988) a relatively large number of soldiers suffered penetrating head injuries. The abundance of such patients mandates collaborated studies concerning clinical features and appropriate management procedures.
In this preliminary report the clinical characteristics and some electrophysiology and neuroimaging findings in a group of post head trauma seizure patients are described.
Methods
Patients suffering from seizure attacks subsequent to head injuries in the Iran-Iraq war and residing in the province of Isfahan, Central Iran were enrolled in this study.
Access to these patients was facilitated by organizations sponsoring the affairs of veterans and disabled former combatants.
Patients suffering from epilepsy or any seizure attack before head injury were excluded. A total number of 153 patients were enrolled.
All patients underwent extensive clinical interviews and data pertinent to age, timing of onset of seizures, type, frequency and interval of seizure attacks were extracted from medical records. The EEGs and Brain CT scans were also analyzed by the authors.
Results
A total of 153 patients were investigated. In this group 44 (29%) were in the 26-30 year age group, 35 (24%) in the 36-40 year age group and 35 (24%) in the 36-40 years old age group. Ninety-seven (64%) of the patients were 14-20 years old at the time of head trauma and only 7 (5%) were older than 30 years.
Among the 153 patients 121 (79.5%) had generalized seizures of which 110 were of tonic-clonic type. Twenty patients (14%) suffered partial seizures and secondary generalized seizures were present in only 11 (7.5%) of the cases. In one patent the seizure type could not be properly defined.
The type of injury was penetrating (mostly shrapnel and bullets) in 132 (86%) and blunt in 13 (8%) of the patients.
In the remaining cases lesions were either unclassified or caused by explosion blast.
Of 125 patients investigated in regard to the site of the lesions, 26 (20%) suffered exclusively from parietal lobe lesions and in 86 (65%) patients some kind of parietal lobe involvement was evident. (Table 1)
Brain CT's of 128 patients were examined and 122 (95%) had abnormal scans. In almost half of the patients foreign bodies with metal densities were detected (Table 2). Eighty-six (67%) showed some kind of brain atrophy and porencephalic cysts were present in 114 (89%) of the patients. The EEG was abnormal in 88% of cases; 11% had spike and wave, 67% had sharp wave, and 42% had slow wave patterns.
Considering drug compliance, 112 patients (77%) consumed anticonvulsants regularly and in 22 patients (15%) the compliance was partial with intervals of no drug use. Single drug therapy was the most common mode of treatment, administered to more than half of the patients. Thirty-six and 9 percent of the patients had 2 and 3 drug therapy schedules respectively.
Brain lesion volume was also estimated: in 44% of the patients the lesions were smaller than 25 cm3, in 26% and 24% the lesions sized 25-75 cm3 and more than 75 cm3 respectively. Analysis of data showed also that there was no significant correlation between the size of the lesion and the occurrence of seizures. The presence of metallic particles in the brain had no impact on the frequency of seizures either. A significant correlation (p= 0.05) was only present between lesion volume and frequency of seizure attacks.
Discussion
Some of the results obtained in this study are incongruent with prevailing data. In our study the most common seizure type was generalized seizure. Partial and secondary generalized seizures ranked second and third respectively. Previous studies have claimed that partial and secondary generalized seizures to be the most common type in similar injuries.2,8
This discrepancy might be due to the high prevalence of penetrating lesions accompanied by the larger volume of brain damage in our sample.
The fact that our patients were selected from volunteers might partially account for preponderance of generalized seizures. One might assume that generalized seizures are more disturbing in comparison to partial ones and hence attract more attention and concern. This might lead to a representation bias of generalized seizures in clinical settings.
In our sample penetrating traumas were much more frequent than blunt traumas (86% vs 8%). This is in agreement with previous reports that penetrating traumas are more commonly associated with seizures than blunt injuries.
We found no significant correlation between the
presence or number of metallic foreign particles in brain tissue and the frequency of seizure attacks in the preceding year.
This is in line with previous reports which imply that deeply located metallic particles in brain tissue do not necessarily predispose the patient to seizure attacks.13 Foreign particles lodged in the brain are usually a product of severe, penetrating and destructive trauma probably accompanied by extensive cortical and meningeal scarring. Thus the results should be evaluated cautiously. Further studies considering confounding factors and accompanying lesions should be carried out.
This study should be considered as a preliminary report. Further investigations with more sophisticated statistical methods and inclusion of more variables are mandatory. The unfortunate abundance of penetrating head injuries in former soldiers of the Iran-Iraq war mandates more research in this field.
References
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