Anticonvulsants for Preventing Seizures in Patients with Chronic Subdural Haematoma: Pilot Study

Introduction: There is increasing of the incidence of chronic subdural hematomas (CSDH), due to increase of the elderly population with increase of intake oral anticoagulation and antiplatelet drugs in this category of patients. Seizures occur as a complication in 2.3% to 20.4% of the patients. There is a considerable side effect associated with using of anti-epileptic drugs (AEDs). Aim of the Study: To rule the value of prophylactic antiepileptic drugs in prevention of seizures after surgical evacuation of chronic subdural hematoma. Methods: A prospective controlled non-randomized study was performed on 26 patients with chronic or subacute subdural hematoma that was surgically evacuated through burr-holes from April 2017 to June 2019. We divided the patients into 2 groups: group A patients received prophylactic antiepileptic drugs for 6 month and group B patients didn’t receive prophylactic antiepileptic drugs and the 2 groups were observed to detect occurrence of post-operative seizures for 6-month follow-up after surgery. Medical history, demographic data and imaging characteristics were recorded. Results: Seizure prevalence for all patients during hospitalization and 6-month follow-up was zero among the 13 patients who received prophylactic anti-seizure medications, and was 1 (7.7%) among the 13 patients who didn’t receive prophylactic anti-seizure medications. Conclusions: The incidence of post-operative seizures in patients with chronic subdural hematoma operated upon by burr holes evacuation is low. The administration of prophylactic antiepileptic drugs decreases the incidence of seizures after evacuation of CSDH, but the difference was not significant. So prophylactic antiepileptic drugs should not be routinely given for all patients with CSDH operated upon by burr hole evacuation unless there is risk factor for seizure development.


Introduction
Chronic subdural hematoma (CSDH) is a common disease in neurosurgical practices. There is increasing of the incidence of chronic subdural hematomas (CSDH), due to increase of the elderly population with increase of intake oral anticoagulation and antiplatelet drugs in this category of patients [1] [2].
Burr-hole surgery is the standard treatment performed with improvement of the symptoms, and good prognosis [3]. Seizures have been noted to develop as a complication in 2.3% to 20.4% of patients [4] [5]. There is a controversy in seizure prophylaxis and prevention of post-operative seizures following evacuation [6]. Due to their negative effect on quality of life, the prevention of seizures is important [7]. When seizures occur in patients with CSDHs, there is increase in the incidence of later seizures and the probability of secondary harm [5] [8]. The risk of seizure in CSDH increases in cases of alcoholic patients, history of stroke, and CT finding of atrophic change of the brain [9], at the time of surgery presence of organized hematoma or insertion of subdural drain associated with higher risk of seizure development [10].
This study is to rule the value of prophylactic antiepileptic drugs in prevention of seizures after surgical evacuation of chronic subdural hematoma.

Patients and Methods
A total of 26 patients with CSDH operated upon by burr hole evacuation surgery from January 2017 to June 2019.
History taken from patients included head trauma, risk factors of seizure like alcohol intake previous stroke, general and neurological examination of patients, laboratory investigation included coagulation profile, and CT brain. The observation period was from the date of the diagnosis of CSDH or the onset of symptoms of CSDH to 6 month after operation.

Results
In the Group A the study population consisted of 13 patients with a mean age of 60.3 years and a range from 30 to 81 years. There were 7 males (53.8%) and 6 females (46.2%) patients. A history of head trauma was obtained in 4 (30.8%) patients, no history of alcohol intake, and history of stroke in 3 patients (23.1%).
The Group B was consisted of 13 patients with a mean age of 63.5 years and a range from 48 to 84 years. There were 6 males (46.2%) patients and 7 females (53.8%). A history of head trauma was obtained in 4 (30.8%) patients no history of alcohol intake, and history of stroke in 4 patients (30.8%).
As regard clinical presentation in Group A the most common presenting symptom was headache in 38.5% of cases followed by weakness in 23.1%, the median Glasgow Coma Score for Group A patients was 14.
In Group B the most common presenting symptom was headache in 46.2% of cases followed by weakness in 30.8%, other presentations in 23%. The median Glasgow Coma Score for Group B patients was 14.
As regard radiological appearance in Group A 12 (92.3%) patients had chronic subdural hematoma (CSDH) while 1 (7.7%) had subacute subdural hematoma, the average thickness was 13 mm and the average midline shift for  (Table 1).

Discussion
The incidence of seizures in patients with chronic subdural hematoma varied from 2.3% to 20.4% [4] [5]. This is higher than the numbers we found in daily clinical practice [11]. The causes of this high incidences and, varied numbers are not obvious. In our study the incidence of seizures in Group B not receiving antiepileptic was 7.7% and in two Groups were 3.8%. In our study the mean age of two Groups 61.6 years with age ranges from 30 to 84 years. Similar to Flores et al.  [12], the mean age was 59 years (range: 18 -98 years), and Huang et al. [13] mean age was 69.0 years and rang from (29 -90 years). In our study in two Groups male equal to female and both of them were 13 patients in contrast to other studies in which male more than female. [12] [13] there is a history of head trauma in 30.8% of the patients. In contrast to other study in which 72% of patients had history of head trauma [13], the reason of that may be due to the minor trauma may pass without observation.
The incidence of seizures in Flores et al. [12] was low 2.3% in spite he didn't give prophylactic antiepileptic in patients of chronic subdural hematoma treated by burr hole evacuation. He decided not to give prophylactic antiepileptic due to their side effect and the risk to develop seizures very low. Similar to results of Chen et al. [4], Ohno et al. [14] and Battaglia et al. [11], in contrast to that Sabo et al. [5] had notice that 32% of patients who didn't receive prophylactic antiepileptic developed seizure with high morbidity so they advice to give prophylactic antiepileptic. In our study, we prospectively analyzed 26 patients treated surgically for CSDH using a burr-hole and irrigation. The 26 patients were divided into two Groups, Group A 13 patients (50%) received prophylactic antiepileptic drugs. In one patients phenytoin resulted in non-dangerous dermatological reaction and we shifted to levetiracetam. None of Group A had developed seizure.
In contrast to that one patient of Group B (7.5%) of the 13 patients who did not receive antiepileptic prophylaxis had develop seizure, not associated with addition in morbidity. This case had left sided chronic subdural hematoma, with no history of stroke in CT brain no atrophic change at time of surgery hematoma wasn't organized, without risk factors mentioned by Won et al. [9] in cases of alcoholic patients, history of stroke, and CT finding of atrophic change of the brain, and Yamada et al. [10] organized hematoma. Though the administration of prophylactic antiepileptic drugs prevents the development of postoperative seizure, the incidence of seizure in the other group was low and the difference was not significant. So, we recommend that antiepileptic drugs should not be given prophylactically for all patients with CSDH due to their side effect on old age patients. This is a pilot study provided for a larger large number of sample size in the future.

Study Limitation
Small sample which will be considered in the future.

Conclusion
The incidence of post-operative seizures in patients with chronic subdural hematoma operated upon by burr holes evacuation is low. The administration of prophylactic antiepileptic drugs decreases the incidence of seizures after evacuation of CSDH but the difference was not significant. So prophylactic antiepileptic drugs should not be routinely given for all patients with CSDH operated upon by burr hole evacuation unless there is risk factor for seizure development.