Seizures are a more common concomitant symptom of craniosynostosis, and they occur in 3-40% of patients after craniosurgery. It is an important responsibility of neurosurgeons to apply antiepileptic drugs before and after craniosurgery to avoid seizures or to control them effectively, and to minimize the harm caused by seizures to patients. The Consensus on the application of antiepileptic drugs before and after epilepsy surgery was published under the auspices of the Association, providing very important theoretical and practical guidance for clinicians engaged in epilepsy surgery. However, the Consensus failed to cover the standardized application of antiepileptic drugs after surgery for other cranio-cerebral diseases. The following consensus has been reached on the application of postoperative antiepileptic drugs in patients with various cranio-cerebral diseases, especially those without preoperative diagnosis of “epilepsy”.
I. Postoperative seizures in cranio-cerebral diseases
Seizures after craniofacial surgery are classified into immediate (≤24 hours), early (>24 hours, ≤2 weeks) and late (>2 weeks) seizures according to the time of occurrence. Postoperative seizures usually occur after supratentorial craniotomy, whereas the incidence of postoperative seizures is low in sub-tentorial craniotomy (except in cases of brain damage due to traction or vascular causes). The diagnosis of “epilepsy” in the postoperative period should be based on the Clinical Guidelines. (hereinafter referred to as the “Guidelines”). Seizures after surgery for craniosynostosis may result in intracranial hemorrhage, cerebral edema, and other hazards, and antiepileptic drugs have potential risks such as hypersensitivity reactions, liver function damage, and drug-drug interactions. If seizures are recurrent or frequent and a diagnosis of “epilepsy” can be established, the patient should be treated aggressively in accordance with the Guidelines.
For patients with craniosynostosis without preoperative seizures, the rules for postoperative prophylactic application of antiepileptic drugs.
(a) Postoperative patients with expected seizures
1. Case selection (usually refers to episodic surgery)
Prophylactic application of antiepileptic drugs can be applied to those with epileptic susceptibility or in the following cases
(1) After craniocerebral trauma surgery, the application of antiepileptic drugs can be considered in those with the following conditions
A. Modified Glasgow Coma Scale (GCS)
Coma Scale (GCS) <10< font="">.
B. Extensive brain contusion or depressed skull fracture.
C. Intracranial hematoma (including intracerebral, subdural, and epidural hematoma);
D. Open cranial injury;
E. prolonged coma or memory loss after trauma (>24 hours)
(2) After surgery for supratentorial brain tumors, routine prophylactic application of antiepileptic drugs is not recommended, but can be considered after comprehensive evaluation in those with the following conditions.
A. temporal lobe lesions
B. ganglion cell tumors, embryonic residual tumors
C. long surgical time (cortical exposure time > 4 hours)
D. malignant tumor surgery with local placement of slow-release chemotherapy drugs
E. Lesions invading the cortex or serious damage to the cortex during surgical resection
F. Surgery for recurrent malignant tumor with severe cortical damage
G. Intraoperative damage to the draining vein or cortical blood supply artery, which is expected to have significant cerebral edema or cortical cerebral infarction
(3) After surgery for supratentorial vascular lesions, routine prophylactic application of antiepileptic drugs is not recommended, but can be considered after comprehensive evaluation in those with the following conditions.
A. cavernous hemangioma or arteriovenous malformation in the subcortex (especially in the temporal lobe)
B. ruptured aneurysm combined with intracerebral hematoma or middle cerebral artery aneurysm
C. spontaneous intracerebral hematoma
D. Intraoperative injury to the draining vein or cortical blood supply artery, which is expected to have significant cerebral edema or cortical cerebral infarction
(4) Other cranial surgical procedures, the application of antiepileptic drugs can be considered in the following cases: [Note: there is no definite evidence whether the use of drugs according to this rule can effectively prevent the appearance of postoperative seizures, which is based on the current clinical practice experience and can be further observed and studied in the future].
A. After cranioplasty of skull defects
B. Brain abscess or intracranial parasites (especially if the lesion is located in the temporal or parietal lobe or craniotomy causes extensive cerebral cortical damage)
2. Timing of antiepileptic drug application
Antiepileptic drugs should be started when anesthetic drugs are stopped to prevent immediate seizures; since there is no evidence that antiepileptic drugs can reduce the occurrence of late seizures, prophylactic application of antiepileptic drugs should usually be gradually discontinued after 2 weeks postoperatively. If immediate or early seizures occur, see the next section “Drug application in case of postoperative seizures” for treatment; in case of intracranial infection or postoperative formation of intracerebral hematoma, the duration of antiepileptic drug application can be extended appropriately.
3. Usage of antiepileptic drugs
(1) Principles of drug selection: less impact on consciousness, less side effects, faster onset of action, and less drug-drug interactions. The later use of drugs can be the same or different from the initial intravenous drugs.
(2) Method: First apply intravenous antiepileptic drugs, and after resuming gastrointestinal feeding, change to oral antiepileptic drugs. (The possibility of poisoning also exists except for phenytoin sodium); prophylactic application of antiepileptic drugs need to reach the therapeutic dose and blood concentration monitoring if necessary.
(3) Commonly used drugs: intravenous drugs: sodium valproate, sodium phenobarbital; oral drugs: oxcarbazepine, levetiracetam, sodium valproate, and carbamazepine.
(B) Anti-epileptic drug application in case of postoperative seizures
1. Indications
For patients who have developed seizures after surgery for cranial diseases and can be diagnosed as “epilepsy”, appropriate antiepileptic drugs should be selected for regular treatment. (If the treatment is limited to patients with “epilepsy”, the title should be changed to (2) Anti-epileptic drug application for postoperative epilepsy, and the description of the following 2.Timing of medication should be added to the indications: “patients with immediate or early postoperative seizures”. (to correspond to the first paragraph in 2. Timing of medication.)
2. Duration of medication
If seizures occur in the early postoperative period (within 2 weeks), if antiepileptic drugs have been used prophylactically, the basic principles of the Guidelines should be followed to increase the dosage of drugs or choose to add other drugs for treatment. If there is no seizure after taking regular antiepileptic drugs, it is recommended to discontinue the drugs after 3 months combined with EEG and other relevant evidence (are these patients diagnosable as “epilepsy” or not?). The recommendation is to discontinue the drug after 3 months, taking into account the EEG and other relevant evidence (are these patients diagnosed with “epilepsy” or not?).
If the seizures are not effectively controlled after 2 weeks or if recurrent seizures occur after 2 weeks, the diagnosis of “epilepsy” can be established in combination with other diagnostic bases, and the basic principles of the Guidelines should be followed for treatment. If a single seizure occurs after 2 weeks, first choose monotherapy and adjust the treatment dose if necessary by monitoring blood levels. Due to the wide variation in the type of cranial surgery and the degree of surgical resection, the decision of when to reduce or discontinue medication after the seizures are completely controlled under regular treatment should be made carefully according to the patient’s specific situation.
3.Drug selection
The selection of drugs should be based on the classification of epilepsy and follow the basic principles of the Guidelines. Commonly used postoperative antiepileptic drugs: carbamazepine (CBZ), oxcarbazepine (OXC), levetiracetam (LEV), sodium valproate (VPA), lamotrigine (LTG) and topiramate (TPM).