Endoscopic Transnasal Transsphenoidal Resection of Left Temporal Encephalocele Resulting in Dramatic Reduction in Seizure Frequency
Introduction: The patient is a 42 year old female who has had long standing intractable seizures who was found to have a left anterior temporal encephalocele into the sphenoid sinus in 2005. She underwent resection of this encephalocele via an endoscopic transnasal transsphenoidal approach in September of 2012.
Methods: The patient is a 42 year old female with a seizure history (both complex partial and generalized tonic clonic) that started when the patient was 28 years of age. She has a history of a head injury at 4 years of age. The patient was followed by the neurology department, and two agents (levetiracetam and carbamazepine) failed to fully control her seizures, averaging 3–4 seizures per month. She had undergone video EEG monitoring in 2005 and 2012 with left frontotemporal origin. MRI of the brain from 2005 demonstrated a left temporal encephalocele herniating into the sphenoid sinus, and this was redemonstrated in the 2012 MRI, with likely increase in amount of herniated left mesial temporal lobe tissue. A PET scan showed somewhat decreased FDG uptake in the left anterior temporal lobe. In addition, the patient would have an occasional salty metallic taste in the back of her mouth, and this was felt to be a possible cerebrospinal fluid leak. The patient underwent endoscopic transnasal transsphenoidal resection of the encephalocele with placement of a lumbar drain. The resection was not total as there was a branch of the MCA that was kept intact that prevented further resection. A nasoseptal flap was used to repair the defect with no evidence of cerebrospinal fluid leak. Pathology was consistent with encephalocele, with mature glial tissue with reactive gliosis with Rosenthal fibers. She had an uncomplicated postoperative course with resolution of her sensation of salty metallic taste. Her seizure frequency in the following year has decreased significantly as she has had had a total of four seizures since the surgery, all provoked by skipping her antiepileptic drugs or sleep deprivation.
Conclusion: Middle fossa encephaloceles that are associated with seizures are rare, and there are fewer than twenty cases in the literature about such patients. This case demonstrates that an endoscopic transnasal transsphenoidal approach to resection of temporal lobe encephaloceles may have a beneficial effect on patients with seizures originating in the temporal region. Our case is likely the second case reported in neurosurgical literature of seizure frequency reduction following endoscopic transnasal transsphenoidal resection of an encephalocele.
References1 Byrne RW, Smith AP, Roh D, Kanner A. Occult middle fossa encephaloceles in patients with temporal lobe epilepsy. World Neurosurg 2010;73(5):541–546
2 Faulkner HJ, Sandeman DR, Love S, Likeman MJ, Nunez DA, Lhatoo SD. Epilepsy surgery for refractory epilepsy due to encephalocele: a case report and review of the literature. Epileptic Disord 2010;12(2):160–166
3 Yang E, Yeo SB, Tan TY. Temporal lobe encephalocoele presenting with seizures and hearing loss. Singapore Med J 2004;45(1):40–42