Retained Intracerebral Depth Electrode after Stereotactic Electroencephalography Monitoring: A Case Report

Stereotactic electroencephalography (SEEG) is an increasingly popular surgical modality for localizing the epileptogenic zone. Robot-guided stereotactic electrode placement has been covered in Japan by National Health Insurance since 2020. However, several surgical devices, such as the anchor bolt (a thin, hollow, metal shaft that serves as a guide screw or fixing for each electrode), have not been approved. A 14-year-old female who underwent SEEG for intractable epilepsy and required additional surgery to remove a retained depth electrode from the skull after the SEEG monitoring was finished. She had uncontrolled focal seizures consisting of nausea and laryngeal constriction at the onset. After a comprehensive presurgical evaluation, robot-guided stereotactic electrode implantation was performed to evaluate her seizures by SEEG. Nine depth electrodes were implanted through the twist drill hole. The electrodes were sutured to her skin for fixation without anchor bolts. When we attempted to remove the electrodes after 8 days of SEEG monitoring, one of the electrodes was retained. The retained electrode was removed through an additional skin incision and a small craniectomy under general anesthesia. We confirmed narrowing of the twist drill hole pathway in the internal table of the skull due to osteogenesis, which locked the electrode. This complication might be avoided if an anchor bolt had been used. This case report prompts the approval of the anchor bolts to avoid difficulty in electrode removal. Moreover, approval of a depth electrode with a thinner diameter and more consistent hardness is needed.

Transcortical selective amygdalohippocampectomy for intractable mesial temporal lobe epilepsy: a review of outcomes in a single center

Introduction: Various surgical procedures have been found to effectively treat intractable temporal lobe epilepsy (TLE), including transcortical selective amygdalohippocampectomy (SAH), which is intended to protect the temporal lobe and to prevent interference with vascular structure. This research analyzed the outcome of post-operative seizure-free with transcortical selective amygdalohippocampectomy for intractable mesial temporal lobe epilepsy patients in a minimum two-year follow-up after surgery. Methods: Data of one hundred ninety-two patients who had undergone transcortical selective amygdalohippocampectomy for non-lesional, medically intractable, temporal lobe epilepsy were analyzed. Result: The statistical analysis indicated that Focal to Bilateral Tonic-Clonic Seizure had a more significant outcome (p=0.019) than other seizures. In all research subjects, after three, six, and twelve years of follow-up, the chance for a seizure-free after surgery was respectively 93.2 percent, 67.9 percent, and 36.7 percent with a median average survival period for all subjects of 11.00 years (95 % CI: 8.55 – 13.44) Conclusions: Transcortical selective amygdalohippocampectomy is an effective therapy for intractable mesial temporal lobe epilepsy and provides a satisfactory outcome. The transcortical approach allows an appropriate operative field by careful dissection with limited retraction to eliminate the epileptogenic target while preventing damage to the underlying vascular and cortical structures.

Initiating an epilepsy surgery program with limited resources in Indonesia

To share the experiences of organizing the epilepsy surgery program in Indonesia. This study was divided into two periods based on the presurgical evaluation method: the first period (1999–2004), when interictal electroencephalogram (EEG) and magnetic resonance imaging (MRI) were used mainly for confirmation, and the second period (2005–2017), when long-term non-invasive and invasive video-EEG was involved in the evaluation. Long-term outcomes were recorded up to December 2019 based on the Engel scale. All 65 surgical recruits in the first period possessed temporal lobe epilepsy (TLE), while 524 patients were treated in the second period. In the first period, 76.8%, 16.1%, and 7.1% of patients with TLE achieved Classes I, II, and III, respectively, and in the second period, 89.4%, 5.5%, and 4.9% achieved Classes I, II, and III, respectively, alongside Class IV, at 0.3%. The overall median survival times for patients with focal impaired awareness seizures (FIAS), focal to bilateral tonic–clonic seizures and generalized tonic–clonic seizures were 9, 11 and 11 years (95% CI: 8.170–9.830, 10.170–11.830, and 7.265–14.735), respectively, with p = 0.04. The utilization of stringent and selective criteria to reserve surgeries is important for a successful epilepsy program with limited resources.

Preoperative sensory aura predicts risk for seizure in temporal lobe epilepsy surgery

BACKGROUND

Patients with temporal lobe epilepsy (TLE) often report viscerosensory and experiential auras, with substantial epilepsy localization. However, few previous studies have investigated the epileptic preoperative aura, particularly with regard to its effect on surgical outcomes in patients with drug-resistant epilepsy.

OBJECTIVE

This study investigated the potential role of preoperative aura in predicting outcomes after surgery for TLE.

MATERIAL AND METHODS

This study included consecutive patients diagnosed with TLE who underwent anterior temporal lobectomy (ATL) for drug-resistant TLE during the period from January 1999 to December 2017. Data pertaining to patient age at the time of surgery, sex, age at initial seizure onset, duration of epilepsy, presence of preoperative aura, comprehensive clinical semiology, side of surgery, and type of pathology were analyzed. Preoperative auras were classified as autonomic, sensory, mental and affective, or multiple manifestations. Patients were followed at 3 and 12 months after surgery and at regular intervals thereafter.

RESULTS AND CONCLUSIONS

A total of 498 patients were included in the study. Positive preoperative aura was observed in 386 patients (77.51%). The correlation of each variable with seizure outcomes was analyzed, and the only variable found to correlate with seizure outcome was the presence of preoperative aura. Compared with those with negative preoperative aura, those with positive preoperative aura were 1.74-fold more likely to be seizure-free after surgery for TLE. The analysis of patient data suggested a later onset of initial seizure in those with positive preoperative aura, compared with those without (p = 0.04, 95% confidence interval (CI): 0.55-3.24). Patients with a shorter duration of disease prior to TLE surgery were more likely to achieve seizure-free status postoperatively. Preoperative sensory aura was a good predictor that a patient would be seizure-free during follow-up (p = 0.022).

Surgery for Radiologically Normal-Appearing Temporal Lobe Epilepsy in a Centre with Limited Resources

Approximately 26-30% of temporal lobe epilepsy (TLE) cases display a normal-appearing magnetic resonance image (MRI) leading to difficulty in determining the epileptogenic focus. This causes challenges in surgical management, especially in countries with limited resources. The medical records of 154 patients with normal-appearing MRI TLE who underwent epilepsy surgery between July 1999 and July 2019 in our epilepsy centre in Indonesia were examined. The primary outcome was the Engel classification of seizures. Anterior temporal lobectomy was performed in 85.1% of the 154 patients, followed by selective amygdalo-hippocampectomy and resection surgery. Of 82 patients (53.2%), Engel Class I result was reported in 69.5% and Class II in 25.6%. The median seizure-free period was 13 (95% CI,12.550-13.450) years, while the seizure-free rate at 5 and 12 years follow-up was 96.3% and 69.0%, respectively. Patients with a sensory aura had better seizure-free outcome 15 (11.575-18.425) years. Anterior temporal lobectomy and selective amygdala-hippocampectomy gave the same favourable outcome. Despite the challenges of surgical procedures for normal MRI TLE, our outcome has been favourable. This study suggests that epilepsy surgery in normal MRI TLE can be performed in centres with limited resources.

A Thyroid-stimulating Hormone (TSH) Producing Adenoma in a Patient with Severe Hypothyroidism: Thyroxine Replacement Reduced the TSH Level and Tumor Size

We treated an extremely rare thyroid-stimulating hormone (TSH)-producing pituitary adenoma in a 63-year-old woman with severe hypothyroidism due to autoimmune thyroiditis. She was presented with dizziness and fatigue. The blood level of TSH, prolactin, and fT4 was 288.2 μIU/mL, 72.9 ng/mL, and 0.24 ng/dL, respectively. Magnetic resonance imaging demonstrated a large pituitary tumor, 31 mm in height, and a normal pituitary gland. Preoperative thyroxine replacement reduced the TSH level to 2.05 μIU/mL and produced a significant reduction in the tumor volume. Histopathologically, the surgically removed tumor was a TSH-producing pituitary adenoma.