A flexible implantable microelectrode array for recording electrocorticography signals from rodents.

Electrocorticography signals, the intracranial recording of electrical signatures of the brain, are recorded by non-penetrating planar electrode arrays placed on the cortical surface. Flexible electrode arrays minimize the tissue damage upon implantation. This work shows the design and development of a 32-channel flexible microelectrode array to record electrocorticography signals from the rat's brain. The array was fabricated on a biocompatible flexible polyimide substrate. A titanium/gold layer was patterned as electrodes, and a thin polyimide layer was used for insulation. The fabricated microelectrode array was mounted on the exposed somatosensory cortex of the right hemisphere of a rat after craniotomy and incision of the dura. The signals were recorded using OpenBCI Cyton Daisy Biosensing Boards. The array faithfully recorded the baseline electrocorticography signals, the induced epileptic activities after applying a convulsant, and the recovered baseline signals after applying an antiepileptic drug. The signals recorded by such fabricated microelectrode array from anesthetized rats demonstrate its potential to monitor electrical signatures corresponding to epilepsy. Finally, the time-frequency analyses highlight the difference in spatiotemporal features of baseline and evoked epileptic discharges.

Factors That Predict Recurrence Following Endoscopic Repair of Cerebrospinal Fluid Rhinorrhea.

BACKGROUND: The endoscopic approach has gained popularity in cerebrospinal fluid (CSF) rhinorrhea repair with high success rates, yet recurrence is frequent. We analyzed our cases to determine the outcomes of endoscopic repair of CSF rhinorrhea and the effect of several perioperative factors on the success of repair. METHODS: A retrospective review of 50 patients who underwent endoscopic repair of CSF rhinorrhea between January 2013 and July 2023 was performed, collecting details of presentation, surgery, and postoperative period. RESULTS: The most frequent etiology was nontraumatic CSF rhinorrhea (76%), in which the defect was most commonly located at the left cribriform plate, followed by traumatic CSF rhinorrhea (24%), in which sphenoid defects were most frequent. Traumatic CSF rhinorrhea was more common among male patients and was significantly associated with anosmia. Success rate at first repair attempt was 84%. Persistent CSF rhinorrhea was present in 3 patients (6%), and 5 patients (10%) developed recurrence of CSF rhinorrhea. Overall, 7 patients required reoperation, with 100% success rate after the second surgery. The use of 3-layered repair with fat, fascia lata, and mucosal flap was protective against repair failure, whereas bilateral defects and duration of symptoms >1 year were significantly associated with repair failure. The use of lumbar drain did not demonstrate a difference in repair success rate. CONCLUSIONS: Endoscopic repair of CSF rhinorrhea appears to be safe and effective when performed with accurate localization of the site of the lesion and multilayered repair. Potential predictors of recurrence include bilateral and long-standing defects.

Surgical management of simultaneous supra- and infratentorial hemorrhages in a pediatric patient with multiple cavernomas.

Multiple intracranial cavernomas are rare and occur mostly in familial cases. Clinical presentation with simultaneous rupture of two or more lesions has only been reported in four cases to date. A 15-year-old boy presented with simultaneous right frontal and superior vermian hematomas with hydrocephalus. The patient underwent a ventriculoperitoneal shunt, and his magnetic resonance imaging (MRI) revealed multiple cavernomas with bleed in the above-mentioned locations. The patient underwent a midline suboccipital craniotomy and excision of the cavernoma. The supratentorial lesions were left in situ in lieu of small size, no history of seizures, mass effect, or other neurological deficits. The patient recovered well from surgery with significant improvement in truncal ataxia. He remained asymptomatic for supratentorial lesions at follow-up. Cavernomas should be considered as differential diagnoses in cases of multiple intraparenchymal hemorrhages, especially in pediatric patients. The surgical management should be rationalized based on the lesion location, the eloquence of the surrounding parenchyma, mass effect, and the risks of re-rupture. Due to the rarity of multiple simultaneous hemorrhages, the management of multiple cavernomas remains controversial. The patient's relatives can be screened with MRI to rule out the familial form of the disease. Strict clinical and radiological follow-up is a must in such patients.