Transcranial Corticospinal Motor-Evoked Potentials in Cases of Ventral and Ventrolateral Intradural Extramedullary Cervical Spinal Cord Tumors.

Background and Objectives: We studied the clinical significance of an amplitude decrement and disappearance alarm criteria in transcranial motor-evoked potential (MEP) monitoring during surgeries on extramedullary tumors at the cervical spine with reference to postoperative morbidity. Material and Methods: We diagnosed and surgically treated fourteen patients with intradural extramedullary ventral or ventrolateral lesions to the cervical spinal cord in the Clinic of Neurosurgery at the University Hospital St Ivan Rilski from January 2018 to July 2022. Eight cases were diagnosed with schwannoma, and the remaining six had meningiomas. The follow-up period for neurological assessment was six months. Results: A decrease in the intraoperative transcranial MEPs of 50% or more compared to baseline in two cases (14.3%) resulted in an immediate postoperative motor deficit. One patient demonstrated full neurological recovery within six months, while the other exhibited only partial improvement. In six cases (42.9%) with preoperative motor deficits, tumor resection and decompression of the cervical spinal cord led directly to an increment of the transcranial MEPs by more than 20%. Postoperatively and at the 6-month follow-up, these patients showed recovery from the preoperative deficits. In the remaining cases, MEPs were stable during surgery with no clinical deterioration of the motor function. Conclusions: The decremented MEP criteria corresponded to postoperative motor deficit, whereas the improvement of the same parameters after decompression implied future recovery of preoperative motor deficits. The combination of different MEP criteria is likely to be helpful when tailored to a specific case of ventral or ventrolateral extramedullary lesions in the cervical spine.

Awake Craniotomy for a Frontal Astrocytoma: A Case Report.

Awake craniotomy is a surgical procedure that has been gaining significance over the past decades. Neuronavigation is an intraoperative technology that locates tumors and monitors the brain cortex during awake craniotomy. The presence of cerebral low-grade gliomas in the frontal lobe creates a risk of affecting vital centers of the brain cortex during surgery. We present a clinical case of a 42-year-old male patient who entered the neurosurgery clinic with a clinical manifestation of headache for two months. MRI showed evidence of the recurrence of a left frontal glioma. Differential diagnoses of frontal gliomas include metastases, abscesses, and cysts. The pathophysiologic background of the disease is the mutation of neuroglial cells, which leads to an abnormal and uncontrollable proliferation. Under sleep-awake anesthesia, operative treatment was performed through left frontal awake craniotomy under neuronavigation. As a result, a total excision was achieved. Motor functions of the right limbs and speech have been preserved. The patient was mobilized on the day after the intervention. Surgery-related complications were not observed. The patient had relief from the symptoms and was discharged on the fifth day. Awake craniotomy combined with neuronavigation was the most efficient and the least harmful method for the excision of the tumor. For low-grade gliomas localized in the frontal area of the encephalon, awake craniotomy is the only secure option for surgery.

Thoracic spinal anesthesia with intrathecal sedation for lower back surgery: a retrospective cohort study.

Background: Spinal anesthesia (SA) is a good alternative to general anesthesia (GA) for spine surgery. Despite that, a few case series concern the use of thoracic spinal anesthesia for short-duration surgical interventions. In search of an alternative approach to GA and a better opioid-free modality, we aimed to investigate the safety, feasibility, and patient satisfaction of thoracic SA for spine surgery. Materials and methods: We analyzed retrospectively a cohort of 24 patients operated on for a degenerative and osteoporotic pathology of the lower thoracic and lumbar spine. Data was collected from medical records, including clinical notes, operative and anesthesia records, and patient questionnaires. Results: Twenty-one surgeries for herniated discs, two for degenerative spinal stenosis, and one for multi-level osteoporotic vertebral body fractures were performed under spinal anesthesia with intrathecal sedation. In all cases, we applied 0.5% isobaric bupivacaine and the following adjuvants: midazolam, clonidine or dexmedetomidine, and dexamethasone. We boosted the anesthesia with local ropivacaine due to inefficient sensory block in two patients. Nobody in the cohort received intravenous opioids, non-steroidal anti-inflammatory drugs, or additional sedation intraoperatively. Postoperative painkillers were upon the patient's request. No significant complications were detected. Conclusion: Thoracic spinal anesthesia incorporating adjuvants such as midazolam, clonidine or dexmedetomidine, and dexamethasone demonstrates not only efficient conditions for spine surgery, a favorable safety profile, high patient satisfaction, and intrathecal sedation but also effective opioid-free pain management.