Unilateral biportal endoscopic (UBE) surgery has developed rapidly during the past decade. Continuous epidural space irrigation is generally considered the principal reason for cerebral complications following UBE surgery. We present a case of mental symptoms during the general anesthesia awakening period due to pneumocephalus.

A 70-year-old woman with lumbar disc herniation underwent UBE surgery stably under general anesthesia. Uncontrollable hypertension occurred immediately after transfer to the postoperative care unit, accompanied by increased heart rate and tachypnea. During the recovery process, the patient responded to external stimuli but was confused and unable to complete command actions. Neck stiffness and significantly increased muscle strength on the left side indicated the presence of de-cerebrate rigidity. An urgent brain computed tomography scan showed pneumocephalus compressing the brainstem. After receiving analgesia and sedation treatment, the patient was conscious three hours later and recovered rapidly. She was discharged on the fifth postoperative day and followed up for 3 months with no surgical or brain complications.

Cerebral complications emerging during the general anesthesia awakening period following UBE surgery are not entirely due to increased intracranial pressure. Pneumocephalus induced by dural injury may also be a potential cause.

Although endoscope-assisted techniques have been described, a full-endoscopic approach is yet to be performed for posterior fossa decompression (PFD) in Chiari malformation type I (CM-I). This study aims to describe the full-endoscopic PFD technique and evaluate its feasibility. Five fresh-frozen anonymized adult human cadavers were operated on using an endoscope with an oval shaft cross-section with a diameter of 9.3 mm, a working length of 177 mm, and a viewing angle of 20°. It also had an eccentric working channel with a diameter of 5.6 mm, a light guide, a sheath for continuous irrigation, and a rod lens system. The instruments were introduced from the working channel. Posterior craniocervical structures were dissected, and PFD was achieved. The planned steps were performed in all five cadavers. The endoscope was introduced to the posterior craniocervical region, dissecting the structures to easily expose the suboccipital bone and C1 posterior arch. Important structures, such as the C1 posterior tubercle, rectus capitis posterior minor muscles, and posterior atlantooccipital membrane, were used as landmarks. PFD was feasible even with the dural opening. Using the full-endoscopic approach, posterior craniocervical structures can be reached, and PFD can be performed successfully. The instruments used are well-defined for spinal usage; thus, this full-endoscopic technique can be widely used in the surgical treatment of patients with CM-I.

To describe the perioperative clinical features, management, and outcomes of patients with seizure after percutaneous endoscopic spine surgery (PESS).

Patients who experienced seizure after PESS in a tertiary orthopedic hospital between January 2016 and June 2022 were retrospectively recruited, and patient charts were reviewed.

Twenty-nine patients were recruited, and the incidence of seizure after PESS was 0.52%. The operation time was 110.0 minutes (interquartile range [IQR], 82.5-235.0 minutes) and the irrigation speed was 109.0 mL/minute (IQR, 86.5-145.5 mL/minute). Definitive dural tears were reported in 15 patients (51.7%). In addition to agitation and myotonia, significant increased respiratory rate (29.9 ± 6.5 breaths/minute), tachycardia (112.1 ± 20.6 beats/minute), and hypertension (systolic, 189.5 ± 21.9 mm Hg; diastolic, 98.3 ± 10.6 mm Hg) were observed. Arterial blood gas analysis showed hypocapnia, metabolic acidosis, and hyperlactatemia. All patients received analgesia and sedation as well as hyperosmolar therapy. The estimated duration of seizure was 3.0 hours (IQR, 2.5-4.0 hours) and the postoperative length of hospital stay was 3.0 (IQR, 3.0-5.5) days. The Japanese Orthopaedic Association score and visual analog scale score improved markedly within 6 months after surgery.

Despite the low incidence and short duration, seizure after PESS should be considered a critical and urgent syndrome. Management strategies for seizure mainly involve intensive care, securing the airway, analgesia and sedation, hyperosmolar therapy, and negative fluid balance. No significant adverse effects of seizure on clinical outcomes were observed during 6 months of follow-up.

In order to analyze the clinical efficacy and recovery of lumbar disc herniation (LDH) treated by lateral and posterior foraminoscopy and posterior approach foraminoscopy (PELD), the comparison of clinical efficacy and recovery effect between lateral and posterior foraminoscopy and PELD in LDH patients was conducted. A total of 96 LDH patients admitted to our hospital from July 2020 to July 2021 were selected, and the lateral and posterior foraminoscopy group and PELD group were, respectively, established according to different surgical intervention methods. The lateral posterior foraminoscopy group is treated with lateral posterior foraminoscopy intervention, and the PELD group is treated with posterior foraminoscopy intervention. The intraoperative and postoperative indicators of the two groups were observed, and the pain improvement, lumbar function, clinical efficacy, and incidence of adverse complications were compared between the two groups before and 3 months after surgery. The Spearman correlation coefficient is used to analyze the correlation between visual analogue scale (VAS) score, lumbar function (ODI) score, and the incidence of complications. For patients with LDH in implementing lientang road intervertebral foramen mirror, the clinical efficacy of the intervertebral foramen to a rear mirror was more apparent. It demonstrates that the treatment can reduce intraoperative blood loss, shorten hospitalization time, improve lumbar vertebral function, and reduce a patient's risk of complications.

Percutaneous endoscopic lumbar discectomy (PELD) is a minimally invasive technique for removing nucleus pulposus and achieving neural decompression via a posterolateral approach. PELD is known to have a very low rate of complications during the perioperative period. Although quite rare, seizures can occur in patients undergoing PELD.

A 58-year-old man with severe low back pain underwent the PELD procedure under general anesthesia. During the recovery phase after general anesthesia, the patient developed a tonic-clonic seizure. Two additional episodes occurred subsequently.

Bilateral disc swelling indirectly supports the diagnosis of intracranial hypertension.

Midazolam and propofol were administered to control seizures. 1.0 g phenobarbital sodium was administered by intravenous injection. Ten milligrams of furosemide and 250 mL of mannitol (20%) were prescribed sequentially. Two hundred milligrams of hydrocortisone and an ice bag were used to protect the brain. Urapidil, metoprolol, and nicardipine were intermittently used to control his blood pressure. A sustained release of sodium valproate was administered and continued prophylactically for 4 weeks.

No further seizures were recorded and the patient recovered well.

We conclude that total volume of fluid used for irrigation was considered a possible cause of seizure. This case illustrates the fact that irrigation should be performed cautiously in PELD procedure. And anesthesiologists should be familiar with the management strategies of perioperative acute seizures.

Percutaneous endoscopic surgery is a popular surgery to treat lumbar spinal disorders. However, seizure after percutaneous endoscopic surgery is an unpredictable complication. The only prodromal sign for seizure currently known is neck pain. We reviewed the incidence of, and risk factors for, seizure during percutaneous endoscopic surgery and present the cases of 3 patients with seizure and our management.

From October 2006 to March 2019, 3 of 816 patients (0.34%) with thoracic lumbar disorders who had undergone percutaneous endoscopic surgery experienced a seizure episode. The cases of those 3 patients were carefully reviewed. Studies of the risk factors for seizure after spinal procedures reported before June 13, 2019 were identified through a PubMed search. We found that infusion fluid containing cefazolin, the infusion rate, a prolonged operative time, the occurrence of a dural tear, and sevoflurane anesthesia might be associated with seizure, both described in the reported data and found in our experience. Three patients who experienced a seizure episode had had general anesthesia with sevoflurane, and the surgical approach used was interlaminar for a herniated disc in L5-S1. We noted a "red flag sign," namely an uncontrollable hypertension episode combined with a decreasing pulse rate, in all 3 patients who had experienced a seizure, which was not observed in the other patients. All 3 patients had received antihypertensive medication (labetalol) ≥3 times without response.

Seizure after percutaneous endoscopic surgery is rare, but lethal. Although its cause remains unknown, all risk factors for seizure should be checked and corrected immediately when a red flag sign, uncontrolled hypertension, appears.

There is no consensus on whether patients undergoing myelography should discontinue medications that could lower their seizure threshold. The purpose of this study was to document the most commonly prescribed seizure threshold-lowering medications in patients undergoing myelography and determine whether withholding such medications decreases the incidence of seizures.

We performed a retrospective observational study of all the myelograms obtained in 2016 at 2 affiliated hospitals. At hospital A, seizure threshold-lowering medications are discontinued before myelography, and prophylactic diazepam is given for all cervical myelograms. At hospital B, seizure threshold-lowering medications are not withheld before the procedure, and medical seizure prophylaxis is not implemented. The seizure threshold-lowering medications the patients were taking at the time of the procedure and postmyelographic seizure incidence were documented.

A total of 311 patients underwent myelography during 2016. One hundred eleven patients (36%) were on at least 1 seizure threshold-lowering medication, and 30 (10%) were on at least 2. The most common medications were duloxetine, sertraline, venlafaxine, bupropion, and trazodone. The most common tricyclic antidepressant was amitriptyline. Three patients across both sites had a controlled seizure disorder and were on antiepileptics. None of the patients at either hospital had seizures during or within 3 hours following any of the myelograms during the study period.

Continuing seizure threshold-lowering medications during myelography does not increase the risk of seizures. Screening for and withholding seizure threshold-lowering medications are not indicated for routine myelography.