Transnasal transsphenoidal pituitary surgery in a large tertiary hospital, a retrospective study.

OBJECTIVES: Pituitary adenomas (PAs), although being small tumours, can have quite an impact on patients' lives causing hormonal and visual disturbances, for which surgery must be performed. As a large peripheral hospital with specialists in pituitary surgery, an assessment of the efficacy and safety of transnasal transsphenoidal pituitary surgery was made. METHODS: A retrospective analysis of neurosurgical reports as well as pre and postoperative imaging was made to evaluate the presenting symptoms, tumoural variables, peri-operative morbidity, and long-term outcome. RESULTS: This cohort included 105 patients who were operated for PAs over a 9-year period, with a slight male predominance. Adenomas had a mean maximum diameter of almost 25 mm, with one-third of tumours presenting with a Knosp-grade 3 or 4. As expected, most patients presented with either visual (32.4%) or hormonal (40.0%) disturbances. After surgery, 85.3% had complete resolution of visual deficits, and 97.1% had normalisation of hormonal hypersecretion. Postoperative hormonal insufficiency requiring substitution was observed in 43.1% and was significantly more frequent in males and in non-functioning pituitary adenomas (NFAs). Postoperative cerebrospinal fluid (CSF) leakage was observed in 2.9%, and merely one patient developed meningitis. Tumour recurrence was significantly more frequent in patients with partial resection as compared to complete resection (25.6 vs. 7.9%). CONCLUSIONS: This study demonstrates that transnasal transsphenoidal pituitary surgery can be performed safely and effectively in a large non-university hospital, improving visual and/or hormonal disturbances as well as providing long-term tumour control. Patients with larger adenomas are at an increased risk to develop postoperative hypopituitarism.

Vagus nerve stimulation lead removal or replacement: surgical technique, institutional experience, and literature overview.

BACKGROUND: With the growing use of vagus nerve stimulation (VNS) as a treatment for refractory epilepsy, there is a growing demand for complete removal or replacement of the VNS system. We evaluate the safety and efficacy of complete removal or replacement of the VNS system and provide an extensive description of our surgical technique. METHODS: We retrospectively reviewed our patient registry for all VNS surgeries performed between January 2007 (the year of our first complete removal) and May 2014. In order to assess patient satisfaction, a written questionnaire was sent to patients or their caregivers. Additionally, we reviewed all literature on this topic. RESULTS: The VNS system was completely removed in 22 patients and completely replaced in 13 patients. There were no incomplete removals. Revision surgery was complicated by a small laceration of the jugular vein in two patients and by vocal cord paralysis in one patient. Seizure frequency was unaltered or improved after revision surgery. Electrode-related side effects all improved after revision surgery. Twenty-one studies reported a total of 131 patients in whom the VNS system was completely removed. In 95 patients, the system was subsequently replaced. The most frequently reported side effect was vocal cord paresis, which occurred in four patients. CONCLUSIONS: Complete removal or replacement of the VNS system including lead and coils is feasible and safe. Although initial results seem promising, further research and longer follow-up are needed to assess whether lead replacement may affect VNS effectiveness.

Infections of the spinal subdural space in children: a series of 11 contemporary cases and review of all published reports. A multinational collaborative effort.

INTRODUCTION: Positioned anatomically between the spinal epidural space and the intramedullary compartment, the spinal subdural space remains the least common area of localized infection in the central nervous system. Infectious processes of the subdural spinal space include subdural spinal empyema, subdural spinal abscess, infected spinal subdural cyst, and infectious spinal subdural cyst. To date, there has been no systematic review of these entities in children, with the cumulative knowledge of the pathophysiologic, microbiologic, and demographic characteristics of these infections relegated solely to few small series and case reports. METHODS: A series of 11 recent cases culled from the collaboration of international authors are presented. In addition, an exhaustive MEDLINE search and manual review of the international literature was performed, identifying a total of 73 cases of spinal subdural infections in patients under the age of 21. Data of interest include the age, sex, signs, and symptoms at presentation, spinal location of infection, presence of spinal dysraphism, and other comorbidities, offending organism, treatment, outcome, and follow-up. RESULTS: Patients ages ranged from 4 weeks to 20 years (mean, 6.5 years). Males outnumbered females by a ratio of 2:1. Over half (53 %) of spinal subdural infections in children were associated with spinal dysraphism or other congenital abnormalities of the spine. The commonest organism to infect the spinal subdural space in children is mycobacterium tuberculosis and the thoracic spinal region was most commonly infected. CONCLUSIONS: The disease is usually treated surgically, although a more expectant approach consisting of antibiotics and observation has also been proposed.

Vagus nerve stimulation in children with intractable epilepsy: a randomized controlled trial.

AIM: The aim of this study was to evaluate the effects of vagus nerve stimulation (VNS) in children with intractable epilepsy on seizure frequency and severity and in terms of tolerability and safety. METHOD: In this study, the first randomized active controlled trial of its kind in children, 41 children (23 males; 18 females; mean age at implantation 11y 2mo, SD 4y 2mo, range 3y 10mo-17y 8mo) were included. Thirty-five participants had localization-related epilepsy (25 symptomatic; 10 cryptogenic), while six participants had generalized epilepsy (four symptomatic; two idiopathic). During a baseline period of 12 weeks, seizure frequency and severity were recorded using seizure diaries and the adapted Chalfont Seizure Severity Scale (NHS3), after which the participants entered a blinded active controlled phase of 20 weeks. During this phase, half of the participants received high-output VNS (maximally 1.75mA) and the other half received low-output stimulation (0.25mA). Finally, all participants received high-output stimulation for 19 weeks. For both phases, seizure frequency and severity were assessed as during the baseline period. Overall satisfaction and adverse events were assessed by semi-structured interviews. RESULTS: At the end of the randomized controlled blinded phase, seizure frequency reduction of 50% or more occurred in 16% of the high-output stimulation group and in 21% of the low-output stimulation group (p=1.00). There was no significant difference in the decrease in seizure severity between participants in the stimulation groups. Overall, VNS reduced seizure frequency by 50% or more in 26% of participants at the end of the add-on phase The overall seizure severity also improved (p<0.001). INTERPRETATION: VNS is a safe and well-tolerated adjunctive treatment of epilepsy in children. Our results suggest that the effect of VNS on seizure frequency in children is limited. However, the possible reduction in seizure severity and improvement in well-being makes this treatment worth considering in individual children with intractable epilepsy.

T3-T4 Disc Herniations: Clinical Presentation, Imaging, and Transaxillary Approach.

OBJECTIVE: To describe a cohort of T3-T4 thoracic disc herniations (TDHs), their clinical and radiologic characteristics, and unique thoracoscopic transaxillary approach (TAA). METHODS: All patients operated on for a T3-T4 TDH with minimal follow-up of 1 year were selected. RESULTS: Eight TAA procedures (6 males and 2 females) were included (1.4%). Six patients reported axial pain, irradiating in 2, 4 sensory changes, 1 objective and 1 merely subjective motor weakness. Only 1 TDH was calcified, none was giant, 2 were accompanied by myelomalacia, and 2 by a small segmental syrinx. A cardiothoracic surgeon helped with exposure through a curved axillary incision using anterior cervical and more recently double-ring wound retractors. All patients were operated on using a 10-mm 30° rigid (three-dimensional) high-definition scope. There were no major complications and a good outcome with symptomatic relief in 7 of 8 patients. CONCLUSIONS: T3-T4 TDHs are infrequent but may be underdiagnosed because they tend to be small and their signs and symptoms may mimic a cervical problem involving the shoulders and even the arms. There may be a male predominance. The TAA is straightforward, safe, efficacious, and well tolerated despite the supposed vulnerability of the upper thoracic spinal cord. Dissection between large crowded subpleural veins characteristic for the upper thoracic spine and ensuring adequate dura decompression when the steep angle may partially obscure the tip of the instruments does require some extra time. Thorough knowledge of the unique anatomy of the upper thorax is mandatory and the assistance of a cardiothoracic surgeon is highly recommended.

Altered Circulating Immune Cell Distribution in Traumatic Spinal Cord Injury Patients in Relation to Clinical Parameters.

Following a spinal cord injury (SCI), an inflammatory immune reaction is triggered which results in advanced secondary tissue damage. The systemic post-SCI immune response is poorly understood. This study aimed to extensively analyse the circulating immune cell composition in traumatic SCI patients in relation to clinical parameters. High-dimensional flow cytometry was performed on peripheral blood mononuclear cells of 18 traumatic SCI patients and 18 healthy controls to determine immune cell subsets. SCI blood samples were collected at multiple time points in the (sub)acute (0 days to 3 weeks post-SCI, (s)aSCI) and chronic (6 to >18 weeks post-SCI, cSCI) disease phase. Total and CD4+ T cell frequencies were increased in cSCI patients. Both CD4+ T cells and B cells were shifted towards memory phenotypes in (s)aSCI patients and cSCI patients, respectively. Most profound changes were observed in the B cell compartment. Decreased immunoglobulin (Ig)G+ and increased IgM+ B cell frequencies reflected disease severity, as these correlated with American Spinal Injury Association (ASIA) impairment scale (AIS) scores. Post-SCI B cell responses consisted of an increased frequency of CD74+ cells and CD74 expression level within total B cells and B cell subsets. Findings from this study suggest that post-SCI inflammation is driven by memory immune cell subsets. The increased CD74 expression on post-SCI B cells could suggest the involvement of CD74-related pathways in neuroinflammation following SCI. In addition, the clinical and prognostic value of monitoring circulating IgM+ and IgG+ B cell levels in SCI patients should be further evaluated.

Epidemiology of spinal metastases, metastatic epidural spinal cord compression and pathologic vertebral compression fractures in patients with solid tumors: A systematic review.

Introduction: Spinal metastases (SM) are a frequent complication of cancer and may lead to pathologic vertebral compression fractures (pVCF) and/or metastatic epidural spinal cord compression (MESCC). Based on autopsy studies, it is estimated that about one third of all cancer patients will develop SM. These data may not provide a correct estimation of the incidence in clinical practice. Objective: This systematic review (SR) aims to provide a more accurate estimation of the incidence of SM, MESCC and pVCF in a clinical setting. Methods: We performed a SR of papers regarding epidemiology of SM, pVCF, and MESCC in patients with solid tumors conform PRISMA guidelines. A search was conducted in the PubMed and Web of Science database using the terms epidemiology, prevalence, incidence, global burden of disease, cost of disease, spinal metastas*, metastatic epidural spinal cord compression, pathologic fracture, vertebral compression fracture, vertebral metastas* and spinal neoplasms. Papers published between 1975 and august 2021 were included. Quality was evaluated by the STROBE criteria. Results: While 56 studies were included, none of them reports the actual definition used for MESCC and pVCF, inevitably introducing heterogenity. The overall cumulative incidence of SM and MESCC is 15.67% and 2.84% respectively in patients with a solid tumor. We calculated a mean cumulative incidence in patients with SM of 9.56% (95% CI 5.70%-13.42%) for MESCC and 12.63% (95% CI 7.00%-18.25%) for pVCF. Studies show an important delay between onset of symptoms and diagnosis. Conclusions: While the overall cumulative incidence for clinically diagnosed SM in patients with a solid tumor is 15.67%, autopsy studies reveal that SM are present in 30% by the time they die, suggesting underdiagnosing of SM. Approximately 1 out of 10 patients with SM will develop MESCC and another 12.6% will develop a pVCF. Understanding these epidemiologic data, should increase awareness for first symptoms, allowing early diagnosis and subsequent treatment, thus improving overall outcome.

Intramedullary cavernoma presenting with hematomyelia: report of two girls.

INTRODUCTION: Less than 20 children with intramedullary cavernoma (ImC) have been reported in the English literature; however, cases with an unfavorable outcome may be underreported. Whereas these are predominantly boys, we report two girls who presented with hematomyelia (one cervical, one thoracic) and an acute, severe neurological deficit. CASE MATERIAL: A 10-year-old girl complaining about lower thoracic pain for several days suddenly developed lower body dysesthesias and paraparesis. Magnetic resonance (MR) demonstrated hematomyelia (T8-T11), intramedullary edema (T6-L1), and an ImC at T9-T10. Within an hour, she progressed to paraplegia and was therefore operated immediately. She slowly recovered regaining independent ambulation and continence. MR after 2 years shows no recurrence. A 7-year-old girl suddenly developed cervicalgia and paresis of her left arm and leg. MR demonstrated hematomyelia and an ImC at C4-C6. She gradually recovered with minimal residual deficit at 3 months and was subsequently operated uneventfully. Multiple cerebral cavernomas and a familial autosomal cavernous malformation syndrome were diagnosed. The following 1.5 years, she complained of intermittent cervicalgia and left brachial dysesthesias, with MR suggesting active residual cavernoma. Interestingly, her complaints gradually disappeared, and she is currently asymptomatic. MR after 3.5 years shows minimal cord swelling no longer suggesting active residual cavernoma. CONCLUSION: With adequate surgical treatment either in the acute phase in case of dramatic deterioration or after clinical recuperation, prognosis of symptomatic ImC may be surprisingly good. However, subtotally resected lesions and/or syndromal cases may recur, requiring further treatment. Definitive answers await more cases with longer follow-up.

The clinical spectrum of Blake's pouch cyst: report of six illustrative cases.

INTRODUCTION: Although Blake's pouch cyst (BPC) is frequently mentioned in the spectrum of posterior fossa cysts and cystlike malformations since its first description in 1996, its natural history, clinical presentation, specific imaging characteristics, optimal treatment, and outcome are relatively unknown. Consequently, BPC may still be underdiagnosed. We therefore report six cases ranging from a fatal hydrocephalus in a young boy, over an increasing head circumference with or without impaired neurological development in two infants, to a decompensating hydrocephalus at an advanced age. DISCUSSION: We focus on their radiological uniformity, which should help making the correct diagnosis, and widely variable clinical presentation, which includes adult cases as well. Differentiating BPC from other posterior fossa cysts and cystlike malformations and recognizing the accompanying hydrocephalus are essentially noncommunicating, not only have important implications on clinical management but also on genetic counseling, which is unnecessary in case of BPC. In our experience, endoscopic third ventriculostomy is a safe and effective treatment option, avoiding the risks and added morbidity of open surgery, as well as many shunt-related problems.

The lumbosacral angle does not reflect progressive tethered cord syndrome in children with spinal dysraphism.

PURPOSE: Our goal was to validate the hypothesis that the lumbosacral angle (LSA) increases in children with spinal dysraphism who present with progressive symptoms and signs of tethered cord syndrome (TCS), and if so, to determine for which different types and/or levels the LSA would be a valid indicator of progressive TCS. Moreover, we studied the influence of surgical untethering and eventual retethering on the LSA. METHODS: We retrospectively analyzed the data of 33 children with spinal dysraphism and 33 controls with medulloblastoma. We measured the LSA at different moments during follow-up and correlated this with progression in symptomatology. RESULTS: LSA measurements had an acceptable intra- and interobserver variability, however, some children with severe deformity of the caudal part of the spinal column, and for obvious reasons those with caudal regression syndrome were excluded. LSA measurements in children with spinal dysraphism were significantly different from the control group (mean LSA change, 21.0° and 3.1° respectively). However, both groups were not age-matched, and when dividing both groups into comparable age categories, we no longer observed a significant difference. Moreover, we did not observe a significant difference between 26 children with progressive TCS as opposed to seven children with stable TCS (mean LSA change, 20.6° and 22.4° respectively). CONCLUSIONS: We did not observe significant differences in LSA measurements for children with clinically progressive TCS as opposed to clinically stable TCS. Therefore, the LSA does not help the clinician to determine if there is significant spinal cord tethering, nor if surgical untethering is needed.

Transdural Thoracic Disk Herniation with Longitudinal Slitlike Dural Defect Causing Intracranial Hypotension: Report of 2 Cases.

BACKGROUND: Intracranial hypotension (IH) has a widely variable clinical and radiologic presentation. Secondary IH may be caused by degenerative spine disorders and in particular by thoracic disk herniations (TDHs). METHODS: We present 2 patients with a transdural TDH, a secondary IH, and superficial siderosis in 1. RESULTS: Case 1 presented with headache, cognitive decline, staggering gait, bilateral subdural effusions, cerebral sagging, an extradural spinal cerebrospinal fluid (CSF) collection suggesting secondary IH, and a calcified TDH at T9-T10. Case 2 presented with intermittent pain at the craniocervical junction provoked exclusively by specific physical activities, superficial siderosis mainly in the posterior fossa, an extradural spinal CSF collection, and a calcified TDH at T7-T8 yet no intracranial signs of IH. In both cases, using strict thoracoscopic technique, we removed a transdural TDH and reconstructed an underlying longitudinal slitlike dural defect with smooth lining. Follow-up magnetic resonance imaging scans confirmed a dramatically improved situation without residual extradural intraspinal CSF collection or signs of IH. CONCLUSIONS: This paper adds to the evidence that some cases of IH and even superficial siderosis are caused by transdural erosion of a TDH that may be otherwise asymptomatic. The dura may degenerate due to chronic compression, and a longitudinal slitlike dural defect with smooth lining may develop, causing continuous (Case 1) or intermittent (Case 2) intraspinal CSF leakage. To the best of our knowledge, such dural defects closely resembling the ones observed in idiopathic spinal cord herniation have never been demonstrated on intraoperative endoscopic video in IH patients.

Chorioamnionitis induced by intraamniotic lipopolysaccharide resulted in an interval-dependent increase in central nervous system injury in the fetal sheep.

OBJECTIVE: We quantified the impact of chorioamnionitis on both the white and gray matter structures of the preterm ovine central nervous system (CNS). STUDY DESIGN: The CNS was studied at 125 days of gestation, either 2 or 14 days after the intraamniotic administration of 10 mg of lipopolysaccharide (LPS) (Escherichia coli) or saline. Apoptotic cells and cell types were analyzed in the brain, cerebellum, and spinal cord using flow cytometry. RESULTS: Apoptosis and microglial activation increased in all regions with prolonged exposure to LPS-induced chorioamnionitis. Astrocytes were increased in the brain and cerebellum of LPS-exposed fetuses but not in the spinal cord. Mature oligodendrocytes decreased in the cerebral and cerebellar white matter, the cerebral cortex, caudate putamen, and hippocampus 14 days after LPS. Neurons in the cerebral cortex, hippocampus, and substantia nigra were reduced 14 days after LPS. CONCLUSION: Fetal inflammation globally but differentially affected the CNS depending on the maturational stage of the brain region.

Two brothers with a symptomatic thoracic disc herniation at T11-T12: clinical report.

BACKGROUND: In contrast to what is commonly believed, thoracic disc herniations are not rare lesions. Their etiopathogenesis is largely unknown, but may be linked to trauma, Scheuermann's disease or a degenerative back. OBJECTIVE: We report two brothers with a symptomatic thoracic disc herniation at T11-T12 and address the possibility of a genetic factor as well as other factors in the etiopathogenesis of (symptomatic) thoracic disc herniations. CLINICAL FEATURES: Both brothers were in their early thirties and had a physically demanding job, however, only the first one was a smoker and was diagnosed with Scheuermann's disease. CONCLUSION: The etiology of thoracic disc herniations is likely multifactorial. Their occurrence in siblings may reflect some genetic predisposition or may be merely coincidental, given the high prevalence of thoracic disc herniations in asymptomatic individuals. Further research, including genetic studies, is warranted.

Short-term discontinuation of vagal nerve stimulation alters 18F-FDG blood pool activity: an exploratory interventional study in epilepsy patients.

BACKGROUND: Vagus nerve activation impacts inflammation. Therefore, we hypothesized that vagal nerve stimulation (VNS) influenced arterial wall inflammation as measured by 18F-FDG uptake. RESULTS: Ten patients with left-sided VNS for refractory epilepsy were studied during stimulation (VNS-on) and in the hours after stimulation was switched off (VNS-off). In nine patients, 18F-FDG uptake was measured in the right carotid artery, aorta, bone marrow, spleen, and adipose tissue. Target-to-background ratios (TBRs) were calculated to normalize the respective standardized uptake values (SUVs) for venous blood pool activity. Median values are shown with interquartile range and compared using the Wilcoxon signed-rank test. Arterial SUVs tended to be higher during VNS-off than VNS-on [SUVmax all vessels 1.8 (1.5-2.2) vs. 1.7 (1.2-2.0), p = 0.051]. However, a larger difference was found for the venous blood pool at this time point, reaching statistical significance in the vena cava superior [meanSUVmean 1.3 (1.1-1.4) vs. 1.0 (0.8-1.1); p = 0.011], resulting in non-significant lower arterial TBRs during VNS-off than VNS-on. Differences in the remaining tissues were not significant. Insulin levels increased after VNS was switched off [55.0 pmol/L (45.9-96.8) vs. 48.1 pmol/L (36.9-61.8); p = 0.047]. The concurrent increase in glucose levels was not statistically significant [4.8 mmol/L (4.7-5.3) vs. 4.6 mmol/L (4.5-5.2); p = 0.075]. CONCLUSIONS: Short-term discontinuation of VNS did not show a consistent change in arterial wall 18F-FDG-uptake. However, VNS did alter insulin and 18F-FDG blood levels, possibly as a result of sympathetic activation.

Multilayer Dura Reconstruction After Thoracoscopic Microdiscectomy: Technique and Results.

BACKGROUND: Anterior transthoracic approaches, including thoracoscopic microdiscectomy (TMD), are the preferred techniques for central, broad-based, calcified thoracic disc herniations (TDHs). Dural defects due to manipulation or transdural extension may create a potentially life-threatening subarachnoid-pleural fistula. We evaluate a fast, sutureless technique for reconstructing the dura. METHODS: We analyzed 476 anterior transthoracic approaches for TDHs (437 TMDs, 31 mini-thoracotomies, 7 transaxillary approaches, and 1 sternotomy). Dural defects were closed using an onlay dura substitute, fibrin glue, an autologous fat graft, and another layer of fibrin glue topped by an absorbable gelatin sponge. A chest tube was used to provide a water seal, and the use of external lumbar drains (ELDs) was discontinued in recent years. RESULTS: We encountered 35 dural defects (7.35%), including 27 in 279 procedures (9.67%) in the first 10 years and 8 in 197 (4.06%) in the past 6 years. Five defects were large, 23 were relatively small, and 5 had an intact arachnoid layer, likely preventing cerebrospinal fluid (CSF) egress. Two CSF leaks in the early series were overlooked intraoperatively; 1 patient died following widespread cortical venous thrombosis, whereas the other merely had a headache that disappeared within 1 week. Overall, an ELD was inserted in 3 of 5 large defects and in 17 of 23 small defects; however, in the past 6 years, an ELD was inserted in no large defects and in only 1 of 5 small defects. The technique was successful in all but 1 patient, who underwent reoperation using a larger fat graft. CONCLUSIONS: Dural defects encountered during anterior transthoracic approaches to TDHs can be reconstructed endoscopically, while avoiding the use of an ELD in most cases.

Elevated inflammatory cytokine expression in CSF from patients with symptomatic thoracic disc herniation correlates with increased pain scores.

BACKGROUND: The pathophysiology of pain in patients with symptomatic thoracic disc herniation (TDH) remains poorly understood. Mere mechanical compression of the spinal cord and/or the exiting nerve root by a prolapsed disc cannot explain the pathogenesis of pain in all cases. Previous studies report a direct correlation between the levels of proinflammatory cytokines in disc biopsies and the severity of leg pain in patients with lumbar disc herniation. A similar correlation in patients with TDH has not been investigated. PURPOSE: To correlate the cerebrospinal fluid (CSF) expression of cytokines and pain-related amino acids with preoperative pain scores in patients with symptomatic TDH. STUDY DESIGN: A prospective human study of CSF samples and clinical outcome scores. METHODS: Using enzyme-linked immunosorbent assay (ELISA) and high-performance liquid chromatography (HPLC), we determined inflammatory cytokine levels (TNF-α, IL-1ß, and IL-10) and amino acid levels (glutamate, aspartate, gamma-aminobutyric acid, glycine, and arginine) in CSF samples from 10 patients with TDH and 10 control subjects who did not suffer an inflammatory disease nor pain related to spinal cord compression and subsequently correlated these levels with preoperative pain scores. Differences between both groups were evaluated by a Mann-Whitney U test. In order to estimate the correlation between cytokine or amino acid expression and pain scores, data were analyzed using a linear regression analysis. RESULTS: No inflammatory cytokines were found in CSF samples from control subjects, whereas TNF-α, IL-1ß, and IL-10 were detectable by ELISA in all CSF samples from patients with TDH. TNF-α and IL-10 but not IL-1ß levels moderately correlated with preoperative pain scores. Elevated TNF-αlevels positively correlated with high pain scores; elevated IL-10 levels negatively correlated with high pain scores. Amino acids were detectable in all samples from both groups. There were no significant differences between the groups in any of the amino acids measured with HPLC. CONCLUSION: Increased proinflammatory cytokine expression is associated with elevated pain scores in patients with symptomatic TDH. On the other hand, there is no conclusive correlation between the intensity of pain and the local or systemic presence of amino acids associated with pain transmission.

Improved seizure control and regaining cognitive milestones after vagus nerve stimulation revision surgery in Lennox-Gastaut syndrome.

We report a child with Lennox-Gastaut syndrome with an increase in seizure frequency and loss of psychomotor skills due to a disintegrated cervical VNS lead, not detected during standard device monitoring. The lead was completely removed and replaced by a new 303 lead on the same nerve segment. After reinitiating VNS, side effects forced us to switch it off, resulting in immediate seizure recurrence. EEG recording demonstrated a non-convulsive status epilepticus that was halted by reinitiating VNS therapy. Thereafter, he remained seizure free for eight months, and regained psychomotor development.

Fatal cerebral and cerebellar hemorrhagic infarction after thoracoscopic microdiscectomy. Case report.

The authors present a rare case of fatal cerebral and cerebellar hemorrhagic infarction following an uneventful thoracoscopic microdiscectomy. They hypothesize that this complication was associated with cortical venous thrombosis secondary to intracranial hypotension, which was caused by an unnoticed leak of cerebrospinal fluid (CSF) into the thoracic cavity. Cortical venous thrombosis and intrathoracic CSF were confirmed at autopsy. The former disorder is the most severe manifestation of the pathophysiological mechanism occurring to a lesser degree in patients affected by mild intracranial hypotension, and occurs more frequently in these patients. Intracranial hypotension (of an orthostatic nature or not) must be considered in the differential diagnosis of every patient who complains of headaches after thoracoscopic or open transthoracic microdiscectomy.

Anterior Transthoracic Surgery with Motor Evoked Potential Monitoring for High-Risk Thoracic Disc Herniations: Technique and Results.

OBJECTIVE: To present our experience with anterior transthoracic surgery for high-risk thoracic disc herniations (TDHs) using motor evoked potential monitoring (MEPm). METHODS: We estimated surgical risk based on clinical and radiologic characteristics, including anteroposterior (AP) spinal canal occupation (SCO), AP spinal cord compression (SCC), residual AP spinal cord diameter (RSCD), and intramedullary signal changes (ISC). We analyzed Anand, ASIA, and Nurick scores, anesthesiologic, neurophysiological, and surgical reports. We considered >50% MEP signal deterioration significant. RESULTS: Out of 435 anterior transthoracic procedures, 77 concerned high-risk TDH(s): 69 single-level, 8 multilevel, 61 with clinical myelopathy, 6 with merely ISC. Mean SCO and SCC were 55.4% and 54.0% for single-level, 31.8% and 33.9% for multilevel cases. ISC were present in 64% of single-level and 50% of multilevel cases, calcifications in 87% of single-level and 84% of multilevel TDHs. We initially performed 23 mini-transthoracic approaches (mini-TTAs) and 24 thoracoscopic microdiscectomies (TMDs), more recently 29 TMDs (23 giant TDHs) and 1 transaxillary mini-TTA. Overall, 72 patients had reliable MEP signals. Isolated lower extremity MEP signal deteriorations (n = 21) correlated with maximal TDH AP diameter, SCO, SCC, and ISC. ASIA and Nurick scores improved in 45% and 66% respectively. One patient became paraplegic. MEP signal deterioration had 100% sensitivity, 75% specificity, and 19% positive predictive value during and 44% at the end of surgery. CONCLUSIONS: Maximal TDH AP diameter, SCO, SCC, (sub)total calcification, and ISC correlate with lower extremity MEP signal deterioration. In experienced hands, TMD with MEPm support is a safe, efficient procedure for high-risk TDHs.