Preoperative Motor Deficit Research Articles

Perioperative complications in patients aged ≥85 years undergoing spinal surgery: a retrospective comparative study of pre-old and old patients in Japan.

A retrospective comparative study. To compare the characteristics of perioperative complications in patients aged ≥85 years with those of younger patients undergoing similar spine surgery and examine factors associated with perioperative complications and clinical outcomes among patients aged ≥85 years. The risk factors for perioperative complications and their effect on outcomes in patients aged ≥85 years remain unclear. Furthermore, no study has compared younger patients with similar surgeries and condition with those aged ≥85 years. The study included patients aged ≥65 years who underwent spinal surgeries. The patients aged ≥85, 75-84, and 65-74 years were categorized into the super-old, old, and pre-old groups, respectively. The differences in perioperative age-related complications were compared among the three groups while matching for surgical procedures and general conditions (study 1). Furthermore, preoperative and intraoperative factors were examined for perioperative complications in the super-old group (study 2). Complications were categorized into surgical site and systemic complications. The analysis included 44 patients from each group. In study 1, the total complication rates were 40.9%, 25%, and 18.2% of the super-old, old, and pre-old groups, respectively. Differences in complication rates were observed between the super-old and pre-old groups (p=0.011). In study 2, 58 patients from the super-old group were analyzed. Surgical site complications were significantly associated with longer surgical duration (p=0.02) and more estimated blood loss (p=0.003). Systemic complications were significantly associated with previous cerebrovascular disease (p=0.014), preoperative motor deficit (p=0.023), and emergency case (p=0.006) and negatively associated with diabetes mellitus (p=0.048). Perioperative complications increased with advancing age in the super-old, old, and pre-old groups. The complication type is associated with specific background factors; therefore, determining them may help prevent perioperative complications.

THE IMPACT OF THE FRONTAL ASLANT TRACT ON POST-OPERATIVE OUTCOMES IN GLIOMA SURGERY

Abstract AIMS The frontal aslant tract (FAT) has a role in speech and language functions and visual-motor activities. It is also not clear whether location of FAT relative to gliomas affects post-operative motor and language outcomes. Our hypothesis is FAT protects the cortico-spinal tract and other subcortical white matter tracts involved in speech. METHOD We conducted a retrospective cohort study. We used electronic patient records to search for all patients who had frontal tumours resected between Jan 2018 and August 2022. We included all adult patients (>18 years) with gliomas located in the SMA region and dorsal premotor cortex who had pre-op diffusion tensor imaging and underwent debulking / resection surgery. The patients were divided into 3 groups based on the location of the tumour relative to FAT. In group 1 patients had tumours located anterior to FAT, in group 2 patients had tumours infiltrating FAT and in group 3 patients had tumours located posterior to FAT. Our outcome measure was new post-operative language or motor deficit. RESULTS Our search yielded 197 patients, of these 43 fulfilled the inclusion criteria. Sixteen patients were included in group 1, 9 patients included in group 2 and 18 included in group 3. Pre-operative motor deficit was significantly more common in patients with tumours posterior to FAT (p=0.046). Post-operative motor deficit at hospital discharge was also more common on this group of patients (p=0.048). At 6 months follow up there was no significant difference post-operative motor and language deficits between the groups but there was a trend towards worse motor outcomes in patients with tumour located posterior to FAT. CONCLUSION There is a suggestion motor outcomes are worse in tumours located posterior to FAT. This can be considered when counselling patients for surgery with tumours related to FAT.

Influence of Preoperative Motor Score and Patient Comorbidities on Transcranial Motor-Evoked Potential Acquisition in Intracranial Surgery: A Retrospective Cohort Study.

Intraoperative neurophysiological monitoring plays a pivotal role in modern neurosurgery, aiding in real-time assessment of eloquent neural structures to mitigate iatrogenic neural injury. This study represents the largest retrospective series to date in monitoring corticospinal tract integrity during intracranial surgery with transcranial motor-evoked potentials (TCMEPs), focusing on the influence of demographic factors, comorbidities, and preoperative motor deficits on the reliability of intraoperative neurophysiological monitoring. While the impact of patient-specific factors affecting TCMEP monitoring in spine surgery is well-documented, similar insights for intracranial surgery are lacking. A total of 420 craniotomy patients were retrospectively analyzed from electronic medical records from December 2017 to February 2023, excluding patients without preoperative Medical Research Council scores or medical histories. Using intrinsic hand muscles as a robust data set, 840 hand TCMEPs acquired during intracranial surgery were assessed. Demographic and clinical factors, including preoperative motor scores, were analyzed to identify associations with TCMEP acquisition and amplitude. Nonparametric statistics and multivariate regression analysis were employed. TCMEPs were successfully acquired in 734 (87.7%) patient hands, even in the presence of preoperative motor deficits in 13.9% of total patient hands. Preoperative motor scores did not predict the ability to acquire baseline TCMEPs ( P = .6). Notably, older age ( P < .001) and hypertension ( P = .01) were independent predictors of lower TCMEP acquisition rates. Preoperative motor scores significantly influenced TCMEP amplitudes, with higher scores correlating with higher amplitudes (1771 [SD = 1550] eve vs 882 [SD = 856] μV, P < .0001). Older age ( P < .001) and chronic kidney disease ( P = .04) were also associated with reduced TCMEP amplitudes. Our investigation into TCMEPs during intracranial surgery demonstrated a notably high acquisition rate in hand muscles, irrespective of preoperative motor deficits. Preoperative motor scores reliably correlated with TCMEP amplitudes in a linear fashion while advanced age and renal disease emerged as independent predictors of lower TCMEP amplitudes.

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.

Development and Validation of a Supplementary Grading Scale for Outcomes of Brainstem Cavernous Malformations.

Surgical risk assessment is intriguing for clinical decision-making of brainstem cavernous malformation (BSCM) treatment. While the BSCM grading scale, encompassing size, developmental venous anomaly, crossing axial midpoint, age, and timing of intervention, is increasingly utilized, the clinical relevance of neurological fluctuation and recurrent hemorrhage has not been incorporated. This study aimed to propose a supplementary grading scale with enhanced predictive efficacy. Using a retrospective nationwide registry of consecutive patients with BSCMs undergoing surgery in China from March 2011 to May 2023, a new supplementary BSCM grading scale was developed from a derivative cohort of 260 patients and validated in an independent concurrent cohort of 67 patients. The primary outcome was unfavorable neurological function (modified Rankin Scale score >2) at the latest follow-up. The performance of the supplementary grading system was evaluated for discrimination, calibration, and clinical utility and further compared with its original counterpart. Over a follow-up of at least 6 months after surgery, the unfavorable outcomes were 31% in the overall cohort (101/327 patients). A preoperative motor deficit (odds ratio, 3.13; P=0.001), recurrent hemorrhage (odds ratio, 3.05; P<0.001), timing of intervention (odds ratio, 7.08; P<0.001), and crossing the axial midpoint (odds ratio, 2.57; P=0.006) were associated with the unfavorable outcomes and composed the initial Huashan grading variables. A supplementary BSCM grading system was subsequently developed by incorporating the Huashan grading variables into the original BSCM grading scale. The predictive capability of the supplementary scale was consistently superior to the original counterpart in either the derivative cohort (area under the receiver operating characteristic curve, 0.74 [95% CI, 0.68-0.80] for the supplementary versus 0.68 [95% CI, 0.61-0.74] for the original) or the validation cohort (0.75 [95% CI, 0.62-0.87] versus 0.64 [95% CI, 0.48-0.81]). This study highlights the neurological relevance of BSCM hemorrhage in surgical risk assessment. Via compositing preoperative motor function and recurrent hemorrhages, a supplementary grading scale may improve a dynamic risk assessment for clinical decisions in the management of BSCMs.

Functional outcome after introduction of hemilaminectomy in management of spinal schwannomas and meningiomas

BackgroundSchwannomas and meningiomas are intradural extramedullary spinal tumors which are regularly encountered in the neurosurgical clinic. These tumors cause neurological deficit by compression on the spinal cord and commonly pain when affecting the cauda equina. The traditional treatment with standard laminectomy (SL) can cause instability to the dorsal segments of the spinal column, and the less invasive option of hemilaminectomy (HL) has therefore been developed. We aim in this study to investigate transition from SL to HL in a population-based cohort. MethodsAdult patients (18 years and older) undergoing primary surgery due to spinal meningioma or schwannoma between 2007 and 2022 at the neurosurgical clinic were included. Data related to clinical, surgical and outcome variables were retrospectively collected. ResultsA total of 187 patients were identified: 155 in the SL group, 26 in the HL group and in 6 patients a combination of SL and HL. The mean age of the SL group was 62.7 years (SD14.2) compared to 58.0 (SD15.7) in the HL group (p = 0.16). Preoperative motor deficit was more common in SL group compared to HL group (76.8 % and 61.5 %, respectively, p = 0.14). Thoracal location was most common for both groups (SL 65.8 % and HL 61.5 %). Postoperative change in McCormick grades and early complications were similar between groups. ConclusionOutcome after hemilaminectomy due to intradural extramedullary schwannoma or meningioma is comparable to standard laminectomy with regards to postoperative complications and neurological improvement. Our findings support the transition to hemilaminectomy in selected cases.

Tumor-Specific Alterations in Motor Cortex Excitability and Tractography of the Corticospinal Tract-A Navigated Transcranial Magnetic Stimulation Study.

Non-invasive brain mapping using navigated transcranial magnetic stimulation (nTMS) is a valuable tool prior to resection of malignant brain tumors. With nTMS motor mapping, it is additionally possible to analyze the function of the motor system and to evaluate tumor-induced neuroplasticity. Distinct changes in motor cortex excitability induced by certain malignant brain tumors are a focal point of research. A retrospective single-center study was conducted involving patients with malignant brain tumors. Clinical data, resting motor threshold (rMT), and nTMS-based tractography were evaluated. The interhemispheric rMT-ratio (rMTTumor/rMTControl) was calculated for each extremity and considered pathological if it was >110% or <90%. Distances between the corticospinal tract and the tumor (lesion-to-tract-distance - LTD) were measured. 49 patients were evaluated. 16 patients (32.7%) had a preoperative motor deficit. The cohort comprised 22 glioblastomas (44.9%), 5 gliomas of Classification of Tumors of the Central Nervous System (CNS WHO) grade 3 (10.2%), 6 gliomas of CNS WHO grade 2 (12.2%) and 16 cerebral metastases (32.7%). 26 (53.1%) had a pathological rMT-ratio for the upper extremity and 35 (71.4%) for the lower extremity. All patients with tumor-induced motor deficits had pathological interhemispheric rMT-ratios, and presence of tumor-induced motor deficits was associated with infiltration of the tumor to the nTMS-positive cortex (p = 0.04) and shorter LTDs (all p < 0.021). Pathological interhemispheric rMT-ratio for the upper extremity was associated with cerebral metastases, but not with gliomas (p = 0.002). Our study underlines the diagnostic potential of nTMS motor mapping to go beyond surgical risk stratification. Pathological alterations in motor cortex excitability can be measured with nTMS mapping. Pathological cortical excitability was more frequent in cerebral metastases than in gliomas.

Identifying functional cortical plasticity after spinal tumour resection using navigated transcranial magnetic stimulation.

Our aim was to investigate the effectiveness of navigated transcranial magnetic stimulation (nTMS) brain mapping to characterise preoperative motor impairment caused by an intradural extramedullary (IDEM) tumour and postoperative cortical functional reorganisation. Preoperative and 1-year follow-up clinical, radiological and nTMS data from a case of thoracic spinal meningioma that underwent surgical resection of the lesion were collected and compared. A 67-year-old patient presented with severe progressive thoracic myelopathy (hypertonic paraparesis, clonus, insensate urinary retention) secondary to an IDEM tumour. Initial nTMS assessment showed bilateral upper limb representation with no positive responses for both lower limbs. He underwent successful surgical resection for his IDEM (meningioma WHO grade 1). At 1-year follow-up, the patient's gait was improved and his bladder function normalised. nTMS documented positive responses for both upper and lower limbs and a decrease in the area (right side: 1.01 vs 0.39cm2; left side: 1.92 vs 0.81cm2) and volume (right side: 344.2 vs 42.4uVcm2; left side: 467.1 vs 119uVcm2) of cortical activation for both upper limbs, suggesting a functional reorganisation of the motor areas after tumour resection. nTMS motor mapping and derived metrics can characterise preoperative motor deficit and cortical plasticity during follow-up after IDEM resection.

Which patients do we need to consider augmentation of muscle active potentials regarding transcranial electrical stimulation motor-evoked potentials monitoring before spine surgery?

BACKGROUND CONTEXTTranscranial electrical stimulation motor-evoked potentials (Tc-MEPs) are the current trend and are important in preventing intraoperative neurological deficits. Posttetanic Tc-MEPs (p-MEP) can augment the amplitudes of compound muscle active potentials (CMAPs), especially in the case of insufficient conventional Tc-MEPs (c-MEP). PURPOSETo retrospectively investigate pre- and intraoperative factors necessitating p-MEP monitoring and to examine changes in the success rates of baseline Tc-MEP monitoring before and after tetanic stimulation in patients with such factors. STUDY DESIGNRetrospective observational study. PATIENT SAMPLEPatients (n=184) who underwent spinal surgery with Tc-MEP monitoring in our department between August 2020 and July 2022. OUTCOME MEASURESManual muscle testing (MMT) scores were calculated to identify patients with preoperative motor deficits. c-MEP and p-MEP amplitudes were recorded from the defined muscles. METHODSWe compared preoperative and intraoperative factors between the c-MEP and p-MEP groups (study 1). In cases where the factors were identified, we investigated the success rate of the baseline MEP measurement of each muscle before and after tetanic stimulation (study 2). RESULTSOne hundred fifty-seven patients were included. Of those, 87 showed sufficient CMAPs with c-MEP. Meanwhile, 70 needed p-MEP because of insufficient CMAPs. In univariate analysis, cervical/thoracic surgery (p<.001), preoperative MMT 3 or below (p=.009), shorter duration of illness (p=.037), previous cerebrovascular disease (p=.014), and dialysis (p=.031) were significantly associated with p-MEP group. Preoperative MMT 3 or below was the only factor requiring p-MEP (odds ratio, 3.34; 95% confidence interval, 1.28-8.73, p=.014) in multivariate analysis. In the p-MEP group, 24 patients had preoperative motor deficits; 16 patients with complete data were included in the analysis (study 2). The success rates of MEP monitoring before and after tetanic stimulation of the entire lower-extremity muscles were 42.7 and 57.3%, respectively (p<.001). The success rates for each muscle before and after tetanic stimulation were abductor pollicis brevis: 81.3% and 96.9%, tibialis anterior: 34.4% and 50.0%, gastrocnemius: 25% and 40.6%, and abductor hallucis: 68.8% and 81.3%, respectively. No significant differences were observed in success rates for any of the muscles. CONCLUSIONSPatients with preoperative MMT 3 or below highly needed p-MEP. The success rate of baseline MEP monitoring increased with tetanic stimulation, even in patients with preoperative motor deficits. We believe that p-MEP monitoring can result in reliable CMAP recording, especially in cases of preoperative motor deficits with MMT scores of 3 or below.

Asleep triple-modality motor mapping for perirolandic gliomas: an update on outcomes.

Maximal safe resection of gliomas near motor pathways is facilitated by intraoperative mapping. Here, the authors review their results with triple-modality asleep motor mapping with motor evoked potentials and bipolar and monopolar stimulation for cortical and subcortical mapping during glioma surgery in an expanded cohort. This was a retrospective analysis of patients who underwent resection of a perirolandic glioma near motor pathways. Clinical and neuromonitoring data were extracted from the electronic medical records for review. All patients with new or worsened postoperative motor deficits were followed for at least 6 months. Regression analyses were performed to assess factors associated with a persistent motor deficit. Between January 2018 and December 2021, 160 operations were performed in 151 patients with perirolandic glioma. Sixty-four patients (40%) had preoperative motor deficits, and the median extent of resection was 98%. Overall, patients in 38 cases (23.8%) had new or worse immediate postoperative deficits by discharge, and persistent deficits by 6 months were seen in 6 cases (3.8%), all in patients with high-grade gliomas. There were no new persistent deficits in low-grade glioma patients (0%). The risk factors for a persistent deficit included an insular tumor component (OR 8.6, p = 0.01), preoperative motor weakness (OR 8.1, p = 0.03), intraoperative motor evoked potential (MEP) changes (OR 36.5, p < 0.0001), and peri-resection cavity ischemia (OR 7.5, p = 0.04). Most persistent deficits were attributable to ischemic injury despite structural preservation of the descending motor tracts. For patients with persistent motor deficits, there were 3 cases (50%) in which a change in MEP was noted but subsequent subcortical monopolar stimulation still elicited a response in the corresponding muscle groups, suggesting axonal activation distal to a point of injury. Asleep triple motor mapping results in a low rate of permanent deficits, especially for low-grade gliomas. Peri-resection cavity ischemia continues to be a significant risk factor for permanent deficit despite maintaining appropriate distance for subcortical tracts based on monopolar feedback.

Evaluation of risk factors for postoperative neurologic intensive care admission after brain tumor craniotomy: A single-center longitudinal study.

Perioperative variable parameters can be significant risk factors for postoperative intensive care unit (ICU) admission after elective craniotomy for intracranial neoplasm, as assessed by various scoring systems such as Cranio Score. This observational study evaluates the relationship between these factors and early postoperative neurological complications necessitating ICU admission. In total, 119 patients, aged 18 years and above, of either sex, American Society of Anesthesiologists (ASA) grades I-III, scheduled for elective craniotomy and tumor excision were included. The primary objective was to evaluate the relationship between perioperative risk factors and the incidence of early postoperative complications as a means of validation of the Cranio Score. The secondary outcomes studied were 30-day postoperative morbidity/mortality and the association with patient-related risk factors. Forty-five of 119 patients (37.82%) required postoperative ICU care with the mean duration of ICU stay being 1.92 ± 4.91 days. Tumor location (frontal/infratemporal region), preoperative deglutition disorder, Glasgow Coma Scale (GCS) less than 15, motor deficit, cerebellar deficit, midline shift >3 mm, mass effect, tumor size, use of blood products, lateral position, inotropic support, elevated systolic/mean arterial pressures, and duration of anesthesia/surgery were associated with a higher incidence of ICU care. Maximum (P = 0.035, AOR = 1.130) and minimum systolic arterial pressures (P = 0.022, Adjusted Odds Ratio (AOR) = 0.861) were the only independent risk factors. Cranio Score was found to be an accurate predictor of complications at a cut-off point of >10.52%. The preoperative motor deficit was the only independent risk factor associated with 30-day morbidity (AOR = 4.66). Perioperative hemodynamic effects are an independent predictor of postoperative ICU requirement. Further Cranio Score is shown to be a good scoring system for postoperative complications.

Preoperative motor deficits and depressive symptoms predict quality of life in patients with Parkinson’s disease at different time points after surgery for subthalamic stimulation: a retrospective study

BackgroundWhile subthalamic nucleus deep brain stimulation (STN-DBS) improves the quality of life (QoL) of patients with Parkinson’s disease (PD), the clinical parameters that predict this improvement remain debated. This retrospective study explored whether preoperative motor, cognitive, and affective parameters predict QoL or its components at 6 and 12 months after STN-DBS surgery.MethodsQoL was assessed with the Parkinson’s Disease Questionnaire-39 (PDQ-39) before (baseline), at 6 months (N = 90) and 12 months (N = 63) after STN-DBS surgery. Changes in the PDQ-39 and its subdomains were analysed with Wilcoxon signed-rank tests. In total, seven motor, cognitive, and affective parameters recorded at baseline were used in multiple linear regressions to predict QoL and its subdomains.ResultsQoL had improved significantly at six months post STN-DBS surgery. After 12 months, this effect remained significant but was less pronounced. At both time points, significant improvements in mobility, activities of daily living, stigma, and bodily discomfort were present. Correlation and linear regression analyses showed that preoperative QoL status and changes in QoL at 6 and 12 months after surgery were driven by preoperative dopaminergic medication, as well as motor (UPDRS-III medOFF and PIGD-subscore medOFF) and affective (HADS anxiety and depression) symptoms. In contrast, preoperative cognitive performance did not predict QoL at any time point.ConclusionData show that preoperative motor and affective symptoms drive both QoL baseline status and changes in QoL after STN-DBS surgery. Thus, these clinical parameters need to be assessed appropriately to provide comprehensive presurgical advice to patients suffering from PD.

Outcomes of Operated Cases of Central Nervous System Metastases at a Tertiary Cancer Hospital – An Analysis

Abstract Background: Recent advances in the treatment have increased the survival of patients with common cancers. As a result, the incidence of symptomatic central nervous system (CNS) metastases has increased over time. Although systemic therapies remain the mainstay of metastatic cancers, surgical treatment is often required for progressive neurological deficits and to buy time for other modalities to be effective. The present retrospective study aimed to analyze various demographic, neurological, and short-term survival outcomes among operated cases of symptomatic CNS metastases. Materials and Methods: All surgically treated symptomatic brain and spine metastasis patients between August 2018 and March 2022 were included in the study. Patients who underwent procedures for primary tumors of the brain and spine were excluded. The details of demographic and clinical profile, neurological data, surgical treatment, and short-term survival data were retrieved from hospital medical records and analyzed. Patients with motor deficits (power grade 3/5 or less) were analyzed to look for improvement in motor deficits after surgery. Results: The first 100 operated cases of symptomatic CNS metastases were reviewed. The mean age of presentation was 46.42 years (females – 44.28, males – 49.13). Breast malignancy was the most common source of primary overall (29%) and lung malignancy (15%) was second most common. A total of 53 brain surgeries and 47 spine surgeries were performed. Preoperative motor deficits were seen more commonly among spine metastases (30/47) than brain metastases (17/53) patients. Around 64% of patients who presented with neurological deficits (motor deficits) had improvement postsurgery. Such improvement from deficits was observed more in patients with spine metastases (23/30; 76.7%) than brain metastases (7/17; 41.2%). Conclusion: Neurosurgery has an important role in the management of CNS metastases, and timely surgical intervention in a selected group of symptomatic CNS metastases can improve the quality of life of the patients.

Clinical utility of intraoperative direct wave monitoring in patients with pre-operative motor deficits: Case series

Introduction and importanceD-wave (Direct waves) are Motor Evoked Potentials (MEPs) generated by a single transcranial stimulation and captured by attaching an epidural recording electrode caudal to the vulnerable area. Intraoperative neurophysiologic monitoring (IONM) is widely used in neurosurgery to recognize important neurological structures but can be challenging in the pediatric population due to incomplete neural development. Case presentationCase 1: A 48-year-old female presented to the outpatient department with complaints of difficulty walking for the past six months, numbness and weakness in bilateral lower limbs with recurrent falls for the past 1 month. Case 2: A 12-year-old boy presented to the emergency room with a history of inability to use both upper and lower limbs on the right side with tremulousness. Clinical discussionMagnetic resonance imaging (MRI) Spine in the first case revealed a D9-D10 calcified meningioma with significant spinal cord compression. In the second case, MRI Spine showed C1-C2 Intramedullary Space Occupying Lesion (SOL) and was planned for C1-C2 laminectomy with midline myelotomy. The first case was planned for microsurgical excision of the lesion under IONM guidance. The procedure went smoothly. Microsurgical gross total resection (GTR) of the intramedullary SOL under IONM Guidance was done for the second case. Postoperatively, the first patient showed no neurological compromise or complications. In the second case, following surgery, the child recovered gradually from surgery. ConclusionThis case series demonstrates the successful surgical management of two cases of spinal cord tumors through an IONM-guided surgery and the effective use of D waves in such challenging cases.

A novel radiological classification of midbrain pilocytic astrocytomas and its implication for surgical management: a single-institution experience of 57 cases.

Surgery for midbrain pilocytic astrocytoma (PA) remains a formidable challenge. To facilitate decision-making and achieve a better outcome in the management of patients with midbrain PA, the authors have proposed a novel radiological classification of midbrain PAs with long-term follow-up. Fifty-seven midbrain PA patients who underwent surgery at Beijing Tiantan Hospital, Capital Medical University, from January 2008 to June 2021, were reviewed. Based on tumor location and the topological anatomical change identified on MRI, midbrain PAs were categorized into four types: crural (12/57, 21.1%), tegmental (25/57, 43.9%), aqueductal (5/57, 8.8%), and tectal (15/57, 26.3%) PAs. The relevant clinical, radiological, and pathological data; surgical procedures and results; and long-term outcomes were collected and analyzed. The 1-, 3-, and 5-year survival rates reached 98%, 96%, and 96%, respectively, with gross-total resection achieved in 66.7% of cases, followed by near-total resection in 17.5% cases. The clinical and radiological features, selection of surgical approaches, and long-term postoperative deficits were distinct among each type. Crural PAs were associated with younger age (median 9 years, IQR 5.0-12.8 years); the largest tumor volume (median 31.9 cm3, IQR 17.2-42.6 cm3); the lowest preoperative Karnofsky Performance Scale (KPS) score (median 65, IQR 50-70); the most frequent preoperative motor deficit (91.7%); a mixed solid-cystic component (75%); occupation of the crural cistern; elevation and rotation of the thalamus (medial and/or lateral); displacement of the anterior third ventricle, uncus, and anterior commissure; the most diverse surgical approaches; more frequent use of multimodality image-guided surgery (58.3%); and the most remarkable improvement in KPS score at long-term follow-up. Tegmental PAs were associated with adolescents and young adults (median age 21 years, IQR 8-33 years); tumor volume (median 13.9 cm3, IQR 9.5-20.5 cm3); a good preoperative KPS score (median 80, IQR 70-80); a mixed solid-cystic component (72%); occupation of the ambient cistern and cerebellomesencephalic fissure; a close relationship with the dorsal pons, superior cerebellar peduncle, and posterior inferior third ventricle; and a higher probability of permanent postoperative sensory deficits (40%). Aqueductal and tectal PAs were associated with small tumor volume (median 9.14 cm3, IQR 5.1-17.4 cm3 and median 11.84 cm3, IQR 5.7-18.3 cm3, respectively), a higher percentage of hydrocephalus (80% and 86.7%, respectively), and a straightforward selection of limited surgical approaches. A novel and comprehensive radiological classification of midbrain PAs was established, which will serve as a valuable tool in patient management and promote uniform communication and comparison across different studies and publications.

Variability of somatosensory evoked potential and motor evoked potential change criteria in thoracic spinal decompression surgery based on preoperative motor status

Background contextCombined somatosensory- and motor-evoked potential (SSEP and MEP) changes for predicting prognosis in thoracic spinal surgery have been variably reported. PurposeWe aimed to explore the validity of combined SSEP and MEP for predicting postoperative motor deficits (PMDs) in thoracic spinal decompression surgery (TSDS) and identify a relatively optimal neurophysiological predictor of PMDs in patients based on preoperative motor status. Study settingRetrospective study. Patient sampleA total of 475 patients were analyzed. Outcome MeasuresA reduction in muscle strength by more than or equal to one manual muscle testing (MMT) grade postoperatively compared with the preoperative MMT grade was identified as PMDs. Postoperative motor deficits were detected by comparing the preoperative and postoperative physical examination findings in short- and long-term follow-up visits. MethodsAll patients were divided into two subgroups according to preoperative motor status. The following data were collected: (1) demographic data; (2) IONM (intraoperative neuromonitoring) data; and (3) postoperative motor outcomes. Binary logistic regression analysis was performed to assess the efficacy of IONM change to predict PMDs. A receiver operating characteristic curve (ROC) was used to establish optimal IONM warning criteria. ResultsNinety-eight patients had severe preoperative motor deficits (Group S), and 377 patients did not (Group N). MEP and SSEP change was effective for predicting PMDs in the short term (p<.01) and long term (p<.01) for TSDS patients. In Group N, the cutoff values for predicting PMDs in the short term were a decrease of 65% in SSEP amplitude and 89.5% in MEP amplitude of the baseline value. Furthermore, the cutoff values for predicting PMDs in the short term were durations of change of 24.5 minutes for SSEP and 32.5 minutes for MEP. In Group S, however, the cutoff values for predicting PMDs in the short term were a decrease of 36.5% in SSEP amplitude and 59.5% in MEP amplitude of the baseline value. Moreover, the critical values for predicting short-term PMDs were durations of change of 16.5 minutes for SSEP and 17.5 minutes for MEP. ConclusionsThe optimal IONM changes for prediction vary depending on preoperative motor status. Combined SSEP and MEP are excellent for predicting PMDs in TSDS.

Impact of Preoperative Motor Status for the Positive Predictive Value of Transcranial Motor-Evoked Potentials Alerts in Thoracic Spine Surgery: A Prospective Multicenter Study by the Monitoring Committee of the Japanese Society for Spine Surgery and Related Research.

Prospective multicenter study. To investigate the validity of transcranial motor-evoked potentials (Tc-MEP) in thoracic spine surgery and evaluate the impact of specific factors associated with positive predictive value (PPV). One thousand hundred and fifty-six cases of thoracic spine surgeries were examined by comparing patient backgrounds, disease type, preoperative motor status, and Tc-MEP alert timing. Tc-MEP alerts were defined as an amplitude decrease of more than 70% from the baseline waveform. Factors were compared according to preoperative motor status and the result of Tc-MEP alerts. Factors that showed significant differences were identified by univariate and multivariate analysis. Overall sensitivity was 91.9% and specificity was 88.4%. The PPV was significantly higher in the preoperative motor deficits group than in the preoperative no-motor deficits group for both high-risk (60.3% vs 38.3%) and non-high-risk surgery groups (35.1% vs 12.8%). In multivariate logistic analysis, the significant factors associated with true positive were surgical maneuvers related to ossification of the posterior longitudinal ligament (odds ratio = 11.88; 95% CI: 3.17-44.55), resection of intradural intramedullary spinal cord tumor (odds ratio = 8.83; 95% CI: 2.89-27), preoperative motor deficit (odds ratio = 3.46; 95% CI: 1.64-7.3) and resection of intradural extramedullary spinal cord tumor (odds ratio = 3.0; 95% CI: 1.16-7.8). The significant factor associated with false positive was non-attributable alerts (odds ratio = .28; 95% CI: .09-.85). Surgeons are strongly encouraged to use Tc-MEP in patients with preoperative motor deficits, regardless of whether they are undergoing high-risk spine surgery or not. Knowledge of PPV characteristics will greatly assist in effective Tc-MEP enforcement and minimize neurological complications with appropriate interventions.

Cortical-Subcortical Functional Preservation and Rehabilitation in Neuro-Oncology: Tractography-MIPS-IONM-TMS Proof-of-Concept Study.

Surgical management of deep-seated brain tumors requires precise functional navigation and minimally invasive surgery. Preoperative mapping using navigated transcranial magnetic stimulation (nTMS), intraoperative neurophysiological monitoring (IONM), and minimally invasive parafascicular surgery (MIPS) act together in a functional-sparing approach. nTMS also provides a rehabilitation tool to maximize functional recovery. This is a single-center retrospective proof-of-concept cohort study between January 2022 and June 2023 of patients admitted for surgery with motor eloquent deep-seated brain tumors. The study enrolled seven adult patients, five females and two males, with a mean age of 56.28 years old. The lesions were located in the cingulate gyrus (three patients), the central core (two patients), and the basal ganglia (two patients). All patients had preoperative motor deficits. The most common histological diagnosis was metastasis (five patients). The MIPS approach to the mid-cingulate lesions involved a trajectory through the fronto-aslant tract (FAT) and the fronto-striatal tract (FST). No positive nTMS motor responses were resected as part of the outer corridor for MIPS. Direct cortical stimulation produced stable motor-evoked potentials during the surgeries with no warning signs. Gross total resection (GTR) was achieved in three patients and near-total resection (NTR) in four patients. Post-operatively, all patients had a deterioration of motor function with no ischemia in the postoperative imaging (cavity-to-CST distance 0-4 mm). After nTMS with low-frequency stimulation in the contralateral motor cortex, six patients recovered to their preoperative functional status and one patient improved to a better functional condition. A combined Tractography-MIPS-IONM-TMS approach provides a successful functional-sparing approach to deep-seated motor eloquent tumors and a rehabilitation framework for functional recovery after surgery.

The role of functional magnetic resonance imaging in evaluating the hand motor area in patients with perirolandic lesion

ObjectiveThis study aims to investigate the role of functional magnetic resonance imaging (fMRI) in localization of the hand motor area compared to conventional magnetic resonance imaging (cMRI) in patients with perirolandic lesions and to analyze the correlation of lesion to activation distance (LAD) with presurgical motor deficit. MethodsA single-center, retrospective case series of 37 patients with perirolandic lesions who underwent both cMRI and fMRI prior to neurosurgical intervention was performed. The anatomical landmarks associated with the hand motor area in both hemispheres were interpreted using cMRI. The distance between the hand motor areas localized on fMRI and cMRI was measured. LAD on fMRI was determined and based on that, the patients were categorized into three groups: LAD less than 1 cm, 1–2 cm, and greater than 2 cm. The percentages of preoperative motor deficit among these patient groups were subsequently compared. ResultsThe rates of detecting anatomical landmarks related to the hand motor area on lesion-affected hemispheres were significantly lower than those on unaffected hemispheres. The average distance between the hand motor areas as determined by fMRI and cMRI was 11.81 ± 5.83 mm, and in 22.58% of cases, this distance exceeded 20 mm. The frequency of preoperative motor deficit increased from 7.69% in patients with LAD exceeding 2 cm to 53.33% in patients with LAD between 1 and 2 cm, and further to 77.78% in patients with LAD of less than 1 cm. This study revealed a significant correlation between LAD and the degree of motor deficit before surgery (p = 0.002). ConclusionfMRI was found to be significantly better than cMRI at localizing the hand motor area in patients with perirolandic lesions and might be considered as a valuable tool for neurosurgical planning.

Tumors of the brachial plexus region: A 15-year experience with emphasis on motor and pain outcomes and literature review.

Brachial plexus region tumors are rare. In this study, we reviewed our experience with resection of tumors involving or adjacent to the brachial plexus to identify patterns in presentation and outcome. We report a retrospective case series of brachial plexus tumors operated on by a single surgeon at a single institution over 15 years. Outcome data were recorded from the most recent follow-up office visit. Findings were compared to a prior internal series and comparable series in the literature. From 2001 to 2016, 103 consecutive brachial plexus tumors in 98 patients met inclusion criteria. Ninety percent of patients presented with a palpable mass, and 81% had deficits in sensation, motor function, or both. Mean follow-up time was 10 months. Serious complications were infrequent. For patients with a preoperative motor deficit, the rate of postoperative motor decline was 10%. For patients without a preoperative motor deficit, the rate of postoperative motor decline was 35%, which decreased to 27% at 6 months. There were no differences in motor outcome based on extent of resection, tumor pathology, or age. We present one of the largest recent series of tumors of the brachial plexus region. Although the rate of worsened postoperative motor function was higher in those without preoperative weakness, the motor deficit improves over time and is no worse than antigravity strength in the majority of cases. Our findings help guide patient counseling in regard to postoperative motor function.