Tag: neurological deficit

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Clinical Significance and Utility of Early Postoperative Computed Tomography Scan Head after Brain Surgery

Neurosurgery 98:810–817, 2026

This prospective single-center study assesses the clinical value of routine early (within 6 hours) postoperative CT scans in 339 adults after intracranial surgery, correlating immediate neurological status with CT findings and resulting management changes. Results show 97.3% had only expected postoperative changes, 2.7% had hematoma without mass effect, and none required surgical intervention; only six patients had medical management altered.

The authors conclude that routine early CT provides minimal benefit for extubated, neurologically stable or expected-deficit patients and advocate selective imaging for clinical deterioration or unreliable examinations, highlighting cost, radiation, and logistical considerations particularly relevant to resource-limited settings.

Aim Evaluate whether an early postoperative head CT within 6 hours after intracranial surgery changes patient management and assess its clinical utility.

Design/setting Single-center prospective cohort of 339 intracranial surgery patients; all received CT within 6 hours and were grouped clinically as no deficit, expected deficit, or unexpected deficit.

CT classification Imaging findings were categorized as postoperative changes only, operative site hematoma without mass effect, or hematoma with mass effect (with management options: no change, medical change, or surgery).

Key findings (imaging) 97.3% (330/339) showed postoperative changes only; 2.7% (9/339) had operative site hematoma without mass effect; 0% had hematoma with mass effect.

Key findings (management impact) 98.2% (333/339) had no change in management based on early CT; 1.8% (6/339) had a change in medical management; 0% required surgical intervention.

Neurological status distribution Postoperatively, 90.9% had no fresh deficit, 7.1% had an expected deficit, and 2.1% had an unexpected deficit.

Association signal Patients with unexpected neurological deficits were more likely to have abnormal CT findings (reported OR 6.22, wide CI, P = .193, not statistically significant).

Bottom line Early postoperative CT offers minimal benefit for extubated patients with no or expected deficits; CT should be reserved for clinical deterioration or unreliable neurological examination.

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Integrated insular phenotype (IIP) versus Berger–Sanai and Yasargil classifications: comparative prognostic value in surgery of insular gliomas

Acta Neurochirurgica (2025) 167:324

This study compares the Integrated Insular Phenotype (IIP), a three-level ordinal topographic classification of insular gliomas, with Berger–Sanai and Yasargil systems to evaluate prognostic performance for extent of resection, seizure control, and persistent neurological deficit at 90 days. Using retrospective analysis of 167 surgically treated patients, logistic regression and model metrics (AUC, AIC, LR χ2) assessed associations between classification complexity and outcomes.

Results show increasing IIP complexity strongly predicted lower resectability, poorer seizure control, and higher persistent deficit risk; IIP produced more stable odds ratios, lower AIC, and higher LR χ2 than traditional systems. The authors propose IIP as a practical risk-stratification tool to balance oncological radicality and functional safety, recommending multicenter prospective validation and integration with molecular and intraoperative technologies.

Integrated Insular Phenotype (IIP): An ordinal classification system for insular gliomas that incorporates tumor topographic complexity and multizonal involvement, outperforming traditional Berger–Sanai and Yasargil systems in prognostic accuracy for surgical outcomes.

Prognostic Value: IIP demonstrates superior and more stable associations with key surgical outcomes—extent of resection, seizure control, and persistent neurological deficit at 90 days—compared to Berger–Sanai and Yasargil classifications, as shown by higher informativeness, lower AIC, and more reproducible odds ratios.

Surgical Complexity: Higher IIP complexity (IIP-M) is linked to reduced likelihood of total/subtotal resection, poorer seizure control, and increased risk of persistent neurological deficits, while simpler phenotypes (IIP-L) are associated with more favorable outcomes.

Traditional Classifications: Berger–Sanai and Yasargil systems provide limited prognostic value; Berger–Sanai yields high but unstable odds ratios with wide confidence intervals, while Yasargil offers consistent but less discriminative results.

Clinical Implications: IIP can guide individualized surgical strategies by balancing oncological radicality against functional safety, supporting the principle of maximal safe resection and informing risk stratification.

Seizure Outcomes: Multizonal and widespread IIP phenotypes (IIP-M) are associated with poorer postoperative seizure control, reflecting the challenge of eliminating diffuse epileptogenic networks.

Study Limitations: The findings are based on a single-center retrospective cohort; external validation and integration with molecular, histopathological, and neurocognitive factors are needed for broader applicability.

Future Directions: Prospective multicenter validation, integration with intraoperative technologies, and use of AI/ML for risk stratification and personalized planning are recommended to enhance the utility of IIP in clinical practice

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

J Neurosurg 140:1029–1037, 2024

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.

METHODS 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.

RESULTS 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.

CONCLUSIONS 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.

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Navigated transcranial magnetic stimulation for glioma removal- prognostic value in motor function recovery from postsurgical neurological deficits

J Neurosurg 127:877–891, 2017

The aim of the present study was to evaluate the usefulness of navigated transcranial magnetic stimulation (nTMS) as a prognostic predictor for upper-extremity motor functional recovery from postsurgical neurological deficits.

METHODS Preoperative and postoperative nTMS studies were prospectively applied in 14 patients (mean age 39 ± 12 years) who had intraparenchymal brain neoplasms located within or adjacent to the motor eloquent area in the cerebral hemisphere. Mapping by nTMS was done 3 times, i.e., before surgery, and 1 week and 3 weeks after surgery. To assess the response induced by nTMS, motor evoked potential (nTMS-MEP) was recorded using a surface electromyography electrode attached to the abductor pollicis brevis (APB). The cortical locations that elicited the largest electromyography response by nTMS were defined as hotspots. Hotspots for APB were confirmed as positive responsive sites by direct electrical stimulation (DES) during awake craniotomy. The distances between hotspots and lesions (DHS-L) were measured. Postoperative neurological deficits were assessed by manual muscle test and dynamometer. To validate the prognostic value of nTMS in recovery from upper-extremity paresis, the following were investigated: 1) the correlation between DHS-L and the serial grip strength change, and 2) the correlation between positive nTMS-MEP at 1 week after surgery and the serial grip strength change.

RESULTS From the presurgical nTMS study, MEPs from targeted muscles were identified in 13 cases from affected hemispheres. In one case, MEP was not evoked due to a huge tumor. Among 9 cases from which intraoperative DES mapping for hand motor area was available, hotspots for APB identified by nTMS were concordant with DES-positive sites. Compared with the adjacent group (DHS-L < 10 mm, n = 6), the nonadjacent group (DHS-L ≥ 10 mm, n = 7) showed significantly better recovery of grip strength at 3 months after surgery (p < 0.01). There were correlations between DHS-L and recovery of grip strength at 1 week, 3 weeks, and 3 months after surgery (r = 0.74, 0.68, and 0.65, respectively). Postsurgical nTMS was accomplished in 13 patients. In 9 of 13 cases, nTMS-MEP from APB muscle was positive at 1 week after surgery. Excluding the case in which nTMS-MEP was negative from the presurgical nTMS study, recoveries in grip strength were compared between 2 groups, in which nTMS-MEP at 1 week after surgery was positive (n = 9) or negative (n = 3). Significant differences were observed between the 2 groups at 1 week, 3 weeks, and 3 months after surgery (p < 0.01). Positive nTMS-MEP at 1 week after surgery correlated well with the motor recovery at 1 week, 3 weeks, and 3 months after surgery (r = 0.87, 0.88, and 0.77, respectively).

CONCLUSIONS Navigated TMS is a useful tool for identifying motor eloquent areas. The results of the present study have demonstrated the predictive value of nTMS in upper-extremity motor function recovery from postsurgical neurological deficits. The longer DHS-L and positive nTMS-MEP at 1 week after surgery have prognostic values of better recovery from postsurgical neurological deficits.

 

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Risk factor analysis of the development of new neurological deficits following supplementary motor area resection

Supplementary motor area

J Neurosurg 119:7–14, 2013

Supplementary motor area (SMA) resection often induces postoperative contralateral hemiparesis or speech disturbance. This study was performed to assess the neurological impairments that often follow SMA resection and to assess the risk factors associated with these postoperative deficits.

Methods. The records for patients who had undergone SMA resection for pharmacologically intractable epilepsy between 1994 and 2010 were gleaned from an epilepsy surgery database and retrospectively reviewed in this study.

Results. Forty-three patients with pharmacologically intractable epilepsy underwent SMA resection with intraoperative cortical stimulation and mapping while under awake anesthesia. The mean patient age was 31.7 years (range 15–63 years), and the mean duration and frequency of seizures were 10.4 years (range 0.1–30 years) and 14.6 per month (range 0.1–150 per month), respectively. Pathological examination of the brain revealed cortical dysplasia in 18 patients (41.9%), tumors in 16 patients (37.2%), and other lesions in 9 patients (20.9%). The mean duration of the follow-up period was 84.0 months (range 24–169 months). After SMA resection, 23 patients (53.5%) experienced neurological deficits. Three patients (7.0%) experienced permanent deficits, and 20 (46.5%) experienced symptoms that were transient. All permanent deficits involved contralateral weakness, whereas the transient symptoms patients experienced were varied, including contralateral weaknesses in 15, apraxia in 1, sensory disturbances in 1, and dysphasia in 6. Thirteen patients recovered completely within 1 month. Univariate analysis revealed that resection of the SMA proper, a shorter lifetime seizure history (< 10 years), and resection of the cingulate gyrus in addition to the SMA were associated with the development of neurological deficits (p = 0.078, 0.069, and 0.023, respectively). Cingulate gyrus resection was the only risk factor identified on multivariate analysis (p = 0.027, OR 6.530, 95% CI 1.234–34.562).

Conclusions. Resection of the cingulate gyrus in addition to the SMA was significantly associated with the development of postoperative neurological impairment.

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Predictive Value and Safety of Intraoperative Neurophysiological Monitoring With Motor Evoked Potentials in Glioma Surgery

Neurosurgery 70:1060–1071, 2012 DOI: 10.1227/NEU.0b013e31823f5ade

Resection of gliomas in or adjacent to the motor system is widely performed with intraoperative neuromonitoring (IOM). Despite the fact that data on the safety of IOM are available, the significance and predictive value of the procedure are still under discussion. Moreover, cases of false-negative monitoring affect the surgeon’s confidence in IOM.

OBJECTIVE: To examine cases of false-negative IOM to reveal structural explanations.

METHODS: Between 2007 and 2010, we resected 115 consecutive supratentorial gliomas in or close to eloquent motor areas using direct cortical stimulation for monitoring of motor evoked potentials (MEPs). The monitoring data were reviewed and related to new postoperative motor deficit and postoperative imaging. Clinical outcomes were assessed during follow-up.

RESULTS: Monitoring of MEPs was successful in 112 cases (97.4%). Postoperatively, 30.3% of patients had a new motor deficit, which remained permanent in 12.5%. Progression- free follow-up was 9.7 months (range, 2 weeks-40.6 months). In 65.2% of all cases, MEPs were stable throughout the operation, but 8.9% showed a new temporary motor deficit, whereas 4.5% (5 patients) presented with permanently deteriorated motor function representing false-negative monitoring at first glance. However, these cases were caused by secondary hemorrhage, ischemia, or resection of the supplementary motor area.

CONCLUSION: Continuous MEP monitoring provides reliable monitoring of the motor system, influences the course of operation in some cases, and has to be regarded as the standard for IOM of the motor system. In our series, we found no false-negative MEP results.

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Risk of stereotactic biopsy in eloquent brain regions

J Neurosurg 111:820–824, 2009. DOI: 10.3171/2009.3.JNS081695

Object. Frameless stereotactic biopsy has been shown in multiple studies to be a safe and effective tool for the diagnosis of brain lesions. However, no study has directly evaluated its safety in lesions located in eloquent regions in comparison with noneloquent locations. In this study, the authors determine whether an increased risk of neurological decline is associated with biopsy of lesions in eloquent regions of the brain.
Methods. Medical records, including imaging studies, were reviewed for 284 cases in which frameless stereotactic biopsy procedures were performed by 19 neurosurgeons at 7 institutions between January 2000 and December 2006. Lesion location was classified as eloquent or noneloquent in each patient. The incidence of neurological decline was calculated for each group.
Results. During the study period, 160 of the 284 biopsies predominately involved eloquent regions of the brain. In evaluation of the complication rate with respect to biopsy site, neurological decline occurred in 9 (5.6%) of 160 biopsies in eloquent brain areas and 10 (8.1%) of 124 biopsies in noneloquent regions; this difference was not statistically significant (p = 0.416). A higher number of needle passes was associated with the presence of a postoperative hemorrhage at the biopsy site, although not with a change in the result of neurological examination.
Conclusions. Frameless stereotactic biopsy of lesions located in eloquent brain regions is as safe and effective as biopsy of lesions in noneloquent regions. Therefore, with careful planning, frameless stereotactic biopsy remains a valuable and safe tool for diagnosis of brain lesions, independent of lesion location.

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