Super-selective injection of propofol into the intracranial arteries enables Patient's self-evaluation of expected neurological deficit.

INTRODUCTION: It is hard to realize the extent of the expected postoperative neurological deficit for patients themselves. The provision of appropriate information can contribute not only to examining surgical indications but also to filling the gap between patient and expert expectations. We hypothesized that propofol infusion into the intracranial arteries (ssWada) could induce focal neurological symptoms with preserved wakefulness, enabling the patients to evaluate the postsurgical risk subjectively. METHODS: Presurgical evaluation using ssWada was performed in 28 patients with drug-resistant epilepsy. Based on anatomical knowledge, propofol was super-selectively infused into the intracranial arteries including the M1, M2, and M3 segments of the middle cerebral artery (MCA), A2 segment of the anterior cerebral artery, and P2 segment of the posterior cerebral artery to evaluate the neurological and cognitive symptoms. We retrospectively analyzed a total of 107 infusion trials, including their target vessels, and elicited symptoms of motor weakness, sensory disturbance, language, unilateral hemispatial neglect (UHN), and hemianopsia. We evaluated preserved wakefulness which enabled subjective evaluations of the symptoms and comparison of the subjective experience to the objective findings, besides adverse effects during the procedure. RESULTS: Preserved wakefulness was found in 97.2% of all trials. Changes in neurological symptoms were positively evaluated for motor weakness in 51.4%, sensory disturbance in 5.6%, language in 48.6%, UHN in 22.4%, and hemianopsia in 32.7%. Six trials elicited seizures. Multivariate analysis showed significant correlations between symptom and infusion site of language and left side, language and MCA branches, motor weakness and A2 or M2 superior division, and hemianopsia and P2. Transient adverse effect was observed in 8 cases with 12 infusion trials (11.2 %). CONCLUSION: The ssWada could elicit focal neurological symptoms with preserved wakefulness. The methodology enables specific evaluation of risk for cortical resection and subjective evaluation of the expected outcome by the patients.

Waveform Analysis of STA-MCA Bypass graft in Revascularization Surgery for Moyamoya Disease.

BACKGROUND: Postoperative hyperperfusion syndrome (PHS) is a well-known complication following superficial temporal artery (STA)-middle cerebral artery (MCA) bypass for moyamoya disease (MMD). The early detection of postoperative radiological hyperperfusion (PRH), characterized by a transient increase in local cerebral blood flow (CBF), is crucial for the early diagnosis of PHS. This study aimed to investigate the effectiveness of waveform analysis for early PRH detection. METHODS: We reviewed 52 consecutive patients who underwent STA-MCA bypass for MMD. Patients were divided into PRH and non-PRH groups based on the postoperative/preoperative CBF ratio. We collected the intraoperative bypass graft waveform and bypass flow data using a flowmeter. The pulsatile index (PI), an indicator of peripheral vascular resistance (PVR), was calculated from bypass flow data. Next, the newly proposed index of PVR, the ratio of the time from peak to 50% decay and to 100% decay (RT50), was calculated through waveform analysis. The values were then compared between the PRH and non-PRH groups. RESULTS: Twenty-seven of the 52 patients met the inclusion criteria. Fourteen of these 27 patients showed PRH. The RT50, but not the PI, was significantly higher in the PRH group. Linear regression analysis revealed a significant correlation between the RT50 and PI. In the receiver operating characteristic for predicting PRH, the area under the curve of RT50 was 0.750, with a cutoff value of 0.255, a sensitivity of 0.928, and a specificity of 0.500. CONCLUSIONS: The RT50 obtained from waveform analysis is associated with PVR and can be useful for the early detection of PRH in patients with MMD.

Language MEG predicts postoperative verbal memory change in left mesial temporal lobe epilepsy.

OBJECTIVE: To clarify whether preoperative language magnetoencephalography (MEG) predicts postoperative verbal memory (VM) changes in left mesial temporal lobe epilepsy (LMTLE). METHODS: We reviewed 18 right-handed patients with LMTLE who underwent anterior temporal lobectomy or selective amygdala hippocampectomy, 12 with (HS+) and 6 without hippocampal sclerosis (HS-). Patients underwent neuropsychological assessment before and after surgery. MEG was measured with an auditory verbal learning task in patients preoperatively and in 15 right-handed controls. Dynamic statistical parametric mapping (dSPM) was used for source imaging of task-related activity. Language laterality index (LI) was calculated by z-score of dSPM in language-related regions. LI in the region of HS+ and HS- was compared to controls. The correlation between LI and postoperative VM change was assessed in HS+ and HS-. RESULTS: Preoperative LI in supramarginal gyrus showed greater right-shifted lateralization in both HS+ and HS- than in controls. Right-shifted LI in supramarginal gyrus was correlated with postoperative VM increase in HS+ (p = 0.019), but not in HS-. CONCLUSIONS: Right-shifted language lateralization in dSPM of MEG signals may predict favorable VM outcome in HS+ of LMTLE. SIGNIFICANCE: Findings warrant further investigation of the relation between regional language laterality index and postoperative verbal memory changes.

Efficacy of repeat arterial spin labeling for angiogram-negative ruptured micro-arteriovenous malformation: A case report.

Background: Diagnosing ruptured micro-arteriovenous malformation (AVM) could be difficult using digital subtraction angiography (DSA) in the acute stage, and a repeat DSA is recommended in DSA-negative cases. Arterial spin labeling (ASL) is a useful noninvasive tool for detecting AVM, but the efficacy of a repeat ASL for DSA and ASL-negative ruptured micro-AVM in the acute stage is unclear. Here, we report a case of ruptured micro-AVM that was not detected in the acute stage by ASL but in the chronic stage by ASL. Case Description: A 43-year-old man developed right upper-extremity paralysis, and computed tomography (CT) revealed a left frontal lobe hemorrhage. Magnetic resonance imaging, including ASL, CT angiography, and DSA, showed no abnormal findings associated with hemorrhage in the acute stage. The second ASL 93 days after the hemorrhage showed a high signal on the cortical vein of the left frontal lobe and superior sagittal sinus, and subsequent DSA detected a micro-AVM in the left precentral gyrus. Conclusion: Repeat ASL is less invasive and useful for detecting micro-AVMs which showed no findings on ASL and DSA in the acute stage.

Causal involvement of medial inferior frontal gyrus of non-dominant hemisphere in higher order auditory perception: A single case study.

The medial side of the operculum is invisible from the lateral surface of cerebral cortex, and its functions remain largely unexplored using direct evidence. Non-invasive and invasive studies have proved functions on peri-sylvian area including the inferior frontal gyrus (IFG) and superior temporal gyrus within the language-dominant hemisphere for semantic processing during verbal communication. However, within the non-dominant hemisphere, there was less evidence of its functions except for pitch or prosody processing. Here we add direct evidence for the functions of the non-dominant hemisphere, the causal involvement of the medial IFG for subjective auditory perception, which is affected by the context of the condition, regarded as a contribution in higher order auditory perception. The phenomenon was clearly distinguished from absolute and invariant pitch perception which is regarded as lower order auditory perception. Electrical stimulation of the medial surface of pars triangularis of IFG in non-dominant hemisphere via depth electrode in an epilepsy patient rapidly and reproducibly elicited perception of pitch changes of auditory input. Pitches were perceived as either higher or lower than those given without stimulation and there was no selectivity for sound type. The patient perceived sounds as higher when she had greater control over the situation when her eyes were open and there were self-cues, and as lower when her eyes were closed and there were investigator-cues. Time-frequency analysis of electrocorticography signals during auditory naming demonstrated medial IFG activation, characterized by low-gamma band augmentation during her own vocal response. The overall evidence provides a neural substrate for altered perception of other vocal tones according to the condition context.

Efficacy of arterial spin labeling for detection of the ruptured micro-arteriovenous malformation: illustrative cases.

BACKGROUND: Diagnosis of a microarteriovenous malformation (micro-AVM) is difficult, especially in the acute stage of rupture because of the small size of the nidus and the existence of hematoma. We report two cases of ruptured micro-AVMs detected by arterial spin labeling (ASL). OBSERVATIONS: In one case, a 45-year-old male was transported with a complaint of right hemiparesis. Computed tomography (CT) revealed a right parietal lobar hemorrhage. Standard magnetic resonance imaging (MRI) showed no abnormal findings as the cause of the hemorrhage. ASL 23 days after the onset demonstrated high signals on the medial wall of the hematoma. Digital subtraction angiography (DSA) showed a micro-AVM in accordance with the site of high signals on ASL. In another case, a 38-year-old female was transported with a complaint of left hemianopsia. CT on admission revealed a right parietal lobar hemorrhage. Standard MRI showed no abnormal findings as the cause of the hemorrhage. ASL 15 days after the onset demonstrated high signals on the internal wall of the hematoma. DSA showed micro-AVM in accordance with the site of high signaling on ASL. Both cases were successfully treated with open surgery. LESSONS: ASL can manifest micro-AVMs as high signals within the hematoma. ASL is a useful less-invasive screening tool for the detection of ruptured micro-AVMs.

Deep Learning-Based Functional Independence Measure Score Prediction After Stroke in Kaifukuki (Convalescent) Rehabilitation Ward Annexed to Acute Care Hospital.

Introduction Prediction models of functional independent measure (FIM) score after kaifukuki (convalescent) rehabilitation ward (KRW) are needed to decide the treatment strategies and save medical resources. Statistical models were reported, but their accuracies were not satisfactory. We made such prediction models using the deep learning (DL) framework, Prediction One (Sony Network Communications Inc., Tokyo, Japan). Methods Of the 559 consecutive stroke patients, 122 patients were transferred to our KRW. We divided our 122 patients' data randomly into halves of training and validation datasets. Prediction One made three prediction models from the training dataset using (1) variables at the acute care ward admission, (2) those at the KRW admission, and (3) those combined (1) and (2). The models' determination coefficients (R2), correlation coefficients (rs), and residuals were calculated using the validation dataset. Results Of the 122 patients, the median age was 71, length of stay (LOS) in acute care ward 23 (17-30) days, LOS in KRW 53 days, total FIM scores at the admission of KRW 85, those at discharge 108. The mean FIM gain and FIM efficiency were 19 and 0.417. All patients were discharged home. Model (1), (2), and (3)'s R2 were 0.794, 0.970, and 0.972. Their mean residuals between the predicted and actual total FIM scores were -1.56±24.6, -4.49±17.1, and -2.69±15.7. Conclusion Our FIM gain and efficiency were better than national averages of FIM gain 17.1 and FIM efficiency 0.187. We made DL-based total FIM score prediction models, and their accuracies were superior to those of previous statistically calculated ones. The DL-based FIM score prediction models would save medical costs and perform efficient stroke and rehabilitation medicine.

Chronic subdural hematoma in patients over 65 years old: Results of using a postoperative cognitive evaluation to determine whether to permit return to driving.

BACKGROUND: Chronic subdural hematoma (CSDH) is usually associated with good recovery with burr hole irrigation and postoperative drainage under local anesthesia. In Japan, traffic accidents by the elderly drivers over 65 years old are severely increasing, and there is no consensus on whether or not to return to driving after CSDH treatment. We perform a postoperative cognitive assessment. We retrospectively investigated the return-to-driving rate and associated factors. METHODS: Of the 45 patients over 65 y.o. and who had usually driven, 30 patients wished to drive again. We performed tests composed of Mini-Mental State Examination (MMSE), line cancellation and line bisection task, Kohs block design test, trail making test (TMT)-A and B, Kana-hiroi test, Rey-Osterrieth complex figure test, and behavioral assessment of the dysexecutive syndrome, in order. When all tests' scores were better than the cutoff values, we let patients drive again. When some of the scores were worse than the cutoff values, we reevaluated the patients at the outpatient every month. If the patients' scores could not improve at the outpatient, we recommended them to stop driving. RESULTS: Nineteen of 30 patients could return to driving. Worse MMSE, Kohs block design test, TMT-A, TMT-B scores, higher age, dementia, or consciousness disturbance as chief complaints were associated with driving disability. CONCLUSION: CSDH is known as treatable dementia. However, we should perform an objective cognitive assessment before discharge because only 63% of the patients over 65 y.o. who wished to drive could return to driving.

Preliminary development of a prediction model for daily stroke occurrences based on meteorological and calendar information using deep learning framework (Prediction One; Sony Network Communications Inc., Japan).

BACKGROUND: Chronologically meteorological and calendar factors were risks of stroke occurrence. However, the prediction of stroke occurrences is difficult depending on only meteorological and calendar factors. We tried to make prediction models for stroke occurrences using deep learning (DL) software, Prediction One (Sony Network Communications Inc., Tokyo, Japan), with those variables. METHODS: We retrospectively investigated the daily stroke occurrences between 2017 and 2019. We used Prediction One software to make the prediction models for daily stroke occurrences (present or absent) using 221 chronologically meteorological and calendar factors. We made a prediction models from the 3-year dataset and evaluated their accuracies using the internal cross-validation. Areas under the curves (AUCs) of receiver operating characteristic curves were used as accuracies. RESULTS: The 371 cerebral infarction (CI), 184 intracerebral hemorrhage (ICH), and 53 subarachnoid hemorrhage patients were included in the study. The AUCs of the several DL-based prediction models for all stroke occurrences were 0.532-0.757. Those for CI were 0.600-0.782. Those for ICH were 0.714-0.988. CONCLUSION: Our preliminary results suggested a probability of the DL-based prediction models for stroke occurrence only by meteorological and calendar factors. In the future, by synchronizing a variety of medical information among the electronic medical records and personal smartphones as well as integrating the physical activities or meteorological conditions in real time, the prediction of stroke occurrence could be performed with high accuracy, to save medical resources, to have patients care for themselves, and to perform efficient medicine.

Where to make burr hole for endoscopic hematoma removal against intracerebral hemorrhage at the basal ganglia to increase the hematoma removal rate - Comparison between trans-forehead and along-the-long-axis approaches.

BACKGROUND: Endoscopic hematoma removal is performed to treat intracerebral hemorrhage (ICH) at the basal ganglia. In our hospital, young neurosurgical trainees perform it for the only 1st to the 3rd time. We perform a "trans-forehead approach" and hypothesized that our technique would contribute to higher hematoma removal rate and easiness despite their inexperience. We compared our dataset with an open dataset with along-the-long-axis approaches using pre- and intraoperative neuronavigation by well-trained neurosurgeons and tested the utility of our trans-forehead approach. METHODS: We retrospectively investigated our 17 consecutive patients with hypertensive ICH who underwent endoscopic hematoma removal using the trans-forehead approach. We obtained the open dataset and compared our data with the 12 patients from the open dataset using the inverse probability weighting method. Operative time, hematoma removal rate, postoperative hematoma volume, Glasgow Coma Scale (GCS) on day 7, and modified Rankin Scale (mRS) at 6 months were assessed as outcomes. RESULTS: The median age was 68 (interquartile range; 58-78) years. Median postoperative hematoma volume, removal rate, operative time, GCS on day 7, and mRS at 6 months were 9 (2-24) mL, 90 (79-98)%, 53 (41-80) min, 13 (12-13), and 4 (2-5), respectively. The weighted generalized estimating equations revealed that operative time was shorter in the along-the-long-axis group, but other items were not significantly different between the two approaches. CONCLUSION: The hematoma removal rate of endoscopic hematoma removal with the trans-forehead approach by young trainees was not different from that of the along-the-long-axis approach by well-trained neurosurgeons using neuronavigation.

Spontaneous Development of Encapsulated Subdural Hematoma in the Posterior Cranial Fossa after Cardiac Surgery: A Case Report.

We report a case of an encapsulated subdural hematoma in the posterior cranial fossa, showing spontaneous development and rapid increase in size after cardiac surgery. An 86-year-old woman underwent aortic valve replacement for aortic valve stenosis, followed by anticoagulant therapy with heparin. Three days after the cardiac surgery, she complained of headache. Computed tomography revealed development of a subdural hematoma in the posterior cranial fossa. The hematoma rapidly increased in size within 7 days. Eleven days after cardiac surgery, she underwent removal of the subdural hematoma by craniotomy. Intraoperatively, the subdural hematoma was covered by a thick granulomatous capsule, with histopathological findings similar to those of a chronic subdural hematoma. She was discharged 2 weeks after the craniotomy without any neurological deficits. Encapsulated subdural hematoma in the posterior cranial fossa is rare and its etiology is unknown. In this case, postoperative anticoagulant therapy can promote the rapid growth of thick hematoma capsule. It is possible that previously reported cases of "posterior fossa chronic subdural hematoma" contain similar lesions to that in our patient.

Outflow Occlusion with Occipital Artery-Posterior Inferior Cerebellar Artery Bypass for Growing Vertebral Artery Fusiform Aneurysm with Ischemic Onset: A Case Report.

Surgical treatments should be considered for vertebral artery fusiform aneurysms, which become symptomatic due to cerebral ischemia or mass effect. Ischemic complication is one of the major problems after surgical or endovascular trapping, which is associated with unfavorable outcomes. The authors present a case with growing vertebral artery (VA) fusiform aneurysm with ischemic onset successfully treated with outflow occlusion with occipital artery-posterior inferior cerebellar artery (OA-PICA) bypass. A 50-year-old woman presented with left PICA territory infarction. Left vertebral angiography (VAG) showed occlusion of the left VA at the proximal V4 segment. Right VAG revealed that the distal part of the left V4 segment with fusiform aneurysmal dilatation was reconstituted through vertebrobasilar junction, and the left PICA was the outlet of the blood flow from the fusiform aneurysm. Although the patient was treated conservatively, enlargement of the left VA fusiform aneurysm was observed 8 months after the initial presentation. Considering the potential risks for future stroke or bleeding, we performed clip occlusion of the origin of the left PICA, which could achieve outflow occlusion of the fusiform aneurysm with preservation of the perforators arising around the aneurysm. We created OA-PICA anastomosis for revascularization of the distal PICA. The postoperative course was uneventful, and the postoperative right VAG revealed occlusion of the fusiform aneurysm. Outflow occlusion instead of trapping is an effective surgical option for VA fusiform aneurysm to achieve obliterate the aneurysm with preservation of the perforator at the blind end.