Timing of chronic subdural hematoma treatment affects middle meningeal artery embolization outcome.

Background: Chronic subdural hematoma (CSDH) is a condition that tends to recur frequently. Although middle meningeal artery embolization (MMAE) is an effective CSDH treatment, there is currently no consensus regarding the optimal timing for embolization. Methods: In this single-center and retrospective study, we reviewed 72 cases with 1st-time recurrent CSDH from January 2018 to July 2023 and identified those treated with MMAE to examine its effect and the impact of differences in the timing of treatment. Results: Of the 72 cases with CSDH recurrence for the 1st time (mean age: 80.4 ± 9.7 years; men: 62 [86.1%]; mean first recurrence interval: 33 ± 24 days), 27 (37.5%) experienced a second recurrence. The mean first recurrence interval was shorter in cases with a second recurrence compared to cured cases: 24.3 ± 18.6 versus 38.3 ± 25.6 days, respectively (P = 0.005). MMAE was performed in 17 (23.6%) cases (mean age: 82 ± 6.2 years; men: 14 [82.4%]). The mean time from initial surgical treatment to embolization was 52.4 ± 35.4 days, and the mean recurrence interval before MMAE was 24.9 ± 19.6 days. Six cases (35.3%) experienced post-embolization recurrence and required surgical treatment. The mean recurrence interval before MMAE was shorter in cases with recurrence after MMAE (15 ± 6.4 vs. 30 ± 22.1 days, P = 0.023). The time from initial surgical treatment to embolization was significantly shorter: 31.3 ± 12.8 versus 63.9 ± 38.9 days (P = 0.039). Conclusion: Cases with a short first recurrence interval were more likely to experience a second recurrence. Repeated recurrences within a short time increased the likelihood of post-embolization recurrence. MMAE performed early following the initial surgical treatment increased the recurrence risk.

Evaluation of brain tumors using dynamic 11C-methionine-PET.

The aim of this study is to assess whether dynamic imaging of (11)C-methionine (MET) uptake on positron emission tomography (PET) is useful for the differential diagnosis of brain tumor histology. Regional MET uptake in static brain PET scans from three consecutive phases (5-15, 15-25, and 25-35 min) after intravenous injection were measured in 144 patients with brain tumors. Regions of interest (ROI) were placed in the pituitary gland, confluence, choroid plexus, coronal radiation, brainstem, frontal cortex, parietal cortex, cerebellum, and brain tumors. The standard uptake value (SUV) of the ROIs in the normal brain structures and brain tumors were measured, and the mean MET SUV region/normal frontal lobe cortex uptake ratio (R/N ratio) of the normal brain structures and the maximum MET SUV tumor/normal frontal cortex uptake ratio (T/N ratio) were evaluated semi-quantitatively. There were significant dynamic declines of the mean MET R/N ratio in the normal pituitary gland and confluence; however, there were significant dynamic increases in white matter. Significant dynamic decrease of the maximum MET T/N ratio was seen in meningiomas and oligodendrocytic tumors, whereas significant dynamic increase was seen in glioblastomas and malignant lymphomas. Dynamic changes of MET uptake vary significantly with the normal brain structures and brain tumor histology. These results suggest that MET-PET may be useful in the differential diagnosis of brain tumors.

A speech expression disorder in patients with severe diffuse brain injury who emerged from a vegetative or minimally conscious state.

OBJECTIVE: The purpose of this study was to highlight a speech expression disorder considered as a mixed speech apraxia (SA) and dysarthria syndrome in patients with chronic severe diffuse brain injury (DBI) and to determine its correlation with anatomical localizations of brain lesions using neuroimaging. METHODS: Among 140 patients with chronic severe DBI, eight showed this type of speech disorder. MRI (five patients) and FDG-PET (six patients) procedures were performed. RESULTS: Affected patients could comprehend verbally, read words silently and express words using a word board. Compared with SA, the disorder is characterized by similarities in regards to reduced phonation and marked facio-oral apraxia, but by distinct differences in terms of an accompanying dysphagia and pyramidal/extra-pyramidal symptoms that are similar to symptoms associated with dysarthria due to pseudobulbar palsy. Diffuse regions of the white matter including the left arcuate fasciculus (AF) were significantly decreased in fractional anisotropy value. However, there was no significant cortical metabolic damage in FDG-PET. CONCLUSIONS: The observed speech disorder in these patients is a characteristic entity related to dysfunction of speech expression and may be attributable to damage of not only the AF but also a number of fibres that are related to dysarthria, cognitive and emotional impairments and pyramidal/extra-pyramidal symptoms.

Acupuncture Increases the Excitability of the Cortico-Spinal System in Patients with Chronic Disorders of Consciousness Following Traumatic Brain Injury.

OBJECTIVE: To evaluate the immediate effect of acupuncture on cortico spinal tract (CST) activity in patients with chronic disorders of consciousness (DOC) after traumatic brain injury (TBI) by measuring motor-evoked potential (MEP) using transcranial magnetic stimulation (TMS). DESIGN: Changes in several variables in the acupuncture session were compared with those in the control session without acupuncture in the same patients. SETTING: Chubu Medical Center for Prolonged Traumatic Brain Dysfunction, Gifu, Japan. PATIENTS: Fourteen patients (mean age ± standard deviation, 39 ± 17 years; 12 men) with chronic DOC (5 in a vegetative state and 9 in a minimally conscious state) following severe TBI. INTERVENTION: Acupuncture treatment was performed at GV 26, Ex-HN 3, bilateral LI 4, and ST 36 for 10 minutes. OUTCOME MEASURES: Main outcome measure was MEP amplitude. MEP amplitude, measured by using TMS on the primary motor cortex, was recorded from the abductor pollicis brevis muscle. MEP recordings were performed before acupuncture (baseline), 10 minutes after needle insertion (phase 1), and 10 minutes after needle removal (phase 2). As a control, the same procedure without acupuncture was performed on another day with the order randomized. MEP amplitude and latency were calculated. Evoked F-wave measurements were also performed to calculate maximum M-wave amplitude (Mmax), M-wave latency, and F-wave latency in the same muscle. Central motor conduction time (CMCT) and MEP/Mmax ratio were also calculated from the MEP and F-wave measurement data. RESULTS: MEP amplitude and MEP/Mmax were increased significantly in the acupuncture session at phases 1 and 2 compared with the control session (p < 0.001, p < 0.001, p < 0.001, and p = 0.001, respectively). CMCTs were reduced at phases 1 and 2 in the acupuncture session compared with the control session, and the change at phase 1 was statistically significant (P = 0.002). CONCLUSIONS: Acupuncture treatment increased the CST activity of patients with chronic DOC after severe TBI.

Utility of fractional anisotropy imaging analyzed by statistical parametric mapping for detecting minute brain lesions in chronic-stage patients who had mild or moderate traumatic brain injury.

Diffusion tensor imaging (DTI) has recently evolved as valuable technique to investigate diffuse axonal injury (DAI). This study examined whether fractional anisotropy (FA) images analyzed by statistical parametric mapping (FA-SPM images) are superior to T(2)*-weighted gradient recalled echo (T2*GRE) images or fluid-attenuated inversion recovery (FLAIR) images for detecting minute lesions in traumatic brain injury (TBI) patients. DTI was performed in 25 patients with cognitive impairments in the chronic stage after mild or moderate TBI. The FA maps obtained from the DTI were individually compared with those from age-matched healthy control subjects using voxel-based analysis and FA-SPM images (p < 0.001). Abnormal low-intensity areas on T2*GRE images (T2* lesions) were found in 10 patients (40.0%), abnormal high-intensity areas on FLAIR images in 4 patients (16.0%), and areas with significantly decreased FA on FA-SPM image in 16 patients (64.0%). Nine of 10 patients with T2* lesions had FA-SPM lesions. FA-SPM lesions topographically included most T2* lesions in the white matter and the deep brain structures, but did not include T2* lesions in the cortex/near-cortex or lesions containing substantial hemosiderin regardless of location. All 4 patients with abnormal areas on FLAIR images had FA-SPM lesions. FA-SPM imaging is useful for detecting minute lesions because of DAI in the white matter and the deep brain structures, which may not be visualized on T2*GRE or FLAIR images, and may allow the detection of minute brain lesions in patients with post-traumatic cognitive impairment.

Clinical value of [¹¹C]methionine PET for stereotactic radiation therapy with intensity modulated radiation therapy to metastatic brain tumors.

PURPOSE: This study investigated the clinical impact of (11)C-labeled methionine-positron emission tomography (MET-PET) for stereotactic radiation therapy with intensity modulated radiation therapy (SRT-IMRT) in metastatic brain tumors. METHODS AND MATERIALS: Forty-two metastatic brain tumors were examined. All tumors were treated with SRT-IMRT using a helical tomotherapy system. Gross tumor volume (GTV) was defined and drawn on the stereotactic magnetic resonance (MR) image, taking into account the respective contributions of MR imaging and MET-PET. Planning target volume (PTV) encompassed the GTV-PET plus a 2-mm margin. SRT-IMRT was performed, keeping the dose for PTV at 25-35 Gy in 5 fractions. The ratio of the mean value of MET uptake to the contralateral normal brain (L/N ratio) was plotted for the PTV prior to SRT-IMRT, at 3 months following SRT-IMRT, and at 6 months following SRT-IMRT. Tumor characteristic changes of MET uptake before and after SRT-IMRT were evaluated quantitatively, comparing them with MRI examination. RESULTS: Mean ± SD L/N ratios were 1.95 ± 0.83, 1.18 ± 0.21, and 1.12 ± 0.25 in the pre-SRT-IMRT group, in the 3 months post-SRT-IMRT group, and in the 6 months post-SRT-IMRT group, respectively. Differences in the mean L/N ratio between the pre-SRT-IMRT group and the 3-month post-SRT-IMRT group and between the pre-SRT-IMRT group and the 6 month post-SRT-IMRT group were statistically significant, irrespective of MRI examination. CONCLUSIONS: We showed examples of metastatic lesions demonstrating significant decreases in MET uptake following SRT-IMRT. MET-PET seems to have a potential role in providing additional information, although MRI remains the gold standard for diagnosis and follow-up after SRT-IMRT. The present study is a preliminary approach, but to more clearly define the impact of PET-based radiosurgical assessment, further experimental and clinical analyses are required.

Metabolic assessment of monofocal acute inflammatory demyelination using MR spectroscopy and (11)C-methionine-, (11)C-choline-, and (18)F-fluorodeoxyglucose-PET.

Monofocal acute inflammatory demyelination (MAID), which is observable by CT and MRI as a well-enhanced mass lesion with prominent perifocal edema, is very similar to malignant gliomas radiologically, making differential diagnosis of the two pathologies difficult. The aim of this study was to assess the different metabolic activities between MAID and malignant gliomas by MRS, methionine-PET, choline-PET, and FDG-PET. Six patients with MAID underwent methionine, choline, and FDG-PET, and 4 of the patients also underwent magnetic resonance spectroscopy (MRS). The images obtained from these patients were compared with the corresponding images of 19 anaplastic astrocytomas (AA) and 21 glioblastomas (GBM). The mean choline/creatine ratio of MAID was significantly lower than that of GBM. There were no significant differences in the mean NAA/creatine and lactate/creatine ratios among these pathologies. The methionine T/N ratio of MAID was significantly lower than those of AA and GBM. The choline T/N ratio of MAID was significantly lower than that of GBM. There were no significant differences in the FDG T/N ratios among these pathologies. These results demonstrate that the metabolic activity of MAID significantly differs in part from that of malignant gliomas. Combined PET and MRS neuroimaging examinations may be useful for differential diagnosis of these pathologies.