Association between preoperative cortical magnetic susceptibility and postoperative changes in the cerebral blood flow on cognitive improvement following carotid endarterectomy.

INTRODUCTION: While patients who experience improved cognition following carotid endarterectomy (CEA) typically demonstrate restored brain perfusion after the procedure, it is worth noting that less than 50% of patients in whom postoperative cerebral blood flow (CBF) restoration is achieved actually show improved cognition after postoperatively. This suggests that factors beyond the mere restoration of CBF may play a role in postoperative cognitive improvement. Increased iron deposition in the cerebral cortex may cause neural damage, and quantitative susceptibility mapping (QSM) obtained using magnetic resonance imaging (MRI) quantifies magnetic susceptibility in the cerebral cortex, allowing for the assessment of iron deposition in vivo. The purpose of the present study was to determine whether preoperative cortical magnetic susceptibility as well as postoperative changes in CBF are associated with cognitive improvement after CEA. METHODS: Brain MRI with a three-dimensional gradient echo sequence was preoperatively performed in 53 patients undergoing CEA for ipsilateral internal carotid artery stenosis (≥70%), and QSM with brain surface correction and vein removal was obtained. Cortical magnetic susceptibility was measured in the cerebral hemisphere ipsilateral to surgery on QSM. Preoperatively and at two months after the surgery, brain perfusion single-photon emission computed tomography (SPECT) and neuropsychological assessments were conducted. Using these collected data, we evaluated alterations in CBF within the affected hemisphere and assessed cognitive improvements following the operation. RESULTS: A logistic regression analysis showed that a postoperative greater increase in CBF (95% confidence interval [CI], 1.06-1.90; p = 0.0186) and preoperative lower cortical magnetic susceptibility (95% CI, 0.03-0.74; p = 0.0201) were significantly associated with postoperatively improved cognition. Although sensitivity, specificity, and positive- and negative-predictive values with the cutoff value lying closest to the upper left corner of a receiver operating characteristic curve for the prediction of postoperatively improved cognition did not differ between postoperative changes in CBF and preoperative cortical magnetic susceptibility, the specificity and the positive-predictive value were significantly greater for the combination of postoperative changes in CBF and preoperative cortical magnetic susceptibility (specificity, 95% CI, 93-100%; positive-predictive value 95% CI, 68-100%) than for the former parameter alone (specificity, 95% CI, 63-88%; positive-predictive value 95% CI, 20-64%). CONCLUSION: Preoperative cortical magnetic susceptibility as well as postoperative changes in CBF are associated with cognitive improvement after CEA.

Spontaneous middle meningeal arteriovenous fistula without cortical venous reflux presenting with acute subdural hematoma: illustrative case.

BACKGROUND: Dural arteriovenous fistula (AVF) without cortical venous reflux (CVR) has a relatively benign course. Here, the authors describe a patient presenting with subdural hematoma due to a middle meningeal AVF without CVR. OBSERVATIONS: A 17-year-old male was admitted to the emergency department with acute headache without an episode of head trauma. Computed tomography demonstrated a left acute subdural hematoma (SDH). Because the nontraumatic SDH raised the suspicion of vascular pathology, emergent angiography was performed, which demonstrated an AVF fed by the middle meningeal artery and draining to the diploic vein via the serpentine meningeal vein without CVR. T2-weighted magnetic resonance imaging (MRI) revealed no signs of venous congestion. Given the proximity of the AVF to the SDH and the MRI findings, we suspected that the serpentine meningeal vein was responsible for the SDH. The patient was successfully treated with transarterial Onyx embolization. During the injection, Onyx migrated to the extravascular space following its penetration into the serpentine meningeal vein, suggesting the meningeal vein was a bleeding source of the subdural hematoma. LESSONS: Despite the absence of cortical venous reflux, serpentine meningeal venous drainage of middle meningeal AVF can be a source of subdural hemorrhage.

Effect of the addition of 123I-iomazenil single-photon emission computed tomography to brain perfusion single-photon emission computed tomography on the detection accuracy of misery perfusion in adult patients with ischemic moyamoya disease.

OBJECTIVE: The present prospective study aimed to determine whether the addition of 123I-iomazenil (IMZ) single-photon emission computed tomography (SPECT) to brain perfusion SPECT could improve the detection accuracy of misery perfusion on positron emission tomography (PET) in adult patients with ischemic moyamoya disease (MMD). METHODS: Oxygen extraction fraction (OEF) and brain perfusion were assessed using 15O gas PET and N-isopropyl-p-[123I]-iodoamphetamine (IMP) SPECT, respectively, in 137 patients. IMZ SPECT was also performed. Regions of interest (ROIs) were automatically placed in the five middle cerebral artery (MCA) territories ipsilateral to the symptomatic cerebral hemisphere and in the contralateral posterior cerebral artery territory using a three-dimensional stereotaxic ROI template. The radioactive count of the MCA ROI to the contralateral posterior cerebral artery ROI was calculated on IMP SPECT (relative SPECT-IMP uptake) and IMZ SPECT (relative SPECT-IMZ uptake). The relative SPECT-IMZ uptake to the relative SPECT-IMP uptake was also calculated (relative SPECT-IMZ/IMP uptake). Of the five MCA ROIs in the symptomatic cerebral hemisphere in each patient, the ROI with the highest PET-OEF value (one ROI per patient) was selected for analysis. RESULTS: Significant correlations were observed between the PET-OEF and relative SPECT-IMP uptake (correlation coefficient, - 0.683) and relative SPECT-IMZ/IMP uptake (correlation coefficient, 0.875). The area under the receiver operating characteristic curve for detecting misery perfusion (PET-OEF > 51.3%) was significantly greater for the relative SPECT-IMZ/IMP uptake than for the relative SPECT-IMP uptake (difference between areas, 0.080; p = 0.0004). The sensitivity, specificity, and positive- and negative-predictive values for the relative SPECT-IMZ/IMP uptake for detecting misery perfusion were 100%, 92%, 81%, and 100%, respectively. The specificity and positive-predictive value were significantly greater for the relative SPECT-IMZ/IMP uptake than for the relative SPECT-IMP uptake. CONCLUSIONS: The addition of IMZ SPECT to brain perfusion SPECT improves the detection accuracy of misery perfusion on PET in adult patients with ischemic MMD.

Development of cerebral microbleeds and its impact on cognitive function in adult patients receiving medical management alone for ischemic moyamoya disease: supplementary analysis of a 5-year prospective cohort.

OBJECTIVE: De novo cerebral microbleeds (CMBs) on T2*-weighted magnetic resonance imaging (MRI) develop over time in adult moyamoya disease (MMD) and are generally associated with a decline in global cognitive function. The present supplementary analysis of a 5-year prospective cohort aimed to elucidate the incidence of an interval increase in CMBs in adult patients receiving medical management alone for ischemic MMD and its impact on cognitive function. METHODS: Sixty-four patients without misery perfusion in the symptomatic cerebral hemispheres at inclusion who did not experience any further ischemic symptoms or new hemorrhagic events during a 5-year follow-up period underwent T2*-weighted MRI and five kinds of neuropsychologic tests at inclusion and the end of the 5-year follow-up. RESULTS: When T2*-weighted MRI was compared between inclusion and the end of the 5-year follow-up, 10 patients (15%) had an interval increase in CMBs in the symptomatic cerebral hemisphere at inclusion. The scores from two kinds of neuropsychologic tests significantly deteriorated at the end of the 5-year follow-up compared with those at inclusion in patients with an interval increase in CMBs, whereas the scores of four kinds of neuropsychologic tests significantly improved at the end of the 5-year follow-up compared with those at inclusion in patients without interval increases in CMBs, asymptomatic ischemic lesions, or angiographic disease progression. CONCLUSIONS: The incidence of an interval increase in CMBs was 15% per 5 years in adult patients receiving medical management alone for ischemic MMD, and this increase was associated with a decline in cognitive decline.

Five-Year Outcomes of Medical Management Alone for Adult Patients with Ischemic Moyamoya Disease without Cerebral Misery Perfusion.

INTRODUCTION: No clear guidelines for treating adult patients with ischemic moyamoya disease (MMD) without cerebral hemodynamic compromise such as misery perfusion have been established. Our previous prospective cohort study of adult patients with MMD without misery perfusion who were treated with medical management alone, including an antiplatelet drug, showed a recurrent ischemic event rate of 3% per 2 years. The present prospective study aimed to elucidate the 5-year clinical, cerebral perfusion, and cognitive outcomes of medical management alone for Japanese adult patients with ischemic MMD without cerebral misery perfusion by following the same patients for another 3 years. METHODS: In total, 68 patients without recurrent events at a 2-year follow-up were prospectively followed up for another 3 years. Cerebral blood flow (CBF) in the symptomatic cerebral hemisphere was measured using brain perfusion single-photon emission computed tomography at inclusion and at the end of the subsequent 3-year follow-up. Neuropsychological testing was performed at inclusion and at the end of the initial 2- and subsequent 3-year follow-ups. RESULTS: During the subsequent 3-year follow-up, 2 patients (3%) developed further ischemic events. In patients without further ischemic events, CBF was significantly greater at the end of the subsequent 3-year follow-up than at inclusion (p = 0.0037), and all neuropsychological test scores improved or remained unchanged at the end of initial 2- and subsequent 3-year follow-ups compared with that at inclusion. CONCLUSION: In adult patients receiving medical management alone for ischemic MMD without cerebral misery perfusion, the incidence of further ischemic events was 6% per 5 years and did not change between the initial 2 years after the last is-chemic event and the subsequent 3 years. In patients without further ischemic events, CBF and cognitive function had not deteriorated at 5 years after the last ischemic event.

Angiographic disease progression in medically treated adult patients with ischemic moyamoya disease without cerebral misery perfusion: supplementary analysis of a 5-year prospective cohort.

Angiographic disease progression reportedly develops in adult moyamoya disease (MMD). However, more than half of patients analyzed underwent revascularization surgery. The present supplementary analysis of a 5-year prospective cohort with follow-up using magnetic resonance angiography (MRA) and cerebral blood flow (CBF) measurements was to elucidate the incidence and clinical features of angiographic disease progression in adult patients receiving medical management alone for ischemic MMD. Sixty-eight patients without misery perfusion in the symptomatic cerebral hemispheres underwent MRA and CBF measurement using brain perfusion single-photon emission computed tomography at inclusion and at the end of the 5-year follow-up. When neurological symptoms recurred or newly developed during the 5-year follow-up period, additional MRA and CBF measurements were also performed at that time. All four patients with further ischemic events during the 5-year follow-up period exhibited angiographic disease progression on MRA at such events. Of the remaining 64 patients without further events during the 5-year follow-up period, four exhibited angiographic disease progression on MRA at the end of the 5-year follow-up. CBF was significantly lower at the time of further ischemic events or at the end of the 5-year follow-up than at inclusion in eight patients with angiographic disease progression (p = 0.0117). The incidence of angiographic disease progression was 12% for 5 years in medically treated adult patients with ischemic MMD without cerebral misery perfusion. Patients with further ischemic events always exhibited angiographic disease progression. Cerebral perfusion was reduced in patients with angiographic disease progression even when further ischemic events did not occur.

Long-Term Cognitive Changes after Revascularization Surgery in Adult Patients with Ischemic Moyamoya Disease.

INTRODUCTION: Revascularization surgery for adult moyamoya disease (MMD) with ischemic presentation changes cognitive function and prevents further cerebral ischemic events. Most studies however repeated neuropsychological evaluation within 1 year after surgery. Our previous prospective cohort study of adult patients with MMD with misery perfusion who underwent direct revascularization surgery showed cognitive improvement and decline in 31% and 44%, respectively, of the patients 2 months after surgery. The present prospective study aimed to elucidate the 5-year cognitive changes after direct revascularization surgery in adult patients with cerebral misery perfusion due to ischemic MMD by following the same patients. METHODS: In total, 31 patients were prospectively followed up for 5 years after direct revascularization surgery. Five types of neuropsychological tests were performed preoperatively, 2 months after surgery, and at the end of the 5-year follow-up. Cerebral blood flow (CBF) in the symptomatic cerebral hemisphere relative to that in the ipsilateral cerebellar hemisphere (hemispheric relative CBF [RCBF]) was measured using brain perfusion single-photon emission computed tomography preoperatively and at the end of the 5-year follow-up. RESULTS: Based on results of pre- and postoperative neuropsychological tests, 11, 10, and 10 patients showed cognitive improvement, no change in cognitive function, and cognitive decline, respectively, at the end of the 5-year follow-up. These ratios were not significantly different compared with those 2 months after surgery (cognitive improvement, no change in cognitive function, and cognitive decline in 10, 8, and 13 patients, respectively). Although hemispheric RCBF was significantly greater at the end of the 5-year follow-up than before surgery in patients with cognitive improvement (80.7 ± 6.1% vs. 92.9 ± 5.5%; p = 0.0033) and in those showing no change in cognitive function (85.6 ± 3.5 vs. 91.5 ± 5.2%; p = 0.0093), this value was significantly lower at the end of the 5-year follow-up than before surgery in patients with cognitive decline (83.8 ± 3.7 vs. 81.0 ± 5.8%; p = 0.0367). CONCLUSION: One-third of adult patients with cerebral misery perfusion due to ischemic MMD who underwent direct revascularization surgery exhibited cognitive improvement, and one-third exhibited decline at the end of the 5-year follow-up. The former and latter patients had increased and decreased CBF, respectively, in the affected cerebral hemisphere at the end of the 5-year follow-up compared with preoperative brain perfusion.