Background: There is an association between anterior cerebral artery vessel asymmetry and anterior communicating artery aneurysm, presumably based on flow dynamics. The purpose of this study is to investigate the potential relationship between aortic arch branching patterns and incidence of intracranial aneurysm. Methods: This study included patients scanned over 1 year at our tertiary care center who underwent high-resolution imaging (computed tomography angiography or digital subtracted angiogram) of the head and neck arteries, aortic arch, and superior mediastinum. Exclusion criteria included patients with suboptimal images. Patient age, gender, aortic arch branching pattern, and the presence, location, and number of aneurysms were documented. Results: Among the 1082 patients analyzed, 250 (23%) patients had a variant aortic arch branching pattern, 22 (8.8%) of whom had aneurysms. There were 104 patients with 126 aneurysms, with majority of patients with normal aortic arch branching pattern (n = 82, 79%). The most common variant was a common origin of the left common carotid artery and brachiocephalic trunk with or without direct origin of the left vertebral artery. Twenty-two patients with aneurysms had an aberrant aortic arch (21%), compared to 232 patients without an aneurysm (24%). Fischer exact test showed no statistically significant difference between the incidence of aneurysm with different aortic arch variant groups (two-tailed p-value = 0.715). Conclusion: To our knowledge, this is the first study to examine the association between aortic arch branching patterns and incidence of intracranial aneurysm. No significant association was found between aortic arch branching pattern and the incidence of intracranial aneurysm.

Background: Assessment of patients for temporal lobe epilepsy (TLE) surgery requires multimodality input, including EEG to ensure optimal surgical planning. Often EEG demonstrates abnormal foci not detected on clinical MRI. 7T MRI provides improved resolution and we investigated its utility to detect potential abnormalities associated with EEG. Methods: Images were acquired on 7T MRI scanner (N=13) in oatients with TLE. Evaluation of 7T imaging for focal abnormalities was performed. Correlation of 7T MRI findings with EEG of focal slowing or interictal epileptic spikes (IEDs) and seizures was performed. Results: Assessment of 7T MRI demonstrated concordance with TLE in 8/13 cases. Three cases exhibited abnormal 7T MRI abnormalities not detected by 1.5 T MRI. Eleven out of 13 cases had EEG findings without anatomic correlates on MRI, with IEDs localizing to contralateral temporal, frontal, and parieto-occipital lobes. 7T images did not reveal focal anatomical abnormalities to account for the EEG findings in these patients. Conclusions: To our knowledge, this is the first study to investigate the role of 7T MRI in relation to EEG abnormalities. 7T RI findings show concordance with clinical data. 7T MRI did not reveal anatomical findings to account for EEG abnormalities, suggesting that such changes may be functional rather than anatomical.

OBJECTIVE:There is limited information on neuroimaging changes in status epilepticus (SE). The objective of this study was to characterize the abnormalities associated with SE in cranial MRI of patients with SE. METHODS:A retrospective review of our records from 2001 to 2010 identified 203 patients with SE. Magnetic resonance imaging (MRI) changes considered were not attributable to any neurological disorder. RESULTS:Ten patients who met the inclusion criteria were found to have significant abnormalities. Magnetic resonance imaging findings included increased T2 signal changes in the gray and/or white matter with corresponding diffusion-weighted imaging (DWI) abnormalities (n=9). Apparent diffusion coefficient (ADC) values were both reduced (n=3) and increased (n=3). Other findings included changes affecting one hemisphere, a perilesional and homologous region, hippocampal changes, and findings in the thalamus, basal ganglia, brain stem, and cerebellum. CONCLUSIONS:Magnetic resonance imaging changes were diffuse. Notably, MRI changes were found to involve the brain stem, cerebellum, basal ganglia, and thalamus. Magnetic resonance imaging changes in the latter areas have not been previously well described. In addition, MRI changes tended to evolve after 1week; therefore, serial MRI is recommended in order to follow and highlight the MRI changes related to the neuroanatomic involvement seen in status epilepticus.

OBJECTIVE:To evaluate the possible role of the default mode network (DMN) in consciousness and assess the diagnostic or prognostic potential of DMN connectivity measures in the assessment of a patient group lacking cognitive awareness.METHODS:DMN connectivity was established using independent component analysis of resting-state fMRI data in patients with reversible (n = 2) and irreversible (n = 11) coma following cardiac arrest and compared to healthy controls (n = 12).RESULTS:A present and intact DMN was observed in controls and those patients who subsequently regained consciousness, but was disrupted in all patients who failed to regain consciousness.CONCLUSIONS:The results suggest that the DMN is necessary but not sufficient to support consciousness. Clinically, DMN connectivity may serve as an indicator of the extent of cortical disruption and predict reversible impairments in consciousness.

CASE REPORT This otherwise healthy Caucasian woman had presented at the age of 20 with left optic neuritis, which had resulted in complete loss of vision in this eye, followed by several episodes of transverse myelitis and contralateral optic neuritis, with partial recovery. One year later, she was diagnosed with MS, and treated with varying doses of oral prednisone and azathioprine. She continued to have repeated episodes of optic neuritis and transverse myelitis. Five years since onset, interferon beta1-b 250 mcg SC qod was started in combination with azathioprine. She had no further neurologic episodes over the following year, until azathioprine was discontinued due to neutropenia, and interferon beta1-b was continued at half dose. Subsequently, she had recurrent episodes of optic neuritis and transverse myelitis, treated with high dose steroids at least twice a year. Eight years after presentation, interferon beta1-b was discontinued, and she started glatiramer acetate 20 mg qd. She continued to experience optic neuritis at least twice a year, treated with high dose steroids. When she presented to us 18 years after initial presentation, her best visual acuity was finger counting at three meters on the right, and no light perception on the left. Pupils were dilated and unreactive to light on the left, with a sluggish response to light on the right. She had left exophoria and nystagmus in all directions of gaze. She had a spastic quadriparesis, and was able to take a few steps with a walker. Laboratory investigations revealed weakly positive ANA, elevated rheumatoid factor of 158 IU/mL, negative anti-dsDNA, negative anti-ENA screen, normal vitamin B12 levels. Serum NMO antibody was reported positive by Mayo Clinic laboratory in Rochester Minnesota, USA. Brain MRI showed callosal atrophy, centrally in the body. A few nonspecific high T2 signal white matter abnormalities were seen in the deep white matter of the hemispheres. No lesions were seen in the posterior fossa or the periventricular areas. The spinal cord was markedly atrophic, and no signal change was seen in the spinal cord. No abnormal enhancement was seen with Gadolinium (Gd) injection. (Figure) We recommended discontinuation of glatiramer actete; azathioprine was initiated. At the time of preparation of this

Background: Functional MRI was used to study the impact of temporal lobe epilepsy (TLE) and anterior temporal lobectomy (ATL) on the cortical language network in patients with medically refractory TLE.Methods: Nineteen patients with medically refractory TLE and 11 healthy control subjects were enrolled in this study. Ten patients underwent left ATL (mean age 35.2 +/- 3.8 years), and 9 underwent right ATL (mean age 35.9 +/- 2.6 years). The subjects silently generated verbs in response to a series of visually presented nouns inside the scanner. Correlation analysis was performed between the subjects' performance on the clinical language tests and their neural response in the a priori cortical regions.Results: Preoperative data revealed that the patients with TLE showed increased neural activity in the right inferior frontal gyri (IFG) and middle frontal gyri (MFG). The right TLE patients demonstrated strong correlation between their language performance and the level of cortical activation within the typical language areas. However, such a correlation was absent in the left TLE patients. After the ATL surgery, the left TLE patients showed reduced activation in the left MFG and right IFG, whereas no difference was observed in the right TLE patients. In the right TLE patients, the correlation between language performance and neural response shifted from the typical language areas to the anterior cingulate cortex.Conclusion: This study demonstrates that the cortical language network is affected differently by the left and right temporal lobe epilepsy and is reorganized after anterior temporal lobectomy. Neurology (R) 2009;73:518-525

We studied the usefulness of an MR imaging-compatible electroencephalography (EEG) electrode system for continuous EEG recordings in our epilepsy monitoring unit (EMU) by comparing 100 consecutive patients with MR imaging-compatible and MR imaging-incompatible EEG recording electrodes who underwent MR imaging between 3:00 pm and 7:00 am. The MR imaging-compatible system captured seizures in 21/50 (42%) patients and clinically valuable new electrographic data in 13/50 (26%) patients during the study interval, whereas possible seizures were lost to recording in 19/50 (38%) patients in the MR imaging-incompatible system. EEG recording was comparable by both systems, but the nurses could disconnect and reconnect the patients to their electrode cables only in the MR imaging-compatible system during the study interval while the EEG technologists were off duty. This study shows that the MR imaging-compatible system could be used routinely for long-term monitoring of the patients in EMUs.

Described here is a patient with medically intractable generalized epilepsy who developed status epilepticus (SE) affecting his right cerebral hemisphere for about 48 hours, which led to irreversible injury to that hemisphere. His partial SE did not respond to the first-line therapies, repeated doses of midazolam, or continuous intravenous infusion of propofol. Extensive investigations failed to find a cause of his SE except for a low serum valproic acid. A minor trauma that he suffered 1 week prior to his SE was of questionable significance. Neurological examination, neuropsychological testing, electroencephalography, and magnetic resonance imaging all demonstrated striking abnormalities limited to the affected cerebral hemisphere that did not resolve with repeated testing. This case illustrates permanent focal brain injury following prolonged partial SE in a patient with previously known generalized seizure disorder.

Background and Purpose— We investigated whether computed tomography (CT) perfusion–derived cerebral blood flow (CBF) and cerebral blood volume (CBV) could be used to differentiate between penumbra and infarcted gray matter in a limited, exploratory sample of acute stroke patients. Methods— Thirty patients underwent a noncontrast CT (NCCT), CT angiography (CTA), and CT perfusion (CTP) scan within 7 hours of stroke onset, NCCT and CTA at 24 hours, and NCCT at 5 to 7 days. Twenty-five patients met the criteria for inclusion and were subsequently divided into 2 groups: those with recanalization at 24 hours (n=16) and those without (n=9). Penumbra was operationally defined as tissue with an admission CBF <25 mL · 100 g −1 · min −1 that was not infarcted on the 5- to 7-day NCCT. Logistic regression was applied to differentiate between infarct and penumbra data points. Results— For recanalized patients, CBF was significantly lower ( P <0.05) for infarct (13.3±3.75 mL · 100 g −1 · min −1 ) than penumbra (25.0±3.82 mL · 100 g −1 · min −1 ). CBV in the penumbra (2.15±0.43 mL · 100 g −1 ) was significantly higher than contralateral (1.78±0.30 mL · 100 g −1 ) and infarcted tissue (1.12±0.37 mL · 100 g −1 ). Logistic regression using an interaction term (CBF×CBV) resulted in sensitivity, specificity, and accuracy of 97.0%, 97.2%, and 97.1%, respectively. The interaction term resulted in a significantly better ( P <0.05) fit than CBF or CBV alone, suggesting that the CBV threshold for infarction varies with CBF. For patients without recanalization, CBF and CBV for infarcted regions were 15.1±5.67 mL · 100 g −1 · min −1 and 1.17±0.41 mL · 100 g −1 , respectively. Conclusions— We have shown in a limited sample of patients that CBF and CBV obtained from CTP can be sensitive and specific for infarction and should be investigated further in a prospective trial to assess their utility for differentiating between infarct and penumbra.

Objective: We report on the development of an electroencephalographic (EEG) recording system that is Magnetic Resonance Imaging (MRI) compatible and can safely be left on the scalp during anatomical imaging or used to obtain simultaneous EEG and metabolic or hemodynamic data using functional imaging techniques such as functional MRI or MR spectroscopy. Methods: We assembled a versatile EEG recording set-up with medically acceptable materials that contained no ferromagnetic components. It was tested for absence of excess heating and distortion of the image quality in a spherical phantom similar in size to average adult human head in a clinical 1.5 T GE scanner. After testing its safety in four volunteers, 100 consecutive patients from our epilepsy long-term monitoring unit were studied. Results: There was no change in the temperature of the EEG electrode discs during the various anatomical MRI sequences used in our routine clinical studies (maximum temperature change was −0.45 °C with average head SAR≤1.6 W/Kg in the selected subjects) nor were there any reported complications in the others. The brain images were not distorted by the susceptibility artifact of the EEG electrodes. Conclusions: Our MRI compatible EEG set-up allows safe and artifact free brain imaging in 1.5 T MR scanner with average SAR≤1.6 W/Kg. This EEG system can be used for EEG recording during anatomical MRI studies as well as functional imaging studies in patients requiring continuous EEG recordings.

BACKGROUND:Dural cavernous angiomas are uncommon benign vascular malformations which may present intraoperative difficulties in hemostasis when the diagnosis is not suspected preoperatively. Preoperative diagnosis can be difficult when angiomas show atypical features and share imaging characteristics with other entities.METHODS:A patient presented with a radiographically aggressive lesion, subsequently identified as a dural cavernous angioma. The lesion is reviewed and its clinical, radiographic, and pathological features are compared with other vascular malformations.CASE REPORT:A 40-year-old man presented with new onset seizures and an enhancing lesion infiltrating the floor of the right middle cranial fossa. Due to its aggressive radiographic appearance, initial considerations included chondrosarcoma, meningioma or metastasis. Pathological examination, however, revealed the lesion to be a cavernous angioma of dura.CONCLUSION:This uncommon lesion may present a diagnostic challenge with significant intraoperative implications. T2 sequence hyperintensity in a relevant lesion should raise suspicion of an hemangioma. It is important to be aware of this entity and its potential to mimic other entities on radiographic grounds.

The June COM. A 61 year old female presents with a three week history of increasing confusion, lethargy and headache. A neurological exam revealed disorientation, mild expressive aphasia, bilateral papilledema, and a right pronator drift. She had a craniotomy and resection of tumor. The tumor histologically was consistent with a solitary fibrous tumor displaying malignant features of hypercellularity, marked nuclear atypia, high mitotic activity, and a high proliferation index. This case is unique as the first malignant variant of solitary fibrous tumor to be reported intracranially.

The aim of this prospective study was to assess the feasibility and diagnostic relevance of repetitive dynamic (contrast-enhanced) CT measurements of cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) in the first 3 weeks after aneurysmal subarachnoid hemorrhage (SAH). In 15 patients with SAH, 59 dynamic CT studies including 944 regions of interest (ROI) were analyzed. The results were correlated with the clinical course and time after the event and the occurrence of vasospasm. Values for the entire series were 33.8 ± 19.3 ml/100 g/min (CBF), 3.3 ± 1.3 ml/100 g (CBV), and 7.3 ± 3.9 s (MTT). Significant differences in CBF and CBV were found between ROI in grey and white matter, with time after the event, between patients with significant and absent or minor vasospasm, and between patients with and without a presumed vasospasm-related infarct.

87 Background: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited arterial disease of mid-adulthood resulting from mutations of the Notch3 gene on chromosome 19. The presence of granular and osmiophilic material surrounding smooth muscle cells visualized under electron microscopy in a skin biopsy allows confirmation of the intra vitam diagnosis. The literature suggests that skin biopsy can establish the diagnosis with high certainty and that it be considered the diagnostic method of first choice. Until the sensitivity and specificity have rigorously been assessed, results from such tests should be interpreted with caution. Objective: To raise some concerns about the possible lack of sensitivity of skin biopsy in the early diagnosis of CADASIL by describing the second large Canadian kindred with this condition. Methods: All siblings of this family in which there was a clinical suspicion of CADASIL underwent neurological evaluation, magnetic resonance imaging (MRI), skin biopsy, and genetic testing. Findings: Nine siblings ranged in age from 40 to 63 years. Two (aged 60 and 62) presented with dementia, strokes, and depression, two (aged 58 and 63) presented with stroke and migraine with aura, three (aged 40, 48, and 51) presented with only migraine with aura, and two (aged 53 and 57) were asymptomatic. Eight consented to diagnostic evaluation. All eight siblings’ DNA-sequence analysis of the Notch3 gene revealed an Arg207Cys mutation in exon 4. All have MRI scans consistent with a diagnosis of CADASIL. Full thickness skin biopsies from all eight were submitted for histopathological and ultrastructural examination. Granular electron dense osmiophilic material was not found in any of the material submitted. Conclusions: In addition to providing an illustrative clinical example of the broad phenotypic variation of CADASIL in a Canadian kindred, this family demonstrates how insensitive the skin biopsy might be. The sensitivity and specificity of various non-genetic diagnostic tests such as skin and muscle biopsy must be rigorously assessed before claiming them as standards for screening or diagnosing CADASIL.

P32 Purpose To establish normal values of cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) as measured by dynamic contrast enhanced computed tomography (CT Perfusion) and to determine their short-term variabilities in healthy volunteers. Method and Materials The studies involved ten healthy volunteers, 6 females and 4 males, between 39 and 49 years old. For each subject two single-slice contrast enhanced dynamic CT studies separated by an interval of 30 min were performed at the level of the basal ganglia. Arterial oxygen saturation (SaO 2 ), end-tidal CO 2 tension (ETCO 2 ), and blood pressure(BP) were continuously monitored to ensure the same basal conditions were maintained throughout the studies and the waiting period between them. Each study began with intravenous injection of 40 ml of contrast at 4 ml/s and at 5 s into the injection, 60 1 s CT scans were acquired continuously. Functional images of absolute CBF, CBV, and MTT were calculated by deconvolution of an intracranial artery’s contrast enhancement curve with tissue curves. Normal CBF, CBV and MTT values of the entire slice as well as those of frontal and insular grey matter, basal ganglia, frontal white matter, and the cerebellum were analyzed. Short-term variability was calculated using a standardized set of 24 regions of interest (ROI). The size of each ROI was about 4% of the entire brain slice. Results There were no significant differences in SaO 2 , ETCO 2 and BP between the two studies for each subject. CBF was the highest in insular grey matter (67.8 ml/100g/min), intermediate in frontal grey matter, basal ganglia, and cerebellum (42–48 ml/100g/min), and the lowest in frontal white matter (14.5 ml/100g/min). The values of CBV followed the same trend as CBF. Short-term variability was 13.3%, 12.4% and 8.8% for CBF, CBV and MTT respectively without significant differences among the parameters. Conclusion CT imaging of absolute CBF, CBV, and MTT in healthy volunteers provides results similar to those known from the literature. The short-term variabilities of these quantitative functional images are acceptable for clinical applications.

Magnetic resonance imaging (MRI) techniques allow for significantly better imaging of the temporal lobe compared to computed tomography (CT) or other non-invasive modalities. For detection of foreign tissue lesions, MRI surpasses CT. For the highest non-invasive yield for detection of mesial temporal sclerosis, optimal sequences that should be employed are a heavily T1-weighted volumetric acquisition (to enable both volumetric calculation of hippocampal volume, and, if needed, intracranial volume), T2-weighted coronal sequences, with or without T2-mapping, fluid-attenuated inversion recovery (FLAIR) and, to exclude subtle susceptibility effects from hematoma or cavernoma, gradient echo scans. Magnetic resonance spectroscopy (MRS) may show a decrease in N-acetyl aspartate (NAA) concentration, or NAA: Choline + creatine ratio. Functional MRI is a new and exciting tool that offers the promise of accurately localizing hemispheric functions; its role in the preoperative evaluation of temporal lobe seizures remains uncertain at present.

Background: The treatment of primary hypertensive intracerebral hemorrhage remains one of the most controversial and least well-studied areas from a medical or surgical perspective. Therefore, the aim of the present study was to determine the impact of surgical treatment on a short term survival of patients with PHICH together with the role of other possible prognostic factors. Methods and results: During 1988–1992, 165 patients with PHICH 25–64 years were hospitalized in four Kaunas city hospitals. Surgical treatment was assigned to 51 (31%) of patients, and 114 (69%) were treated conservatively. The independent role of various prognostic signs for death from PHICH during the first 28 days of illness were determined with the Cox proportional hazards model. The worst prognosis at the 28th day of illness was related with the Glasgow Coma Scale grade on admission, size of hematoma, and with the site of hematoma. Surgical treatment statistically significantly improved 28-day survival of patients with PHICH when compared to those treated conservatively (RR D 0.29; 95% confidence interval 0.17–0.49). Conclusion: Despite the positive role of surgery in respect of outcome of the patients with PHICH observed in our present study, we are still reluctant in making the indisputable conclusion. Further studies are needed in order to elucidate the true role of surgery in the management of PHICH. Poster Session I: Hemorrhage