0632 Magnetic resonance imaging and spectroscopy in Adult-Onset citrullinaemia

Poster Abstracts (N -- 3, age 2.7-8.4 years), accompanied by sustained seizure-freedom and improvement of epileptiform activity over the previously hypometabolic region. Conclusion: Focal glucose metabolic changes in SWS reflect the dynamic aspects of the underlying pathology and also seizure-related transient metabolic changes. Focal hypometabolism outside the angioma can progress but also be partially reversible if seizures become controlled. F D G PET provides unique insights into dynamic changes of brain metabolism in SWS.

0628 Venous Sinus Thrombosis - A Clinical Study and Spectrum of MRI and MRV Findings K. K a c ~ l, T. Stosic-Opincal ~, A. Kacar 3, S. Lavnic 2. 1Diagnostic

Imaging Center, CBC "Bezanijska kosa", Belgrade; 2Magnetic .Resonance Center, CCS, Belgrade; 3Department of Urgent Neurology, Institute of Neurology, CCS, Belgrade Purpose: Cerebral venous sinus thrombosis is a rare disease with a heterogentius clinical features and variety of simptoms. The aim of this study was to determine magnetic resonance venography (MRV) in conjuction with convenctional magnetics resonance imaging (MRI) for reliable diaguosis of venous sinus thrombosis. Malbefial and methods: 10 patients underwent M R I (1,0 T-Siemens) in TI and T2-weighted mxial, sagital and coronal sequences. We also aquired M R V images. At the time of examinations all patient have different symptoms: headache, focal deficit, epileptic seizures, impaired consdusness and papilloedema. Results: M R I was performed in all 10 patients and M R V was performed in 9 patients. The abnormalities of brain included multiple infarct unilaterally or bilaterally in 3 patients. Unilareral haemorrhagich infarct in 4 patients with thrombosis of the lateral and sigmoid sinuses. Multifocal haemorrhagic infarctions in both cerebral hemispheres in 2 cases. Falx cerebral meningeoma was found in 1 case. Conclusion: Cerebral venous sinus thrombosis (CWST) often present with hemorrhagic infarction areas atypical for arterial vascular distribution. Magnetic resonance venography (MRV) in conjuction with convenctional M R I can accurately diagnose cerebral venous thrombosis because (CVST) m a y be difficult to diagnoses clinically of various nonspecific manifestation. Reterences: 1. Karthikeyan D, Vijay S, K u m a r T, K a n t h L Cerebral Venous Thrombosis, CI'. Ind J Radiol Imag. 2004. 14:02:129-137 2. Patel MR. Brain. Venous Sinus Thrombosis. Article on line. June 2003. Available from: URL:htt-p//www.emedicine.com/radio/ topicl 05.htm 3. Casey SO, Ozvath RR, Alberico RA, Rubinstein D. CT Venography of dural sinus thrombosis. R S N A eJurnal (online). 1998 march. 4. Fink JN, McAuley DL. Mastoid air sinus abnormalites associated with lateral venous sinus thrombosis: cause or consequences? Stroke. 2002; 33:290 292 5. L a m y C, H a m o n JB, Coste J, M a s JL. Ischemic stroke in y o u n g women: risk of recurrence during subsequent pregnancies: French Study Group on Stroke in Pregnancy. Neurology. 2000; 55: 269-274. 0629 To detemlMe ou|come of patients with diflusion negative strokes and H V S on FLAIR

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occlusion was confirmed by M R A or cerebral angiogram. Patients were treated if presented within 3 hours with r-tPA or if not r-tPA candidates with stenting, angioplasty or surgery if lesion was accessible. Clinical outcome was graded using NIHSS. M R I repeated 24 hours after treamrent. Results- Out of 97 acute stroke MRI, HVS was observed in 44; 45%. 12/97 12.5% HVS had diffusion negative strokes. Time to first M R I was 3.30 hours. M R A showed M C A occlusion (n -- 9), M C A stenosis (in -- 1), I C A occlusion or stenosis (in -- 3). Perfusion deficit on TTP and SPECT (in - 4) correlated with area of HVS. Average T C D velocity was 29% of the contralateral asymptonmtic MCA. Seven patients treated with r-tPA (in -- 4), extracranial-intracranial bypass (in -- 1), carotid stenring/angioplasty (n -- 2). Time to repeat M R I was 38 hours Post-treatment HVS resolved in 6 patients who recanlized with average T C D of 79% (p < 0.001), with NIHSS of 3.5 (p < 0.001). Patients who failed recanalization (n - 6) infarct size was smaller than HVS. Clinical outcome with average NIHSS 11 in patients who failed recanalization. Conclusion: HVS is a sign of impending infarction and can be seen in diffusion negative strokes. The diagnosis o f stroke should not be ruled out on the basis of early negative D W I studies.

0630 Non-Traumatic Acule Paraplegia ~esulfing from Cervical Disc Herniation Sa-Yoon Kang, M.D. l, Jay Chol Choi, M.D. 1, Ji-Hoon Kang, M . D ~.

1Department of Neurology, College of Medicine, Cheju National University, Yeju, South Korea Acute progression of myelopathy into complete paraplegia resulting from disc herniation is rare. Non-traumatic acute paraplegia attributable to disc herniation is known to occur most frequently at the thoracic level. We report a rare case o f non-traumatic acute paraplegia caused by disc herniation at the cervical level. A 50-year-old m a n was admitted to our service with progressive paraplegia for 2 weeks. He h a d experienced minor neck pain and tingling sense in the lower extremities 3 weeks before admission, although he had no history of t r a u m a to his neck. One week before the admission, he h a d noticed weakness in both arms. On admission to our service, neurological examination revealed a flaccid paraplegia. Deep tendon reflexes were hyporeflexia. Hypesthesia at the level below the T10 dermatome was noticed. There were no upper motor neuron sign such as Babinski sign or ankle clonus. There was no abnormality in nerve conduction study. The C-spnie M R I revealed a high signal intensity lesion on T2-weighted image in the spinal cord at the level of C6/7. Tiffs lesion was associated with herniation o f C6/7 disc. He underwent emergency surgery consisting o f laminoplasty a n d removal of the C6-C7 herniated disc. Eight m o n t h s after operation, he could walk independently. We emphasize that there is a possibility of acute progression of paralysis secondary to non-traumatic enlargement of cervical disc herniation.

0631 V o x d based inoxphoinetry de|eels subtle dysplasia and neoplasia in dfildhood epilepsy Bruggemann, J~, Wilke, M ~, Sore, S ~, Bye, A ~, Bleasel, A ~, Lawson, J~.

Kanlran, S 1. 2Hamad General Hospital, Qatar

lSydney Children's Hospital and University of New South Wales, Randwick, New South Wales, Australia; 2Paediatric Neurology', University Children's Ho@ital, Tuebingen, Germany; 3Children's Hospital Westrnead, Westrnead, NSW, Australia

Background: Diffusion M R m a y fail to detect early acute strokes. Hyperintense vessels sign (HVS) on F L A I R in acute stroke has been reported in patients with large vessel occlusion or stenosis. Patients and Melhods: Acute stroke patients with F L A I R HVS and diffusion negative strokes were prospectively evaluated with diffusionperfusion M R , transcranial doppler (TCD) and SPECT. Large vessel

Background: Focal cortical dysplasia (FCD) and neoplasms are often causal o f intractable epilepsy in children. Detection and delineation of these lesions via visual examination o f M R I can be difficult. Tile primary aim was to evaluate voxel-based morphometry (VBM) image quantification and analysis as a tool for detecting focal lesions underlying childhood epilepsy. A secondary aim was to compare the

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Tuesday, November 8, 2005

Poster Abstracts

sensitivity of combined grey/white matter (GM/WM) analyses versus GM-only analyses. Method: The patients were 16 children (10 boys) aged 5.9 to 15.2 years (111.3 ± 2.8 years; mean ± SD) with epilepsy and F C D or neoplasia. The control group comp tired 24 normal children (12 boys), age and sex matched to the patients. MRI volumes were spatially normalised to a custom template (using SPM2 VBM), then segmented into G M and WM. The G M segment from each patient was subsequently contrasted with the mean G M segment o f the control group. Maps showing increased/decreased areas of grey matter were generated and compared with visually identified lesions and electro-clinical localisation. A similar approach was utilised in combined G M / W M analyses. Results: The GM-oniy analysis lesion detection rate was identical for F C D and neoplasia at 5/8. The best combined G M / W M technique substantially increased the yield, detecting 8/8 FCD and 6/8 neoplasia. Relative to other G M / W M combinations, increased GM/decreased WM produced the highest yield overall. Conclnsion: VBM identified abnormalities concordant with visually identified lesions. As FCD is a disorder involving both G M and WM, combined G M / W M VBM analysis is essential and superior to GM-only methods.

fiber assignment by continuous tracking (FACT) was performed to quantify the fiber volume of the CST and the posterior thalamic radiation (PTR), a non-motor tract. Results: Patients showed significantly lower F A (p < 0.001) but not MD (p - 0.0878) titan controls in the PIC. In the CST, the volume of fibers was decreased in the CST compared to nomtal controls (lJ - 0.0274) but not the PTR (lJ -- 0.3171). Conehision: F A and fiber tracking can visualise and measure mxonal degeneration in the CST in ALS, DTI markers of upper motor neuron damage in ALS have the potential to be used as surrogate markers in measuring disease progression, which would be helpful in future studies and clinical trials.

0632 Magnetic ~eSonanCe inmging and spectroscopy in Adult-Onset Citrullinaemia

Baekg~ouud: The pathophysiology of the syndrome of conduction aphasia had been viewed as a discom~ection between posterior and the anterior language areas. The arcuate fascicuhis(AF) has been thought to be anatomical linkage between Wernicke's area and Broca's area. However, its actual role in the syndrome remains difficult to be clarified. Methods: A retrospective case series of 6 patients with the clinical syndrome of conduction aphasia were studied for the presentation, aetiology and associated clinical features. All patients underwent CT brain, Three had SPECI" scan, Three had MRI of brain in which two .were also examined by M R diffusion tensor tractography to delineate the area of destruction in the white matter. Results: Different modalities including SPECT can help to locate the anatomical lesion and functional deficit area in patients having conduction aphasia. M R diffusion tensor can clearly define the interruption of the A F in some patients. A video of the 2 patients is shown. Conehision: Presentation of conduction aphasia as expressive aphasia while CT shows a posteriorly situated lesion; clinically often misdiagnosed as expressive Broca's dysphasia;2) motor deficits are usually minimal; 3) a mJsdiagnosis of dementia can occur; 4) Neuroimaging with M R diffusion can demonstrate the involvement of 'AF" in the syndrome; 5) Conduction aphasia typically has deficits in the expressive , repetitive component of speech and improves on repetitive testing; 6) some patients presents also with visual agnosia as demonstrated on one of our patients; 7) longer term follow up of these patients is required to morfitor for cognitive deterioration and development of dementing features.

Lim, CCT ~,2, Wong, YC 1, Tan, K 1, Xu, MS 1, Au, WL 1, Umapathi, T ~,

Hui, F ~. iNational Neuroscience Institute, SNgapore; 2National University of Singapore, Singapore Background: Citrullinemia is a rare inherited disorder caused by an enzyme defect in the urea cycle, leading to accumulation of plasma ammonia, citrulline, and glutamate. We present the diffusion-weighted M R imaging (DWI) and spectroscopy (MRS) findings in two patient with undiagnosed adult-onset citrullinenffa. Method: A 25-year-old man with recurrent coma, and a 27-year-old man with giddiness, altered mental state and psychiatric ssanptoms underwent MRS (single-voxel point resolved spectroscopy TR/TE 1500/30 ms) and DWI (echo-planar imaging, 3 orthogonal directions, b - 1000). Results: MRS revealed decreased N A A and elevated glutamate/ glutanffne levels in the basal ganglia. DWI showed hyperintensities in the basal ganglia, cingnlated gyms, insula, and in the depths o f the cortical sulci. Both patients had extremely elevated plasma ammonia level, with raised citrulline level and absence of argininosuccinic acid. One patient died before blood test results were known. Conclusion: MRS can detect abnormal metabolite accumulation in the brain, and DWI can delineate the extent of involvement in citrullinemJa. Although rare, tiffs characteristic pattern of neuroimaging should be recognised. 0633 Diffusion tensor MR tractography visualizes corticospinal tract degeneration in Amyotrophie Lateral Sclerosis

LhI1, CCT 1,z, Cheng, SliT 1, Yin, H 3, Lin, M 3, Guo, X G 3. 2Nationai Neuroscience Institute, Singapore; 2National University of Singapore, Singapore; 3Chinese PLA General Hospital, Beijing, China Background: Motor neuron damage and cortical spinal tract (CST) degeneration are pathological features of amyotrophic lateral sclerosis (ALS). Recently, several reports have found that diffusion tensor M R imaging (DTI), measuring fractional anisotropy (FA) and mean diffusivity (MD), was useful in diagnosing upper motor neuron involvement. We applied a novel tractography technique that measures the fiber volume of the CST. Method: Eight ALS patients were compared to normal controls. Fractional anisotropy (FA) and mean diffusivity (MD), were measured at the posterior limb of the internal capsule (PIC), fiber tracking using

0634 A case series of conduction aphasia with neuroimaging correlation.

I.iu, K 1, Wang, K 2,Dai, D 1, Wong, K 1, Wong, A 1 , Chan, y2, Woo, j1.

1Division of Geriatric and Neurology" of Department of Medicine and Therapeutics, Prince of Wales Hospital, Shatin, Hong Kong, People's Republic of China; 2Diagnostic Radiology and Organ Imaging Department Prince of Wales Hospital, Shatin, Hong Kong, People's Republic of China

0635 Combined DC-Magnetoencephalography and time-resolved nearhd~a~ed spectroscopy: An app~oadl to etla~acte~ise Neurovascula~ Coupling non-invaSively in the huInan b~ain

Mackert, BM l, Leistner, S ~, Sander, T ~, Liebert, A ~, Wabnitz, H ~, Burghoff, M a, Macdonald, R ~, Trahms, L ~, Curio, G ~. 1Department of

Neurology, Campus Benjamin Franklin, Charite - University Medicine Berlin, Germany; ~Physikalisch-TechnischeBundesanstalt, Institute Berlin, Germany Most functional brain imaging methods detect neuronal activation indirectly through the accompanying neurovascular/metabolic response. Awareness, however, is increasing that the link between neuronal and vascular/metabolic task-related responses is not a simple linear transform. As DC- magnetoencephalography (DC-MEG) measures low amplitude neuronal activity in the time scale of vascular responses and time-resolved near-infrared spectroscopy (trNIRS)