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Byline: Claudia A. Doege (1), Ramin Tavakolian (2), Christian M. Kerskens (1), Berenice I. Romero (1), Rudiger Lehmann (2), Karl M. Einhaupl (1), Arno Villringer (1) Keywords: Key words Sinus thrombosis; Magnetic resonance imaging; Human; Perfusion; Diffusion Abstract: Background Diagnosis of cerebral venous thrombosis (CVT) is usually achieved by digital subtraction angiography or magnetic resonance angiography, while structural brain tissue damage can be assessed by computed tomography or magnetic resonance imaging (MRI). Using perfusion and diffusion weighted imaging (PWI, DWI) we aimed in this study to identify pathophysiological patterns corresponding to only functional and hence reversible tissue involvement. Methods PWI, DWI, and conventional MRI were performed in six CVT patients acutely and after 16--26 days when their clinical condition had improved. All patients were treated with partial thromboplastin time-effective intravenous heparin. After intravenous administration of a paramagnetic contrast agent, bolus track PWI allows pixel based determination of mean transit time (MTT) and cerebral blood volume (CBV). DWI was performed with two different b values (0, 1000 s/mm.sup.2) for calculation of apparent diffusion coefficient (ADC) maps. Results In five of six cases increased MTT values were observed initially, whereas the CBV was normal, indicating a reduction of cerebral blood flow. ADC values were normal. On follow up after clinical recovery MTT prolongations had resolved. Areas with prolonged MTT did not evolve into structural lesions. Conclusion In patients with CVT, prolongations of MTT in the absence of changes in CBV and ADC seem to indicate reversible involvement of brain tissue, a situation corresponding to the ischaemic penumbra. Author Affiliation: (1) Klinik und Poliklinik fur Neurologie, Universitatsklinikum Charite, Campus Mitte, Medizinische Fakultat der Humboldt-Universitat zu Berlin, Schumannstr. 20/21, 10117 Berlin, Germany Tel.: ++49-30-2802-2834 Fax: ++49-30-2802-8480 e-mail: claudia.doege@charite.de, DE (2) Department of Neuroradiology, Charite, Humboldt University, Berlin, Germany, DE Article note: Received: 20 June 2000 / Received in revised form: 27 November 2000 / Accepted: 19 January 2001

Byline: Simone Roricht (1), B.-U. Meyer (1), Christian Woiciechowsky (2), Rudiger Lehmann (3) Keywords: Key words Corpus callosum; Corticospinal tract; Hydrocephalus; Brain morphometry; Transcranial magnetic brain stimulation Abstract: In 15 patients with symptomatic hydrocephalus, pressure-induced morphological changes of the brain and the function of callosal and corticospinal fibres were studied. Morphometry of the corpus callosum (CC) was performed on midsagittal MR images. Focal transcranial magnetic stimulation of the motor cortex was used to assess simultaneously excitatory motor responses in contralateral hand muscle (corticospinally mediated effect) and inhibition of tonic EMG activity in ipsilateral hand muscles (transcallosal inhibition (TI) of the contralateral motor cortex). Before a shunt operation, the midsagittal area of the CC was reduced by 34% on average. The height and, to a lesser degree the length, of the CC were increased before the shunt operation. Thresholds and central motor latencies of corticospinally mediated responses were normal, response amplitudes were smaller than in normal subjects. Motor thresholds increased from 38, SD 5 to 52, SD 8% (P&lt 0.01) within 7 days after ventricular drainage, reflecting the increase in the distance between stimulation coil and brain. The threshold increase paralleled a restoration of normal anatomical conditions within 7 days after shunt operation and the improvement of motor symptoms and might be a predictor of successful decompression. Transcallosal inhibition could be elicited in all patients. The measurements of TI lay within the normal range except the duration, which was prolonged in 73% of 15 patients before shunt operation as a probable indicator of an increased dispersion of callosal conduction. The normalization of the area and shape of the CC after shunt operation and the normal corticospinal and callosal conduction times exclude degeneration, demyelination or functional block of a large proportion of callosal or corticospinal tract fibres or a substantial loss of nerve cells in motor cortex. Author Affiliation: (1) Department of Neurology of the Charite, Humboldt-University of Berlin, Augustenburger Platz 1, D-13353 Berlin, Germany Tel.: 40-30-45060012 Fax: 40-30-45060901, DE (2) Department of Neurosurgery of the Charite, Humboldt-University of Berlin, Berlin, Germany, DE (3) Department of Neuroradiology of the Charite, Humboldt-University of Berlin, Berlin, Germany, DE Article note: Received: 22 October 1997 Received in revised form: 13 January 1998 Accepted: 17 January 1998