Edgar Dettmann

Time course in the development of cerebral vasospasm after experimental subarachnoid hemorrhage: clinical and neuroradiological assessment of the rat double hemorrhage model.

OBJECTIVE:The “double hemorrhage” model in the rat is frequently used to simulate delayed cerebral vasospasm (CVS) after subarachnoid hemorrhage (SAH) in humans. However, an exact neurological and angiographic characterization of the CVS is not available for this model so far and is provided in the present investigation. Additionally, perfusion weighted imaging (PWI) at 3 tesla magnetic resonance (MR) tomography was implemented to assess the reduction in cerebral blood flow (CBF). METHODS:In a prospective, randomized setting CVS was induced by injection of 0.2 ml autologous blood twice in the cisterna magna of 45 male Sprague-Dawley rats. The surviving animals were examined on Days 2, 3, 5, 7 and 9 and compared to a sham operated control group (n = 9). Rats were neurologically graded between 0 and 3, followed by MRI and selective digital subtraction angiography (DSA). The relative CBF was set in relation to the perfusion of the masseter muscle. RESULTS:The neurological state was significantly worsened on Day 2 (Grade 3), 3 (Grade 3), and 5 (Grade 2) (medians). The relative CBF/muscle BF ratio (2.5 ± 0.8 (SAH) versus 9.2 ± 1.3 (sham) (mean ± SEM) and the basilar artery (BA) diameter (0.15 ± 0.02 mm (SAH) versus 0.32 ± 0.01 mm (sham) were significantly decreased on Day 5. Correlation between relative CBF/muscle BF ratio and BA diameter was 0.70. CONCLUSION:A valid and reproducible CVS simulation was proven by neurological score, DSA, and PWI on Day 5. Furthermore, our data demonstrate the practicability and validity of MR PWI for the monitoring of CVS in a rat SAH model.

Cerebral Erdheim-Chester disease: case report and review of the literature

Erdheim-Chester disease is a rare systemic non-Langerhans histiocytosis of unknown etiology that affects multiple organ systems. Cerebral involvement is most often caused by extra-axial masses of foamy histiocytes, whereas intraparenchymal manifestations are less frequent. Review of the literature yielded a total of seven patients with increased signal intensities on T2-weighted images in both dentate nuclei and the peridentate regions. We report on a 44-year-old man with biopsy-proven Erdheim-Chester disease and slowly progressive cerebellar dysfunction. MRI showed additional symmetrical hyperintense signal changes in the superior cerebellar peduncle as well as in the trigonum lemnisci on coronal FLAIR images. The widespread neurological manifestations of cerebral Erdheim-Chester disease and differential diagnosis are discussed.

Intracranial hypotension after chiropractic manipulation of the cervical spine

The aetiology of intracranial hypotension is not fully understood, but CSF leakage from spinal meningeal diverticula or dural tears may be involved. In the majority of patients without a history of mechanical opening of the dura the cause of intracranial hypotension is unknown and the syndrome is termed “spontaneous” intracranial hypotension. We report a case of intracranial hypotension ensuing after a spinal chiropractic manipulation leading to CSF isodense effusion in the upper cervical spine. A 40 year old woman undertook a spinal chiropractic manipulation. The chiropractioner grasped the head of the supine patient and exerted axial tension while rotating the head. During this manoeuvre the patient complained of a sudden sharp pain in her upper neck, and the procedure had to be stopped immediately. Subsequently she complained of headaches and after 24 hours she developed nausea and vomiting. Her headaches worsened, and lying down gave the only measure of limited relief. On the sixth day she developed double vision and presented to the neurology department of a community hospital. She had a right abducens palsy and pachymeningeal gadolinium enhancement on magnetic resonance imaging (MRI). …

Diffusionsgewichtete MRT bei spinalen Infarkten

ZusammenfassungSpinale Infarkte sind selten und haben eine heterogene Ätiologie. Die in der Akutdiagnostik eingesetzte spinale Magnetresonanztomographie (MRT) dient vor allem dem differenzialdiagnostischem Ausschluss spinaler Raumforderungen, die einer raschen neurochirurgischen Entlastung bedürfen. Wir berichten über 2 Patienten mit einem Syndrom der A. radicularis magna (Adamkiewicz) und Infarzierung des thorakolumbalen Myelons einschließlich des Conus medullaris. Während die T2-gewichteten Sequenzen 4 und 28 h nach dem Infarktereignis keine beziehungsweise nur diskrete unspezifische Signalanhebungen zeigten, ergab die ergänzende diffusionsgewichtete Bildgebung (DWI) eine deutliche Diffusionsstörung. Vergleichbar mit der modernen MRT-Diagnostik bei akuten zerebralen Infarkten hebt die Diskrepanz zwischen minimalen Signalveränderungen in den T2-gewichteten Sequenzen und deutlicher Diffusionsstörung den Stellenwert der DWI in der Akutdiagnostik spinaler Infarkte hervor. Allerdings stehen systematische DWI-Untersuchungen bei akuten entzündlichen und vaskulären spinalen Prozessen noch aus.SummarySpinal cord infarctions occur rarely and are due to various aetiologies. In an emergency setting with acute spinal cord symptoms, magnetic resonance imaging (MRI) is used to exclude space-occupying lesions which require neurosurgical intervention. We report on two patients presenting with an anterior spinal artery syndrome caused by infarction of the thoracolumbar spinal cord including the conus medullaris. While T2-weighted images 4 h and 28 h after onset of clinical symptoms showed only slight unspecific signal changes, diffusion-weighted imaging revealed clear infarction and detected spinal cord ischaemia in an early stage, showing signal intensity conversion comparable to that in acute cerebral stroke.

Assessment of Regional Cerebral Blood Flow and Blood Volume after Aneurysmal Subarachnoid Hemorrhage

Purpose:The aim of this prospective study was to evaluate changes of regional cerebral blood flow (rCBF) and regional cerebral blood volume (rCBV) in the first days after aneurysmal subarachnoid hemorrhage (SAH) in patients with and without unilateral cerebral vasospasm (CVS).Patients and Methods:In 48 patients perfusion-weighted magnetic resonance imaging (MRI) and digital subtraction angiography (DSA) were performed 5 ± 3 days after SAH. Local CVS was analyzed in the anterior cerebral artery (ACA) and middle cerebral artery (MCA) territory as well as in the basal ganglia. Each territory was compared with the corresponding contralateral area and SAH patients (control group) exhibiting no signs of CVS on follow-up DSA. Ratios of rCBV and rCBF of the vasospastic and the corresponding contralateral territory of local mild (11–33%), moderate (34–66%) and severe CVS (67–100%) were statistically evaluated using the Kruskal-Wallis test followed by Conover-Iman post-hoc test.Results:A significant decrease of rCBF under moderate CVS was seen in the ACA territory and in the basal ganglia in comparison to the control group of SAH patients without CVS (p < 0.05); furthermore, in the ACA territory rCBF significantly decreased under moderate CVS in comparison to mild CVS (p < 0.01). Comparison of rCBV in all three areas showed no significant differences in all grades of CVS.Conclusion:Regional CBV as an indicator of autoregulatory vasodilatation did not increase with higher CVS, suggesting an at least partially impaired autoregulation in the early phase after SAH. However, hemodynamic relevance of this impaired autoregulation might be dependent on the degree of CVS, the vascular territory, and the involvement of the microcirculation.ZusammenfassungZiel:In dieser prospektiven Studie sollten Veränderungen des regionalen zerebralen Blutflusses (rCBF) und Blutvolumens (rCBV) in den ersten Tagen nach aneurysmatischer Subarachnoidalblutung (SAB) anhand von Patienten mit und ohne unilateralen zerebralen Vasospasmus (CVS) untersucht werden.Patienten und Methodik:Bei 48 Patienten wurden 5 ± 3 Tage nach SAB sowohl eine perfusionsgewichtete Magnetresonanztomographie als auch eine digitale Subtraktionsangiographie (DSA) durchgeführt. Der lokale CVS im Territorium der Arteria cerebri anterior (ACA) und der Arteria cerebri media (MCA) sowie in den Stammganglien wurde analysiert. Jedes Areal wurde sowohl mit der korrespondierenden Gegenseite sowie mit SAB-Patienten ohne CVS (Kontrollgruppe) verg addilichen. Die Verhältnisse von rCBV und rCBF der vasospastischen Seite und des korrespondierenden kontralateralen Territoriums bei mildem (11–33%), moderatem (34–66%) und ausgeprägtem CVS (67–100%) wurden mit dem Kruskal-Wallis-Test und dem Conover-Iman-post-hoc-Test statistisch ausgewertet.Ergebnisse:Bei moderatem CVS reduzierte sich der rCBF im ACA-Territorium und in den Stammganglien signifikant (p < 0,05) im Vergleich zur Kontrollgruppe ohne CVS; des Weiteren sank der rCBF im ACA-Gebiet unter moderatem CVS auch im Vergleich zum milden CVS signifikant (p < 0,01). Der Vergleich von rCBV aller CVS-Grade der drei untersuchten Areale ergab keine signifikanten Unterschiede.Schlussfolgerung:Da das rCBV als Indikator für autoregulative Vasodilatation nicht mit höhergradigem CVS anstieg, sprechen die vorliegenden Daten für eine zumindest partielle Störung der Autoregulation in der Frühphase nach SAB. Die hämodynamische Relevanz dieser Autoregulationsstörung scheint von der Ausprägung des CVS-Grads, vom Gefäßareal und von der möglichen Kompromittierung der Mikrozirkulation abhängig zu sein.