S Fitzek — Page 2 | Search PubMed

PubMed1999

Ipsilateral facial weakness in upper medullary infarction-supranuclear or infranuclear origin?

We describe two patients with upper medullary infarctions showing ipsilateral facial weakness and relative sparing of the upper facial muscles. Electrophysiological follow-up using transcranial magnetic stimulation of the motor cortex in combination with stimulation of the peripheral facial nerve disclosed a supranuclear (corticofacial) tract lesion in one patient and a partial nuclear/infranuclear intra-axial facial nerve lesion in another.

Aged↗

PubMed1999

Blink reflex R2 changes and localisation of lesions in the lower brainstem (Wallenberg's syndrome): an electrophysiological and MRI study.

OBJECTIVES: Pathways of late blink reflexes are detected by high resolution MRI. Electronically matched stroke lesions superimposed to an anatomical atlas show the suspected course. METHODS: Fifteen patients with infarction of the lower brainstem, MRI lesions and electrically elicited blink reflexes were examined. The involved structures in patients with R2 and R2c blink reflex changes were identified by biplane high resolution MRI with individual slices matched to an anatomical atlas at 10 different levels using digital postprocessing methods. RESULTS: The blink reflexes were normal in five of 15 patients (33%) and showed loss or delay of R2 and R2c to stimulation ipsilaterally to lesion (R2-i and R2c-i) in eight (53%). Loss or delay of R2-i/R2c-i was seen in lesions covering the entire trigeminal spinal tract and nucleus (TSTN) at at least one level. These infarctions were located more dorsally within the medulla. Patients with normal blink reflexes showed lesions sparing or involving the TSTN only partially. They more often had incomplete Wallenberg's syndromes and MRI lesions were located more ventrally. CONCLUSIONS: Using digital postprocessing MRI methods it was possible to identify central pathways of late blink reflex in patients with Wallenberg's syndrome. This method is suggested as a new approach to identify incompletely understood functional structures of the brainstem.

Aged↗

PubMed1998

Differentiation of recent and old cerebral infarcts by diffusion-weighted MRI.

We performed MRI, including diffusion-weighted imaging, in 15 patients with recurrent strokes with acute ischaemia and at least one old lesion according to the clinical history and/or CT. Routine MRI showed similar signal intensity changes in both situations. Diffusion-weighted images, however, were positive in all acute or subacute infarcts. The high signal of acutely disturbed diffusion due to intracellular oedema could also be identified in small brain stem lesions. Spatial resolution was increased by applying separate gradients in each axis instead of creating anisotropy-independent trace images.

Adult↗