Zytotoxische Balkenläsionen haben viele Ursachen. Sie müssen als das angesehen werden,
was sie sind – als sekundäre Läsionen. Es ist daher wichtig, dass Ärzte mit den bekannten
Ursachen zytotoxischer Balkenläsionen vertraut sind, damit diese ermittelt und angegangen
werden können und nicht fälschlicherweise eine Ischämie diagnostiziert wird. Deshalb
schildert dieser Artikel Mechanismen, Ursachen und Manifestationen zytotoxischer Balkenläsionen.
Abstract
Cytotoxic lesions of the corpus callosum (CLOCCs) are secondary lesions associated
with various entities. CLOCCs have been found in association with drug therapy, malignancy,
infection, subarachnoid hemorrhage, metabolic disorders, trauma, and other entities.
In all of these conditions, cell-cytokine interactions lead to markedly increased
levels of cytokines and extracellular glutamate. Ultimately, this cascade can lead
to dysfunction of the callosal neurons and microglia. Cytotoxic edema develops as
water becomes trapped in these cells. On diffusion-weighted magnetic resonance (MR)
images, CLOCCs manifest as areas of low diffusion. CLOCCs lack enhancement on contrast
material-enhanced images, tend to be midline, and are relatively symmetric. The involvement
of the corpus callosum typically shows one of three patterns: (a) a small round or
oval lesion located in the center of the splenium, (b) a lesion centered in the splenium
but extending through the callosal fibers laterally into the adjacent white matter,
or (c) a lesion centered posteriorly but extending into the anterior corpus callosum.
CLOCCs are frequently but not invariably reversible. Their pathologic mechanisms are
discussed, the typical MR imaging findings are described, and typical cases of CLOCCs
are presented. Although CLOCCs are nonspecific with regard to the underlying cause,
additional imaging findings and the clinical findings can aid in making a specific
diagnosis. Radiologists should be familiar with the imaging appearance of CLOCCs to
avoid a misdiagnosis of ischemia. When CLOCCs are found, the underlying cause of the
lesion should be sought and addressed.
Schlüsselwörter
zytotoxische Balkenläsionen - Entstehungsmechanismus - bildgebendes Muster - Ursachen
Keywords
cytotoxic lesions of the corpus callosum - molecular basics - MR imaging findings
- causes