Cytotoxic lesions of the corpus callosum (CLOCCs)

Authors: J. Mračková 1;  R. Tupý 2;  V. Rohan 1;  J. Mraček 3;  P. Ševčík 1
Authors‘ workplace: Neurologická klinika LF UK a FN Plzeň 1;  Klinika zobrazovacích metod LF UK a FN Plzeň 2;  Neurochirurgická klinika LF UK a FN Plzeň 3
Published in: Cesk Slov Neurol N 2020; 83/116(4): 347-352
Category: Review Article
doi: 10.14735/amcsnn2020347


Cytotoxic lesions of the corpus callosum (CLOCCs) represent a group of conditions that cause MRI signal intensity changes in the corpus callosum. Etiology of this phenomenon is very heterogenous. CLOCCs are associated with a spectrum of metabolic disorders, drug therapy, infections, epileptic seizures and many other causes. It appears that these lesions result from a stereotyped inflammatory cascade which leads to a massive increase in levels of extracellular glutamate. The final result is development of cytotoxic edema. The range of clinical features is very wide. Neurological symptoms include motor and/or sensory involvement, cognitive decline, behavioral changes, dizziness, loss of consciousness and others. The main dia­gnostic tool is MRI, especially diffusion-weighted images, where CLOCCs manifest as regions of restricted diffusion. CLOCCs are reversible in most cases. Prognosis and treatment generally depend on the etiology, but clinical outcome is usually favorable. Physicians should be familiar with this recently named dia­gnosis, primarily because most of the underlying causes are treatable. In this article, we summarize the current knowledge and describe five cases of CLOCCs.


Corpus callosum – magnetic resonance imaging – reversible lesions – cytotoxic edema – restricted diff usion


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