Cytotoxic Lesions Of the Corpus Callosum (CLOCCs)

-


45 years old patient on antiepileptic (lamotrigine) and antidepressant medication. Presents with unspecific neurological symptoms. MRI without contrast shows diffusely demarcated oval lesion with edema in splenium of corpus callosum.


Diffusion weighted imaging shows restricted diffusion with high signal on DWI and low on ADC corresponding with cytotoxic edema. However location is not specific for infarction. Given the history of treatment together with appearance of the lesion the Cytotoxic Lesions Of the Corpus Callosum (CLOCCs) was presumed to be the most likely diagnosis. CLOCCs do no enhance. Medication was stopped and follow up scan was scheduled.


Control scan 1 month later was performed without and with contrast and as expected no contrast enhancement was seen. The lesion has decreased in size. Patient symptoms have resolved.


Reduction of edema in the lesion is well seen on T2 sequence.

As a side note: the control scan was performed on 1.5T vs 3.0T MRI scanner for initial exam - that does not influence the depiction - only gives slightly different appearance of the brain structures. 


No diffusion restriction was noted on the control scan - compared with initial MRI.




CLOCCS present with cytotoxic edema in the splenium of corpus callosum. It can be caused by metabolic disturbance (electrolyte imbalance, etc.), infections, but also by drugs and toxins: chemotherapy, antidepressants, antiepileptics, etc.

Also known as: transient lesions of the splenium of corpus callosum, mild encephalitis/encephalopathy with a reversible isolated SCC lesion (MERS), reversible splenial lesions and reversible splenial lesion syndrome (RESLES).

Take home message is when you see cytotoxic edema "strange looking infarct-like" lesion in the splenium think about patient's medical history especially for medication. 

Popular posts from this blog

Huntington Disease

-
Image
10 years old boy from parents being cousins to each other presents with progressive rigidity and dystonia. Initial MR showing significant bilateral atrophy in caudate nuclei and putamina with high signal on FLAIR and T2 consistent with gliosis. Note striking symmetric atrophy of the putamina and caudate nuclei on T2 and IR. Huntington disease (HD) is also known as Huntington chorea. HD is an autosomal dominant chronic hereditary neurodegenerative disorder with complete penetrance [Osborn].  Aggregates of huntingtin protein accumulate in axonal terminals, which eventually leads to the death of medium spiny neurons. Autopsy shows generalized cerebral atrophy with an average of 30% reduction in brain weight. Both the cortex and hemispheric WM are affected. The most characteristic gross abnormality is volume loss with rarefaction of the caudate nucleus, putamen, and globus pallidus [Osborn].  Microscopically, HD features neuronal loss with huntingtin nuclear inclusi...
Read more

Hemorrhagic Choroid Plexus Cyst

-
Image
Transversal Diffusion Weighted sequence shows high signal in the left choroid plexus with corresponding low signal on ADC (restricted diffusion). Finding represents acute Hemorrhagic Choroid Plexus Cyst . It is also known as Choroid Plexus Xanthogranuloma . Gradient Echo sequence (third image) shows low signal in the right choroid plexus representing hemosiderine deposits after previous hemorrhage. Coronal T1 shows intermediate to high signal in the plexus cyst. Note also low signal in the right plexus on T2 (old hemorrhage) and high signal on FLAIR in the left plexus (acute hemorrhage). Choroid Plexus Cysts are very common normal finding. Those often show restricted diffusion. However in our case of patient with hypertension this finding is of interest to the clinicians as a requirement to more closely monitor patient's blood pressure. There were no signs of intraventricular hemorrhage.
Read more

Dilated Perivascular Spaces in the Brain

-
Image
Above images (tra T2, tra FLAIR, cor T2 and sag T1) show enlarged Perivascular Spaces (PVS) in the right frontal lobe of the elderly patient with dementia. Note that signal follows that of the CSF (see FLAIR). Moreover note moderate general cortical atrophy. PVS, also known as Virchow-Robin spaces are considered normal finding although perhaps in the future we should know more about the exact patophysiology and possible relations till dementia and other conditions.
Read more