Corpus callosum impingement syndrome (CCIS) is caused by impingement of the corpus callosal fibers against inferior free margin of the falx cerebri due to longstanding and severe hydrocephalus and stretching of the lateral ventricles. This results in ischaemia and eventually atrophy of the neural fibers in corpus callosum. CCIS does not appear to produce any clinical symptoms but recognition of this is crucial to avoid misinterpretation which can lead to unnecessary intervention.
MRI shows severe hydrocephalus and stretching of the lateral ventricles.
Initially, the corpus callosum appears swollen with low signal on T1WI and hyperintensity on T2/FLAIR sequences. Longstanding changes include hyperintensity of the corpus callosum (CC) on T2/FAILR as well as volume loss and atrophy which is most pronounced in the rostral portion and body of the CC. These findings can persist even after decompression of the ventricles.
- 1. Lane JI, Luetmer PH, Atkinson JL. Corpus callosal signal changes in patients with obstructive hydrocephalus after ventriculoperitoneal shunting. AJNR Am J Neuroradiol. 2001;22 (1): 158-62. AJNR Am J Neuroradiol (full text) - Pubmed citation
- 2. Jinkins JR, Rauch RA, Hagino N et-al. Evaluation of histopathologic changes in an animal model of mechanical corpus callosum impingement as seen in hydrocephalus. Acad Radiol. 1998;2 (7): 614-7. Pubmed citation