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Neuroradiology Case of the Week

Case 421

July 2009

Hisao Nakamura, MD

Clinical Presentation: Patient is a 22-year-old male with a history of epilepsy and right temporal lobe seizures.

Imaging Findings: Diffusion-weighted images shows a hyperintensity in the splenium of the corpus callosum.

Diagnosis: Demyelination of the splenium of corpus callosum secondary to anti-epileptic drug

Discussion: There are at least 32 reported epilepsy cases that describe circumscribed lesions in the splenium of the corpus callosum. Fifteen of these were associated with withdrawal of antiepileptic drug as in this patient. This patient namely had the drug stopped eight days before this study in order for him to undergo long term monitoring.
     The etiology of the lesion in the splenium of the corpus callosum is generally unknown. It is probably of no clinical significance and seem to be caused by rapid reduction in antiepileptic drugs rather than toxicity from the drug. For unknown reasons, this type of lesion occurs in the center of the splenium of the corpus callosum more often than in other locations.
     This patient was on levetiracetam (LEV) and this drug was withdrawn 8 days before the MRI examination.

References:

1. Gürtler S, Ebner A, Tuxhorn I, Ollech I, Pohlmann-Eden B, Woermann FG. Transient lesion in the splenium of the corpus callosum and antiepileptic drug withdrawal. Neurology. 2005 Oct 11;65(7):1032-6. PMID: 16217055 [PubMed]