Abstracts

Rationale: Focal lesion of the splenium of the corpus callosum has been reported in many different clinical settings ranging from viral encephalitis to hypoglycemic encephalopathy (1). However, this lesion is most commonly reported in patients with epilepsy and seizure disorder. The lesion has been seen in cases of intoxication and withdrawal with antiepileptic medications and generalized seizures (2). A single etiology cannot explain this finding and multiple mechanisms have been proposed. We present a case of patient having transient MRI findings due to a first time generalized seizure. Methods: Case report Results: 20 year old right handed female with history of Bipolar disorder type 2, Asperger's syndrome, had one episode of witnessed tonic clonic seizure. This was the first episode of seizure in her life. She had no injury from the seizure. No loss of urinary continence or tongue biting. The seizure lasted for several minutes. She had post-ictal confusion for 10 minutes. Patient had been on bupropion 300 mg daily for 5 months prior to the seizure. She was also on lamotrigine 200 mg daily for mood control. She was apparently recently weaned down from lamotrigine 400 mg daily over a few weeks to 200 mg daily. She had a MRI of the brain within 12 hrs after the seizure episode. The MRI of the brain w and w/o contrast showed a small less than 1 mm diffusion restriction within the midline corpus callosum (Image 1,2). She had repeat MRI of the brain in 2 months with complete resolution of the lesion. She had no history of CNS infection or head trauma. She was adopted and no family history was available. Her bupropion was stopped after the seizure episode since this medication can lower seizure threshold. Her lamotrigine dose was increased to 300 mg daily to control her mood disorder. She was followed for over 6 months and remained without any neurological deficits or further seizures. Conclusions: Seizures can cause transient reversible MRI abnormalities in splenium of corpus callosum (2). Our patient had several predisposing factors to cause this phenomenon with a recent change of antiepileptic medication dosage and simultaneous use of medication that lowers seizure threshold, bupropion . Seizures affect more than the cortical gray matter but also affect large white matter connections of brain, ie corpus callosum (1,2). MRI abnormalities in the postictal state may show a physiological change in brain rather than a structural lesion.Seizure related MR signal changes may aid in the overall differential diagnosis and increased recognition of this phenomena will likely decrease misdiagnosis and avoid invasive diagnostic testing . Bibiologrophy 1.Gallucci M, Limbucci N, Paonessa A, Caranci F. Reversible focal splenial lesions. Neuroradiology. 2007 Jul;49(7):541-4. 2.Gröppel G, Gallmetzer P, Prayer D, Serles W, Baumgartner C. Focal lesions in the splenium of the corpus callosum in patients with epilepsy. Epilepsia. 2009 Jun;50(6):1354-60.