Thalamic laminar necrosis

Abstract

We present two cases, one after status epilepticus and one after brain radiation therapy, with bilateral hyperintense thalamic lesions on T1-weighted imaging. The first patient (54-year-old woman) presented with a generalized status epilepticus following diffuse hemispheric subarachnoid hemorrhage. Initial brain MRI showed multifocal hyperintense cerebral cortex and thalami on FLAIR and DWI sequences (probably related to status epilepticus), in absence of T1-weighted signal changes. After successful antiepileptic treatment, MRI, 24 days later, showed near normalization of FLAIR/DWI abnormalities, but now showed hyperintense thalami and rightsided parietal cortex (Fig. 1). MRI, 5 months later, continued to show stable T1-weighted abnormalities. The second patient (37-year-old woman) with a history of cerebellar astrocytoma was (WHO grade III) treated at age 18 by complete surgical resection and large-field radiation therapy (including the occipital lobes and both thalami). Her clinical and radiological state (follow-up was performed with low field MRI scans) was stable for many years. There was no history of status epilepticus. A follow-up MRI, this time with a high-field 3T MRI scan at age 33, showed hyperintense occipital cortex and thalami on T1-weighted imaging (Fig. 1), still in the absence of tumor recurrence. 3T MRI, 4 years later, was stable.