A case of 55-year-old man with first-ever generalized seizure diagnosed with Sturge-Weber syndrome type III by characteristic MRI findings.

A 55-year-old man with no mental retardation had presented a history of frequent transient clumsiness of his right upper and lower extremities for about 20 years. He was admitted to a general hospital with weakness of right side of the body, and first-ever generalized seizure attack occurred the next day. Brain CT showed calcification in the left cerebral cortices. So he was referred to our hospital. On neurological examination, he had mild clumsiness of his right upper limb and right pyramidal tract sign. He had neither facial port-wine stain nor glaucoma. The blood test and cerebrospinal fluid analysis were unremarkable. Electroencephalogram showed slowing and reduction of activity at the left frontal and parietal areas with no epileptic activities. Brain CT showed "tram-track calcification" and lobar atrophy in the left fronto-parietal cortices. Susceptibility weighted imaging (SWI) on MRI revealed enlarged transmedullary veins in the left periventricular white matter and low intensity lesions along the cortical gyri. Post gadolinium fluid-attenuated inversion recovery imaging (FLAIR-Gd) showed leptomeningeal enhancement in the left fronto-parietal lobes more extensively than those by post gadolinium T1-weighted image. Brain perfusion single photon emission computed tomography with a technetium-99m-ethyl cysteinate dimer (99mTc-ECD SPECT) revealed hypoperfusion in the fronto-parietal lobes. These clinical and neuroimaging findings were compatible with type III Sturge-Weber syndrome (SWS). His condition was improved after treatment with oral levetiracetam (1,000 mg daily). Although adult-onset type III SWS is very rare, it is important to perform SWI and post-contrast FLAIR for assessing leptomeningeal angioma in patients with seizure with focal cortical calcification even if they have no facial nevus.