Isolated leptomeningeal angiomatosis in the sixth decade of life, an adulthood variant of Sturge Weber Syndrome (Type III): role of advanced Magnetic Resonance Imaging and Digital Subtraction Angiography in diagnosis.

Background: Sturge-Weber syndrome (SWS) is primarily diagnosed in pediatric population, but clinical presentation in late adulthood is rarely reported. Evolution of radiological findings in the adulthood variant of SWS with isolated leptomeningeal angiomatosis has never been reported to our knowledge.
Case Presentation: We report here a case of an isolated temporo-parieto-occipital leptomeningeal angiomatosis on the right cerebral hemisphere in a sixty-two-year-old male who presented with generalized seizure, GCS score 14/15 (E4 V4 M6) with equal and reacting pupils, psychomotor slowing, left hemineglect and grade 4 power in the left upper and lower limbs. Over a period of 48 h his neurological status deteriorated, but recovered spontaneously over a week on titration with anticonvulsants. He had a prior history of treatment for focal leptomeningitis, three years ago. Cerebrospinal fluid (CSF) analysis showed glucose of 75 mg/dL, proteins of 65 mg/dL and culture grew no organisms. On follow-up, he had intermittent episodes of focal seizure for two years. Initial, computed tomography of brain showed hyperdense lesion in the parieto-occipital convexity subarachnoid space on the right cerebral hemisphere mimicking subarachnoid hemorrhage and computed tomography angiography showed no significant abnormality. Magnetic resonance imaging (MRI) of brain showed intense pial enhancement in the right temporo-parieto-occipital region with a subtle T2W hyperintense signal in the underlying subcortical white matter without edema or infarct or mass effect. Digital subtraction cerebral angiography (DSA) showed hypertrophy of the cerebral arteries, arteriolo-capillary bed and venules in the right temporo-parieto-occipital territory associated with early arterio-capillary and venous opacification. Serial MRI done after six months, one and two years showed increase in the T2W hyperintense signal in the subcortical white matter and cortical atrophy with no changes in the pial enhancement. MR perfusion imaging showed reduced cerebral blood flow (CBF) and cerebral blood volume (CBV) in the right parieto-temporo-occipital cortical and subcortical regions and increased perfusion in the leptomeninges with reduction of the NAA / Cr ratios in spectroscopy.
Conclusion: Conglomeration of various radiological findings in MRI, Perfusion, MRS and DSA with the clinical presentation can aid in establishing the diagnosis of this rare presentation of SWS-type 3 variant in late adulthood.