A spectrum of unusual neuroimaging findings in patients with suspected Sturge-Weber syndrome

Abstract

Background and purpose: Sturge-Weber syndrome (SWS) is frequently associated with neurologic complications such as seizures, so diagnosing this condition has important implications for patient management. The purpose of this study was to report unusual neuroimaging findings in patients with facial port-wine stain (PWS) and clinically suspected SWS.

Materials and methods: Cranial MR imaging was reviewed for all children with facial port-wine stain (PWS) involving the upper face and eyelids who were referred to Great Ormond Street Hospital between 2003 and 2007 for investigation of suspected SWS. Patients were excluded from further analysis if the imaging findings were normal on initial and subsequent scans and the subject remained free of neurologic disease, or if the imaging showed the well-recognized pattern of exclusively supratentorial pial enhancement representing the pial angioma of SWS. For the remaining patients, the neurologic, dermatologic, and ophthalmologic records were examined and all available imaging was reviewed by a neuroradiologist. We documented the presence and distribution of pial enhancement; corroborative features of SWS, such as atrophy, calcification, choroid plexus changes, and ocular abnormalities; and all other intracranial abnormalities.

Results: Of the 62 patients referred for assessment, imaging findings were considered typical of SWS in 32 (52%) and were normal or showed abnormalities attributable to an unrelated pathology in 20 (32%). Of the remaining 10 patients, in 7 (11%), there was evidence of a pial angioma in an unusual distribution involving infratentorial structures, with the angioma in 1 patient being diagnosed at postmortem only; in 2 (3%), there were imaging abnormalities with some features in common with typical SWS, such as subcortical calcification, but with no evidence of pial enhancement; in 1 (1.6%), the initial MR imaging finding was normal, but repeat imaging subsequently revealed pial enhancement.

Conclusions: Involvement of infratentorial structures is common but may be relatively subtle and should be actively sought. Cases in which there are certain patterns of imaging abnormalities but an apparent absence of supratentorial pial enhancement on MR imaging may represent formes frustes of SWS; visualization of pial angiomatosis may also be delayed until later in childhood than expected.

Fig 1.

Pial angioma involving both supra- and infratentorial compartments. A and B, T1WI postgadolinium MR images of different patients (8 and 5 months of age, respectively) demonstrate pial enhancement of the left cerebral hemisphere (white arrows) and midbrain bilaterally (arrowheads). Choroidal angiomas (black arrow) and choroid plexus hypertrophy were also evident localized to the side of supratentorial involvement.

Fig 2.

Coronal MR images of an 8-month-old boy. A, T2WI image demonstrates atrophy of the right cerebral hemisphere and left cerebellar hemisphere. B, T1WI postgadolinium image demonstrates pial enhancement of the right cerebral hemisphere (white arrows) and left cerebellar hemisphere. C, Magnified T1WI postgadolinium image of the left cerebellar hemisphere demonstrates enhancement of the pial surface of the folia (white arrows). Bilateral midbrain pial enhancement and choroid plexus hypertrophy were also evident in this case.

Fig 3.

Pial angioma involving the infratentorial compartment only. A, Axial T1WI postgadolinium image of a 12-month-old boy demonstrates pial enhancement of the left cerebellar hemisphere (arrows) and medulla bilaterally (arrowheads). B, Axial T1WI postgadolinium image demonstrates pial enhancement of the ventral pons (arrowhead) and interpeduncular region of the midbrain (inset, arrowhead).

Fig 4.

Female patient with left-sided facial PWS isolated to V1 and V2, who developed early-onset seizures and developmental delay and died at 6 years of age secondary to pneumonia. Initial MR imaging at 6 months of age (not shown) demonstrated postural plagiocephaly and mild global delay in myelination, but no features of SWS. A and B, Axial T1WI postgadolinium MR images at 32 months of age. At the time of the examination, the images were interpreted as showing no features of SWS. Retrospectively, possible subtle pial enhancement is seen overlying the left pons and cerebellar hemisphere (arrows). C, Postmortem gross pathologic specimen of the cerebellum and brain stem viewed from the ventral surface. A fine plexus of abnormal vessels is seen overlying the left side of the pons, medulla, and left cerebellar hemisphere (arrows). P indicates pons; m, medulla; ba, basilar artery.

Fig 5.

Serial imaging of a child with a clinical complex of bilateral facial PWS, early-onset severe seizures, and fatally progressive encephalopathy. Imaging demonstrates progressive cerebral atrophy and calcification without evidence of pial enhancement. A, Contrast-enhanced CT scan at 1 month of age demonstrates mild cerebral atrophy and bilateral choroid plexus hypertrophy (black arrow). B, Axial T1WI postgadolinium image at 12 months of age shows further cerebral volume loss but no evidence of abnormal pial enhancement. C, CT scan at 15 months of age demonstrates progressive symmetric cerebral volume loss with calcification of the cortex and subcortical white matter, most marked within the frontal lobes bilaterally (white arrows).