A rare presentation of bilateral Sturge-Weber syndrome.

Introduction

Sturge-Weber syndrome (SWS), or encephalotrigeminal angiomatosis, is a non-hereditary, non-familial, and congenital disorder of unknown etiology. The condition belonging to the group phakomatoses is diagnosed by the triad of skin (unilateral facial port-wine staining (PWS) often involving the ophthalmic division of trigeminal nerve), central nervous system (intracranial leptomeningeal venous angiomas), and ocular (glaucoma and choroidal hemangioma) involvement. Bilateral PWS can be seen in 10% to 30% cases of SWS implicating both ophthalmic and maxillary trigeminal nerve distributions. Bilateral SWS is a rare entity, and little is known about the course and progression of this variant. We are presenting a rare case of bilateral SWS (type II) involving the first two divisions of trigeminal nerve with late onset glaucoma but without any clinical neurological affection.

Case Report

A 22-year-old female presented with complaint of progressive diminution of vision in both eyes for past 4-5 years. There was no history of seizures, hemiparesis, mental, or growth retardation.

On examination, patient had bilateral capillary hemangioma involving upper two-thirds of the face as well as both eyelids [Figure 1]. The upper lip was protruding and hypertrophied along with upper gingival hypertrophy [Figure 2]. Best corrected visual acuity was 6/24, N8 in both eyes (OU). Intraocular pressure (IOP) measured with applanation tonometer was 40-mm Hg in the right eye (OD) and 36-mm Hg in the left (OS). Central corneal thickness was 497 and 484 μm in OD and OS, respectively. The corrected IOP was 44-mm Hg in OD while it was 40-mm Hg in OS. There was episcleral telangiectasia in the inferonasal quadrant of OD [Figure 3]. There was no such finding in OS. Anterior segment examination was unremarkable. Gonioscopy showed open angles with no angle anomaly. Dilated fundus examination showed a large excavated cup of around 0.95 with very thin neuroretinal rim OU. Ophthalmoscopically and angiographically dilated tortuous central retinal vessels with arteriovenous malformation were seen in superior retina of OD [Figure 4] while the retinal vessels were of normal caliber in OS. There was marked constriction of visual fields on automated perimetry with only a small central island of vision in both eyes.

Figure 1

Facial nevus flammeus involving V1 and V2 dermatomes of trigeminal nerve with upper lip hypertrophy

Figure 2

Oral involvement showing gingival hypertrophy

Figure 3

Dilated and telangiectatic episcleral vessels in right eye

Figure 4

(a) Dilated and tortuous retinal blood vessels in right eye (b) Normal retinal vessels in left eye. Optic disks showing bilateral advance glaucomatous cupping

Magnetic resonance imaging (MRI) of brain with gadolinium contrast revealed dilated medullary veins in right temporoparietal region with enlarged ipsilateral choroid plexus. The lateral ventricles were also enlarged [Figure 5]. Gadolinium-enhanced MRI of orbit showed no enhancing lesion. Computerized tomography scan of brain was normal.

Figure 5

Contrast-enhanced MRI T1-weighted images showing (a) Dilated medullary vein (white arrow) and dilated choroid plexus (black arrow) on right side (b) Bilaterally dilated lateral ventricles

A diagnosis of type II SWS was made on the basis of clinical cutaneous and ocular findings and absence of any neurological symptoms and signs. Topical anti-glaucoma treatment was started to lower the IOP in order to prevent further optic nerve damage. In the second stage, sequential mitomycin C augmented filtration surgery was planned.

Discussion

SWS is classified by Roach,[1] according to the presenting symptoms into three types as shown in Table 1.

Table 1

Roach scale classification

The hallmark of SWS is the presence of facial nevus flammeus or PWS, which is present in about 96% of cases. It usually occurs in the distribution of ophthalmic division of trigeminal nerve. It represents dilated dermal capillaries due to capillary vascular malformation causing PWS of the skin of face.

The most striking neurological feature of SWS is leptomeningeal angioma ipsilateral to the facial PWS. It is rather a key diagnostic feature in SWS.[2] Clinically, it may present as seizures, hemiparesis, developmental delay, and mental retardation.

A close association between neurological affection and severity of cutaneous involvement in SWS had been described in the past. But, more recent studies have shown that neither the size nor the distribution of facial PWS correlate with the neurological features.[3] The present case had bilateral nevus flammeus involving the dermatomes of both first and second divisions of trigeminal nerve but without neurological impairment. Interestingly, the palpebral distribution of PWS was asymmetric and incomplete, being more evident in upper eyelids than the lower.

An MRI brain with contrast is the gold standard for diagnosing SWS. In our case, MRI brain with contrast showed dilated medullary veins in right temporoparietal region with slight enlargement of ipsilateral choroid plexus. The lateral ventricles were also enlarged. However, no leptomeningeal angioma could be demonstrated on neuroimaging.

Ocular abnormality is more commonly seen in patients with PWS in the first and second divisions of trigeminal nerve.[4] Glaucoma is a prominent feature of SWS. Bilateral glaucoma is seen in about 45% of patients of bilateral SWS. Choroidal and episcleral hemangiomas are other ocular findings commonly found in patients of SWS. The episcleral vessel tortuosity, probably resulting from arteriovenous shunts within the episcleral hemangiomas, represents raised episcleral venous pressure that is implicated in causation of late onset glaucoma.[56] Facial nevus flammeus involving the palpebral area is a strong indicator of choroidal hemangioma.[3] Dilated and tortuous retinal vessels with peripheral retinal arteriovenous communications may also be visible some time.

The episcleral telangiectasia was seen only in the right eye in this case, but the patient had bilateral open-angle glaucoma, who presented quite late to us. At the time of presentation, the patient already had tubular vision in both eyes. Moreover, there were dilated tortuous retinal vessels in right eye with arteriovenous communication in peripheral superior retina, but no choroidal hemangioma was found either on clinical examination or fundus fluorescein angiography, or on gadolinium enhancement of MRI of orbit.

Gingival involvement is reported in 40% cases of SWS. The oral lesions include gingival hemangioma, gum hypertrophy, and asymmetric jaw growth.[7]

Sturge-Weber syndrome closely resembles Klippel-Trenaunay-Weber syndrome, which presents with PWS of face and limbs, hypertrophy of soft and bony tissues, and all the characteristics of SWS.[8] Facial PWS, macroglossia, omphalocele, and visceral hyperplasia characterize Beckwith-Wiedemann syndrome. Differential diagnosis of facial PWS along with gingival hyperplasia consists of Rendu-Osler-Weber syndrome (dilatation of terminal vessels of skin, mucosa, and viscera) and angio-osteodystrophy (facial PWS, varices, and hypertrophy of long bones).

To summarize, the current case of type II SWS presented with bilateral advanced juvenile glaucoma. In spite of nevus flammeus on the eyelids, there was no choroidal hemangioma. The episcleral and retinal arteriovenous malformations were limited only to the right eye. The oral involvement was in the form of gingival hypertrophy. Although there was no clinical evidence of neurological deficit, gadolinium-enhanced MRI of brain showed dilated medullary veins in right temporoparietal region with ipsilateral enlarged choroid plexus.

In conclusion, the absence of classical triad of central nervous system, ocular, and dermal impairment does not preclude the diagnosis of SWS. Furthermore, SWS may present with incomplete and atypical presentation as highlighted in the reported case.