Retrospective review of screening for Sturge-Weber syndrome with brain magnetic resonance imaging and electroencephalography in infants with high-risk port-wine stains

BACKGROUND

There is a lack of consensus regarding how best to screen children with facial port-wine stains for Sturge-Weber syndrome. Many favor brain magnetic resonance imaging, and adjunctive electroencephalography is increasingly used. However, the sensitivity, specificity, and negative and positive predictive value of magnetic resonance imaging and electroencephalography and whether screening improves seizure recognition is unclear.

METHODS

A retrospective review of children with high-risk port-wine stains presenting consecutively to the outpatient laser clinic of a tertiary pediatric hospital between December 2015 and November 2016 was undertaken. Primary outcome measures were yield, accuracy, age of and protocols for screening magnetic resonance imaging and electroencephalography, type of and age at presenting seizure, and percentage referred to neurology.

RESULTS

Of 126 patients with facial port-wine stains, 25.4% (32/126) were at high risk of Sturge-Weber syndrome (hemifacial, median, and forehead PWS phenotypes); 43.7% of these (14/32) underwent screening magnetic resonance imaging. Sturge-Weber syndrome was detected in 7.1% (1/14). Magnetic resonance imaging had false-negative results in 23.1% (3/13) of those screened. Screening magnetic resonance imaging had sensitivity of 25%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 76.9% for the detection of Sturge-Weber syndrome (hemifacial, median and forehead PWS phenotypes). Only one-third of those with false-negative magnetic resonance imaging were referred to neurology. Mean age of first seizure in those with false-negative screening magnetic resonance imaging was 28 months, vs 14 months in those not screened. Abnormal electroencephalographic signs were detected in the two infants who underwent presymptomatic electroencephalography.

CONCLUSIONS

Findings from this small cohort of individuals with port-wine stains that put them at high risk of Sturge-Weber syndrome suggest that children with positive screening magnetic resonance imaging will almost certainly develop Sturge-Weber syndrome but that negative screening magnetic resonance imaging cannot exclude Sturge-Weber syndrome (in up to 23.1% of cases). False-negative magnetic resonance imaging may delay seizure recognition. Seizure education, monitoring, and consideration of adjunctive electroencephalography are important irrespective of magnetic resonance imaging findings.

Screening for Sturge-Weber syndrome: A state-of-the-art review

Infants with a high-risk distribution of port-wine stains are commonly screened for Sturge-Weber syndrome using brain magnetic resonance imaging. There is no consensus about which port-wine stain phenotypes to screen, optimal timing, screening sensitivity, or whether presymptomatic diagnosis improves neurodevelopmental outcomes. This state-of-the-art review examines the evidence in favor of screening for Sturge-Weber syndrome, based on its effect on neurodevelopmental outcomes, against the risks and limitations of screening magnetic resonance imaging and electroencephalography. A literature search of PubMed/MEDLINE was conducted between January 2005 and May 2017 using key search terms. Relevant articles published in English were reviewed; 34 articles meeting the search criteria were analyzed according to the following outcome measures: neurodevelopmental outcome benefit of screening, diagnostic yield, financial costs, procedural risks, and limitations of screening magnetic resonance imaging and electroencephalography. There is no evidence that a presymptomatic Sturge-Weber syndrome diagnosis with magnetic resonance imaging results in better neurodevelopmental outcomes. The utility of electroencephalographic screening is also unestablished. In Sturge-Weber syndrome, neurodevelopmental outcomes depend on prompt recognition of neurologic red flags and early seizure control. Small numbers and a lack of prospective randomized controlled trials limit these findings. For infants with port-wine stain involving skin derived from the frontonasal placode (forehead and hemifacial phenotypes), we recommend early referral to a pediatric neurologist for parental education, counselling, and monitoring for neurologic red flags and seizures and consideration of electroencephalography regardless of whether magnetic resonance imaging is performed or its findings.

Debunking the Myth of Wool Allergy: Reviewing the Evidence for Immune and Non-immune Cutaneous Reactions

Although wool is commonly believed to cause irritant (non-immune) and hypersensitivity (immune) cutaneous reactions, the evidence basis for this belief and its validity for modern garments have not been critically examined. Publications from the last 100 years, using MEDLINE and Google Scholar, were analysed for evidence that wool causes cutaneous reactions, both immune-mediated (atopic dermatitis exacerbation, contact urticaria, allergic contact dermatitis) and non-immune-mediated (irritant contact dermatitis, itch). Secondary aims of this paper were to examine evidence that lanolin and textile-processing additives (formaldehyde, chromium) cause cutaneous reactions in the context of modern wool-processing techniques. Current evidence does not suggest that wool-fibre is a cutaneous allergen. Furthermore, contact allergy from lanolin, chromium and formaldehyde is highly unlikely with modern wool garments. Cutaneous irritation from wool relates to high fibre diameters (≥ 30-32 µm). Superfine and ultrafine Merino wool do not activate sufficient c-fibres to cause itch, are well tolerated and may benefit eczema management.