Importance of utilizing a sensitive free thyroxine assay in Sturge-Weber syndrome

Hypothalamic-pituitary dysfunction in Sturge-Weber syndrome: case report and review of the literature

OBJECTIVES

Sturge-Weber syndrome (SWS) is a rare neurocutaneous disorder that is characterized by a segmental dermatomal facial port-wine stain birthmark and is frequently accompanied by ipsilateral brain and eye abnormalities. We present a case of a patient with SWS who exhibited hypogonadotropic hypogonadism, growth hormone (GH) deficiency, and central hypothyroidism at the age of 20 despite the absence of radiographic findings in the pituitary and hypothalamus.

CASE PRESENTATION

A 20-year-old male with SWS with epilepsy and Klippel-Trenaunay syndrome presents with delayed pubertal development, short stature, and obesity. Upon further examination, he was found to have biochemical and clinical evidence of hypogonadism, hypothyroidism, and GH deficiency. A pituitary MRI displayed no abnormalities of the pituitary or hypothalamus. Treatment with testosterone cypionate and levothyroxine was initiated. Despite successful pubertal induction, IGF-1 levels have remained low and treatment with recombinant human growth hormone (rhGH) is now being considered for metabolic benefits.

CONCLUSIONS

This case emphasizes the importance of endocrine evaluation and treatment of hormonal deficiencies in patients with SWS despite the absence of radiographic findings.

Less known aspects of central hypothyroidism: Part 2 - Congenital etiologies

Central hypothyroidism (CH) occurs approximately in 1:50,000, and therefore is expected to be one thousand times rarer compared with primary hypothyroidism. Despite its rarity in the general population, it is much more common in certain disorders, in which it is frequently associated with other pituitary hormone deficiencies. The aim of this paper is to provide an updated review on the frequency of congenital CH, which is <1:50,000, and on its etiology, disregarding CH caused by other genetic defects, such as mutations of transcription factors involved in pituitary organogenesis or mutations of the genes encoding TRH or TRH receptor.

Sturge-Weber syndrome

Sturge-Weber syndrome is the third most common neurocutaneous disorder, after neurofibromatosis and tuberous sclerosis, and impacts approximately 1 in 20000 live births. Sturge-Weber syndrome is not inherited, but rather occurs exclusively sporadically, in both males and females and in all races and ethnic backgrounds. Sturge-Weber syndrome presents at birth with a capillary malformation on the face (port-wine birthmark) with later diagnosis of abnormal vasculature in the eye and the brain which result in a range of complications. The underlying somatic mosaic mutation causing both Sturge-Weber syndrome and isolated port-wine birthmarks was recently discovered and is an activating mutation in GNAQ. When a newborn presents with a facial port-wine birthmark on the upper face, that child has a 15-50% risk of developing Sturge-Weber syndrome brain and/or eye involvement, depending on the extent of the birthmark, and close monitoring and appropriate screening is essential for early diagnosis and optimal treatment. Treatment options include laser therapy for lightening of the birthmark, eye drops and surgery for glaucoma management, and aggressive anticonvulsant treatment, low dose aspirin, and neurosurgery where necessary. Future possible treatments based upon new knowledge of the somatic mutation and downstream pathways are currently being considered and studied.

Analysis of Sturge-Weber syndrome: A retrospective study of multiple associated variables

INTRODUCTION

Sturge-Weber syndrome is a congenital vascular disorder characterised by facial capillary malformation (port-wine stain) associated with venous and capillary malformations in the brain and eye. Neurological symptoms and alterations in other locations may also be observed.

OBJECTIVES

This study describes the clinical and epidemiological characteristics and different treatments in a cohort of patients diagnosed with Sturge-Weber syndrome in a tertiary hospital.

MATERIAL AND METHODS

This comparative, retrospective and cross-sectional study was conducted by reviewing the medical records of patients diagnosed with Sturge-Weber syndrome between 1998 and 2013.

RESULTS

The study included 13 patients (54% male, 46% female) diagnosed with Sturge-Weber syndrome. The mean age at diagnosis was 15 months. Leptomeningeal angiomatosis was present in 100% of cases: right hemisphere (46%), left hemisphere (38%), and bilateral (15%). Facial angioma was present in 61% of the cases: right (23%), left (38%) and bilateral (7%). Other skin disorders were found in 23% of the cases, including 2 with hemilateral involvement on the side where facial and leptomeningeal angiomatosis was present and one case of generalised cutis marmorata. Ocular disease was found in 77% of patients; the most common conditions were glaucoma (46%), strabismus (23%) and choroidal angioma (23%). Epilepsy was present in 100% of the cases, with partial seizures (simple or complex) being the most frequent (62%). Seizure control was highly variable; 31% of the patients had needed to try more than 3 drugs, 15% 3 drugs, and 31% 2 drugs, while 23% experienced good seizure control with monotherapy. One patient required surgery for epilepsy (left hemispherectomy) and has been seizure-free since then. The most frequent observations in electroencephalograms were spikes, polyspikes, and wave spikes in the lobes affected by leptomeningeal angiomatosis (46%). Other neurological symptoms were hemiparesis (39%), recurrent headaches (39%), stroke-like episodes (23%), psychomotor retardation (46%), and mental retardation (46%). Leptomeningeal calcifications could be seen in 85% of patient MRIs, as well as increased calcification in 70%; 54% of the patients had been treated with aspirin.

CONCLUSIONS

There are multiple clinical manifestations of Sturge-Weber syndrome. Being familiar with all of them is vitally important for diagnosing and for monitoring and treating the condition correctly, which will improve the quality of life of these patients.

Current Therapeutic Options in Sturge-Weber Syndrome

Sturge-Weber syndrome is a vascular malformation syndrome consisting of a facial port-wine birthmark associated with malformed leptomeningeal blood vessels and a choroid "angioma" of the eye. It is a rare neurocutaneous disorder that occurs sporadically, is not inherited, and is caused by a somatic mosaic mutation in GNAQ. In patients with Sturge-Weber syndrome, brain involvement typically presents in infancy with seizures, strokes, and stroke-like episodes, and a range of neurologic impairments. Standard treatment includes laser therapy for the birthmark, control of glaucoma through eyedrops or surgery, and the use of anticonvulsants. Increasingly low-dose aspirin is offered. Treatment with propranolol has been tried generally without the dramatic results seen in hemangiomas. Treatment with an anticonvulsant or low-dose aspirin or both before the onset of seizures is an option. Surgical resection may be offered to those whose seizures are medically refractory. Endocrine, medical rehabilitation and cognitive comorbidities are important to manage. In the future, new therapeutic options are likely to be offered stemming from preclinical studies and small pilot clinical trials currently ongoing. Discovery of the causative somatic mosaic mutation suggests new insights into the pathophysiology of this vascular malformation disorder, and potential novel treatment strategies for future study. The mutation results in constitutive overactivation of the Ras-Raf-MEK-ERK and the HIPPO-YAP pathways and inhibitors of these pathways may in the future prove useful in the treatment of Sturge-Weber syndrome.

Treatment of hypopituitarism in patients receiving antiepileptic drugs

Evidence suggests that there may be drug interactions between antiepileptic drugs and hormonal therapies, which can present a challenge to endocrinologists dealing with patients who have both hypopituitarism and neurological diseases. Data are scarce for this subgroup of patients; however, data for the interaction of antiepileptic drugs with the pituitary axis have shown that chronic use of many antiepileptic drugs, such as carbamazepine, oxcarbazepine, and topiramate, enhances hepatic cytochrome P450 3A4 (CYP3A4) activity, and can decrease serum concentrations of sex hormones. Other antiepileptic drugs increase sex hormone-binding globulin, which reduces the bioactivity of testosterone and estradiol. Additionally, the combined oestrogen-progestagen contraceptive pill might decrease lamotrigine concentrations, which could worsen seizure control. Moreover, sex hormones and their metabolites can directly act on neuronal excitability, acting as neurosteroids. Because carbamazepine and oxcarbazepine can enhance the sensitivity of renal tubules, a reduction in desmopressin dose might be necessary in patients with central diabetes insipidus. Although the effects of antiepileptic drugs in central hypothyroidism have not yet been studied, substantial evidence indicates that several antiepileptic drugs can increase thyroid hormone metabolism. However, although it is reasonable to expect a need for a thyroxine dose increase with some antiepileptic drugs, the effect of excessive thyroxine in lowering seizure threshold should also be considered. There are no reports of significant interactions between antiepileptic drugs and the efficacy of human growth hormone therapy, and few data are available for the effects of second-generation antiepileptic drugs on hypopituitarism treatment.

Sturge-weber syndrome

OPINION STATEMENT

We try to see the babies prior to the onset of symptoms so that their parents can receive anticipatory guidance regarding seizures and how to recognize and respond to them and so that proper referrals to ophthalmology can be made. If there is any concern on history, exam, or EEG then we obtain a magnetic resonance imaging (MRI) with contrast. If presymptomatic diagnosis of brain involvement is made then treatment with low-dose aspirin is offered and if the brain involvement is extensively bilateral then an anticonvulsant such as levetiracetam is offered as well. Seizures are treated aggressively with a goal of obtaining and maintaining complete seizure suppression as much as possible often with a combination of low-dose aspirin and two anticonvulsants such as levetiracetam and oxcarbazepine. For many patients, this will provide adequate control of their seizures and stroke-like episodes. If the patient fails medical management and seizures are regular and accompanied by plateaued development, significant hemiparesis and visual field deficit and the patient is unilaterally involved and a surgical candidate then surgical management is urged. When the seizures are less regular, little or no hemiparesis or visual field deficit exist, and development is reasonable then this decision is more difficult. For bilaterally involved patients surgery is usually not a good option unless seizures are very severe and mostly coming from one side. Other therapeutic options include the ketogenic/Atkins diet and vagal nerve stimulator although in our experience these usually do not result in cessation of seizures. Endocrine problems occur with increased frequency and must be treated when they are present. The recent discovery of the somatic mutation causing Sturge-Weber syndrome holds promise for new treatment options in the future.