Sturge-Weber Syndrome (SWS)

Overview

Epidemiology

The incidence Incidence The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from prevalence, which refers to all cases in the population at a given time. Measures of Disease Frequency is approximately 1 in 20,000 to 50,000 live newborns.

Etiology

• Congenital but not inherited
• Sporadic Sporadic Selective IgA Deficiency mutation Mutation Genetic mutations are errors in DNA that can cause protein misfolding and dysfunction. There are various types of mutations, including chromosomal, point, frameshift, and expansion mutations. Types of Mutations with no known cause
• In 80-90% of cases, caused by a somatic mosaic variant in the GNAQ gene Gene A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. Basic Terms of Genetics → not passed onto offspring

Pathophysiology

• GNAQ gene Gene A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. Basic Terms of Genetics: encodes G-alpha-q, a guanine Guanine Nucleic Acids nucleotide-binding protein → regulates intracellular signaling pathways
• Mutation Mutation Genetic mutations are errors in DNA that can cause protein misfolding and dysfunction. There are various types of mutations, including chromosomal, point, frameshift, and expansion mutations. Types of Mutations results in irregular growth of vascular endothelial cells.
• Presents as capillary-venous malformation, especially in the dermal and leptomeningeal regions

Clinical Presentation

Symptoms are usually due to the effect of capillary-venous malformation within the brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification, skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions, and eye. Not all symptoms have to be present in an individual for them to be diagnosed with SWS, and some symptoms may develop later in life.

Dermatological

Port-wine stain (PWS):

• Also known as nevus flammeus Nevus Flammeus Physical Examination of the Newborn 
• Present from birth
• Distribution:
  • Facial: ophthalmic and maxillary branches of the trigeminal nerve Trigeminal nerve The 5th and largest cranial nerve. The trigeminal nerve is a mixed motor and sensory nerve. The larger sensory part forms the ophthalmic, mandibular, and maxillary nerves which carry afferents sensitive to external or internal stimuli from the skin, muscles, and joints of the face and mouth and from the teeth. Most of these fibers originate from cells of the trigeminal ganglion and project to the trigeminal nucleus of the brain stem. The smaller motor part arises from the brain stem trigeminal motor nucleus and innervates the muscles of mastication. The 12 Cranial Nerves: Overview and Functions
  • May extend to:
    • Trunk
    • Arm Arm The arm, or “upper arm” in common usage, is the region of the upper limb that extends from the shoulder to the elbow joint and connects inferiorly to the forearm through the cubital fossa. It is divided into 2 fascial compartments (anterior and posterior). Arm: Anatomy
• Light pink to deep red

Neurological

• Leptomeningeal vascular malformation, also called leptomeningeal angioma
• Benign Benign Fibroadenoma tumor Tumor Inflammation of the arachnoid and pia mater Pia mater The innermost layer of the three meninges covering the brain and spinal cord. It is the fine vascular membrane that lies under the arachnoid and the dura mater. Meninges: Anatomy ( leptomeninges Leptomeninges Meninges: Anatomy)
• Ipsilateral to PWS
• Mainly in parietal Parietal One of a pair of irregularly shaped quadrilateral bones situated between the frontal bone and occipital bone, which together form the sides of the cranium. Skull: Anatomy and occipital Occipital Part of the back and base of the cranium that encloses the foramen magnum. Skull: Anatomy lobes
• Leads to atrophy Atrophy Decrease in the size of a cell, tissue, organ, or multiple organs, associated with a variety of pathological conditions such as abnormal cellular changes, ischemia, malnutrition, or hormonal changes. Cellular Adaptation and calcifications in the cerebral cortex Cerebral cortex The cerebral cortex is the largest and most developed part of the human brain and CNS. Occupying the upper part of the cranial cavity, the cerebral cortex has 4 lobes and is divided into 2 hemispheres that are joined centrally by the corpus callosum. Cerebral Cortex: Anatomy below the tumor Tumor Inflammation, causing:
  • Seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures:
    • Early onset (by 6 months)
    • Usually the presenting complaint
    • Focal seizures Focal Seizures Seizures in Children
  • Hemiparesis Hemiparesis The term hemiparesis refers to mild to moderate weakness involving one side of the body. Epidural Hemorrhage/ hemianopia Hemianopia Transient Ischemic Attack (TIA):
    • Stroke-like symptoms
    • Transient 
  • Intellectual disability Disability Determination of the degree of a physical, mental, or emotional handicap. The diagnosis is applied to legal qualification for benefits and income under disability insurance and to eligibility for social security and workman’s compensation benefits. ABCDE Assessment, learning difficulties
  • Mood disorders

Ophthalmological

• Glaucoma Glaucoma Glaucoma is an optic neuropathy characterized by typical visual field defects and optic nerve atrophy seen as optic disc cupping on examination. The acute form of glaucoma is a medical emergency. Glaucoma is often, but not always, caused by increased intraocular pressure (IOP). Glaucoma (early onset), potentially caused by:
  • Abnormal anterior chamber Anterior chamber The space in the eye, filled with aqueous humor, bounded anteriorly by the cornea and a small portion of the sclera and posteriorly by a small portion of the ciliary body, the iris, and that part of the crystalline lens which presents through the pupil. Eye: Anatomy angle
  • ↑ Episcleral venous pressure → obstructed aqueous outflow
• Homonymous hemianopia Hemianopia Transient Ischemic Attack (TIA) (from vascular malformations affecting the optic tracts or occipital Occipital Part of the back and base of the cranium that encloses the foramen magnum. Skull: Anatomy lobes)
• Strabismus Strabismus Strabismus is the misalignment of the eyes while fixating the gaze on an object. Strabismus can be idiopathic, but it may also be caused by cerebral palsy, uncorrected refractive errors, and extraocular muscle or cranial nerve dysfunction. Strabismus
• Increased tearing
• Vascular anomalies, which can affect:
  • Choroid Choroid The thin, highly vascular membrane covering most of the posterior of the eye between the retina and sclera. Eye: Anatomy
  • Episclera
  • Conjunctiva Conjunctiva The mucous membrane that covers the posterior surface of the eyelids and the anterior pericorneal surface of the eyeball. Eye: Anatomy
  • Retina Retina The ten-layered nervous tissue membrane of the eye. It is continuous with the optic nerve and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the choroid and the inner surface with the vitreous body. The outermost layer is pigmented, whereas the inner nine layers are transparent. Eye: Anatomy
  • Ciliary body Ciliary body A ring of tissue extending from the scleral spur to the ora serrata of the retina. It consists of the uveal portion and the epithelial portion. The ciliary muscle is in the uveal portion and the ciliary processes are in the epithelial portion. Eye: Anatomy

Endocrine

• Reduced growth hormone (GH) → short stature
• Central hypothyroidism Hypothyroidism Hypothyroidism is a condition characterized by a deficiency of thyroid hormones. Iodine deficiency is the most common cause worldwide, but Hashimoto’s disease (autoimmune thyroiditis) is the leading cause in non-iodine-deficient regions. Hypothyroidism

Mnemonic

An easy way to remember is by using the mnemonic STURGE:

• Stain (port wine)
• Tram track-like calcification
• Unilateral weakness
• Recurrent seizure
• Glaucoma
• Eye signs

Diagnosis and Management

Diagnosis

• Neuroimaging Neuroimaging Non-invasive methods of visualizing the central nervous system, especially the brain, by various imaging modalities. Febrile Infant:
  • MRI with contrast: enhances leptomeningeal angiomas
  • CT: tram track-like cortical calcification due to leptomeningeal vascular malformations
  • Done immediately if patient presents with neurological symptoms
  • Done after 1 year of age in patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with PWS
• Eye exam, measurement of intraocular pressure Intraocular Pressure The pressure of the fluids in the eye. Ophthalmic Exam (IOP) to assess for glaucoma Glaucoma Glaucoma is an optic neuropathy characterized by typical visual field defects and optic nerve atrophy seen as optic disc cupping on examination. The acute form of glaucoma is a medical emergency. Glaucoma is often, but not always, caused by increased intraocular pressure (IOP). Glaucoma
• EEG EEG Seizures → to assess seizure activity
• Confirmation: genetic testing Genetic Testing Detection of a mutation; genotype; karyotype; or specific alleles associated with genetic traits, heritable diseases, or predisposition to a disease, or that may lead to the disease in descendants. It includes prenatal genetic testing. Myotonic Dystrophies for mutations in GNAQ

Management

• Focuses on symptom treatment, such as cutaneous lesions, seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures, and glaucoma Glaucoma Glaucoma is an optic neuropathy characterized by typical visual field defects and optic nerve atrophy seen as optic disc cupping on examination. The acute form of glaucoma is a medical emergency. Glaucoma is often, but not always, caused by increased intraocular pressure (IOP). Glaucoma:
  • PWS: pulsed dye laser therapy Laser Therapy The use of photothermal effects of lasers to coagulate, incise, vaporize, resect, dissect, or resurface tissue. Glaucoma
  • Seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures:
    • Anticonvulsants ( carbamazepine Carbamazepine A dibenzazepine that acts as a sodium channel blocker. It is used as an anticonvulsant for the treatment of grand mal and psychomotor or focal seizures. It may also be used in the management of bipolar disorder, and has analgesic properties. First-Generation Anticonvulsant Drugs)
    • Hemispherectomy in refractory cases
  • Glaucoma Glaucoma Glaucoma is an optic neuropathy characterized by typical visual field defects and optic nerve atrophy seen as optic disc cupping on examination. The acute form of glaucoma is a medical emergency. Glaucoma is often, but not always, caused by increased intraocular pressure (IOP). Glaucoma: topical or surgical management 
• Prevention:
  • Low-dose aspirin Aspirin The prototypical analgesic used in the treatment of mild to moderate pain. It has anti-inflammatory and antipyretic properties and acts as an inhibitor of cyclooxygenase which results in the inhibition of the biosynthesis of prostaglandins. Aspirin also inhibits platelet aggregation and is used in the prevention of arterial and venous thrombosis. Nonsteroidal Antiinflammatory Drugs (NSAIDs) (likely reduces the risk of cerebral ischemic events and seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures)
  • Regular Regular Insulin ophthalmological examination to monitor IOP

Prognosis Prognosis A prediction of the probable outcome of a disease based on a individual’s condition and the usual course of the disease as seen in similar situations. Non-Hodgkin Lymphomas

• Determined by extent of lesion and age of onset for seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures
• Neurological function likely deteriorates with age, impairing daily function.

Differential Diagnosis

• Klippel-Trenaunay syndrome (KTS): a rare congenital and sporadic Sporadic Selective IgA Deficiency disease that results in vascular malformation similar to SWS. In contrast to SWS, neurological and ophthalmological symptoms are rare and PWSs are more commonly noted on the limbs. Bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types and muscle involvement results in hypertrophy Hypertrophy General increase in bulk of a part or organ due to cell enlargement and accumulation of fluids and secretions, not due to tumor formation, nor to an increase in the number of cells (hyperplasia). Cellular Adaptation of limbs. Treatment consists of surgical debulking or sclerotherapy Sclerotherapy Treatment of varicose veins, hemorrhoids, gastric and esophageal varices, and peptic ulcer hemorrhage by injection or infusion of chemical agents which cause localized thrombosis and eventual fibrosis and obliteration of the vessels. Hemorrhoids of the malformed vessels.
• Von Hippel-Lindau (VHL) disease: an autosomal dominant Autosomal dominant Autosomal inheritance, both dominant and recessive, refers to the transmission of genes from the 22 autosomal chromosomes. Autosomal dominant diseases are expressed when only 1 copy of the dominant allele is inherited. Autosomal Recessive and Autosomal Dominant Inheritance genetic neurocutaneous condition that results from a deletion or mutation Mutation Genetic mutations are errors in DNA that can cause protein misfolding and dysfunction. There are various types of mutations, including chromosomal, point, frameshift, and expansion mutations. Types of Mutations in the VHL gene Gene A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. Basic Terms of Genetics. Individuals diagnosed with VHL disease VHL disease Von Hippel-Lindau (VHL) disease is an autosomal dominant genetic condition resulting from a deletion or mutation in the VHL gene. Individuals diagnosed with VHL disease have tumors and cysts in various parts of their bodies and may present with hemangioblastomas, renal cell carcinoma (RCC), pheochromocytoma, endolymphatic sac tumors of the middle ear, pancreatic tumors, and papillary cystadenomas of the epididymis or the broad ligament. Von Hippel-Lindau Disease have tumors and cysts Cysts Any fluid-filled closed cavity or sac that is lined by an epithelium. Cysts can be of normal, abnormal, non-neoplastic, or neoplastic tissues. Fibrocystic Change in various parts of their bodies and may present with hemangioblastomas Hemangioblastomas A benign tumor of the nervous system that may occur sporadically or in association with von Hippel-Lindau disease. It accounts for approximately 2% of intracranial tumors, arising most frequently in the cerebellar hemispheres and vermis. Histologically, the tumors are composed of multiple capillary and sinusoidal channels lined with endothelial cells and clusters of lipid-laden pseudoxanthoma cells. Usually solitary, these tumors can be multiple and may also occur in the brain stem, spinal cord, retina, and supratentorial compartment. Cerebellar hemangioblastomas usually present in the third decade with intracranial hypertension, and ataxia. Von Hippel-Lindau Disease, renal cell carcinoma Renal cell carcinoma Renal cell carcinoma (RCC) is a tumor that arises from the lining of the renal tubular system within the renal cortex. Renal cell carcinoma is responsible for 80%-85% of all primary renal neoplasms. Most RCCs arise sporadically, but smoking, hypertension, and obesity are linked to its development. Renal Cell Carcinoma ( RCC RCC Renal cell carcinoma (RCC) is a tumor that arises from the lining of the renal tubular system within the renal cortex. Renal cell carcinoma is responsible for 80%-85% of all primary renal neoplasms. Most RCCs arise sporadically, but smoking, hypertension, and obesity are linked to its development. Renal Cell Carcinoma), pheochromocytoma Pheochromocytoma Pheochromocytoma is a catecholamine-secreting tumor derived from chromaffin cells. The majority of tumors originate in the adrenal medulla, but they may also arise from sympathetic ganglia (also referred to as paraganglioma). Symptoms are associated with excessive catecholamine production and commonly include hypertension, tachycardia, headache, and sweating. Pheochromocytoma, endolymphatic sac tumors of the middle ear Middle ear The space and structures directly internal to the tympanic membrane and external to the inner ear (labyrinth). Its major components include the auditory ossicles and the eustachian tube that connects the cavity of middle ear (tympanic cavity) to the upper part of the throat. Acute Otitis Media, pancreatic tumors, and/or papillary cystadenomas of the epididymis Epididymis The convoluted cordlike structure attached to the posterior of the testis. Epididymis consists of the head (caput), the body (corpus), and the tail (cauda). A network of ducts leaving the testis joins into a common epididymal tubule proper which provides the transport, storage, and maturation of spermatozoa. Testicles: Anatomy or the broad ligament Broad Ligament A broad fold of peritoneum that extends from the side of the uterus to the wall of the pelvis. Uterus, Cervix, and Fallopian Tubes: Anatomy. The diagnosis is by genetic testing Genetic Testing Detection of a mutation; genotype; karyotype; or specific alleles associated with genetic traits, heritable diseases, or predisposition to a disease, or that may lead to the disease in descendants. It includes prenatal genetic testing. Myotonic Dystrophies, laboratory evaluation, fundoscopic exam Fundoscopic Exam Head and Neck Examination, and CT/MRI to detect tumors. Management of the disease includes surgical removal of tumors.
• Neurofibromatosis type 1 Type 1 Spinal Muscular Atrophy ( NF1 NF1 Neurofibromatosis type 1 (NF1), also known as phakomatosis, is a neurocutaneous disorder that is most commonly of autosomal dominant inheritance due to mutations in the NF1 gene. Neurofibromatosis type 1 presents a range of clinical manifestations with the most prominent features being various pigmented skin lesions called café au lait macules (CALMs), neurofibromas, freckling of the inguinal and axillary regions, and iris hamartomas. Neurofibromatosis Type 1): an autosomal dominant Autosomal dominant Autosomal inheritance, both dominant and recessive, refers to the transmission of genes from the 22 autosomal chromosomes. Autosomal dominant diseases are expressed when only 1 copy of the dominant allele is inherited. Autosomal Recessive and Autosomal Dominant Inheritance inherited neurocutaneous disorder characterized by an abnormality in the tumor Tumor Inflammation suppressor gene Gene A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. Basic Terms of Genetics, giving rise to nerve tumors. Affected individuals present with café au lait spots, neurofibromas, skinfold freckling Freckling Neurofibromatosis Type 1, optical pathway gliomas, and Lisch nodules Lisch Nodules Neurofibromatosis Type 1. The diagnosis is based on the NIH clinical criteria and imaging studies. Selumetinib and surgery are the treatment modalities.
• Tuberous sclerosis Sclerosis A pathological process consisting of hardening or fibrosis of an anatomical structure, often a vessel or a nerve. Wilms Tumor: an autosomal dominant Autosomal dominant Autosomal inheritance, both dominant and recessive, refers to the transmission of genes from the 22 autosomal chromosomes. Autosomal dominant diseases are expressed when only 1 copy of the dominant allele is inherited. Autosomal Recessive and Autosomal Dominant Inheritance disorder that mainly presents with neurocutaneous symptoms. Mutation Mutation Genetic mutations are errors in DNA that can cause protein misfolding and dysfunction. There are various types of mutations, including chromosomal, point, frameshift, and expansion mutations. Types of Mutations in the TSC TSC Tuberous sclerosis or tuberous sclerosis complex (TSC) is an autosomal dominant disorder with mainly neurocutaneous symptoms. Mutation in the tsc genes causes excessive tumor-like growths in the brain, eyes, heart, kidney, and lungs. Cutaneous manifestations include hypopigmentation (i.e., ash leaf spots, confetti lesions) or excessive growth (i.e., angiofibroma, shagreen patch). Tuberous Sclerosis gene Gene A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. Basic Terms of Genetics causes excessive tumor-like growth in the brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification, eyes, heart, kidney, and lungs Lungs Lungs are the main organs of the respiratory system. Lungs are paired viscera located in the thoracic cavity and are composed of spongy tissue. The primary function of the lungs is to oxygenate blood and eliminate CO2. Lungs: Anatomy. Cutaneous manifestations include hypopigmentation Hypopigmentation A condition caused by a deficiency or a loss of melanin pigmentation in the epidermis, also known as hypomelanosis. Hypopigmentation can be localized or generalized, and may result from genetic defects, trauma, inflammation, or infections. Malassezia Fungi (i.e., ash-leaf spots Ash-Leaf Spots Physical Examination of the Newborn) or excessive growth (i.e., angiofibroma Angiofibroma A benign neoplasm of fibrous tissue in which there are numerous small and large, frequently dilated, vascular channels. Tuberous Sclerosis). The diagnosis is made clinically and confirmed by genetic testing Genetic Testing Detection of a mutation; genotype; karyotype; or specific alleles associated with genetic traits, heritable diseases, or predisposition to a disease, or that may lead to the disease in descendants. It includes prenatal genetic testing. Myotonic Dystrophies. Management entails a multidisciplinary approach that targets the monitoring and treatment of various manifestations of the disorder.