Clinical manifestations of hereditary hemorrhagic telangiectasia (HHT) include vascular malformations of the skin, nasal mucosa, gastrointestinal tract, lungs, liver and central nervous system. These malformations range from punctate telangiectasias to larger arteriovenous malformations within visceral organs and the central nervous system. Vascular malformations increase risk for acute and chronic bleeding, anemia, as well secondary complications related to arterial-venous shunting. Diagnosis can be made with the Curaçao criteria, which includes the presence of epistaxis, telangiectasias, arteriovenous malformations, and first-degree family member with HHT. Nearly all patients with HHT will have a pathogenic variant in the ENG or ACVRL1 genes, while a smaller number will have a variant in SMAD4 or no clear genetic etiology. While there is no cure for HHT, medical management of vascular complications may include oral tranexamic acid and IV bevacizumab. Endovascular and surgical treatments are clinically indicated when the benefits outweigh the risks of the interventions.

Neurofibromatosis type 2-related schwannomatosis (NF2-SWN) is an autosomal dominant inherited disorder with 100 % penetrance associated with pathogenic variants of the NF2 gene on the long arm of chromosome 22. It was previously known as central neurofibromatosis and neurofibromatosis type 2. NF2-SWN has a global incidence of about 1 in 50,000. This disorder is characterized by the formation of multiple types of central nervous system tumors. While bilateral vestibular schwannomas affect more than 95 % of individuals with NF2-SWN, meningiomas, ependymomas, gliomas, other schwannomas, and ophthalmologic abnormalities are also common. Careful dermatologic, ophthalmologic, and neurologic examination can identify signs of NF2-SWN to allow timely initiation of disease specific treatment. Most patients benefit from multimodal treatment, including surgery.

Encephalocraniocutaneous lipomatosis (ECCL), also known as Haberland syndrome, is a sporadic tumor predisposition neurocutaneous disorder, included in the oculoectodermal syndrome group of mosaic RASopathies. ECCL primarily affects the skin, central nervous system and eyes. Key diagnostic features include nevus psiloliparus, a hallmark subcutaneous lipomatous hamartoma associated with alopecia, along with subcutaneous lipomas, focal skin aplasia, and patchy alopecia. Neurologically, intracranial lipomas, particularly in the cerebellopontine angle, are prevalent, along with cortical dysplasia, ventriculomegaly, and vascular malformations. Ocular findings commonly involve choristomas, lipodermoids, and dermoids, which may impair vision. Diagnosis can be made clinically, but further confirmatory genetic testing can in some cases identify a pathogenic variant in the FGFR1 or KRAS genes. Molecular testing aids diagnosis but is not always conclusive. Management is multidisciplinary with focus on symptomatic management, typically involving dermatological, neurological, and ophthalmologic evaluations with consideration of brain and spine neuroimaging and surgical management of tumors. The prognosis varies, with most individuals leading generally normal lives, though there is a risk of developmental delay, seizures, and low-grade gliomas. The severity of CNS involvement does not consistently correlate with cutaneous or ocular abnormalities.

Chedíak-Higashi Syndrome (CHS) is a rare autosomal recessive disorder caused by mutations in the Lysosomal Trafficking Regulator (LYST) gene, leading to defective lysosomal function in immune cells, melanocytes, and neurons. Clinically, CHS is characterized by a spectrum of symptoms, including immunodeficiency, partial oculocutaneous albinism, bleeding tendencies, neurodevelopmental deficits and progressive neurodegenerative symptoms. The severity of CHS correlates with the type of LYST mutation: the classic form, linked to nonsense or frameshift mutations, presents early in childhood with severe immune dysfunction, recurrent infections, and a high risk of hemophagocytic lymphohistiocytosis (HLH), a life-threatening hyperinflammatory state. Without timely treatment, including hematopoietic stem cell transplantation (HSCT), prognosis is poor, with high mortality in early life. Atypical forms, associated with missense mutations, manifest later with milder immunologic symptoms but inevitably progress to neurological impairment, including cognitive decline and motor dysfunction. Diagnosing CHS is complex due to its rarity, phenotypic variability, and overlap with other disorders. A thorough approach, incorporating clinical evaluation, peripheral blood smear for giant granules in leukocytes, and genetic testing for LYST mutations, is crucial for accurate diagnosis. Management of CHS requires a multidisciplinary approach, focusing on HSCT for immunologic and hematologic stabilization and symptomatic and supportive care for neurological symptoms. Even those patients who undergo stabilizing HSCT eventually develop neurological difficulties. This review provides an in-depth exploration of CHS, covering its epidemiology, clinical presentation, molecular genetics, diagnostic challenges, and current management strategies, while emphasizing the necessity of a comprehensive, multidisciplinary approach to improve patient outcomes.

Neurofibromatosis type 1 (NF1) is one of the most common genetic conditions. It can be inherited in an autosomal dominant manner, but almost half of cases occur de novo. NF1 is associated with café-au-lait macules, freckles in the inguinal and axillary region, neurofibromas, Lisch nodules of the iris or choroidal abnormalities, optic pathway gliomas, and distinctive bone anomalies. It has complete penetrance but highly variable disease manifestations. Certain features including café-au-lait macules, bony abnormalities, and optic pathway gliomas emerge by early childhood, but others appear later in life. A cure for NF1 has not been found, however emerging treatments have involved modulation of the RAS/MAPK signaling pathway.

Ataxia telangiectasia (AT) is a rare neurocutaneous syndrome that results from biallelic pathogenic variants in the ataxia telangiectasia mutated (ATM) gene, named for its characteristic cerebellar ataxia in the early toddler years and variable oculocutaneous telangiectasias in the school age years. While its name only hints at neurologic and cutaneous manifestations, this multisystemic disorder also has important immunologic, oncologic, respiratory, and endocrinologic implications. This article will review the function of the ATM gene, the neurologic manifestations of AT, non-neurologic complications, mimickers of AT (including other disorders of defective DNA repair), and the realm of therapeutic research for AT.

First described in the late 1800's, Sturge-Weber syndrome is one of the more common neurocutaneous disorders. In most cases, it is caused by a somatic mosaic variant in the GNAQ gene driving aberrant overgrowth in endothelial cells which leads to capillary-venous malformations. Characteristic findings are unilateral facial port-wine stain, ipsilateral parieto-occipital leptomeningeal angioma with calcifications and atrophy, and ipsilateral glaucoma, though there is significant variability. The predilection for facial skin and brain is likely due to common embryologic progenitors. The risk of brain involvement is increased with a hemifacial, forehead, or medial facial port-wine stain. Neurologic features include epilepsy, stroke-like episodes, transient or permanent hemiparesis and visual field deficit, headaches, and cognitive and behavioral impairment. Magnetic resonance imaging reveals contrast-enhancing leptomeningeal angiomatosis, progressive atrophy, calcifications, and ipsilateral dilated choroid plexus. The treatment of glaucoma typically requires surgery and port-wine stains are treated with laser therapy. Retrospective data from small cohorts show potential benefits of presymptomatic treatment with anti-seizure medications and/or low dose aspirin. Epilepsy surgery can benefit those with a greater degree of hemiparesis and intractable seizures. Low-dose aspirin has proven effective in lowering the frequency and severity of recoverable stroke-like events. Sirolimus has been reported preliminarily to have satisfactory results regarding cognitive function in pediatric patients, but is not a mainstay of treatment to date. Quality of life is often negatively affected by port-wine stain appearance, intractable seizures, headaches, and mood disorders. Future studies are warranted assessing medication and surgery outcomes, quality of life measures, and timing of imaging and treatment initiation.

PHACE syndrome is a neurocutaneous disorder consisting of posterior fossa brain abnormalities, facial infantile hemangioma, arterial anomalies, cardiac anomalies (most commonly coarctation of the aorta), and eye anomalies. While the cutaneous finding of infantile hemangioma represents the most clinically apparent feature, extracutaneous findings-specifically, developmental abnormalities of the aorta and medium-sized thoracic, cervical, and cerebral arteries-are common and pose significant potential morbidity and mortality. Cerebral arteriopathy can be progressive and lead to arterial ischemic stroke in childhood and increased stroke risk in adulthood; headache and neurodevelopmental symptoms are also common. Thus, it is important for pediatric neurologists to be familiar with this disorder and its potential structural and functional neurological sequelae. This review article summarizes the clinical features, diagnostic considerations, epidemiology, and management of this condition with an emphasis on features most pertinent to the practicing pediatric neurologist.

Incontinentia pigmenti (IP) is a rare X-linked dominant, multi-system genetic disorder characterized by evolving skin lesions that occurs almost exclusively in females. Additional manifestations most often involve embryologically-derived ectodermal tissues including the central nervous system (CNS), eyes, hair, teeth and nails. IP is associated with a wide range of neurologic abnormalities, several of which can be associated with significant morbidity. In the neonatal period, while the pathophysiology is poorly understood, inflammatory microvascular changes can lead to ischemic strokes in non-vascular territories and acute disseminated encephalomyelitis, resulting in serious chronic neurologic sequelae such as epilepsy, cerebral palsy and intellectual disability. Additional neuroimaging findings may include periventricular and subcortical white matter abnormalities and cerebral as well as cerebellar dysgenesis. Advancements over time have allowed for improved phenotyping, identification of the causative IKBKG pathogenic variant, creation and refinement of clinical diagnostic criteria and the development of management guidelines which promote multi-disciplinary care. Due to frequent CNS involvement, neurologists play a critical role in the treatment of individuals with IP throughout the lifespan.

Tuberous sclerosis complex (TSC) is a rare neurocutaneous disorder of mTOR pathway dysregulation resulting from pathogenic variants in the TSC1 or TSC2 genes. Expression of this disorder may involve abnormal tissue growth and dysfunction within the brain, kidneys, heart, lungs, eyes, skin, bones, and teeth. Neurological manifestations can include subependymal giant cell astrocytomas (SEGAs), high rates of infantile spasms, drug-resistant epilepsy, developmental delay, cognitive impairment, autism spectrum disorder, and other neurobehavioral manifestations. Here we review the potential clinical manifestations of TSC by system, recommended diagnostic and surveillance testing, genetic testing, currently available therapeutic options, and considerations for education and social support resources given the unique challenges of this multi-system disorder.

Congenital melanocytic nevus syndrome describes congenital melanocytic nevi (CMN) associated with extracutaneous abnormalities, most often involving the nervous system. CMN syndrome is usually caused by postzygotic mutations in the neuroblastoma RAS viral oncogene homolog (NRAS) gene. CMN, collections of melanocytes within the skin, are typically multiple in number and serve as a visible, cutaneous marker of this syndrome. CMN can be classified by predicted maximum diameter in adulthood as well as other clinical features such as anatomic location, color heterogeneity, hypertrichosis, number of satellite nevi, nodules, and surface rugosity. Common neurological abnormalities in CMN syndrome include melanin with the central nervous system (CNS), seizures, and neurodevelopmental delays. Early screening magnetic resonance imaging (MRI) of the CNS during the initial months of life is crucial for predicting the risk of neurodevelopmental abnormalities, seizures, and the need for neurosurgical intervention. Children with a normal screening CNS MRI or intraparenchymal melanosis alone tend to have favorable outcomes. Prognosis otherwise varies widely given the breadth of neurological abnormalities that can occur in CMN syndrome, however if primary melanoma develops in the skin or CNS then outcomes are typically poor.

A detailed understanding of genetics is critical to the diagnosis, management, and prognostication of neurocutaneous disorders. Inheritance patterns can provide a key to the identification of different neurocutaneous disorders. Autosomal dominant disorders, like neurofibromatosis type 1 and tuberous sclerosis complex, affect males and females equally and are typically seen in every generation of a pedigree due to pathogenic changes to one copy of a gene on a somatic chromosome. Autosomal recessive disorders, such as ataxia-telangiectasia, affect males and females equally but typically skip generations on pedigrees as there needs to be a pathogenic variant of the gene on each of the pair of somatic chromosomes. X-linked disorders such as incontinentia pigmenti and Fabry disease primarily affect males or affect them more severely, but in the case of incontinentia pigmenti, the condition is lethal in males and only females are noted to be affected. The pathogenic variant that is disease causing is on the X sex chromosome, of which females have two and males have one. Somatic mosaic disorders like Sturge Weber syndrome are due to pathogenic variants only in a subset of cells post-fertilization and are not present in gametes, and so are not passed on to the next generation. Conditions that are a result of germline mosaicism are usually identified as autosomal dominant conditions that have not been present in the family prior to a single child being affected, with suspicion strengthening if siblings are diagnosed with the same condition. Regardless of the suspected inheritance pattern, it is essential to consider the ethical implications of genetic testing, including family planning, discovery of consanguinity, disclosure to other potentially affected family members, and diagnostic uncertainty.

Hypomelanosis of Ito is a rare neurocutaneous disorder named after the Japanese dermatologist Minoru Ito who in 1952 described the condition. Characteristically, the hypopigmented lesions in this condition follow Blaschko lines. Extracutaneous manifestations of the disease include neurological, musculoskeletal, cardiac, endocrine, and renal signs and symptoms. The most common neurological manifestation is cognitive impairment. Seizures, developmental delay, and abnormal tone can also be present. In this review we discuss the condition's clinical presentations, its diagnostic criteria, and consensus recommendations.

Abusive head trauma (AHT) is associated with high mortality and poorer outcomes compared to accidental head injuries. The short and long-term developmental outcomes for AHT are not well identified. Variability in outcome measures, small sample sizes, difficulty in measuring domain-specific developmental skills, co-existence of comorbidities, genetic and environmental factors and high attrition rates all contribute to the challenges on providing data in this area. The objective of this article is to review the scientific literature on the developmental outcomes of AHT, highlighting factors that affect outcomes, the available assessment tools, and short and long-term developmental outcomes, recommended follow up, societal costs, and future opportunities for research. Authors searched OVID Medline and PubMed for articles published between 2013 and 2023 using the terms "abuse", "craniocerebral trauma" and "development". Fifty-five records were included for this review. The data shows that injuries sustained from AHT result in a spectrum of outcomes ranging from normal development to death. There are more than 100 outcome assessment tools limiting the ability to compare studies. More than half of patients are left with disabilities post discharge. Gross motor and cognition/academics are the 2 most common domains studied. Advancement in surgical and neurocritical care management has influenced AHT outcomes. Close long-term follow up is recommended to maximize each child's developmental potential, irrespective of the presence of disability at discharge. We suggest that future research should focus on adopting a consistent diagnostic and assessment approach and explore the social environmental factors that can affect recovery.

Child physical abuse is a common cause of pediatric morbidity and mortality. Up to half of all children presenting with abusive injuries have a history of a prior suspicious injury, suggesting a pattern of repeated physical abuse. Medical providers are responsible for identifying children with suspicious injuries, completing mandated reporting to child protective services for investigation, and screening for occult injuries and underlying medical conditions that can predispose to injuries. Early identification of inflicted injuries appropriate evaluations may serve as an opportunity for life-saving intervention and prevent further escalation of abuse. However, identification of abuse can be challenging. This article will review both physical exam findings and injuries that suggest abuse as well as the evaluation and management of physical abuse.

In recent years, trauma informed care has become a heavily researched topic; however, it has yet to achieve a universal standard in the field of pediatric medicine. One of the primary tenants of trauma informed care is a clear understanding of the pervasiveness and complexities of childhood trauma, and its intersection with a child and caregiver's physical wellness. A major component of trauma informed care is addressing the way medical providers may be exposed to vicarious trauma, secondary traumatic stress, and compassion fatigue. By taking proactive steps to educate medical providers on the effects of trauma, they are better equipped to assess a family's needs and provide enhanced quality of care for their patients and themselves.

This focused review on abusive head trauma describes the injuries to the head, brain and/or spine of an infant or young child from inflicted trauma and their neuroimaging correlates. Accurate recognition and diagnosis of abusive head trauma is paramount to prevent repeated injury, provide timely treatment, and ensure that accidental or underlying medical contributors have been considered. In this article, we aim to discuss the various findings on neuroimaging that have been associated with AHT, compared to those that are more consistent with accidental injuries or with underlying medical causes that may also be on the differential.

A leading cause of death and disability in infancy is abusive head trauma (AHT) and there are common clinical signs that help to establish this diagnosis. Children diagnosed with AHT can have many ophthalmologic findings, including retinal hemorrhages, retinoschisis, subconjunctival hemorrhages, corneal injury, and globe rupture. If any such injuries are suspected, an ophthalmologic consultation, with indirect ophthalmoscopy, should be completed. In addition to a complete physical exam, a thorough history imaging, and lab work, should be obtained to investigate the etiology of ophthalmic pathology including accidental and systemic causes. In general, studies show that retinal hemorrhages that are multilayered, too numerous to count, and located from the posterior pole to the ora serrata are highly suspicious for abusive head trauma.

Previously known as Munchausen syndrome by proxy, medical child abuse is a form of child maltreatment whereby the caregiver creates an environment in which medical care harms or threatens the wellbeing of a child. Approximately 40-50 % of medical child abuse cases involve neurological symptoms, with fabricated or induced seizures accounting for a significant proportion. Identifying fictitious seizures is often difficult even for the most experienced clinicians. Therefore, having a low threshold for clinical suspicion is essential in the timely diagnosis of medical child abuse. This article provides a review of the epidemiology, diagnosis, and management of medical child abuse when it involves seizures.