Articles

Articles are a collaborative effort to provide a single canonical page on all topics relevant to the practice of radiology. As such, articles are written and edited by countless contributing members over a period of time. A global group of dedicated editors oversee accuracy, consulting with expert advisers, and constantly reviewing additions.

168 results found
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Multiple system atrophy

Multiple system atrophy (MSA) is a sporadic neurodegenerative disease (one of the synucleinopathies) characterized by varying degrees of cerebellar ataxia, autonomic dysfunction, parkinsonism and corticospinal dysfunction.  Epidemiology Multiple systemic atrophy is a sporadic disease, with a p...
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Muscle-eye-brain disease

Muscle-eye-brain disease is a congenital muscular dystrophy with associated progressive eye and brain abnormalities. Clinical presentation There is severe intellectual disability, in combination with seizures. Motor development is usually severely delayed. Eye abnormalities include choroidal h...
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Myoclonic epilepsy with red ragged fibers (MERRF)

Myoclonic epilepsy with red ragged fibers (MERRF) is a rare, multisystem mitochondrial disorder.  Clinical presentation Patients usually present in late adolescence or early adulthood with 1-3 myoclonus epilepsy cerebellar ataxia intellectual disability vision and/or hearing loss cardiom...
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Neck tongue syndrome

Neck tongue syndrome (NTS) is rare and comprises altered sensation in one side of the tongue aggravated by neck movement, with ipsilateral neck pain 1.  Epidemiology NTS is seen in a wide range of ages but is more commonly reported in older children and young adults 1-3.  Clinical presentatio...
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Neuroacanthocytosis syndromes

Neuroacanthocytosis syndromes (NAS), previously known collectively as Levine-Critchley syndrome, are characterized by basal ganglia degeneration, acanthocytosis, and normal serum lipoprotein. There are four core NAS: chorea-acanthocytosis (ChAc) McLeod syndrome (MLS) Huntington disease-like ...
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Neurocutaneous melanosis

Neurocutaneous melanosis or neurocutaneous melanomatosis, is a rare sporadic phakomatosis characterized by multiple congenital cutaneous nevi and meningeal melanocytosis / meningeal melanomatosis.  Epidemiology Neurocutaneous melanosis tends to be diagnosed in the first few years of life with ...
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Neuroferritinopathy

Neuroferritinopathy, also known as neurodegeneration with brain iron accumulation type 2 (NBIA type 2), is a disorder of iron metabolism caused by a mutation in the ferritin light chain 1 gene (FTL1) on chromosome 19. Epidemiology Neuroferritinopathy is a rare disorder first described in 2001 ...
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Neurofibromatosis type 1

Neurofibromatosis type 1 (NF1), also known as von Recklinghausen disease, is a multisystem neurocutaneous disorder, the most common phakomatosis, and a RASopathy. Additionally, it is also one of the most common inherited CNS disorders, autosomal dominant disorders and inherited tumor syndromes. ...
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Neurofibromatosis type 1 (cutaneous manifestations)

Cutaneous manifestations of neurofibromatosis type 1 (NF1), or von Recklinghausen disease, are the heralding features of this multisystem neurocutaneous disorder, which is the most common phakomatosis. Nowadays genetic testing permits the laboratory diagnosis of NF1 in as many as 95%, although ...
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Neurofibromatosis type 1 (mnemonic)

Clinical diagnosis requires the presence of at least two criteria to confirm the presence of neurofibromatosis type 1 (NF1) 1. These diagnostic criteria can be remembered with the mnemonic: CAFE SPOT Mnemonic C: café-au-lait spots (greater than six seen during one year) A: axillary or ingui...
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Neurofibromatosis type 1 (thoracic manifestations)

Thoracic manifestations of neurofibromatosis type 1 (NF1), or von Recklinghausen disease, are related to pulmonary and mediastinal features of this multisystem neurocutaneous disorder, which is the most common phakomatosis. For thoracic manifestations involving the skeleton, such as focal thora...
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Niacin deficiency

Niacin (vitamin B3) deficiency, also known as pellagra, is a multisystem disease which involves the skin, gastrointestinal tract and central nervous system.  Epidemiology It use to be widespread until the early twenty century, but after fortification of flour with niacin it was practically era...
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Nijmegen breakage syndrome

Nijmegen breakage syndrome, also known as Seemanova syndrome or Berlin breakage syndrome, is a rare autosomal recessive syndrome of chromosomal instability.  Clinical presentation microcephaly present at birth and progressive with age dysmorphic facial features mild growth retardation mild...
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Nothnagel syndrome

Nothnagel syndrome is a rare midbrain stroke syndrome that involves the tectum of the midbrain, including the quadrigeminal plate 1-4. Clinical presentation Classically, the syndrome involves the oculomotor nerve fascicles and superior cerebellar peduncle, leading to ipsilateral CN III palsy a...
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Occipital horn syndrome

Occipital horn syndrome is a rare X-linked disorder of copper metabolism resulting in connective tissue abnormalities. Menkes disease is the severe form of this disease, with patients rarely surviving past 3 years of age. Occipital horn syndrome (also known as X-linked cutis laxa or Ehlers Danl...
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Ophelia syndrome

Ophelia syndrome is the association of Hodgkin lymphoma with an autoimmune limbic encephalitis, as a result of anti-metabotropic glutamate receptor 5 antibodies  (mGluR5) 1. 
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Opsomyoclonus

Opsomyoclonus (OMS), also known as dancing eyes-dancing feet syndrome and opsoclonus-myoclonus syndrome, is a clinical syndrome which has a strong association with neuroblastoma. Clinical presentation The “opso-“ refers to the presence of intermittent jerky eye movements (dancing eyes) and the...
Article

Organophosphate poisoning

Organophosphate poisoning is an important cause of acute neurological dysfunction and respiratory distress. Epidemiology Organophosphate poisoning is common, often as a result of suicidal ingestion (acute high-level exposure) or occupational exposure to pesticides (chronic low-level exposure) ...
Article

Osteopathia striata with cranial sclerosis

Osteopathia striata with cranial sclerosis (OS-CS) is a clinically separate entity from osteopathia striata (Voorhoeve disease). Bony changes on their own are typically incidental and autosomal dominant, whereas OS-CS is a multisystem, X-linked dominant disorder. Epidemiology OS-CS is extremel...
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Pantothenate kinase-associated neurodegeneration

Pantothenate kinase-associated neurodegeneration (PKAN), historically also known as Hallervorden-Spatz syndrome, is an autosomal recessive disorder causing involuntary spasticity and progressive dementia. It is a subset of neurodegeneration with brain iron accumulation (NBIA). Epidemiology Cla...
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Paradoxical brain herniation

Paradoxical brain herniation, also known as sinking skin flap syndrome or syndrome of the trephined, is a rare and potentially fatal complication of decompressive craniectomy.  Pathology Atmospheric pressure exceeding intracranial pressure at the craniectomy results in displacement of the brai...
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Paraneoplastic syndromes

Paraneoplastic syndromes occur secondary to the indirect effects of a malignancy and occur remotely to the primary malignancy. Symptoms are mediated by cytokines, hormones or immune cross-reactivity. These syndromes can cause a diverse range of symptoms and can affect multiple systems. Epidemio...
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Parinaud syndrome

Parinaud syndrome, also known as the dorsal midbrain syndrome, is a supranuclear vertical gaze disturbance caused by compression of the tectal plate. It is characterized by a classic triad of findings: upward gaze palsy, often manifesting as diplopia pupillary light-near dissociation (pupils ...
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Parkinson-plus syndrome

Parkinson-plus syndrome refers to a loose group of neurodegenerative disorders that are characterized by features of Parkinson disease but with other neurological symptoms/signs. They have a poor response to levodopa, and mostly have fairly characteristic neuroimaging features.  Conditions incl...
Article

Parry-Romberg syndrome

Parry-Romberg syndrome (PRS), also known as progressive facial hemiatrophy (PFH), is a rare progressive craniofacial disorder (phakomatosis). It is classically characterized by a slow progressive degeneration (atrophy) of the soft tissues of half of the face (hemifacial atrophy). This involves ...
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Pendred syndrome

Pendred syndrome is an autosomal recessively inherited disorder characterized by a euthyroid goiter associated with sensorineural hearing loss.  Epidemiology It is considered the most common form of syndromic hearing loss and accounts for upwards of 10% of hereditary deafness. Pathology Ther...
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PHACE syndrome

PHACE syndrome, also known as cutaneous hemangioma–vascular complex syndrome or Pascual-Castroviejo type II syndrome, is a phakomatosis that comprises of: P: posterior fossa malformations (e.g. Dandy-Walker malformation) H: hemangiomas A: arterial anomalies C: coarctation of the aorta and ca...
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Pituitary stalk transection syndrome

Pituitary stalk transection syndrome, also known as pituitary stalk interruption syndrome, is a syndrome characterized by absent or hypoplastic anterior pituitary gland, thin or absent infundibulum, and ectopic posterior pituitary location. Epidemiology Patients with pituitary stalk transectio...
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POEMS syndrome

POEMS syndrome is the acronymic name for a rare multisystem paraneoplastic disorder comprising of a minimum of three of the following features in the setting of a plasma cell dyscrasia: P: polyneuropathy O: organomegaly hepatomegaly, splenomegaly or lymphadenopathy E: endocrinopathy diabete...
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Poland-Möbius syndrome

Poland-Möbius syndrome, is the combination of Möbius syndrome and Poland syndrome, which although very rare, has been well described 1.  History and etymology Sir Alfred Poland (1822-1872): English surgeon 2 Paul Julius Möbius (1853-1907): German neurologist 3
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Posterior choroidal artery stroke

Posterior choroidal artery occlusion uncommonly presents as an isolated stroke syndrome.  It usually coexists with posterior cerebral artery and often superior cerebellar artery involvement.  When seen in isolation damage is characteristically limited to the: lateral geniculate body pulvinar ...
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Posterior reversible encephalopathy syndrome

Posterior reversible encephalopathy syndrome (PRES) is a neurotoxic state that occurs secondary to the inability of the posterior circulation to autoregulate in response to acute changes in blood pressure. Hyperperfusion with resultant disruption of the blood brain barrier results in vasogenic e...
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Posterior spinal artery syndrome

Posterior spinal artery syndrome is a rare syndrome associated occlusion of the posterior spinal artery and results in a unilateral dorsal cord syndrome (since the posterior arteries are paired) 3.  The syndrome is clinically characterized by isolated loss of proprioception and vibratory sensat...
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Primary progressive aphasia

Primary progressive aphasia was first described in 1982 and is the umbrella term for the language-variant frontotemporal dementias associated with frontotemporal lobar degeneration (FTLD) 3. Clinical presentation It is an insidious disorder characterized by gradual impairment of speech and lan...
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Proteus syndrome

Proteus syndrome is a rare congenital, multisystemic, hamartomatous condition characterized by asymmetrical overgrowth of almost any part of the body and a broad spectrum of manifestations. It can affect tissue from any germinal layer. It is suspected to be a genetic condition, but a particular ...
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Radiologically isolated syndrome

Radiologically isolated syndrome (RIS) is defined by MRI findings suggestive of multiple sclerosis (MS) in asymptomatic ("clinically silent") patients. Radiological progression usually occurs in approximately 66% of patients with RIS, while ~33% per 5-year-period will subsequently develop neurol...
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Ramsay Hunt syndrome

Ramsay Hunt syndrome (RMS), also known as herpes zoster oticus, is shingles of the facial nerve. It is due to reactivation of the varicella zoster virus in the geniculate ganglion. Clinical presentation Ramsay Hunt syndrome classically presents with a triad of 3,4: otic pain facial nerve pal...
Article

Raymond syndrome

Raymond syndrome is a posterior circulatory stroke syndrome due to a lesion in the ventral medial mid-pons. It is an extremely rare condition, with only a handful of cases described in the literature. Clinical presentation Clinically, 2 subtypes have been reported 1: classic type abducens ne...
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Rett syndrome

Rett syndrome is a rare neurodegenerative disease seen in young girls in the 2nd to 4th months of life.  The majority of cases result from a mutation in the MECP2 gene; a more severe subset of the disease arises from a CDKL5 mutation1. Clinical presentation Following a period of normal develop...
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Ritscher-Schinzel syndrome

Ritscher-Schinzel syndrome (RTSC), also known as 3C (cranio-cerebello-cardiac) syndrome, is a rare entity with a variable spectrum of CNS (primarily cerebellar), craniofacial, and congenital heart defects. Clinical presentation craniofacial cleft palate ocular coloboma prominent occiput lo...
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Rosai-Dorfman disease

Rosai-Dorfman disease, also known as sinus histiocytosis with massive lymphadenopathy, is a rare benign idiopathic proliferative disease that involves phagocytic histiocytes. Epidemiology The disease predominantly occurs in young adults with a mean age at presentation of 21 years. There may be...
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Rotational vertebral artery occlusion syndrome

Rotational vertebral artery occlusion syndrome, also known as bow hunter's syndrome, is a rare form of vertebrobasilar insufficiency secondary to dynamic compression of the usually-dominant vertebral artery.  Pathology It has many predisposing etiologies, but is most often due to large osteoph...
Article

SADDAN syndrome

SADDAN syndrome is an acronym for severe achondroplasia with developmental delay and acanthosis nigricans. It is an extremely rare condition, and as the name states, comprises a combination of skeletal, brain and cutaneous anomalies. Pathology Genetics The syndrome results from a mutation in ...
Article

Saethre-Chotzen syndrome

Saethre-Chotzen syndrome (also known as type III acrocephalosyndactyly) is characterized by limb and skull abnormalities. Epidemiology It is the most common craniosynostosis syndrome and affects 1:25 - 50,000 individuals. Males and females are equally affected. Clinical presentation The spe...
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Schimmelpenning syndrome

Schimmelpenning syndrome is a rare and variable congenital multisystem condition characterized by extensive linear sebaceous nevi and multisystem neuroectodermal abnormalities. It is an epidermal nevus syndrome (ENS). Clinical presentation Classical triad including sebaceous nevi, seizures, an...
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Sheehan syndrome

Sheehan syndrome is a rare cause of pituitary apoplexy and hypopituitarism. It only occurs in postpartum females who experience large volume hemorrhage and hypovolemic shock, either during delivery or afterwards with resultant necrosis of anterior pituitary cells 4. Epidemiology Advances in ob...
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Shy-Drager syndrome

The Shy-Drager syndrome is a neurodegenerative disease, and one of the manifestations of multiple systemic atrophy (MSA). Terminology It is important to note that the current belief that olivopontocerebellar degeneration, Shy-Drager syndrome and striatonigral degeneration are different manifes...
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Sjögren-Larsson syndrome

Sjögren-Larsson syndrome is a rare inherited autosomal recessive neurocutaneous syndrome and leukodystrophy characterized by the clinical triad of ichthyosis, intellectual disability, and spastic diplegia or tetraplegia. Epidemiology Although considered very rare, the exact prevalence is not k...
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Slit ventricle syndrome

Slit ventricle syndrome refers to cerebrospinal fluid shunt-related symptoms in the setting of small ventricles demonstrated on radiologic studies. Clinical presentation The presence of characteristic symptoms is required to diagnose slit-ventricle syndrome and must be distinguished from slit-...
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SMART syndrome

SMART syndrome, an acronym for stroke-like migraine attacks after radiation therapy, is an uncommon delayed complication of cerebral radiation therapy. Clinical presentation Patients usually present years after radiation therapy (6-30 years in a case series) with seizures and subacute stroke-l...
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Sneddon syndrome

Sneddon syndrome is a type of systemic non-inflammatory vasculopathy characterized by livedo reticularis and progressive and occlusive cerebrovascular thrombosis involving the medium-sized arteries.  Clinical presentation livedo reticularis as a skin manifestation  progressive cerebral stroke...
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Sotos syndrome

Sotos syndrome it is an autosomal dominant syndrome considered as a form of cerebral gigantism, most characterized by the prenatal and postnatal overgrowth. Epidemiology There is no ethnic group predominance and has been detected throughout the world. The prevalence is not known but is estimat...
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Spinal cord injury

Spinal cord injury (SCI) can be traumatic or non-traumatic (i.e. neoplastic/stenosis) but the syndromes associated with spinal cord injury can be seen in all etiologies. Injury to the spinal cord can be incomplete or complete and depends upon the mechanism of injury. This is important as differ...
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Stiff person syndrome

Stiff person syndrome, previously known as stiff man syndrome, was first described in 1956 by Moersch and Woltman of Mayo Clinic 1 and is a very rare neuromuscular disease characterized by: progressive muscle stiffness of the spine and lower extremities muscle spasms triggered by external stim...
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Sturge-Weber syndrome

Sturge-Weber syndrome, or encephalotrigeminal angiomatosis, is a phakomatosis characterized by facial port wine stains and pial angiomas.  It is part of a wide spectrum of possible phenotypes included in the craniofacial arteriovenous metameric syndrome (CAMS). Epidemiology Sturge-Weber syndr...
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Subclavian steal syndrome

Subclavian steal syndrome (SSS) and subclavian steal phenomenon both result from occlusion or severe stenosis of the proximal subclavian artery resulting in retrograde flow in the ipsilateral vertebral artery. Terminology Subclavian steal phenomenon refers to steno-occlusive disease of the pro...
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Subependymal hamartomas

Subependymal hamartomas are seen in patients with tuberous sclerosis. They are located along the ventricles and are mostly asymptomatic. As with other hamartomas, they grow at the same rate as the surrounding tissues. On imaging, they appear as small intraventricular mass, smaller than 1 cm, an...
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Superior orbital fissure syndrome

Superior orbital fissure syndrome (SOFS) (also known as Rochon–Duvigneaud syndrome) is a rare complication of craniofacial trauma with an orbital fracture that extends to the superior orbital fissure that results in injury to the cranial nerves III, IV, V (ophthalmic branch of the trigeminal ner...
Article

Susac syndrome

Susac syndrome (SS), also known as SICRET syndrome (small infarctions of cochlear, retinal and encephalic tissue), is a rare syndrome typically affecting young to middle-age women that is clinically characterized by the triad of acute or subacute encephalopathy, bilateral sensorineural hearing l...
Article

Syndrome of the trigone

Syndrome of the trigone occurs when intracranial tumors that arise in the trigone of the lateral ventricle present with a distinctive constellation of signs and symptoms due to compression of the posterior limb of the internal capsule and the adjacent white matter of the parietal and posterior f...
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Terson syndrome

  Terson syndrome refers to vitreous hemorrhage associated with subarachnoid hemorrhage, however some authors include retinal hemorrhage as well. The syndrome is a poor prognostic marker in patients with subarachnoid hemorrhage. Epidemiology Terson syndrome has been reported to occur in 13-50...
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Thiamine deficiency

Thiamine deficiency is caused by a low level of thiamine (vitamin B1) in the body, and when severe, a deficiency may manifest in adults as beriberi.There are two main forms: wet beriberi: high-output cardiac failure predominates Shoshin beriberi 3: severe acute wet form with high mortality dr...
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Top of the basilar syndrome

Top of the basilar syndrome, also known as rostral brainstem infarction, occurs when there is thromboembolic occlusion of the top of the basilar artery. This results in bilateral thalamic ischemia due to occlusion of perforator vessels. Clinical presentation Clinically, top of the basilar synd...
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Trotter syndrome

Trotter syndrome relates to advanced nasopharyngeal carcinoma and is the constellation of: unilateral conductive hearing loss due to middle ear effusion trigeminal neuralgia due to perineural spread soft palate immobility
Article

Turcot syndrome

Turcot syndrome is one of the variations in polyposis syndromes. It is characterized by multiple colonic polyps and an increased risk of colon and primary brain cancers. Epidemiology Turcot syndrome is a rare disease. Patients typically present in the second decade 3. Pathology Turcot syndro...
Article

Ventral cord syndrome

Ventral cord syndrome (also known as anterior cord syndrome) is one of the incomplete cord syndromes and affects the anterior parts of the cord resulting in a pattern of neurological dysfunction dominated by motor paralysis and loss of pain, temperature and autonomic function. Anterior spinal ar...
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Vernet syndrome

Vernet syndrome, also known as jugular foramen syndrome, is a constellation of cranial nerve palsies due to compression from a jugular foramen lesion, such as a glomus jugulare tumor, schwannoma, or metastasis 2. Clinical presentation It consists of motor paralysis of: glossopharyngeal nerve ...
Article

Von Hippel-Lindau disease

Von Hippel-Lindau (vHL) disease is characterized by the development of numerous benign and malignant tumors in different organs (at least 40 types 1) due to mutations in the VHL tumor suppressor gene on chromosome 3. Epidemiology The disease is rare with an estimated prevalence of 1:35,000-50,...
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Walker-Warburg syndrome

Walker-Warburg syndrome (WWS), sometimes known as HARDE syndrome, is an extremely rare lethal form of congenital muscular dystrophy. It is primarily characterized by: fetal hydrocephalus: almost always present neuronal migrational anomalies: agyria (cobblestone lissencephaly / lissencephaly ty...
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Weber syndrome

Weber syndrome is a midbrain stroke syndrome that involves the cerebral peduncle and the ipsilateral fascicles of the oculomotor nerve 1-3. Clinical presentation ipsilateral CN III palsy contralateral hemiplegia or hemiparesis Pathology It is usually caused by an ischemic stroke, typically ...
Article

Wernicke aphasia

Wernicke aphasia, also known as receptive aphasia or fluent aphasia, is the inability to grasp the meaning of spoken or written words and sentences while producing connected speech is not greatly affected. Receptive aphasia is usually caused by injury to the dominant posterior temporal lobe (We...
Article

Wernicke encephalopathy

Wernicke encephalopathy, also referred as Wernicke-Korsakoff syndrome, is a form of thiamine (vitamin B1) deficiency, and is typically seen in alcoholics. On imaging, it is commonly seen on MRI as areas of symmetrical increased T2/FLAIR signal involving the mammillary bodies, dorsomedial thalam...
Article

Wildervanck syndrome

Wildervanck syndrome, also known as cervico-ocular-acoustic dysplasia, consists of the triad of: Klippel-Feil syndrome congenital ossicular anomalies: usually diffuse ossicular ankylosis and sensorineural deafness. Duane syndrome: an ocular motility disturbance due to fibrosis of the extraocu...
Article

Zellweger syndrome

Zellweger syndrome (ZS), also known as the cerebrohepatorenal syndrome, is a multisystem metabolic abnormality. As the name implies it primarily affects the central nervous system (CNS), liver and kidneys.  Epidemiology The condition typically presents in neonates with poor feeding and/or seiz...
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Zimmerman-Laband syndrome

Zimmerman-Laband syndrome is a rare congenital syndrome, characterized primarily by gingival hypertrophy and skeletal abnormalities.  Pathology The molecular basis of the syndrome is currently unknown. An autosomal dominant mutation with high mutation rate and rare instances of germinal mosaic...

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