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.

639 results found
Article

Mucopolysaccharidoses

Mucopolysaccharidoses (MPS) constitute a group of hereditary disorders, one of a number of lysosomal storage disorders, having in common an excessive accumulation of mucopolysaccharides secondary to deficiencies in specific enzymes (lysosomal hydrolases) responsible for degradation of mucopolysa...
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Multiple endocrine neoplasia type 1

Multiple endocrine neoplasia type 1 (MEN1), also known as Wermer syndrome, is an autosomal dominant genetic disease that results in proliferative lesions in multiple endocrine organs, particularly the pituitary gland, islet cells of the pancreas and parathyroid glands.  There are other multiple...
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Multiple endocrine neoplasia type IIa

Multiple endocrine neoplasia (MEN) type IIa, also known as Sipple syndrome, accounts for most cases of MEN2 and is characterized by: pheochromocytomas: in 50% of patients, often bilateral, and can be extra-adrenal medullary thyroid cancer: 100% of patients, aggressive, and may secrete calciton...
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Multiple endocrine neoplasia type IIb

Multiple endocrine neoplasia (MEN) type IIb, also known as MEN type 3 (MEN3) 3 or mucosal neuroma syndrome 2, accounts for only 5% cases of MEN2 and is characterized by: pheochromocytoma(s): in 50% of patients, often bilateral, and can be extra-adrenal medullary thyroid cancer: 100% of patient...
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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 ...
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Multisystem inflammatory syndrome in children

Multisystem inflammatory syndrome in children (MIS-C) or pediatric inflammatory multisystem syndrome is an emerging pediatric disease occurring after prior SARS-CoV-2 infection and is therefore strongly associated with the ongoing COVID-19 pandemic.  Clinical presentation MIS-C is typically de...
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Muscle-eye-brain disease

Muscle-eye-brain disease, a part of the spectrum of congenital muscular dystrophy-dystroglycanopathy with brain and eye anomalies (type A3; MDDGA3), is a congenital muscular dystrophy with associated progressive eye and brain abnormalities. Clinical presentation There is severe intellectual di...
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Myalgic encephalomyelitis/chronic fatigue syndrome

Myalgic encephalomyelitis/chronic fatigue syndrome or ME/CFS, is a complex organic disorder, characterized by profound fatigue and associated marked impairment of both physical and mental functioning. Its underlying etiology is undetermined and a curative treatment remains elusive. Terminology ...
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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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Nager syndrome

The Nager syndrome (also known as acrofacial dysostosis) is a rare congenital syndrome primarily characterized by facial and skeletal features Clinical presentation Recognized features include: facial: antimongoloid slant lower lid ptosis microtia micrognathia mandibular hypoplasia hear...
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Nail-patella syndrome

Nail-patella syndrome (also known as Fong disease, osteo-onychodysostosis, Österreicher-Turner syndrome 10, Turner-Kieser syndrome, and Trauner-Rieger syndrome) is a rare autosomal dominant condition which results from symmetrical mesodermal and ectodermal abnormalities. Clinical presentation ...
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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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Nelson syndrome

Nelson syndrome is a rare disorder observed in patients with Cushing disease that have undergone bilateral adrenalectomy. It involves enlargement of an existing adrenocorticotropic hormone-secreting pituitary tumor, typically an adenoma, after surgical resection of the adrenal glands.  Epidemio...
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Neonatal encephalopathy

Neonatal encephalopathy is a clinical syndrome referring to signs and symptoms of abnormal neurological function in the first few days of life in a neonate born at or beyond 35 weeks of gestation. It is described as difficulty with initiating and maintaining respiration, depression of tone and r...
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Nephrotic syndrome

Nephrotic syndrome results from loss of plasma proteins in the urine and characterized by hypoalbuminemia, hyperalbuminuria, hyperlipidemia, and edema. It may be caused by primary (idiopathic) renal disease or by a variety of secondary causes. Clinical presentation Patients present with marked...
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Neu-Laxova syndrome

Neu-Laxova syndrome is a lethal autosomal recessive multiple malformation syndrome with a heterogeneous phenotype. Clinical presentation The clinical spectrum can be quite wide and includes: dermal / cutaneous severe skin restriction ichthyosis decreased fetal movement marked intrauterine...
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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 ...
Article

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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Non-steroidal anti-inflammatory drug exacerbated respiratory disease

Non-steroidal anti-inflammatory drug (NSAID) exacerbated respiratory disease, previously known as Samter triad, Samter syndrome, Widal syndrome, aspirin-induced asthma, or analgesic-induced asthma, refers to the constellation of 1,2: hypersensitivity to aspirin (and other NSAIDs) nasal polypos...
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Noonan syndrome

Noonan syndrome (NS) is a genetically and phenotypically heterogeneous non-aneuploidic congenital RASopathy. Affected individuals can bear some clinical features similar to that of Turner syndrome.  Epidemiology The estimated incidence is at ~1 in 1000-2500 10. As individuals have normal numbe...
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Noonan syndrome with multiple lentigines

Noonan syndrome with multiple lentigines, previously known as LEOPARD syndrome (LS), is a rare autosomal dominant RASopathy that has many similarities to Noonan syndrome. Clinical presentation Despite a change in formal name, the 'LEOPARD' acronym is still useful to summarize the clinical feat...
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Norrie disease

Norrie disease is a rare X-linked inherited cause of congenital bilateral blindness. It can present with a retinal mass (pseudoglioma) and cataracts. It is associated with developmental delay and hearing loss. 
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Nothnagel syndrome

Nothnagel syndrome is a rare midbrain syndrome that involves the tectum of the midbrain (quadrigeminal plate) and superior cerebellar peduncles 1-4,6. Clinical presentation Classically, the syndrome involves the oculomotor nerve fascicles and superior cerebellar peduncle, leading to ipsilatera...
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Nutcracker syndrome

Nutcracker syndrome is a vascular compression disorder that refers to the compression of the left renal vein most commonly between the superior mesenteric artery (SMA) and aorta, although other variations can exist 1. This can lead to renal venous hypertension, resulting in rupture of thin-walle...
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Obstructive sleep apnea

Obstructive sleep apnea (OSA), also known as obstructive sleep apnea syndrome (OSAS), is a disorder characterized by repetitive episodes of total (i.e. apnoeas) or reduction (i.e. hypopnoeas) in ventilation due to total or partial collapse of the upper airway during sleep. This condition is dis...
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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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Olecranon bursitis

Olecranon bursitis refers to inflammation of the olecranon bursa. The olecranon bursa is a subcutaneous sac that overlies the olecranon process and contains a small amount of fluid to prevent against injury of subcutaneous tissue and skin from the uncovered bony olecranon. Pathology Etiology ...
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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

Ortner syndrome

Ortner syndrome, also known as cardiovocal syndrome, is characterized by hoarse voice resulting from left recurrent laryngeal nerve palsy secondary to a cardiovascular disorder. Pathology Left recurrent laryngeal nerve palsy in this condition is due to traction or compression of the nerve betw...
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Osmotic demyelination syndrome

Osmotic demyelination syndrome refers to acute demyelination seen in the setting of osmotic changes, typically with the rapid correction of hyponatremia. It is the more recent term replacing central pontine myelinolysis, recognizing that extrapontine structures can also be affected, previously k...
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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Osteoporosis pseudoglioma syndrome

Osteoporosis pseudoglioma syndrome is a rare autosomal recessive disease that is characterized by severe osteoporosis and blindness. This disease is frequently mistaken for osteogenesis imperfecta.  Epidemiology This disease is encountered in approximately 1 in 2 million births.  Pathology T...
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Otopalatodigital syndrome type I

Otopalatodigital syndrome type I is a rare genetic disorder marked by the association of  skeletal dysplasia hearing loss cleft palate and a characteristic face (with hypertelorism, broad nasal root, prominent supraorbital ridges, small flat nose and downslanted palpebral fissures).  It is ...
Article

Ovarian hyperstimulation syndrome

Ovarian hyperstimulation syndrome (OHSS) is a complication of ovarian stimulation treatment (ovarian induction therapy) for in vitro fertilisation. Rarely, it may also occur as a spontaneous event in pregnancy (see spontaneous ovarian hyperstimulation later in the article). The clinical syndrom...
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Ovarian vein syndrome

Ovarian vein syndrome is a relatively rare condition where a dilated ovarian vein (ovarian venous varix) causes notching, dilatation, or obstruction of the ureter. This is usually secondary to varicosities of the ovarian vein or ovarian vein thrombosis and occurs at the point where the ovarian v...
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Paget-Schrötter syndrome

Paget-Schrötter syndrome, alternatively spelled Paget-Schroetter syndrome and also known as effort thrombosis, refers to primary thrombosis of the axillary and/or subclavian vein. It can be thought of as a venous equivalent of thoracic outlet syndrome - i.e venous thoracic outlet syndrome. Epid...
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Pallister-Hall syndrome

Pallister-Hall syndrome displays a wide range of severity and is characterized by hypothalamic hamartomas seen as a mass at the floor of the third ventricle, posterior to the optic chiasm 3,4. Epidemiology Pallister-Hall syndrome is rare and the exact prevalence is unknown. Patients with posta...
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Pallister Killian syndrome

Pallister-Killian syndrome (PKS) is an extremely rare chromosomal anomaly. Epidemiology It may be more prevalent in births from women of advanced age 4. Clinical presentation Phenotypic expression can significantly vary from multiple anomalies resulting in perinatal death to the more charact...
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Pancoast syndrome

Pancoast syndrome (historically known as Ciuffini-Pancoast-Tobías syndrome, Hare syndrome or variation thereof) results from involvement of the brachial plexus and sympathetic chain by a Pancoast tumor or, less commonly, from other tumors - or even non-malignant disease - involving the lung apex...
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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 superior tectal plate. Clinical presentation Parinaud syndrome is characterized by a classic triad of findings: upward gaze palsy, often manifesting as diplo...
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Parkinson-plus syndrome

Parkinson-plus syndromes are 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 included ...
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 slowly progressive degeneration (atrophy) of the soft tissues of half of the face (hemifacial atrophy). This involve...
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Parsonage-Turner syndrome

Parsonage-Turner syndrome is an acute idiopathic brachial neuritis. Epidemiology There is male predominance (M:F 2:1 to 11.5:1) 1. Patients from 3 months to 85 years old have been reported, but the majority are between 3rd to 7th decade of life. Clinical presentation The presentation is typi...
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Patau syndrome

Patau syndrome (also known as trisomy 13) is considered the 3rd commonest autosomal trisomy. Patau syndrome along with Down syndrome (trisomy 21) and Edward syndrome (trisomy 18) are the only three trisomies to be compatible with extrauterine life. However, few infants live more than a few days...
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Pediatric opioid use‐associated neurotoxicity with cerebellar edema (POUNCE) syndrome

Pediatric opioid use‐associated neurotoxicity with cerebellar edema (POUNCE) syndrome is a toxic encephalopathy in children with opioid overdose that features prominent cerebellar edema. Cerebellar predominance, along with variable supratentorial involvement, appears to be a distinct pattern of ...
Article

Pelvic congestion syndrome

Pelvic congestion syndrome (some prefer pelvic venous insufficiency 9) is a condition that results from retrograde flow through incompetent valves in ovarian veins. It is a commonly missed and potentially-treatable cause of chronic abdominopelvic pain.  Epidemiology It tends to be more common ...
Article

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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Pepper syndrome

Pepper syndrome is a term not readily used in day-to-day practice and usually refers to primary adrenal neuroblastoma with extensive liver metastases 1. In essence, it refers to stage 4S neuroblastoma (see staging of neuroblastoma).  Cohen syndrome, a genetic disorder, is sometimes referred to a...
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Perlman syndrome

Perlman syndrome is a rare autosomal recessive overgrowth syndrome with earlier neonatal mortality. Maximum survival documented in the literature is up to nine years 4. Clinical presentation Perlman syndrome is demonstrated by a combination of many clinical features which includes polyhydramni...
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Peroxisome biogenesis disorder

Peroxisome biogenesis disorders (PBDs) are autosomal recessive, inborn errors of peroxisomes, a eukaryotic cell organelle critical to the breakdown of very long chain fatty acids via beta-oxidation.  Clinical presentation There are two main groups 1: Zellweger spectrum disorder (ZSD) Zellweg...
Article

Perry syndrome

Perry syndrome is a rare, progressive, hereditary neurodegenerative movement disorder and TDP-43 proteinopathy. Epidemiology Perry syndrome is considered to be very rare, generally isolated to select families who carry the mutation implicated in the disease 1,2. In one study, the age on onset ...
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Persistent postural perceptual dizziness

Persistent postural-perceptual dizziness refers to a recently (c. 2017) defined diagnostic syndrome. It unifies key features of chronic subjective dizziness, phobic postural vertigo and related disorders. It produces persistent dizziness, non-spinning vertigo and/or unsteadiness.  Clinical pres...
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Peutz-Jeghers syndrome

Peutz-Jeghers syndrome is one of the polyposis syndromes. It has an autosomal dominant inheritance and is characterized by: multiple hamartomatous polyps, most commonly involving the small intestine (predominantly the ileum), but also colon and stomach; mouth and esophagus are spared mucocutan...
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Pfeiffer syndrome

Pfeiffer syndrome (also known as type V acrocephalosyndactyly) is characterized by skull and limb abnormalities. Epidemiology It affects about 1 in 100,000 births Clinical presentation craniosynostosis hypertelorism proptosis maxillary hypoplasia brachydactyly syndactyly Pathology Pfe...
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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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Phakomatoses

Phakomatoses are a group of neurocutaneous disorders characterized by the involvement of structures that arise from the embryonic ectoderm (thus central nervous system, skin, and eyes). Other organs may also be involved. Pathology As a group, they are characterized by widespread abnormalities ...
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Phlegmasia cerulea dolens

Phlegmasia cerulea dolens (PCD) is an uncommon complication of deep venous thrombosis, which results from extensive thrombotic occlusion of the major and collateral veins of an extremity (usually the legs). Epidemiology Left leg is more commonly affected than the right 4. Risk factors Risk f...
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Pickardt syndrome

Pickardt syndrome also known as Pickardt-Fahlbusch syndrome is a rare syndrome characterized by tertiary hypothyroidism, hyperprolactinemia and other pituitary hormone deficiencies resulting from interruption of the portal blood supply of the anterior pituitary via the infundibulum which drains ...
Article

Pickwickian syndrome

Pickwickian syndrome, or obesity hypoventilation syndrome (OHS), comprises the triad of obesity (BMI ≥30 kg/m2), daytime hypoventilation (awake hypercapnia and hypoxemia), and sleep-disordered breathing in the absence of alternative explanations (e.g. severe parenchymal lung disease, mechanical ...
Article

Pinch off syndrome

Pinch-off syndrome is a spontaneous catheter fracture, which is seen as a complication of subclavian venous catheterization. Epidemiology It is a known complication of central venous catheterization with a much-reduced incidence in current practice and is generally considered to be rare. Radi...
Article

Piriformis syndrome

Piriformis syndrome is a rare entrapment neuropathy resulting in radicular pain radiating into the buttock and hamstrings. The entity is controversial as are the putative causes. Clinical presentation Sciatic pain reproduced on passive internal rotation/adduction of a flexed hip is considered ...
Article

Pituitary stalk interruption syndrome

Pituitary stalk interruption syndrome, also known as pituitary stalk transection syndrome, is a syndrome characterized by an absent or hypoplastic anterior pituitary gland, thin or absent infundibulum, and ectopic posterior pituitary location. Epidemiology Pituitary stalk interruption syndrome...
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Plummer-Vinson syndrome

Plummer-Vinson syndrome, also known as the Paterson-Brown Kelly syndrome, is a very rare condition which comprises a classic triad of dysphagia, iron-deficiency anemia and upper esophageal webs. Epidemiology The incidence of Plummer-Vinson syndrome has plummeted in the past fifty years and thi...
Article

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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Poland syndrome

Poland syndrome refers to a congenital unilateral absence of the pectoralis major and minor muscles and is a recognized cause of unilateral hyperlucent hemithorax.  Epidemiology Poland syndrome is usually sporadic, although rare familial cases have been described 1. It is rare, with an estimat...
Article

Polycystic ovarian syndrome

Polycystic ovarian syndrome (PCOS), recently referred also as hyperandrogenic anovulation, is a chronic anovulation syndrome associated with androgen excess.  The diagnosis of PCOS generally requires any two of the following three criteria for the diagnosis, as well as the exclusion of other et...
Article

Polydactyly

Polydactyly (less commonly called hyperdactyly) refers to the situation where there are more than the usual number of digits (five) in a hand or foot. It can be broadly classified as: preaxial polydactyly: extra digit(s) towards the thumb/hallux (radially) postaxial polydactyly: extra digit(s)...
Article

Polysplenia syndrome

Polysplenia syndrome, also known as left isomerism, is a type of heterotaxy syndrome where there are multiple spleens congenitally as part of left-sided isomerism. Epidemiology Polysplenia is seen predominantly in female patients. It is usually diagnosed in childhood or adulthood, later than a...
Article

Popliteal artery entrapment syndrome

Popliteal artery entrapment syndrome refers to symptomatic compression or occlusion of the popliteal artery due to a developmentally abnormal positioning of the popliteal artery in relation to its surrounding structures such as with the medial head of gastrocnemius or less commonly with popliteu...
Article

Post ablation syndrome

Post-ablation syndrome occurs from 24 to 48 hours following ablation and lasts no longer than 10 days 1. It is believed to occur following cytokine release and tumor necrosis, causing patient fever and flu-like symptoms. If symptoms persist following 10 days after the procedure, alternate diagn...
Article

Post-axial polydactyly

Post-axial polydactyly refers to polydactyly where the additional digit is on the ulnar margin of the hand, or lateral to the 5th (little) toe. Epidemiology Post-axial polydactyly is more common than preaxial polydactyly, with an estimated incidence of 1 in 3000 5. Associations Post-axial po...
Article

Post-embolization syndrome

Post-embolization syndrome (PES) is one of the most common complications of transarterial embolization and chemoembolisation. The condition comprises a constellation of symptoms including pain, fever, nausea and vomiting. PES usually occurs within the first 72 hours after solid organ embolizatio...
Article

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 ...
Article

Posterior nutcracker syndrome

Posterior nutcracker syndrome is a rare vascular compression disorder, in which a retroaortic left renal vein is trapped between the aorta and the vertebral column. Clinical presentation The most reported clinical manifestation is microscopic or macroscopic hematuria. See also vascular compr...
Article

Posterior reversible encephalopathy syndrome

Posterior reversible encephalopathy syndrome (PRES), also known as acute hypertensive encephalopathy or reversible posterior leukoencephalopathy, is a neurotoxic state that occurs secondary to the inability of the posterior circulation to autoregulate in response to acute changes in blood pressu...
Article

Posterior semicircular canal dehiscence syndrome

Posterior semicircular canal dehiscence syndrome (PSCD) is the presence of vestibuloauditory symptoms secondary to absence of the bony covering of the posterior semicircular canal (PSC). Epidemiology It is thought to be rare: in a case series of 112 patients with a high riding jugular bulb it ...
Article

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...
Article

Post-pneumonectomy syndrome

Post-pneumonectomy syndrome is delayed complication of pneumonectomy characterized by respiratory compromise caused by severe mediastinal shift and counterclockwise rotation of the heart and great vessels. Epidemiology Rare delayed complication of pneumonectomy, which more commonly involves th...
Article

Post-thrombotic syndrome

Post-thrombotic syndrome (PTS) is a syndrome of chronic venous insufficiency following deep vein thrombosis (DVT) due to valvular incompetence, which results in chronic reflux and chronic venous hypertension. Epidemiology PTS is a common complication following extensive DVT of the limbs. Up to...
Article

PPP syndrome

PPP syndrome is the extremely rare association of pancreatitis, panniculitis, and polyarthritis. Epidemiology Most commonly affects middle-aged male patients with a history of heavy alcohol use 1,2.  Clinical presentation In the majority of cases, abdominal symptoms are mild or absent, makin...

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