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Lateral pontine syndrome

Lateral pontine syndrome, also known as Marie-Foix syndrome or Marie-Foix-Alajouanine syndrome, refers to one of the brainstem stroke syndromes of the lateral aspect of the pons. Clinical presentation There is a characteristic clinical picture from the involvement of the following pontine stru...

Laurin-Sandrow syndrome

Laurin-Sandrow syndrome is a rare disorder characterized by tetrameric polysyndactlyly. Radiographic features polysyndactyly of the hands (both post-axial and pre-axial) "cup-shaped" hands mirror polysyndactyly of the feet ulnar dimelia absence of the radius and tibia possible hypertelori...

Leaky lung syndrome

Leaky lung syndrome refers to a form of non-cardiogenic pulmonary edema. Pathology Pulmonary edema due to increased capillary permeability. Radiographic features Leaky lung syndrome is considered a mild form of a part of the spectrum of acute lung injury with ARDS at the other end of the s...

Leigh syndrome

Leigh syndrome, also known as subacute necrotizing encephalomyelopathy (SNEM), is a mitochondrial disorder with progressive neurodegeneration that invariably leads to death, usually in childhood. Epidemiology Leigh syndrome is encountered in approximately 1 in 40,000 births, although some popu...

Lemierre syndrome

Lemierre syndrome (also known as postanginal septicemia) refers to thrombophlebitis of the internal jugular vein(s) with distant metastatic sepsis in the setting of initial oropharyngeal infection such as pharyngitis/tonsillitis with or without peritonsillar or retropharyngeal abscess. Epidemio...

Lemmel syndrome

Lemmel syndrome is defined as an obstructive jaundice caused by a periampullary duodenal diverticulum compressing the intrapancreatic common bile duct with resultant bile duct dilatation. Clinical presentation Patients may present with recurrent episodes of jaundice, pancreatitis and/or cholan...

Lennox-Gastaut syndrome

Lennox-Gastaut syndrome is a form of refractory childhood-onset epilepsy and is often accompanied by developmental delay and psychological/ behavioral problems. An electroencephalogram (EEG) often shows a slow spike and wave pattern. Epidemiology It often appears between the 2nd and 6th years ...

Leontiasis ossea

Leontiasis ossea is largely a historical term used to describe a number of conditions that result in the affected patient's face resembling that of a lion. Although it is most frequently associated with craniofacial fibrous dysplasia, it has a broader meaning encompassing other lesions that have...

Leprosy

Leprosy, previously known as Hansen's disease, is a chronic infectious disease caused by Mycobacterium leprae and presents mainly in tropical developing countries. Epidemiology It is most common in tropical developing countries and is endemic in over 100 countries. Worldwide, there is a preval...

Lethal omphalocele-cleft palate syndrome

Lethal omphalocele-cleft palate syndrome is, as the name suggests, characterized by the association of omphalocele and cleft palate. Prevalence is assumed to be <1 per 1,000,000. It has been postulated that this syndrome is likely to be an autosomal recessive condition 1. History and etymolog...

Leukoencephalopathy with calcifications and cysts

Leukoencephalopathy with calcification and cysts, also known as Labrune syndrome, is a rare condition that consists of a triad of leukoencephalopathy, cerebral calcification and edematous cysts. Epidemiology Leukoencephalopathy with calcification and cysts is an extremely rare condition, with ...

Levator ani syndrome

Levator ani syndrome (LAS) is a musculoskeletal pain syndrome involving the pelvic floor, thought to be caused by spasm or scarring of the levator ani muscles. Clinical presentation Levator ani syndrome is characterized by recurrent pain, pressure or discomfort in the region of the rectum, sac...

Li-Fraumeni syndrome

Li-Fraumeni syndrome is a hereditary cancer syndrome due to mutations in the tumor suppressor gene TP53. Approximately half of affected individuals are thought to develop invasive cancer by 30 years of age 1. Associated malignancies sarcomas osteosarcoma rhabdomyosarcoma CNS tumors gliomas...

Locked-in syndrome

Locked-in syndrome is one of the brainstem stroke syndromes and can occur as a result of a pontine stroke that damages the ventral brainstem and pyramidal bundles and corticobulbar tracts 5. Clinical presentation Individuals who are "locked-in" are conscious with preserved cognitive function b...

Löffler syndrome

Simple pulmonary eosinophilia (also known as Löffler syndrome) is a type of pulmonary eosinophilia that typically presents with transient radiographic infiltrates, minimal constitutional upset, and an elevated eosinophil count in peripheral blood. Pathology Etiology The cause is not usually i...

Löfgren syndrome

Löfgren syndrome is a specific acute clinical presentation of systemic sarcoidosis that usually manifests with lymphadenopathy, fevers, erythema nodosum, and arthritis. Terminology It is important to not confuse this syndrome with Löffler syndrome, as the names are quite similar but the condi...

Lowe syndrome

Lowe syndrome, also known as the oculocerebrorenal syndrome of Lowe, is a multisystem disorder characterized by anomalies primarily affecting the eyes, nervous system, and kidneys. Epidemiology It is an extremely rare, pan-ethnic disease, with an estimated prevalence in the general population ...

Low phospholipid-associated cholelithiasis syndrome

Low phospholipid-associated cholelithiasis (LPAC) syndrome is one of the syndromes associated with ABCB4/MDR3 mutation. Characteristics of this syndrome include 1,2: intrahepatic microlithiasis/sludge symptomatic cholesterol stones with early onset (<40 years) recurrent symptoms post cholecys...

LUMBAR syndrome

LUMBAR, PELVIS, or SACRAL syndrome is the association of infantile hemangiomas in the lower body with other extracutaneous congenital abnormalities in the region. The syndrome may be incomplete. Pathology LUMBAR 1 lower body hemangiomas urogenital anomalies and ulceration myelopathy bony...

Lutembacher syndrome

Lutembacher syndrome refers to the association of an atrial septal defect (ASD) with mitral stenosis. Both the defects can be either congenital or acquired. History and etymology It is named after Rene Lutembacher 4.

Madelung disease

Madelung disease, also known as Madelung-Launois-Bensaude syndrome or neck lipomatosis or multiple symmetric lipomatosis, is a rare benign entity clinically characterized by the presence of multiple and symmetric, non-encapsulated masses of fatty tissue, usually involving the neck and the upper ...

Maffucci syndrome

Maffucci syndrome is a congenital nonhereditary mesodermal dysplasia characterized by multiple enchondromas with soft-tissue venous malformations (hemangiomas). On imaging, it is usually portrayed by a short limb with metaphyseal distortions due to multiple enchondromas, which may appear grotes...

Mainzer-Saldino syndrome

Mainzer-Saldino syndrome (also known as conorenal syndrome (CRS)) is a rare condition and is one of the ciliopathies. It is due to mutations in the IFT140 gene, whose protein product is one of the six parts of the intraflagellar transport complex A. The syndrome's key characteristics are: phal...

Manganism

Manganism (also known as acquired hypermanganesemia) is the clinical syndrome resulting from acute or chronic overexposure to the transition metal manganese, one of the essential trace elements. It primarily manifests as parkinsonism and is frequently clinically, radiologically and histopatholog...

Man-in-the-barrel syndrome

Man-in-the-barrel syndrome is a neurological syndrome characterized by bilateral brachial muscular weakness. Pathology This syndrome is usually caused by bilateral cerebral lesions in the border zone between the anterior and middle cerebral arteries. Etiology The syndrome has been described ...

Marchiafava-Bignami disease

Marchiafava-Bignami disease (MBD) is a rare CNS disorder usually seen in the context of alcoholism and malnutrition. The condition classically involves the corpus callosum with necrosis and demyelination. Epidemiology MBD is in most instances seen in chronic alcoholics, and as such the epidem...

Marfan syndrome

Marfan syndrome is a multisystem connective tissue disease caused by a defect in the protein fibrillin 1, encoded for by the FBN1 gene. Cardiovascular involvement with aortic root dilatation and dissection is the most feared complication of the disease. Epidemiology The estimated prevalence is...

Marine-Lenhart syndrome

Marine-Lenhart syndrome refers to a variant of Graves disease where there are coexistent autonomous thyroid nodules. It is better described as Graves disease with coexistent multinodular goiter or nodular Graves disease 1. Epidemiology The syndrome is rare with reported prevalence somewhere b...

Marshall-Smith syndrome

Marshall-Smith syndrome (MSS) is a rare genetic syndrome primarily comprising the triad of facial dysmorphism, failure to thrive and accelerated osseous maturation 5. Many cases, however, have a wider clinical spectrum. Clinical presentation general fetal macrosomia failure to thrive skelet...

May-Thurner syndrome

May-Thurner syndrome refers to a chronic compression of the left common iliac vein (CIV) against the lumbar vertebrae by the overlying right common iliac artery (CIA), with or without deep venous thrombosis 2. Although both left and right CIVs lie deep to the right common iliac artery, the left...

Mazabraud syndrome

Mazabraud syndrome is a rare syndrome characterized by skeletal fibrous dysplasia and intramuscular myxomas 1-3. Epidemiology Only 107 cases have been reported in the global literature (as of 2019) 1,3-5,15. The prevalence is ~ 1 in 1,000,000 3 with a strong female predilection (68-84%) 1,3. T...

McCune-Albright syndrome

McCune-Albright syndrome (MAS) (also known as McCune-Albright-Sternberg syndrome) is a genetic disorder characterized by the association of: endocrinopathy: precocious puberty polyostotic fibrous dysplasia: more severe than in sporadic cases cutaneous pigmentation: coast of Maine 'cafe au lai...

McKusick Kaufman syndrome

McKusick Kaufman syndrome (MKS) is an autosomal recessive multiple malformation syndrome primarily characterized by hydrometrocolpos - vaginal atresia post-axial polydactyly congenital heart disease

Meckel-Gruber syndrome

Meckel-Gruber syndrome (MGS) is classically characterized by the triad of: renal cystic dysplasia: multiple renal cysts (present most cases) occipital encephalocoele/holoprosencephaly (~70%) postaxial polydactyly: usually hexadactyly (~65%) Additional hepatic developmental defects and hepati...

Meconium plug syndrome

Meconium plug syndrome refers to a functional colonic obstruction in a newborn due to an obstructing meconium plug. It is usually transient and affects the left colon with meconium plugging the bowel distal to this segment. In this situation, it is also termed the small left colon syndrome. Pat...

Medial medullary syndrome

Medial medullary syndrome, also known as Déjerine syndrome, is secondary to thrombotic or embolic occlusion of small perforating branches from vertebral or proximal basilar artery supplying the medial aspect of medulla oblongata1,2. Epidemiology Represents less than 1% of brainstem stroke sy...

Medial patellar plica syndrome

Medial patellar plica syndrome is one of the conditions that can be associated with the presence of synovial plicae of the knee (in this instance a medial plica). It can be a common source of anterior knee pain. Epidemiology While it can affect those of any age, it typically involves the young...

Medial tibial stress syndrome

Medial tibial stress syndrome (MTSS), also known as shin splints, describes a spectrum of stress injury that occurs at the medial tibia. This term is often used to indicate any type of tibial stress injury or the earlier manifestations of a tibial stress lesion before a fracture component can be...

Megacystis microcolon intestinal hypoperistalsis syndrome

Megacystis microcolon intestinal hypoperistalsis syndrome (MMIHS) (also known as the Berdon syndrome) is a rare congenital disorder characterized by a dilated non-obstructive urinary bladder and hypoperistalsis of the gastrointestinal tract. Epidemiology There is recognized strong female predi...

Megalencephaly-capillary malformation syndrome

Megalencephaly-capillary malformation (MCAP) syndrome, also known as macrocephaly-capillary malformation syndrome, is a rare and well described genetic disorder caused by somatic mutations in the PIK3CA gene on chromosome 3q26 and characterized by early brain overgrowth and body morphogenesis an...

MEGDEL syndrome

MEGDEL syndrome (3-MEthylGlutaconic aciduria, Deafness, Encephalopathy, Leigh-like syndrome) is a recently described syndrome with infantile onset. These patients typically initially receive a diagnosis of Leigh syndrome, based on clinical and biochemical features and an abnormal basal ganglia s...

Mendelson syndrome

Mendelson syndrome or peptic pneumonia refers to acute chemical pneumonitis caused by the aspiration of stomach contents in patients under general anesthesia. Clinical presentation This syndrome develops rapidly (2-12 hours after aspiration) and within hours the patient may become tachypnei...

Menkes disease

Menkes disease, also known as trichopoliodystrophy or kinky hair kinky vessel syndrome, is an X-linked recessive disorder that results in a derangement in copper handling. It results in low copper levels and subsequently, deficiency in copper-dependent mitochondrial enzymes. Epidemiology Menk...

Metabolic syndrome

The metabolic syndrome, also known as syndrome X, is a set of five conditions, which together increase a patient's risk of developing cardiovascular disease 1. Clinical presentation There are five central components of the metabolic syndrome: hyperinsulinemia impaired glucose tolerance dysl...

Metaphyseal chondrodysplasia

Metaphyseal chondrodysplasia (also known as metaphyseal dysplasia or dysostosis) is a type of skeletal dysplasia. Pathology Classification Schmid type - mild type, due to mutation in type X collagen (COL10A1 gene), metaphyses are cupped resembling rickets Pena and Vaandrager type - intermedi...

Metronidazole central nervous system toxicity

Metronidazole, which is used to treat a wide variety of bacterial and protozoal infections can, in exceedingly rare cases, lead to central nervous system toxicity. Epidemiology In a review of the case literature 1, affected patients range widely in age, with the peak incidence occurring in the...

Midaortic syndrome

Midaortic syndrome is an uncommon entity affecting children and young adults. It is characterized by progressive narrowing of the abdominal aorta and its major branches. Clinical presentation The onset of symptoms is usually during childhood or young adulthood 2: hypertension (most common) i...

Middle East respiratory syndrome coronavirus (MERS-CoV) infection

Middle East respiratory syndrome coronavirus (MERS-CoV) infection is an uncommon coronavirus infection (<1000 cases) with the first case reported in Saudi Arabia in 2012. It most commonly causes pneumonia and acute renal failure with a mortality rate of ~40%. MERS-CoV raises concern because of i...

Mikulicz syndrome

Mikulicz syndrome was considered a form of Sjögren syndrome (type 1), however, more recently it is considered to be on the IgG4-related disease spectrum. Terminology It may also be referred to by numerous other eponymous names as well as the catchy: sicca syndrome without a connective tissue ...

Milk-alkali syndrome

Milk-alkali syndrome is the combination of: hypercalcemia renal failure metabolic alkalosis It is due to a large amount of calcium and alkali being ingested (e.g. milk and antacids for peptic ulcer disease treatment or calcium carbonate for osteoporosis). It is a cause of medullary nephrocal...

Millard-Gubler syndrome

Millard-Gubler syndrome, also known as ventral pontine syndrome, is one of the crossed paralysis syndromes, which are characterized by cranial nerves VI and VII palsies with contralateral body motor or sensory disturbances 1-3. Clinical presentation ipsilateral facial and contralateral body he...

Milwaukee shoulder

Milwaukee shoulder refers to a destructive shoulder arthropathy due to deposition of hydroxyapatite crystals, and identification of these crystals in synovial fluid is the cornerstone of diagnosis. Epidemiology Milwaukee shoulder frequently affects older women, often with a history of trauma t...

Mirizzi syndrome

The Mirizzi syndrome refers to an uncommon phenomenon which results in extrinsic compression of an extrahepatic biliary duct from one or more calculi within the cystic duct or gallbladder. It is a functional hepatic syndrome but can often present with biliary duct dilatation and can mimic other ...

Möbius syndrome

Möbius syndrome, also known as congenital facial diplegia syndrome, is a rare congenital condition characterized by the absence or underdevelopment of the abducens nerve (CN VI) and facial nerve (CN VII) nuclei. Epidemiology Möbius syndrome is rare with an estimated incidence of ~1 case per 10...

Morgagni-Stewart-Morel syndrome

Morgagni-Stewart-Morel syndrome consists of the triad of: hyperostosis frontalis interna obesity excessive hair growth (virilism/hirsutism) and is also associated with neuropsychiatric conditions. The cause is unclear. History and etymology It was first described in 1765 by the Italian ...

Morning glory syndrome (eye)

Morning glory disc anomaly (MGDA), also known as morning glory syndrome, is a rare congenital malformation of the optic nerve which is frequently associated with midline abnormalities of the brain and skull 1. Epidemiology Morning glory disc anomaly is rare and is more commonly found in female...

Morquio syndrome

Morquio syndrome (in older literature it is sometimes called Morquio-Brailsford syndrome) is an autosomal recessive mucopolysaccharidosis (MPS) type IV. Epidemiology Incidence estimated at ~1:40,000. Clinical presentation Many cases present at ~2 years of age and have normal intelligence. Cl...

Morvan syndrome

Morvan syndrome, also known as Morvan fibrillary chorea, is a rare syndrome thought to be either paraneoplastic or autoimmune in origin. Clinical presentation It is characterized by: neuromyotonia pain hyperhydrosis weight loss severe insomnia hallucinations Pathology Voltage gated pot...

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...

Multiple endocrine neoplasia type I

Multiple endocrine neoplasia type I (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...

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...

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...

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...

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...

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 ...

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...

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...

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 ...

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...

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...

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...

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...

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 ...

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 ...

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 ...

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. ...

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 ...

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...

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...

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...

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...

Non-steroidal anti-inflammatory drug exacerbated respiratory disease

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

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...

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...

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.

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...

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...

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...

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...

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 ...

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.

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...

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) ...

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