Lacunar stroke syndrome (LACS) is a description of the clinical syndrome that results from a lacunar infarct.
Each of the five classical lacunar syndromes has a relatively distinct symptom complex. Symptoms may occur suddenly, progressively, or in a fluctuating manner (e.g. the capsular warnin...
Lambert-Eaton myasthenia syndrome (LEMS) is rare but is still the second most common neuromuscular junction disease after myasthenia gravis. Two-thirds of LEMS present as a paraneoplastic syndrome secondary to malignancy, most commonly lung cancer but is also associated with breast, ovarian and ...
Lane-Hamilton syndrome (LHS) refers to the rare concurrent association of idiopathic pulmonary haemosiderosis and coeliac disease 1.
It is typically seen in children under the age of 15 but can occasionally be seen in adults.
History and etymology
It was originally described by ...
Langer-Giedion syndrome (LGS), also known as trichorhinophanageal syndrome type II, is an extremely rare autosomal dominant genetic disorder.
The effects are seen mainly on the skeletal system and primarily involves
digits of the hands and feet: phalangeal...
Large vestibular aqueduct syndrome (LVAS) refers to the presence of congenital sensorineural hearing loss with an enlarged vestibular aqueduct. It is thought to be one of the most common congenital causes of sensorineural hearing loss (SNHL).
SNHL starts in childhood and...
Larsen syndrome (LS) is an extremely rare disorder, often classified as a type of osteochondrodysplasia.
The estimated incidence is thought to be at ~ 1 in 100,000 people. There may be an increased female predilection.
It is characterised by many features i...
Lateral medullary syndrome, (or Wallenberg syndrome) is an acute ischemic infarct due to occlusion of the vessels supplying the lateral medulla oblongata; most commonly occlusion of intracranial portion of the vertebral artery followed by PICA and its branches 1-3. This syndrome is characterised...
The lateral meningocele syndrome is an extremely rare hereditary connective tissue disorder characterized by multiple lateral lumbar meningoceles, distinctive facial features, joint hypermobility, hypotonia, skeletal abnormalities, congenital cardiovascular malformations, urogenital anomalies an...
Lateral pontine syndrome, also known as Marie-Foix syndrome or Marie-Foix-Alajouanine syndrome, refers to one of the brainstem stroke syndromes which occurs due to occlusion of perforating branches of the basilar and anterior inferior cerebellar (AICA) arteries 1,2. This results in infarction of...
Laurin-Sandrow syndrome is a rare disorder characterized by tetrameric polysyndactlyly.
polysyndactyly of the hands (both post-axial and pre-axial)
mirror polysyndactyly of the feet
absence of the radius and tibia
Lemierre syndrome refers to thrombophlebitis of the jugular veins with distant metastatic sepsis in the setting of initial oropharyngeal infection such as pharyngitis/tonsillitis with or without peritonsillar or retropharyngeal abscess.
Patients typically present unwell...
Lemmel syndrome is defined as an obstructive jaundice caused by a periampullary duodenal diverticulum (of the second part of the duodenum) compressing the intrapancreatic part of the common bile duct with resultant upstream dilatation of the extra- and intrahepatic bile ducts.
Leprosy, previously known as Hansen's disease, is a chronic infectious disease caused by Mycobacterium leprae and presents mainly in tropical developing countries.
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 is, as the name suggests, characterised 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...
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.
LAS is characterized by recurrent pain, pressure or discomfort in the region of the rectum, sacrum, and coccyx. ...
Locked-in syndrome is a condition that can occur as a result of a stroke involving the brainstem; the stroke damages the ventral brainstem, corresponding to the pyramidal bundles.
The infarct is pontine; the midbrain is preserved. The oculomotor nerve III is intact so the...
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.
The cause is not usually ...
Löfgren syndrome is a specific acute clinical presentation of systemic sarcoidosis, consisting of:
hilar adenopathy: see thoracic manifestations of sarcoidosis
arthritis: see musculoskeletal manifestations of sarcoidosis
Lowe syndrome (also known as the the oculocerebrorenal syndrome of Lowe) is a multi-system disorder characterised by anomalies primarily affecting the eyes, nervous system, and kidneys.
It is an extremely rare, pan-ethnic, x-linked disease, with estimated prevalence in the general po...
Low phospholipid-associated cholelithiasis (LPAC) syndrome is one of the syndromes associated with ABCB4/MDR3 mutation. Characteristics of this syndrome include 1,2:
symptomatic cholesterol stones with early onset (<40 years)
recurrent symptoms post cholecys...
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.
Maffucci syndrome is a congenital nonhereditary mesodermal dysplasia characterised by multiple enchondromas with soft-tissue venous malformations (haemangiomas).
On imaging, it is usually portrayed by a short limb with metaphyseal distortions due to multiple enchondromas, which may appear grote...
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.
MBD is in most instances seen in chronic alcoholics, and as such the epidem...
Marfan syndrome is a multisystem connective tissue disease with autosomal dominant inheritance of defect in fibrillin 1 gene. The affected patients are tall with long disproportionate extremities and have pectus excavatum, arachnodactyly, and may also experience upward and lateral optic lens dis...
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 goitre or nodular Graves disease 1.
The syndrome is rare with reported prevalence somewhere b...
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 is a rare syndrome consisting of:
fibrous dysplasia: usually polyostotic 2
multiple soft tissue myxomas (intramuscular myxomas): typically in large muscle groups
It is most frequently seen in women (~70%) and usually present in middle age (mean age 46; range 1...
McCune-Albright syndrome (MAS) is a genetic disorder characterised by the association of:
endocrinopathy: precocious puberty
polyostotic fibrous dysplasia: more severe than in sporadic cases
cutaneous pigmentation: coast of Maine 'cafe au lait' spots
Presentation is va...
McKusick Kaufman syndrome (MKS) is an autosomal recessive multiple malformation syndrome primarily characterised by
hydrometrocolpos - vaginal atresia
congenital heart disease
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.
Medial medullary syndrome, also known as Déjerine syndrome, represents less than 1% of brainstem stroke syndromes 1,2. Thrombotic or embolic occlusion of small perforating branches from vertebral or proximal basilar artery supplying the medial aspect of medulla oblongata cause this rare 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.
While it can affect those of any age, it typically involves the young...
Megacystis microcolon intestinal hypoperistalsis syndrome (MMIHS) (also known as the Berdon syndrome) is a rare congenital disorder characterised by a dilated non-obstructive urinary bladder and hypoperistalsis of the gastrointestinal tract.
There is recognised strong female predi...
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 characterised by early brain overgrowth and body morphogenesis an...
Mendelson syndrome or peptic pneumonia refers to acute chemical pneumonitis caused by the aspiration of stomach contents in patients under general anesthesia.
The etiologic agents is believed to be aspiration of acidic stomach contents, other compounds, e.g. bile, may also play a rol...
Meningothelial hyperplasia is a poorly defined and likely reactive process characterised by a non-invasive, multicentric proliferation of meningothelial arachnoid cap cells. It is one of the causes of pachymeningeal dural thickening. It is not thought to a neoplastic process or even a precursor ...
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 dependant mitochondrial enzymes.
MERRF (myoclonic epilepsy with red ragged fibres) is a rare, multisystem mitochondrial disorder.
Patients usually present in late adolescence or early adulthood with 1,2,3
vision and/or hearing loss
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.
In a review of the case literature 1, affected patients range widely in age, with the peak incidence occurring in the...
Midaortic syndrome (MAS) is an uncommon entity affecting children and young adults. It is characterised by progressive narrowing of the abdominal aorta and its major branches.
The onset of symptoms is usually during young adulthood or childhood 2:
hypertension (most comm...
Middle East Respiratory Syndrome coronavirus (MERS-CoV) infection is an uncommon viral 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 its sim...
Mikulicz syndrome was considered a form of Sjögren syndrome (type 1) however more recently it is considered in IgG4 related disease spectrum. It is a non-specific inflammatory enlargement of at least two or more of the salivary and lacrimal glands with xerostomia.
It may also be referred to b...
Milk-alkali syndrome is the combination of:
It is due to the large amounts 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 nephr...
Millard-Gubler syndrome, also known as ventral pontine syndrome, is one of the crossed paralysis syndromes, which are characterised by cranial nerves VI and VII palsies with contralateral body motor or sensory disturbances 1-3.
ipsilateral facial and contralateral body he...
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.
Milwaukee shoulder frequently affects older women, often with a history of trauma t...
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, also known as congenital facial diplegia syndrome, is a rare congenital condition characterised by the absence or underdevelopment of the abducens nerve (CN VI) and facial nerve (CN VII) nuclei.
Möbius syndrome is rare with an estimated incidence of ~1 case per 10...
Morgagni syndrome consists of the triad of:
hyperostosis frontalis interna
virilism and hirsutism
History and etymology
It was first described in 1765 by the Italian anatomist and pathologist Giovanni Battista Morgagni (1682-1771)
Morquio syndrome is an autosomal recessive mucopolysaccharidosis (MPS), type IV.
Incidence estimated at ~1:40,000.
Many cases present at ~2 years of age and have normal intelligence. Clinical features:
severe dwarfism (<4 foot)
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 (MEN1) is also known as Wermer syndrome.
Primary hyperparathyroidism is one of the commonest presentations.
The abnormality is related to a tumour suppressor gene located in chromosome 11q13. MEN type I is an autosomal domin...
Multiple endocrine neoplasia (MEN) type IIa, also known as Sipple syndrome, accounts for most cases of MEN2 and is characterised 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 (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 characterised by:
pheochromocytoma(s): in 50% of patients, often bilateral, and can be extra-adrenal
medullary thyroid cancer: 100% of patient...
Nail-patella syndrome, also known as Fong disease or osteo-onychodysostosis, is a rare autosomal dominant condition which results from symmetrical mesodermal and ectodermal abnormalities.
Clinically, the key feature is absent/hypoplastic nails from birth. Individuals may ...
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.
NTS is seen in a wide range of ages but is more commonly reported in older children and young adults 1-3.
Nephrotic syndrome (NS) results from loss of plasma proteins in the urine and characterised by hypoalbuminemia, hyperalbuminuria, hyperlipidemia, and oedema. It may be caused by primary (idiopathic) renal disease or by a variety of secondary causes.
Patients present with ...
Neu-Laxova syndrome is a lethal autosomal recessive multiple malformation syndrome with a heterogeneous phenotype.
The clinical spectrum can be quite wide and includes:
dermal / cutaneous
severe skin restriction
decreased fetal movement
marked intrauterine gro...
Neurocutaneous melanosis or neurocutaneous melanomatosis, is a rare sporadic phakomatosis characterised by multiple congenital cutaneous nevi and meningeal melanocytosis / meningeal melanomatosis.
Neurocutaneous melanosis tends to be diagnosed in the first few years of life with ...
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.
Neuroferritinopathy is a rare disorder first described in 2001 ...
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 tumour syndromes....
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 ...
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 other thoracic manifestations as focal thoracic scoliosis, enlarged...
Niacin (vitamin B3) deficiency, also known as Pellagra, is a multisystemic disease with manifestations from the skin, gastrointestinal tract and central nervous system.
It use to be widespread until the early twenty century, but after fortification of flour with niacin it is prac...
Nijmegen breakage syndrome (NBS) is a rare autosomal recessive syndrome of chromosomal instability.
Clinical and genetic features
The cause is considered a founder mutation in the NBS1 gene (c.657_661del5) on chromosome 8q21. It is most common in West Slavic populations. The role of NBS1 is ...
Nonsteroidal anti-inflammatory drug (NSAID) exacerbated respiratory disease or previously known as Samter syndrome or aspirin or analgesic-induced asthma refers to the constellation of 1-2:
allergy to aspirin
nasal polyposis / rhinosinusitis
In adults, prevalence can ran...
Noonan syndrome with multiple lentigines, previously known as LEOPARD syndrome (LS), is a rare autosomal dominant RASopathy that has many similarities to Noonan syndrome.
Despite a change in formal name, the 'LEOPARD' acronym is still useful to summarise the clinical feat...
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 is a rare midbrain stroke syndrome that involves the tectum of the midbrain, including the quadrigeminal plate 1-4. Although it can be caused by stroke, especially haemorrhages rather than infarctions, it is more commonly seen due to neoplasm 1-4. Classically, the syndrome inv...
Nutcracker syndrome is a vascular compression disorder and refers to the compression of the left renal vein between the superior mesenteric artery (SMA) and aorta. This can lead to renal venous hypertension, resulting in rupture of thin-walled veins into the collecting system with resultant haem...
Occipital horn syndrome is a rare X-linked disorder of copper metabolism resulting in connective tissue abnormalities. The Menkes kinky hair syndrome 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 lax...
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.
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.
Ortner syndrome, also known as cardiovocal syndrome, is characterised by hoarse voice resulting from left recurrent laryngeal nerve palsy secondary to a cardiovascular disorder.
Left recurrent laryngeal nerve palsy in this condition is due to traction or compression of the nerve betw...
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, where OS-CS is a multi system, X-linked dominant disorder.
OS-CS is extremely...
Osteoporosis pseudoglioma syndrome is a rare autosomal recessive disease that is characterised by severe osteoporosis and blindness. This disease is frequently mistaken for osteogenesis imperfecta.
This disease is encountered in approximately 1 in 2 million births.
Otopalatodigital syndrome type I is a rare genetic disorder marked by the association of
and a characteristic face (with hypertelorism, broad nasal root, prominent supraorbital ridges, small flat nose and downslanted palpebral fissures).
It is ...
Ovarian vein syndrome is a relatively rare condition where a dilated ovarian vein causes notching, dilatation, or obstruction of the ureter. This is usually secondary to varicoses of the ovarian vein or ovarian vein thrombosis and occurs at the point where the ovarian vein crosses the ureter.
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.
It is associated with forced...
Pancoast syndrome results from involvement of the brachial plexus and sympathetic chain by a Pancoast tumour, or less commonly from other tumours involving the superior pulmonary sulcus. The syndrome consists of:
C8-T2 radicular pain
The classical syndrome is un...
Pantothenate kinase-associated neurodegeneration (PKAN), previously 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).
Paradoxical brain herniation, also known as sinking skin flap syndrome (SSFS), is a rare and potentially fatal entity complicating decompressive craniectomy.
Atmospheric pressure exceeding intracranial pressure at the craniectomy results in displacement of the brain across various i...
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.
Parinaud syndrome, also known as the dorsal midbrain syndrome, is a supranuclear vertical gaze disturbance caused by compression of the tectal plate.
It is characterised by a classic triad of findings:
upward gaze palsy, often manifesting as diplopia
pupillary light-near dissociation (pupils ...
Parkinson-plus syndrome refers to a loose group of neurodegenerative disorders that are characterised 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.
Parry-Romberg syndrome (PRS), also known as progressive facial hemiatrophy (PFH), is a rare progressive craniofacial disorder (phakomatosis).
It is classically characterised by a slow progressive degeneration (atrophy) of the soft tissues of half of the face (hemifacial atrophy). This involves ...
Parsonage-Turner syndrome is an acute idiopathic brachial neuritis.
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.
The presentation is typi...
Patau syndrome (also known as trisomy 13) is considered the 3rd commonest autosomal trisomy.
This along with Down syndrome (T21) and Edward syndrome (T18) are the only three trisomies to be compatible with extrauterine life. However, few infants live more than a few days.
Pelvic congestion syndrome is a condition that results from retrograde flow through incompetent valves in ovarian veins. It is one of commonly missed and potentially treatable cause of chronic abdominal or pelvic pain.
It tends to be more common in multiparous, premenopausal wome...
PELVIS or LUMBAR syndrome is the combination of pelvic haemangiomas with other extracutaneous abnormalities. The syndrome may be incomplete.
external genital malformations
Pendred syndrome is an autosomal recessively inherited disorder characterised by a euthyroid goitre associated with sensorineural hearing loss.
It is considered the most common form of syndromic hearing loss and accounts for upwards of 10% of hereditary deafness.
Pepper syndrome is of interest only (the term is not readily used in day-to-day practice), and refers to primary adrenal neuroblastoma with extensive liver metastases 1. In essence, it refers to stage 4S neuroblastoma (see staging of neuroblastoma).
Peutz-Jeghers syndrome is one of the polyposis syndromes. It has an autosomal dominant inheritance and is characterised by:
multiple hamartomatous polyps, most commonly involving the small intestine (predominantly the ileum), but also colon and stomach; mouth and oesophagus are spared
Phlegmasia cerulea dolens (Greek: "inflamed blue oedema") 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).
It is characterised by severe pain, swe...