Carotidynia, also known as Fay syndrome, is a rare syndrome characterized by neck pain in the region of the carotid bifurcation.
It was classified by the International Headache Society (IHS) in 1988 as an idiopathic neck pain syndrome associated with tenderness over the carotid bifurcation with...
Carpal tunnel syndrome results from compression of the median nerve within the carpal tunnel. It is a cause of significant disability and is one of three common median nerve entrapment syndromes, the other two being anterior interosseous nerve syndrome and pronator teres syndrome.
Carpenter syndrome, also called acrocephalopolysyndactyly type II (ACPS type II) is an extremely rare autosomal recessive congenital disorder.
It is characterized by a number of features which include:
Cauda equina syndrome is considered an incomplete cord syndrome, even though it occurs below the conus, and refers to a collection of symptoms and signs that result from severe compression of the descending lumbar and sacral nerve roots. It is most commonly caused by an acutely extruded lumbar d...
Caudal regression syndrome represents a spectrum of structural defects of the caudal region. Malformations vary from isolated partial agenesis of the coccyx to lumbosacral agenesis.
Caudal regression syndrome is rare, with an estimated incidence of 1:7500-100,000 7,10.
The vast m...
Cavernous sinus syndromes refer to constellations of clinical signs and symptoms referable to pathology within or adjacent to the cavernous sinus.
Patients present with multiple unilateral cranial neuropathies involving any combination of the following:
Cavitary mesenteric lymph node syndrome is seen in association with celiac disease and is characterized by the triad of:
low-attenuation lymphadenopathy that sometimes contains fat-fluid levels
CEC syndrome refers to the combination of celiac disease, epilepsy and bilateral occipital calcifications. This is also known as Gobbi syndrome. Patients with cerebral calcifications and celiac disease without epilepsy are considered as having an incomplete form of CEC syndrome 1.
Central cord syndrome is the most common type of incomplete spinal cord syndrome, usually the result of trauma, accounting for ~10% of all spinal cord injuries. As the name implies, this syndrome is the result of a damage to the central portion spinal cord and in the setting of trauma most commo...
Cerebellar ataxia with neuropathy and vestibular areflexia syndrome (CANVAS) is a rare neurodegenerative balance disorder characterized by cerebellar ataxia, sensory neuronopathy (ganglionopathy), and bilateral vestibular hypofunction.
The epidemiology is yet to be defined, but CA...
Cerebellar mutism syndrome usually develops after resection of midline cerebellar or intraventricular tumors in the posterior fossa. Typical features of this condition are transient mutism, ataxia, hypotonia and irritability.
The nomenclature of this syndrome has considerable confu...
Cerebral hypoventilation syndrome refers to a congenital condition characterized by hypoventilation during sleep with no other abnormalities of cardio-respiratory system. There is a decrease in the depth of breathing .
It is also known as Congenital central hypoventilation syndrome (CCHS) or On...
Charcot-Marie-Tooth (CMT) disease, also known as hereditary motor and sensory neuropathy (HMSN), is the most commonly inherited neuropathy of lower motor (to a lesser degree sensory) neurons.
The prevalence of CMT in one Norwegian study was 82.3 cases per 100,000 people 4.
CHARGE syndrome is an acronym that classically describes a combination head and neck, cardiac, CNS and genitourinary disorders:
H: heart defects (congenital heart disease)
A: atresia (choanal)
R: retardation of growth and development
G: genital and/or urinary abnormalities
Chilaiditi syndrome is the anterior interposition of the colon to the liver reaching the under-surface of the right hemidiaphragm with associated upper abdominal pain; it is one of the causes of pseudopneumoperitoneum.
Colonic gas in this position may be misinterpreted as true pneumoperitoneum ...
CHILD (congenital hemidysplasia with ichthyosiform erythroderma and limb defects) syndrome comprises:
Ch: congenital hemidysplasia
I: ichthyosiform erythroderma
develops at or shortly after birth
unilateral erythema and scaling, with a distinct demarcation in the middle of the trunk 2
Chinese paralytic syndrome also known as acute motor axonal neuropathy (AMAN) is characterized progressive symmetric flaccid paralysis with areflexia. It is a pure motor axonopathy and a variant of Guillain-Barré syndrome
Chorea-acanthocytosis (ChAc) is an autosomal recessive, progressive neurological disorder. It is the commonest of the four core neuroacanthocytosis syndromes (NAS). Symptomatology includes movement disorder, acanthocytosis, elevated creatinine kinase, and atrophy of the basal ganglia.
There are a large number of recognized chromosomal anomalies (many with eponyms). When there is a change in the absolute number of chromosomes these are subgrouped as aneuploidic anomalies.
They can cause a variable degree of disability with outcomes ranging from no effect (in some balanced tra...
Chromosome 1q21.1 deletion syndrome is a condition caused by the deletion of a short portion of the long arm (q) of chromosome 1 at a locus called q21.1. The disorder demonstrates a heterogenous spectrum of manifestations including delayed milestones, learning difficulties, physical anomalies, c...
Chronic hereditary lymphedema (also known as Milroy disease) is a condition characterized by lower limb lymphedema. Patients typically present with pedal edema at or before birth or soon after. Occasionally, it develops later in life.
Mutations in the FLT4 gene are thought ...
Chronic recurrent multifocal osteomyelitis (CRMO) is an idiopathic inflammatory bone disorder seen primarily in children and adolescents. It is often a diagnosis of exclusion once underlying infection and neoplasia has been ruled out. However, there are some cases in which lesion location and mo...
Clasp-knife deformity is relatively common congenital anomaly found at the lumbosacral junction.
When a clasp-knife deformity is accompanied by pain on extension secondary to protrusion of the enlarged spinous process (knife blade) into the sacral spinal canal, it is called clasp-k...
Claude syndrome is one of the brainstem stroke syndromes in which there is infarction of the dorsomedial aspect of the midbrain.
Clinical picture is characteristic and includes ipsilateral oculomotor nerve palsy and contralateral upper and lower limb ataxia 1-4.
CLOVES syndrome is an acronym denoting a rare condition consisting of:
Congenital Lipomatous Overgrowth
Although first described as CLOVE the term "CLOVES" syndrome, with the "S" emphasizing the skeletal ...
Cobb syndrome, also called cutaneous vertebral medullary angiomatosis, or spinal arteriovenous metameric syndrome, consists of the presence of a vascular nevus with a spinal vascular malformation of the same body somite (metamere).
The importance of this syndrome is the recognition that cutane...
Cockayne syndrome is a rare autosomal recessive dysmyelinating disease. Cockayne syndrome is classified among the childhood leukodystrophies, and brain imaging findings are cardinal features suggesting the diagnosis of Cockayne syndrome. Previously published Cockayne syndrome imaging studies hav...
Celiac artery compression syndrome, also known as median arcuate ligament syndrome, Dunbar syndrome, or Harjola-Marable syndrome, is a rare condition characterized by upper abdominal pain in the setting of compression of the celiac trunk by the diaphragmatic crurae.
Although well-recognized as ...
Coffin-Siris syndrome, first described in 1970, is a rare genetic abnormality.
Coffin-Siris syndrome should not be confused with Coffin-Lowry syndrome.
It occurs more frequently in females (with a M:F of ~4:1).
One of the most typical features is absence o...
Cogan syndrome is a rare vasculitis of young adults that is primarily characterized by 1,4,6:
inflammatory eye disease (classically interstitial keratitis) 6
audiovestibular dysfunction (similar to Meniere disease) 6
Cogan syndrome is rare and can occur in people of any age and ...
Colonic pseudo-obstruction (also known as Ogilvie syndrome) is a potentially fatal condition leading to an acute colonic distention without an underlying mechanical obstruction. It is defined as an acute pseudo-obstruction and dilatation of the colon in the absence of any mechanical obstruction....
Complex regional pain syndrome (CRPS), also known as Sudeck atrophy, is a condition which can affect the extremities in a wide clinical spectrum. CRPS is principally a clinical diagnosis - no one imaging study is sensitive or specific to rule in or rule out the syndrome.
Congenital adrenal hyperplasia (CAH) (also known as adrenogenital syndrome) is a form of adrenal hyperplasia related to a variety of autosomal recessive disorders in adrenal steroidogenesis; characterized by low cortisol, low aldosterone, and androgen excess.
Congenital contractural arachnodactyly (CCA) (also known as Beals syndrome) is a rare connective tissue disorder that bears phenotypic similarities to Marfan syndrome, but is genetically distinct. Affected individuals have arachnodactyly, muscle contractures and ear anomalies, but without any oc...
Congenital high airway obstruction syndrome or sequence (CHAOS) refers to a rare, often lethal, congenital laryngotracheal condition and is primarily characterized by obstruction to the fetal upper airway.
CHAOS can be of three possible types 2:
complete laryngeal atresia without an...
Congenital pulmonary venolobar syndrome is a condition comprising a rare group of cardiac and pulmonary congenital abnormalities occurring variably in combination. The abnormalities include:
anomalous pulmonary venous drainage
particularly scimitar syndrome with hypogenetic right lung
Congenital ventriculomegaly can have a large number of syndromic associations.
fetal alcohol syndrome
Conn syndrome, also known as primary hyperaldosteronism, is a condition of excess of aldosterone production and occurs secondary to adrenal cortical adenoma, bilateral adrenal hyperplasia, or rarely, adrenal carcinoma. Differentiation between the causes is required to avoid unnecessary surgery. ...
Constrictive pericardial syndromes include 1:
transient constrictive pericarditis
a complication of acute (inflammatory) pericarditis in which the inflamed pericardium causes constrictive hemodynamics
resolution occurs within several weeks
chronic constrictive pericarditis
persistence of c...
Conus medullaris syndrome is caused by an injury or insult to the conus medullaris and lumbar nerve roots. It is a clinical subset of spinal cord injury syndromes. Injuries at the level of T12 to L2 vertebrae are most likely to result in conus medullaris syndrome.
Cortical blindness is a condition resulting from lesions in the primary visual cortex (V1) characterized by visual impairment but with an intact anterior visual pathway (normal pupillary reflexes and fundal appearance).
The degree of visual impairment is related to the ex...
Cowden syndrome, also known as multiple hamartoma syndrome, is characterized by multiple hamartomas throughout the body and increased risk of several cancers.
Type 2 segmental Cowden syndrome is the association of Cowden syndrome with a Cowden nevus when it is considered a type of ...
CREST syndrome (also known as. limited systemic sclerosis or limited scleroderma) is a variant of progressive systemic sclerosis (PSS) and stands for
C - calcinosis
R - Raynaud phenomenon
E - oesophageal dysmotility
S - sclerodactyly
T - telangiectasia
Cronkhite-Canada syndrome is a type of non-neoplastic, non-hereditary hamartomatous polyposis syndrome characterized by rash, alopecia, and watery diarrhea.
There is a recognized male predilection. Patients typically are middle age (50-60 years of age) 1.
Crouzon syndrome is rare disorder characterized by premature craniosynostoses.
abnormal calvarial shape: in severe case can give a "cloverleaf skull"
shallow orbits with exophthalmos
mid facial hypoplasia
It carries an autosomal dominant...
Cubital tunnel syndrome is a type of ulnar nerve compression neuropathy due to pathological compression of the ulnar nerve along its course within the cubital tunnel.
The compression of the ulnar nerve at the elbow is the second most common peripheral neuropathy of the upper extre...
Cuboid syndrome is a cause of lateral midoot pain, believed to result from abnormal articulation of the cuboid with the calcaneus (calcaneocuboid joint).
Cuboid syndrome presents with lateral foot pain and swelling, often diffuse and similar to an ankle (ligament) sprain ...
Currarino-Silverman syndrome, also known as pectus carinatum type 2 deformity, is a rare disorder.
Patients present with a high carinate chest deformity due to a premature fusion of the manubriosternal joint and sternal ossification centers. Congenital heart diseases have...
The Currarino syndrome is a complex condition variably comprised of characteristic congenital anomalies of the sacrum, anorectum and presacral soft tissues. It is also known as the Currarino triad or ASP triad, however, not all three features are always present 6.
anorectal malformation or con...
Cyriax syndrome, also known as slipping rib syndrome, occurs when hypermobility of the rib cartilage of the lower ribs slips and moves, leading to pain in lower chest or upper abdomen 1.
This condition may occur at any age, but is reportedly more common in middle-aged adults, and ...
Cystinosis, also known as Abderhalden Kaufmann Lignac syndrome, is the most common hereditary cause of renal Fanconi syndrome. Cystinosis is one of the lysosomal storage disorders.
It has a reported incidence of 1:192,000 1. Cystinosis is typically diagnosed in infancy.
Dandy-Walker variant (DWv) is a less severe posterior fossa anomaly than the classic Dandy-Walker malformation (DWM) and is considered being on the lesser end of the disease spectrum in the Dandy-Walker continuum.
This term was created to include those malformations that do not mee...
Dentatorubral–pallidoluysian atrophy (DRPLA) is a clinically heterogenous autosomal dominant CAG repeat expansion disorder that is particularly prevalent within the Japanese population.
The majority of case reports are in patients of Japanese origin, where disease prevalence is 1...
Diamond-Blackfan anemia (DBA) (previously known as congenital hypoplastic anemia) is the primary congenital form of pure red cell aplasia. It is a rare sporadic genetic form of anemia that typically presents in the first few years of life, and usually only affects cells of the erythroid lineage ...
DICER1 syndrome is a rare autosomal dominant disorder predisposing individual to the development of multiple tumor types. DICER1 is considered a tumor suppressor gene that encodes the endoribonuclease protein Dicer. The first association with pleuropulmonary blastoma was discovered in 2009.
The distal intersection syndrome relates to tenosynovitis of the extensor pollicis longus (EPL) tendon (3rd extensor compartment), where it crosses the extensor carpi radialis longus (ECRL) and brevis (ECRB) tendons (2nd extensor compartment) 1. It is distinct from intersection syndrome which oc...
Doege-Potter syndrome is a non-islet cell tumor hypoglycemia, secondary to a solitary fibrous tumor (SFT). It is rare, and more associated with malignant SFTs.
Dorsal brainstem syndrome is a rare subset of hypoxic ischemic encephalopathy in neonates limited to the isolated involvement of the brainstem with sparing of the supratentorial brain. Due to its subtle imaging features it is often undiagnosed.
Injuries involving the tegm...
Down syndrome (or trisomy 21) is the most common trisomy and also the commonest chromosomal disorder. It is a major cause of intellectual disability, and also has numerous multisystem manifestations.
According to the World Health Organization (WHO), the approximate worldwide incid...
Drash syndrome, also known as the Denys-Drash syndrome, is associated with an abnormal WT1 gene (Wilms tumor gene) and consists of:
Dravet syndrome, previously known as severe myoclonic epilepsy of infancy (SMEI), is a rare form of epilepsy usually presenting in the first 1-2 years of life.
The typical presentation occurs during the first six months to one year of life as tonic-clonic seizures in a fe...
Dressler syndrome (DS) is a delayed immune-mediated or secondary pericarditis developing weeks to months after a myocardial infarction (MI).
Dressler syndrome is not to be confused with pericarditis epistenocardica (which is seen earlier in the post-MI period) and is considered a r...
The drug rash with eosinophilia and systemic symptoms (DRESS) syndrome typically manifests as a skin rash, fever, lymph nodal enlargement with variable internal organ involvement, and represents a hypersensitivity reaction to medication.
Clinical presentation can be vari...
Duane radial ray syndrome (DRRS) (also known as the Okihiro syndrome) is a rare an autosomal dominant condition characterized by radial ray defects and a Duane anomaly (a form of strabismus with horizontal gaze palsy).
Dyke-Davidoff-Masson syndrome (DDMS) is a condition characterized by hemicerebral atrophy/hypoplasia secondary to brain insult usually in fetal or early childhood period and is accompanied by ipsilateral compensatory osseous hypertrophy and contralateral hemiparesis.
It is characterized by:
Dysplasia epiphysealis hemimelica (DEH), also known as Trevor disease, is an extremely rare, non-hereditary disease that is characterized by osteochondromas arising from the epiphyses.
The incidence is estimated at ~1:1,000,000 3. There is a recognized male predilection (M:F = 3:1...
Ectrodactyly-ectrodermal dysplasia-clefting (EEC) syndrome is a rare genetic syndrome that has high clinical variability but typically comprises of the triad of
ectrodactyly +/- syndactyly 1 +/- polydactyly 5
facial clefts: cleft lip and/or palate
Edwards syndrome, also known as trisomy 18, along with Down syndrome (trisomy 21) and Patau syndrome (trisomy 13), make up the only three autosomal trisomies to be compatible with extrauterine life in non-mosaic forms, albeit in the case of Edward syndrome only for a week or so.
Ehlers-Danlos syndrome comprises a heterogeneous group of collagen disorders (hereditary connective tissue disease).
There is a recognized male predominance.
Clinically manifests by skin hyperelasticity and fragility, joint hypermobility and blood vessel fr...
The Eisenmenger syndrome is a complication of an uncorrected high-flow, high-pressure congenital heart anomaly leading to chronic pulmonary arterial hypertension and shunt reversal.
In general, the shunts that lead to Eisenmenger syndrome share high pressure and high flow 3. As su...
Elbow synovial fold syndrome refers to a condition where patients experience a cluster of symptoms due to the presence of synovial folds (also known as synovial fringe or plicae).
It tends to be more common in athletic young adults. It is associated with certain sporting activitie...
The empty nose syndrome refers to a paradoxical sensation of nasal obstruction despite objectively patent nasal airways following inferior and/or middle turbinate resection.
The condition is rare, occuring in a minority of patients who have undergone prior turbinate resection.
Encapsulating peritoneal sclerosis is a rare benign cause of acute or subacute small bowel obstruction. It is characterized by total or partial encasement of the small bowel within a thick fibrocollagenous membrane.
The condition was originally termed abdominal cocoon. The conditio...
Eosinophilia myalgia syndrome (EMS) is a fatal neurological condition caused by ingestion of improperly manufactured L-tryptophan. Impurities and/or metabolites that block histamine degradation result in peripheral blood eosinophilia and myalgia.
In the brain, cortical and basal ganglia atroph...
Eosinophilic granulomatosis with polyangiitis (EGPA), previously known as the Churg-Strauss syndrome (CSS), refers to a small to medium vessel necrotizing pulmonary vasculitis. It is also classified under the spectrum of eosinophilic lung disease and as a type of pulmonary angiitis and granuloma...
Epidermal nevus syndrome (ENS), also known as Solomon's syndrome or Feuerstein and Mims syndrome, represent a group of distinct disorders related to the presence of epidermal nevi and extracutaneous anomalies. It is a syndrome linked to mosaicism, with many of them occurring exclusively sporadic...
Episodic angioedema with eosinophilia (EAE), also known as Gleich syndrome, is a rare condition presenting as a self-limiting cyclic urticaria, fever, angioedema, weight gain and marked eosinophilia, with 3-4 weekly episodes 1.
Episodic angioedema with eosinophilia is rare, only a...
Facial colliculus syndrome refers to a constellation of neurological signs due to a lesion at the facial colliculus, involving:
abducens nerve (CN VI) nucleus
facial nerve (CN VII) fibers at the genu
medial longitudinal fasciculus
lower motor neuron facial nerve palsy ...
Fahr syndrome, also known as bilateral striatopallidodentate calcinosis, is characterized by abnormal vascular calcium deposition, particularly in the basal ganglia, cerebellar dentate nuclei, and white matter, with subsequent atrophy.
It can be either primary (usually autosomal dominant) or se...
Failed back syndrome refers to persistent leg and/or lumbar back pain after a surgical procedure. The pathophysiology of this syndrome is complex, as often the operation was technically successful.
Other names for failed back syndrome include failed back surgery syndrome, post-lam...
Familial adenomatous polyposis syndrome (FAPS) is characterized by the presence of hundreds of adenomatous polyps in the colon. It is the most common of the polyposis syndromes.
Familial polyposis coli, attenuated familial adenomatous polyposis and Gardner syndrome are all variants...
Familial atypical multiple mole melanoma (FAMMM) syndrome is an autosomal dominant genodermatosis characterized by multiple melanocytic nevi (often more than 50) and a family history of melanoma.
It is associated with mutations in the CDKN2A gene and shows reduced penetranc...
Familial multiple cavernous malformation syndrome is uncommon, accounting for only a minority of cavernous malformations.
It has been more frequently reported in patients of Hispanic descent 1.
The presentation is most commonly with seizures (38-55%) 1 and ...
Familial multiple lipomatosis (FML) is a hereditary syndrome of multiple encapsulated lipomas which are found on the trunk and extremities, with relative sparing of the head and shoulders.
It is clinically distinct from the similarly named multiple symmetric lipomatosis with which...
Fatco syndrome is a syndrome consisting of
tibial campomelia and
It is a syndrome of unknown genetic basis and inheritance with variable expressivity and penetrance.
Fuhrmann syndrome and Al-Awadi syndrome are said to be similar to FA...
Fat embolism syndrome (FES) is a rare clinical condition caused by circulating fat emboli leading to a multisystemic dysfunction. The classical clinical triad consists of:
It occurs in ~2.5% (range 0.5-4%) of tho...
Febrile infection-related epilepsy syndrome (FIRES) is a severe postinfectious neurological disorder that presents with status epilepticus in a previously normal child (or less commonly adult) after a febrile illness.
FIRES has received several names in the literature:
Femoral facial syndrome, also known as femoral hypoplasia-unusual facies syndrome, is a rare congenital syndrome characterized by varying degrees of femoral hypoplasia and facial dysmorphism 1.
Femoral facial syndrome can cause varying degrees of femoral malformation rang...
The fetal head sparing theory is one that underpins asymmetrical intra-uterine growth restriction, where the difference between normal head circumference and decreased abdominal circumference is attributed to the fetus's ability to preferentially supply the cerebral, coronary, adrenal and spleni...
Fitz-Hugh-Curtis syndrome (FHCS) refers to the development of perihepatitis in association with pelvic inflammatory disease (PID).
The prevalence in adults with mild to moderate PID (gonorrhea) may approximate 4% 10. The prevalence may be higher in genital tuberculosis 12. It mos...
Flat back syndrome (FBS) refers to the decrease or absence of the normal lumbar lordosis resulting primarily in chronic lumbar pain.
Flat back syndrome is a different condition from straight back syndrome and the two should not be confused or conflated.
Focal dermal hypoplasia syndrome, is also known as Goltz syndrome, and is not to be confused with the similar-sounding Gorlin-Goltz syndrome.
A rare disorder that follows an X-linked dominant inheritance pattern. More commonly seen in males than females. Worldwide only 200-300 cas...
Foster Kennedy syndrome describes the clinical syndrome of unilateral optic atrophy with contralateral papilledema caused by an ipsilateral compressive mass lesion.
The syndrome consists of two cardinal features 1,2:
ipsilateral optic nerve atrophy presenting with centra...