18q-deletion syndrome is a rare chromosomal anomaly where there is a deletion of part of the long arm of chromosome 18. Associated symptoms and findings vary widely, as do their severity. Characteristic clinical features include short stature, intellectual disability, hypotonia, facial and dista...
Acute spinal cord ischemia syndrome is uncommon, but usually presents with profound neurological signs and symptoms, and the prognosis is poor.
Acute spinal cord ischemia syndrome represents only 5-8% of acute myelopathies 4,5 and <1% of all strokes 7. The demographic of affected...
Adie syndrome, also known as Holmes-Adie syndrome, is a rare neurological disorder.
Adie syndrome is a rare condition which is most commonly seen in young females in their fourth decade of life 2,3.
Patients most commonly present with a classic triad of:
Agraphia represents acquired impairments of writing ability secondary to damage or dysfunction of the central nervous system. Impairments caused solely by motor dysfunction (e.g. hand paresis or tremor) are not considered to be forms of agraphia 1.
Agraphia is rarely an i...
Aicardi-Goutières syndrome is a rare hereditary neurodegenerative disease which usually presents in early infancy with systemic and central nervous system inflammatory syndrome characterized by hepatosplenomegaly, vasculopathy and encephalopathy. Many of the features are similar to congenital TO...
Aicardi syndrome is a rare severe developmental disorder. It results from an X-linked genetic defect that is fatal in males and therefore only manifests in females (except for rare 47, XXY cases).
Note: Aicardi syndrome is distinct from Aicardi-Goutieres syndrome although both are named after J...
Alexia (or acquired dyslexia) is a neurological term refers to an acquired impairment of reading resulting from damage of critical brain areas.
Alexia can manifest itself as an impairment of oral reading and reading comprehension alike and can occur in combination with va...
Alpers syndrome, also known as Alpers-Huttenlocher syndrome or progressive cerebral poliodystrophy, is a rare childhood neurodegenerative POLG-related disorder. Along with Leigh syndrome, it is one of the commonest childhood mitochondrial disorders 1.
Alpers syndrome is incredibl...
Alpha-thalassemia/intellectual disability syndrome X-linked (ATRX) gene is an important genomic marker of gliomas and is either intact (ATRX wild-type) or mutated (ATRX-mutant) and is correlated with other important genomic markers including IDH, 1p19q codeletion and p53 expression 1,2.
Alport syndrome is an X-linked dominant disease characterized by progressive sensorineural hearing loss, renal disease and, at times, ocular lesions.
sensorineural hearing loss: typically high frequency 2
anterior lenticonus: most common ...
Anterior choroidal artery (AchA) syndrome is a rare entity characterized by the triad of hemiplegia, hemianaesthesia and contralateral hemianopia as a result of cerebral infarction in the anterior choroidal artery territory.
The syndrome may also be associated with neuropsychological disorders,...
Anti-GQ1b IgG antibody syndrome refers to a number of conditions which share autoantibodies to the ganglioside complex GQ1b, and have overlapping clinical spectrums.
The conditions believed to represent various clinical manifestations of a common immunological disorder include 1:
Antiphospholipid syndrome is a systemic autoimmune disorder. It is usually defined as the clinical complex of vascular occlusion and ischemic events occurring in patients who have circulating antiphospholipid antibodies.
Antiphospholipid syndrome is characterized by venou...
Asymmetric ventriculomegaly, interhemispheric cyst, and dysgenesis of the corpus callosum (AVID) is a triad of congenital cerebral anomalies.
markedly asymmetric enlargement of the lateral ventricles may be the initial finding on routine fetal morphology ultrasound.
Ataxia-telangiectasia is a rare multisystem disorder that carries an autosomal recessive inheritance, sometimes classified as a phakomatosis. It is characterized by multiple telangiectasias, cerebellar ataxia, pulmonary infections, and immunodeficiency.
On brain imaging, it usually demonstrate...
Babinski-Nageotte syndrome is thought to be a brainstem stroke syndrome in between that of the hemimedullary syndrome (Reinhold syndrome) and the lateral medullary syndrome (Wallenberg syndrome) 1,2.
In many texts this eponymous syndrome is incorrectly used synonymously with hemim...
Bálint syndrome is characterized by:
simultanagnosia (inability to perceive more than one object at a time)
It typically results from damage to the parieto-occipital regions, and has been associated with 1-3:
Bannayan–Riley–Ruvalcaba syndrome (BRRS or BRR syndrome) is a very rare autosomal dominant hamartomatous disorder caused by a mutation in the PTEN gene. It is considered in the family of hamartomatous polyposis syndrome.
There are no formal diagnostic criteria for this disease, but characterist...
Bannayan-Zonana syndrome, also known as Bannayan-Riley-Ruvalcaba syndrome, is a rare hamartomatous disorder.
Male predominance is reported 1.
Bannayan-Zonana syndrome is characterized by:
Other findings that...
Bardet-Biedl syndrome (BBS), previously known as the Laurence-Moon-Bardet-Biedl syndrome (LMBBS), is a rare autosomal recessive hereditary condition.
The clinical spectrum includes:
retinal anomalies: similar to that of retinitis pigmentosa
Benedikt syndrome, or paramedian midbrain syndrome, is a midbrain stroke syndrome that involves the fascicles of the oculomotor nerve and the red nucleus.
ipsilateral CN III palsy 1-4
crossed hemiataxia 1-4
crossed choreoathetosis 1-4
It is usually caused by...
Benign paroxysmal positional vertigo (BPPV) is one of the most common causes of vertigo. It occurs secondary to change in posture and typically is associated with nystagmus. The etiology is thought to be due to changes of position of the otoliths in the inner ear, most commonly into the posterio...
Big black brain is a radiologic pattern unique to infants and toddlers in the context of traumatic brain injury, most frequently due to abusive head trauma.
The CT presentation is a parenchymal hypodensity and uniform loss of gray-white differentiation in the entire hemisphere, associated with...
Bing-Neel syndrome is an extremely rare neurological complication of Waldenström macroglobulinemia where there is malignant lymphocyte infiltration into the central nervous system (CNS).
The exact incidence is unknown, however, in one study of patients with Waldenström macroglobul...
Branchio-oculo-facial syndrome (BOFS) is a very rare autosomal dominant genetic disorder that is characterized clinically by abnormalities affecting the eyes, craniofacial structures, and branchial sinuses.
More than 80 cases have been reported in the global literature since its f...
Brissaud-Sicard syndrome is a very rare pontine stroke syndrome that involves the anterolateral and inferior pons.
Classically, the syndrome presents as ipsilateral facial cramps and contralateral hemiparesis 1-3.
It has been postulated that the syndrome is ca...
Brown-Séquard syndrome, also known as hemicord syndrome, is the result of damage to, or impairment of, the left or right side of the spinal cord. It is characterized by a characteristic pattern of motor and sensory deficits that are determined by the decussation pattern of various white matter t...
The Brown syndrome refers to an inability of a patient to perform an upward gaze while the eye is adducted due to an abnormality of the superior oblique tendon sheath complex.
History and etymology
It was first described by Allan Brown in 1950 1.
Bruns syndrome occurs in patients with an obstructing intraventricular mass.It consists of abrupt paroxysms of:
The symptoms are characteristically exacerbated with sudden movements of the head.
There are two main theories as to the pathogenesis o...
Cauda equina syndrome is considered an incomplete cord syndrome, even though it occurs below the conus. Cauda equina syndrome 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...
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:
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 damage to the central portion spinal cord and in the setting of trauma most common...
Central herniation is the subtype of downward transtentorial herniation of the brain that involves descent of the diencephalon and midbrain. It usually occurs with other types of downward herniation such as uncal herniation.
The clinical syndrome of central herniation c...
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...
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.
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.
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.
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...
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...
Computer vision syndrome is a condition that affects primarily workers who use computers (including tablets and other devices with computer screens) many hours a day with symptoms that can include blurred vision, eye strain, and headache.
Computer vision syndrome is a growing phen...
Congenital ventriculomegaly can have a large number of syndromic associations.
fetal alcohol syndrome
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...
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...
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...
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...
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:
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...
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...
The 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 ...
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...
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...
Fowler syndrome, also known as proliferative vasculopathy and hydranencephaly-hydrocephaly syndrome (PVHH), is a rare inherited condition.
Not to be confused with Fowler syndrome of urinary retention, a condition caused by primary failure of urethral sphincter relaxation resulting ...
Frontonasal dysplasia, also known as median cleft face syndrome, is a rare disorder characterized by midline defects involving the face, head, and central nervous system.
Frontonasal dysplasia is considered to be a very rare condition, with approximately 100 cases having been repo...
Galloway-Mowat syndrome (GAMOS) is a rare autosomal recessive disorder characterized by nephrotic syndrome and central nervous system (CNS) abnormalities, namely microcephaly.
Galloway-Mowat syndrome is considered extremely rare. Approximately 40 cases have been reported worldwide...
Gasperini syndrome is a rare pontine stroke syndrome that involves the caudal pons tegmentum.
Classically, the syndrome presents with 1-3:
involvement of the CN V nucleus: ipsilateral facial sensory loss
involvement of the CN VI nucleus: ipsilateral impaired eye abducti...
Gerstmann-Straussler-Scheinker disease is a very rare type of human transmissible spongiform encephalopathy. It manifests with dementia and/or ataxia and is due to a mutation in the prion protein (PRNP) gene, which is inherited in an autosomal dominant pattern.
History and etymology
It is nam...
Gerstmann syndrome, also known as angular gyrus syndrome, is a dominant hemisphere stroke syndrome affecting the left parietal lobe in the region of the angular gyrus, consisting of four components:
agraphia or dysgraphia
acalculia or dyscalculia
Giant axonal neuropathy is a rare, autosomal recessive neurodegenerative disease of both the peripheral nervous system (PNS) and the central nervous system (CNS). It is one of the inherited leukodystrophies.
Approximately 50 affected families have been reported in the literature;...
Gomez-Lopez-Hernandez syndrome, also known as cerebellotrigeminal-dermal dysplasia, is a rare phakomatosis characterized by rhombencephalosynapsis, parietal-occipital scalp alopecia, brachycephaly, facial malformations and trigeminal anesthesia.
History and etymology
It is named after Manuel ...
Gradenigo syndrome consists of the triad of:
abducens nerve palsy, secondary to involvement of the nerve as it passes through Dorello canal
retro-orbital pain, or pain in the cutaneous distribution of the frontal and maxillary divisions of the trigeminal nerve, due to extensi...
Guillain-Barré syndrome (GBS) is defined as a heterogeneous group of autoimmune polyradiculopathies, involving sensory, motor and autonomic nerves. It is the most common cause of rapidly progressive flaccid paralysis. It is believed to be one of a number of related conditions, sharing a similar ...
Heerfordt syndrome, also known as Heerfordt-Waldenström syndrome or uveoparotid fever, is a variant of sarcoidosis, comprising of:
ocular involvement (anterior uveitis)
The exact prevalence is unknown, as only isolated case reports exist....
Hemiconvulsion-hemiplegia epilepsy syndrome (HHE) is a clinical syndrome of infancy or early childhood that is associated with seizures, cerebral hemiatrophy and transient or permanent epilepsy.
It refers to the characteristic holohemispheric global atrophy of one hemisphere, that is independen...
Hemimedullary syndrome, also known as Reinhold syndrome, occurs as a result of the occlusion of the ipsilateral vertebral artery proximal to the posterior inferior cerebellar artery and its anterior spinal artery branches 1-3. This situation causes lateral medullary infarct and medial medullary ...
Hereditary angiopathy with nephropathy, aneurysms, and muscle cramps (HANAC) syndrome is an autosomal dominant monogenic COL4A1-related disorder.
The exact prevalence is unknown.
The cardinal features of HANAC syndrome are helpfully described in the name of...
Hereditary hemorrhagic telangiectasia (HHT), also known as Osler-Weber-Rendu syndrome, is a rare inherited disorder characterized by abnormal blood vessel formation in the skin, mucous membranes, and organs including the lungs, liver, and central nervous system.
Horizontal gaze palsy with progressive scoliosis (HGPPS) is a rare autosomal recessive disease.
Abnormal horizontal gaze while normal vertical gaze and kyphoscoliosis. Horizontal gaze requires the action of ipsilateral abducent nerve and contralateral oculomotor nerve and...
Hyperperfusion syndrome after carotid endarterectomy (CEA) or carotid artery stenting (CAS) is a rare complication.
Hyperperfusion occurs in ~7.5% (range 1-14%) of patients but only a minority (~1.5%) of patients are symptomatic 1,2, with incidence being reported slightly more af...
Hypomelanosis of Ito, also known as incontinentia pigmenti achromians, is the third most frequent phakomatosis, involving a wide spectrum of defects in multiple organ systems.
The prevalence is unknown, being reported as between 1 per 8000 patients in a general pediatric hospital ...
Immune reconstitution inflammatory syndrome (IRIS) is paradoxical deterioration of a pre-existing illness following abrupt improvement in an individual's immune function. It is classically seen in HIV/AIDS patients following initiation of highly active anti-retroviral therapy (HAART). Increasing...
Incontinentia pigmenti, also known as Bloch-Sulzberger syndrome, is a rare condition that can affect many body systems, especially the skin. As an X-linked dominant genetic disorder, it occurs much more often in females than in males.
Incontinentia pigmenti is rare and the true pr...
Inferior medial pontine syndrome, also known as Foville syndrome, is one of the brainstem stroke syndromes occurring when there is infarction of the medial inferior aspect of the pons due to occlusion of the paramedian branches of the basilar artery 1-3. This infarction involves the following 1-...
Internuclear ophthalmoplegia (INO) describes a clinical syndrome of impaired adduction in one eye with dissociated horizontal nystagmus of the other abducting eye, due to a lesion in the medial longitudinal fasciculus (MLF) ipsilateral to the eye unable to adduct. It is a common finding in multi...
Jaffe-Campanacci syndrome is characterized by:
multiple non-ossifying fibromas of the long bones and jaw
café au lait spots
hypogonadism or cryptorchidism
giant cell granuloma of the jaw
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...
Large vestibular aqueduct syndrome (LVAS), also known as enlarged vestibular aqueduct (EVA) or large endolymphatic sac anomaly (LESA), refers to the presence of congenital sensorineural hearing loss with an enlarged vestibular aqueduct due to enlargement of the endolymphatic duct. It is thought ...
Lateral medullary syndrome, also known as Wallenberg syndrome, is a clinical syndrome caused by an acute ischemic infarct of the lateral medulla oblongata. This is most commonly due to occlusion of the intracranial portion of the vertebral artery followed by PICA and its branches 1-3.
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 and ne...
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.
There is a characteristic clinical picture from the involvement of the following pontine stru...
Leigh syndrome, also known as subacute necrotizing encephalomyelopathy (SNEM), is a mitochondrial disorder with progressive neurodegeneration that invariably leads to death, usually in childhood.
Leigh syndrome is encountered in approximately 1 in 40,000 births, although some popu...
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.
It often appears between the 2nd and 6th years ...
Lesch-Nyhan syndrome is a rare X-linked genetic disease caused by a deficiency of the enzyme hypoxanthine-guanine phosphoribosyltransferase (HPRT).
Affects 1 per 380,000 individuals, which are nearly all male given the X-linked inheritance 1.
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.
Leukoencephalopathy with calcification and cysts is an extremely rare condition, with ...
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.
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.
Individuals who are "locked-in" are conscious with preserved cognitive function b...