Cerebellar liponeurocytomas, also known as neurolipocytomas, are rare tumours of the cerebellum with neurocytic differentiation and abundant accumulation of intracellular lipid. They are considered WHO grade II tumours 1.
As only a small number of cases have been reported, detail...
The cerebellar nuclei comprise of 4 paired deep grey matter deep within the cerebellum near the fourth ventricle. They are arranged in the following order:
dentate nuclei (the largest and most lateral)
fastigial nuclei (most medial)
They receive inhibitory...
The cerebellar tonsils are ovoid structures on the inferiormedial surface of each cerebellar hemisphere. They are attached to the underlying cerebellum by the tonsillar peduncle 1-4.
medial: uvula of the vermis
superior: flocculonodular lobe
anterior: posterior surfa...
Acute cerebellitis (AC), also known as acute cerebellar ataxia, is a rare inflammatory process characterised by a sudden onset of cerebellar dysfunction usually affecting children. It is related as a consequence of a primary or secondary infection, or much less commonly as a result of post-vacci...
The cerebellopontine angle cistern is a triangular subarachnoid space that lies between the anterior surface of the cerebellum and the lateral surface of the pons.
superior: tentorium cerebelli
posterior: anterior surface of cerebellum
inferior: lower cranial nerves...
Cerebellopontine angle (CPA) lipomas account for ~10% of all intracranial lipomas.
Characteristically lipomas of the CPA have the facial nerve and vestibulocochlear nerve coursing through it on their way to the IAM. They are associated with intravestibular lipomas and sensorineural hearing loss...
Cerebellopontine angle (CPA) masses frequently occur, many of which are relatively specific for the region.
Cerebellopontine angle masses can be divided into four groups, based on imaging characteristics:
mass with high T1 signal on MRI
mass with CSF intensity/den...
Mnemonics for the common cerebellopontine angle masses include:
AMEN or MEAN
A: acoustic schwannoma (~80%)
M: meningioma (~10%)
E: ependymoma (~5%)
N: neuroepithelial cyst (arachnoid/epidermoid) (~5%)
acoustic schwannoma much more commo...
The cerebellum, meaning "the little brain", sits at the base of the brain in the posterior cranial fossa below the tentorium and behind the brainstem.
The cerebellum has the following features:
three surfaces: anterior (petrosal), superior (tentorial), inferior (suboccipital)
Cerebral abscesses represent focal areas of infection within brain parenchyma, usually containing pus and having a thick capsule. They typically have enhancing walls and can mimic a number of other significant pathologies.
This is a summary article; read more in our article o...
Cerebral air embolism is rare but can be fatal. They may be venous or arterial and are often iatrogenic in cause.
Presentation is often varied and non-specific but include confusion, motor weakness, decreased consciousness, seizure and vision loss.
Cerebral amyloid angiopathy (CAA) is a cerebrovascular disorder caused by the accumulation of cerebral amyloid-β (Aβ) in the tunica media and adventitia of leptomeningeal and cortical vessels of the brain. The resultant vascular fragility tends to manifest in normotensive elderly patients as lob...
Cerebral amyloid angiopathy-related inflammation (also known as cerebral amyloid angiitis or cerebral amyloid inflammatory vasculopathy) is an uncommon cerebral amyloid deposition disease, closely related to the far more common non-inflammatory cerebral amyloid angiopathy, and can present as are...
Cerebral amyloid deposition diseases are a group of related conditions characterised by the accumulation of cerebral amyloid-β (Aβ) in various parts of the central nervous system. They lead to inflammation, neurotoxicity, and vascular friability, and are typically encountered in the elderly.
Cerebral amyloidomas are the rarest manifestation of cerebral amyloid deposition, typically appearing as solidly enhancing masses.
Reported numbers are low due to the rarity of this condition, making generalisations about epidemolgical features difficult. Generally, cases have b...
Cerebral angiography is an interventional procedure for the diagnosis and/or treatment of intracranial pathology.
Cerebral digital subtraction angiography (DSA) is indicated in a variety of settings including:
diagnosis and treatment of:
acute ischaemic stroke
The cerebral aqueduct (of Sylvius) is the structure within the brainstem that connects the third ventricle to the fourth. It is located within the midbrain, surrounded by periacqueductal grey matter (PAG) with the tectum of midbrain located posteriorly and the tegmentum anteriorly.
It is filled...
Cerebral arteriovenous fistulae (CAVF) are cerebral vascular malformations or acquired conditions in which there is an abnormal direct communication between a venous and an arterial channel without the presence of a true nidus.
dural arteriovenous fistula (DAVF)
caroticocavernous fistula (CCF...
Cerebral arteriovenous malformations (CAVMs), also known as classic brain AVMs, are a common form of cerebral vascular malformation and are composed of a nidus of vessels through which arteriovenous shunting occurs.
This article corresponds to the classic form of arteriovenous malf...
Cerebral atrophy is the morphological presentation of brain parenchymal volume loss that is frequently seen on cross sectional imaging. Rather than being a primary diagnosis, it is the common endpoint for range disease processes that affect the central nervous system. Though often no identifiabl...
Cerebral blood flow (CBF) is one of the parameters generated by perfusion techniques (CT perfusion and MR perfusion). CBF is defined as the volume of blood passing through a given amount of brain tissue per unit of time, most commonly milliliters of blood per minute per 100g of brain tissue 1.
Cerebral blood volume (CBV) (often relative CBV: see below) is one of the parameters generated by perfusion techniques (CT perfusion and MR perfusion). CBV is defined as the volume of blood in a given amount of brain tissue, most commonly milliliters of blood per 100 g of brain tissue 1.
Cerebral cavernous venous malformations, commonly known as cavernous haemangioma or cavernoma, are common cerebral vascular malformations, usually with characteristic appearances on MRI.
Cavernous malformations are found throughout the body. This article focuses on cerebral cavernous venous ma...
The cerebral cortex and underlying connecting white matter accounts for the largest part of the human brain. It is composed of five different types of neurones arranged into distinct layers (in most places 6 layers) admixed with supporting glial cells (astrocytes, oligodendrocytes and microglia)...
Cerebral fat embolism (CFE) is one of a manifestations of fat embolism syndrome.
It typically occurs in patients with bony fractures (usually long bones of the lower limb).
Fat emboli usually reach the brain through a either right-to-left cardiac shunt or through an in...
Cerebral haemorrhagic contusions are a type of intracerebral haemorrhage and are common in the setting of significant head injury. They are usually characterised on CT as hyperdense foci in the frontal lobes adjacent to the floor of the anterior cranial fossa and in the temporal poles.
Cerebral hemiatrophy has a variety of causes, and is generally associated with seizures and hemiplegia. Causes include:
intrauterine vascular injury
perinatal intracranial haemorrhage
There are two cerebral hemispheres, divided in the midline in the sagittal plane by the interhemispheric fissure. Together they fill most the intra-cranial cavity.
The medial surface of each cerebral hemisphere is flat, the inferior surface is irregular and even slightly concave ...
Cerebral herniation, also referred to as acquired intracranial herniation, refers to shift of cerebral tissue from its normal location, into an adjacent space as a result of mass effect.
There are a number of different patterns of cerebral herniation which describe the type of herni...
Cerebral hydatid disease (neurohydatidosis) is caused by Echinococcus granulosus or less commonly E. alveolaris or E. multilocularis. The larval stage is the cause of hydatid disease in humans 1.
Cerebral hydatid disease is a rare parasitic infestation and accounts for 1-2 % of al...
Cerebral intraparenchymal hyperattenuations have been increasingly recognised on CT scans following mechanical thrombectomy for treatment of thromboembolic ischaemic stroke. It is a term that encompasses both contrast staining and petechial haemorrhagic change, and is used as distinguishing betw...
Cerebral malaria is a rare intracranial complication of a malarial infection.
Cerebral malaria is mainly encountered in young children and adults living or travelling in malaria-endemic areas. It is estimated to occur in ~2% of patients with acute Plasmodium falciparum infection, ...
The cerebral meninges surround the brain and is made up of three layers (from outermost to innermost):
The dura mater can also be known as pachymeninx. The arachnoid mater and pia mater are collectively known as the leptomeninges 3. The spinal meninges ar...
Cerebral oedema refers to a number of interconnected processes which result in abnormal shifts of water in various compartments of the brain parenchyma.
It has traditionally been broadly divided into vasogenic cerebral oedema and cytotoxic cerebral oedema, the latter a commonly used term used t...
Cerebral oedema describes the collection of additional fluid within the white matter of the brain. It is the brain's response to an insult and may take one of two broad forms: vasogenic (white matter) and cytotoxic oedema.
This is a summary article; read more in our article o...
The cerebral peduncles (also known as the cerebral crus) are the part of the midbrain that link the remainder of the brainstem to the thalami and thereby, the cerebrum. They are the most anterior structure in the midbrain and contain the large ascending and descending tracts that run to and from...
Cerebral perfusion pressure (CPP) is the pressure gradient between the systemic blood pressure (MAP) and the intracranial pressure (ICP) 1. It is expressed by the following equation:
CPP = MAP - ICP
CPP corresponds to the pressure necessary to pump blood from the aorta into the cranial compar...
Cerebral proliferative angiopathy (CPA), previously known as diffuse nidus type AVM, is a cerebral vascular malformation separated from classic brain AVM and characterised by the presence of normal brain parenchyma interspersed throughout the tangle of vessels that corresponds to the nidus 1,2.
Cerebral radiation necrosis refers to necrotic degradation of brain tissue following intracranial or regional radiation either delivered for the treatment of intracranial pathology (e.g. astrocytoma, cerebral arteriovenous malformation) or as a result of irradiation of head and neck tumours (e.g...
The differential for peripheral or ring enhancing cerebral lesions includes:
subacute infarct /haemorrhage /contusion
demyelination (incomplete ring)
tumefactive demyelinating lesion (incomplete ring)
Convenient mnemonics for the causes of cerebral ring enhancing lesions are:
MAGIC DR or DR MAGIC
DR MAGIC L
MAGIC DR or DR MAGIC
I: infarct (subacute phase)
D: demyelinating disease
R: radiation necrosis or re...
Cerebral sparganosis is a rare parasitic infection of the brain by the second-stage larva of Spirometra mansoni, most commonly encountered in Southeast Asia, China and South America.
Infection occurs from drinking contaminated water, ingesting poorly cooked or raw snake or frog ...
Cerebral involvement can be seen transthyretin-associated amyloidoses and presents as a neurodegenerative disease.
Age of presentation is very wide, ranging from adolescence to old age 1.
Clinical presentation is variable, but includes 1:
Vascular malformations of the central nervous system can be divided, as they can elsewhere, into high and low flow malformations.
arteriovenous malformation (AVM)
cerebral AVM (pial/parenchymal AVM)
cerebral proliferative angiopathy
dural arteriovenous fistula (DAVF)
An understanding of cerebral vascular territories is important in understanding stroke and complications from surgery and endovascular procedures.
Although one could be excused for thinking that within the brain, such a carefully organised organ, blood supply would be constant, the truth is th...
The cerebral veins drain the brain parenchyma and are located in the subarachnoid space. They pierce the meninges and drain further into the cranial venous sinuses.
The cerebral veins lack muscular tissue and valves. The cerebral venous system can be divided into:
superficial (cortical) cerebr...
Cerebral venous infarction is an uncommon form of stroke, and is most commonly secondary to cerebral venous thrombosis.
Cerebral venous infarction is usually the sequelae of cerebral venous thrombosis, complicating both dural venous sinus thrombosis and deep cerebral venous thrombos...
The cerebral venous system, somewhat unlike the majority of the rest of the body, does not even remotely follow the cerebral arterial system.
The cortical veins lie superficially, unlike cortical arteries, and are adherent to the deep surface of the arachnoid mater so that they keep the sulci o...
Cerebral venous thrombosis (CVT) refers to occlusion of venous channels in the cranial cavity, including dural venous thrombosis, cortical vein thrombosis and deep cerebral vein thrombosis. They often co-exist and the clinical presentation among them is very similar and nonspecific. Furthermore,...
Cerebrofacial arteriovenous metameric syndrome (CAMS) is a syndrome encompassing encompassing maxillofacial/intracranial vascular malformation complexes including Wyburn-Mason Syndrome and Sturge-Weber syndrome 1-4. Three types are described depending on location 2,6:
CAMS I: medial prosencepha...
Cerebrotendinous xanthomatosis is an autosomal recessive lipid storage disorder caused by defects in sterol-27-hydroxylase enzyme in bile acid synthesis. This leads to early cataract formation, atherosclerosis, hypercholesterolemia, and tendinous xanthomas.
The cerebrum, or telencephalon, is paired structure composed of two cerebral hemispheres (left and right) each containing a central space, the lateral ventricle.
The cerebrum takes up most of the intracranial cavity and lies above the tentorium cerebelli. The cerebrum includes:
The cervical enlargement is the source of the spinal nerves that contribute to the brachial plexus and supply the upper limbs.
It is one of two symmetrical enlargements which occupy the segments of the limb plexuses, the other being the lumbosacral enlargement for the lumbar and ...
Cervical interlaminar epidural injections are one of some possible spinal epidural injections. For an alternative approach for the same region, please refer to the article on cervical transforaminal epidural injections.
Typically epidural injections are performed in patients with ...
Cervical spine injuries can involve the cervical vertebral column, intervertebral discs and cervical spine ligaments, and/or cervical spinal cord. The cervical spine accounts for ~50% of all spinal injuries.
5-10% of patients with blunt trauma have a cervical spine injury 1.
The term cervical stenosis can refer to:
stenosis of the uterine cervix
bony cervical canal stenosis (cervical spinal stenosis)
Chagas disease, also referred as trypanosomiasis, is a tropical parasitic infection with a wide spectrum of clinical manifestations, since it can virtually affect any organ, but there are characteristic radiological features.
Chagas disease is endemic to Central and South America....
The Children’s Head injury ALgorithm for prediction of Clinically Important Events (CHALICE) clinical decision rule was developed to predict clinically important brain injuries in children with head trauma. This rule identifies high-risk criteria and divides them into history, examination and me...
Chamberlain line is a line joining the back of hard palate with the opisthion on a lateral view of the craniocervical junction.
It helps to recognise basilar invagination which is said to be present if the tip of the dens is >3 mm above this line.
McGregor developed a modificatio...
Charcot-Bouchard aneurysms are minute aneurysms which develop as a result of chronic hypertension and appear most commonly in the basal ganglia and other areas such as the thalamus, pons and cerebellum, where there are small penetrating vessels (diameter < 300 micrometres) 1-3.
They should not ...
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.
Signs and symptoms usually become first evident in childhood. Typically this sta...
Charles-Bonnet syndrome occurs in patients with loss of vision (usually due to ocular pathology) who experience visual hallucinations.
Although numerous causes are seen (any cause of gradual ocular visual failure can theoretically produce Charles Bonnet syndrome, as can other loc...
"Chasing the dragon" is a sign seen in toxic leukoencephalopathy caused by inhalation of heroin fumes.
Three stages are recognised:
cerebellar signs and motor restlessness
pyramidal and pseudobulbar signs
spasms, hypotonic paresis, and ultimately death
Only a minorit...
Chiari 1.5 malformation, or bulbar variant of Chiari I malformation, is a term used in the literature to describe the combination of cerebellar tonsillar herniation (as seen in Chiari I malformation) along with caudal herniation of some portion of the brainstem (often obex of the medulla oblonga...
Chiari I malformation is the most common variant of the Chiari malformations, and it is characterised by a caudal descent of the cerebellar tonsil (and brainstem in its subtype, Chiari 1.5) through the foramen magnum. Symptoms are proportional to the degree of descent. MRI is the imaging modalit...
Chiari III malformation is an extremely rare anomaly characterized by a low occipital and high cervical encephalocele with herniation of posterior fossa contents, that is, the cerebellum and/or the brainstem, occipital lobe, and fourth ventricle.
agenesis of the corpus...
Chiari IV malformation was a term some authors gave to describe a form of extreme cerebellar hypoplasia. This can be associated with hypoplasia of pons as well as a small funnel shaped posterior fossa. It is now considered to be an obsolete term.
Chinese paralytic syndrome also known as acute motor axonal neuropathy (AMAN) is characterised progressive symmetric flaccid paralysis with areflexia. It is a pure motor axonopathy and a variant of Guillain-Barré syndrome
Choline is a precursor of acetylcholine (ACH), a component of cell membranes which is commonly examined in MR spectroscopy. It resonates at 3.2 ppm chemical shift.
It is a marker of cellular membrane turnover and therefore elevated in neoplasms, demyelination and gliosis. In the setting of glio...
Chondrosarcomas are malignant cartilaginous tumours that account for ~25% of all primary malignant bone tumours. They are most commonly found in older patients within the long bones, and can arise de novo or secondary from an existing benign cartilaginous neoplasm. On imaging these tumours have ...
Chondrosarcomas of the base of the skull are rare compared with other skull base tumours but are an important differential diagnosis as surgical resection and management are affected by the preoperative diagnosis.
Chondrosarcomas of the base of the skull make up only a small fract...
The Chorda tympani is a nerve that arises from the mastoid segment of the facial nerve, carrying afferent special sensation from the anterior two-thirds of the tongue via the lingual nerve, as well as efferent parasympathetic secretomotor innervation to the submandibular and sublingual glands.
Chordoid gliomas of the third ventricle are rare slow growing well-circumscribed low-grade tumours lesions that arise from the anterior wall or roof of the third ventricle.
Epidemiological data is limited due to the rare nature of this finding and less than 100 cases have been pu...
Chordoid meningiomas are uncommon histological variants of meningiomas, and due to their predilection for rapid growth and local recurrence are designated as grade 2 tumours under the current WHO classification of CNS tumours.
Chordoid tumours are encountered in a very wide age range (possibly...
Chorea is a type of dyskinesia characterised by sudden, rapid, involuntary, and purposeless movements that happen during a person’s normal voluntary movement. It is a clinical symptom related to different aetiologies, such as infectious, inflammatory, vascular, hereditary (e.g. Huntington's dise...
Chorioretinitis refers to inflammation of the retina and choroid. As a delayed sequelae, it is one of the causes of calcification of the globe. It is often considered a form of posterior uveitis.
various congenital infections such as 2-3
rubella: ocular rubella
A choristoma is simply a collection of microscopically normal cells or tissues in an abnormal location. This is different to a hamartoma which is derived only from local tissues.
adrenal choristoma (myelolipoma)
facial nerve choristoma
Choroid plexitis is a general term referring to an inflammatory process affecting the choroid plexus; it is usually due an infectious process. It is rarely seen as an isolated process and is commonly found in association with encephalitis, meningitis, or ventriculitis 1. The choroid plexus can a...
The choroid plexus is located within the cerebral ventricles and is made of epithelial cells, loose connective tissue (tela choroidea) and permeable capillaries. It produces cerebrospinal fluid.
roof of the temporal horns of the lateral ventricles, extending along the floor of the bo...
Choroid plexus carcinomas are malignant neoplasms arising from the choroid plexus. They are classified as a WHO grade III tumour and while there is considerable overlap in imaging characteristics it carries significantly poorer prognosis than both WHO grade II atypical choroid plexus papilloma, ...
Antenatal choroid plexus cysts are benign and are often transient typically resulting in utero from an infolding of the neuroepithelium.
They should not be confused with adult choroid plexus cysts (which are very commonly found at autopsy and likely degenerative), large intraventricular simpl...
Choroid plexus hyperplasia (CPH), also known as villous hypertrophy of the choroid plexus, is a rare benign condition that is characterised by bilateral enlargement of the entire choroid plexus in lateral ventricles without any discrete masses. This can result in overproduction of CSF and commun...
Metastases to the choroid plexus from extracranial tumours are rare, but nonetheless should be included in the differential diagnosis of an intraventricular mass. They are most commonly found within the lateral ventricles, presumably because a large proportion of the choroid plexus is located th...
Choroid plexus papillomas are an uncommon, benign (WHO grade I) neuroepithelial intraventricular tumour which can occur in both the paediatric (more common) and adult population.
On imaging, these tumours are usually identified in the fourth ventricle in adults and in the lateral ventricles in...
Choroid plexus tumours can be classified as primary or secondary neoplasms of the choroid plexus:
choroid plexus papilloma (CPP)
WHO Grade I, and WHO Grade II when atypical
choroid plexus carcinoma (CPC)
WHO Grade III
Choroid plexus xanthogranulomas are common, incidental and almost invariably asymptomatic lesions. It is unclear in much of the literature whether they represent a distinct entity from adult choroid plexus cysts, but they share imaging characteristics and are only likely to be distinguishable on...
Choroidal detachment is a detachment of the choroid from the underlying sclera due to increased intraocular pressure (IOP), and occurs in some settings:
exudative: fluid accumulating in the suprachoroidal space secondary to many causes, most commonly inflammation (e.g. uve...
A choroidal effusion is an accumulation of fluid in the supra-choroidal space (between the choroid and sclera). It differs from a retinal detachment in its clinical presentation and radiologic appearance.
Choroidal effusions can be associated with :
ocular hypotony : small globe with a charact...
Choroidal epithelial cells are one of the three types of ependymal cells, themselves a type of glial cell. They cover the surface of the choroid plexus 1.
The choroidal fissure is a thin C-shaped cleft of the lateral ventricle, located along the medial wall, and to which choroid plexus is attached. It runs between the fornix and the thalamus, and it separates the temporal lobe from the optic tract, midbrain and hypothalamus.
A choroidal fissure cyst refers to a benign intracranial cyst occurring at the level of choroidal fissure. They frequently represent either an arachnoid cyst, neuroglial cyst or a neuroepithelial cyst 2. They are therefore a location based diagnosis rather than a distinct pathological entity.
There are many signs in radiology that are related to Christmas:
snowcap sign in avascular necrosis
in total anomalous pulmonary venous return
in pituitary macroadenomas
snowstorm appearance in complete hydatidiform and testicular microlithiasis
holly leaf sign in calcified pl...
There are several viral and prion infections which can result in a chronic encephalitis with slow progression into brain atrophy. These have very poor prognosis with no effective treatment. Some of these include:
progressive multifocal leukoencephalitis
subacute sclerosing panencephalitis