Articles

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2,953 results found
Article

Lateral thoracic meningocele

Lateral thoracic meningoceles are a type of spinal meningocele. Pathology As with any meningocele, it results from herniation of the meninges through a foramen or a defect in the vertebral column.  Associations They are typically associated with neurofibromatosis type I but can rarely occur ...
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Perivascular pseudorosettes (ependymoma)

Perivascular pseudorosettes are a common histologic feature of central nervous system ependymomas. They represent sections through papillary structures composed of tumor cells arranged radially around a central vessel. Between the central vessel and the tumor cells is a relatively microscopicall...
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Posterior fossa ependymoma

Posterior fossa ependymomas are the most common type of ependymoma, most commonly occurring in children. They are divided on the basis of DNA-methylation profiling into two groups, A and B.  Epidemiology Posterior fossa ependymomas are encountered in all age groups but are usually encountered ...
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Pituitary stalk abnormal enhancement (differential)

Abnormal nodular enhancement of the pituitary stalk can be seen in a number of entities. Differential diagnosis tumors germinoma craniopharyngioma hypothalamic glioma pituitary lymphoma pituicytoma granular cell tumor of the pituitary (pituitary choristoma) pilocytic astrocytoma of the...
Article

Venous circle of Trolard

The anastomotic venous circle of the base of the brain 1, also referred to as the venous circle of Trolard 2,3,5, is an inconsistently found venous homologue of the better-known arterial circle of Willis. It should not be confused with other venous structures also described by Trolard such as t...
Article

Canadian CT head rule

The Canadian CT head rule (CCTHR) is a validated clinical decision rule to determine the need for CT head in adult emergency department patients with minor head injuries. Inclusion criteria Patient has suffered minor head trauma with resultant: loss of consciousness GCS 13-15 confusion amn...
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Pallister-Hall syndrome

Pallister-Hall syndrome displays a wide range of severity and is characterized by hypothalamic hamartomas seen as a mass at the floor of the third ventricle, posterior to the optic chiasm 3,4. Epidemiology Pallister-Hall syndrome is rare and the exact prevalence is unknown. Patients with posta...
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Callosomarginal artery

The callosomarginal artery, also known as median artery of corpus callosum, is the largest branch of the pericallosal artery. It courses within or posterior to the cingulate sulcus, in parallel orientation to the pericallosal artery. It divides to give two or more cortical branches to supply the...
Article

Basilar artery fenestration

Basilar artery fenestration (or more simply, basilar fenestration) is the most common intracranial arterial fenestration and most common congenital anomaly of the basilar artery. This anatomic variant is characterized by duplication of a portion of the artery that are connected proximally and di...
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Sensorineural hearing loss

Sensorineural hearing loss (SNHL) refers to deafness secondary to conditions affecting the inner ear, internal acoustic canal, cerebellopontine angle, or vestibulocochlear nerve. It an be classified audiometrically into two types sensory (cochlear) neural (retrocochlear)  Pathology Conditio...
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Diffuse brainstem glioma (historical)

Diffuse brainstem gliomas or diffuse intrinsic pontine gliomas was a term used to describe infiltrating astrocytomas arising in the brainstem, usually in children. It is no longer recognized as a distinct entity, removed from the 2016 update to the WHO classification of CNS tumors replaced by a ...
Article

Convolutional markings

Convolutional markings are normal impressions of the gyri on the inner table of the skull. They appear during the period of rapid brain development, typically between 3 and 7 years of age 4.  They are seen predominantly posteriorly. Anterior involvement of the skull is referred to as a copper b...
Article

Meningocele manqué

Meningocele manqué (from French, literally "missed meningocele") is a rare condition characterized by focal dorsal tethering of the spinal cord. The term is used to designate a meningocele which failed to develop and became atretic. Epidemiology It has been reported in neonates, but median age...
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Suprasellar arachnoid cyst

Suprasellar arachnoid cysts can be challenging to diagnose and, unlike many other arachnoid cysts, are usually symptomatic.  For a general discussion, please refer to the article on arachnoid cysts. Clinical presentation As can be expected from its location, suprasellar arachnoid cysts manife...
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Idiopathic intracranial hypertension

Idiopathic intracranial hypertension (IIH), also known as pseudotumor cerebri, is a syndrome with signs and symptoms of increased intracranial pressure but where a causative mass or hydrocephalus is not identified. Terminology The older term benign intracranial hypertension is generally frowne...
Article

Cephalohematoma

Cephalohematomas are traumatic subperiosteal hematomas of the skull that are usually caused by birth injury. They are bound between the periosteum and cranium, and therefore cannot cross sutures. Being bound by a suture line distinguishes them from subgaleal hematoma, which can cross sutures. E...
Article

Tectal glioma

Tectal gliomas fall under the grouping of childhood brainstem gliomas and unlike the other tumors in that group they are typically low grade astrocytomas with good prognosis.  Epidemiology Tectal plate gliomas are encountered in children and adolescents 4. A male predilection has sometimes bee...
Article

Tuberculosis

Tuberculosis (commonly abbreviated to TB, short for tubercle bacillus) encompasses an enormously wide disease spectrum affecting multiple organs and body systems predominantly caused by Mycobacterium tuberculosis. A small proportion can also be caused by Mycobacterium bovis through drinking unpa...
Article

Gliosis

Gliosis is a reactive process occurring after some time following most types of central nervous system injuries and is the result of focal proliferation of glial cells, particularly astrocytes.  Terminology Although the terms astrocytic gliosis or astrocytosis are often used interchangeably wi...
Article

Allodynia

Allodynia refers to pain due to a stimulus which does not normally provoke pain. Temperature or physical stimuli can provoke allodynia, and it often occurs after injury to a site. Etymology The word allodynia is derived from the Greek words άλλος (állos) meaning "other" and οδύνη (odýni) meani...

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