Articles
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2,943 results found
Article
Superior hypophyseal artery
The superior hypophyseal artery (or arteries) is a branch from the C6 segment of the internal carotid artery. It is usually a single trunk arising from the medial or posteromedial aspect of the internal carotid artery within 5 mm of the origin of the ophthalmic artery 2. The trunk then divides i...
Article
Paracentral lobule
The paracentral lobule is located on the medial surface of the cerebral hemisphere, and includes parts of both the frontal and parietal lobes. It is the medial continuation of the precentral and postcentral gyri. It has motor and sensory functions related to the lower limb.
Gross anatomy
Relat...
Article
Aicardi syndrome
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).
Terminology
Aicardi syndrome is distinct from Aicardi-Goutieres syndrome although both are named ...
Article
Nasal dermoid cyst
Nasal dermoids (or nasal dermoid sinus cysts) are the most common congenital midline nasal lesion typically presenting in early childhood.
Epidemiology
Nasal dermoids are rare and account for only 4-12% of all dermoid cysts of the head and neck, far less common than angular dermoids 1,2. They ...
Article
First-episode psychosis
First-episode psychosis refers to a clinical psychotic phenomenon occurring for the first time in an individual and can have a varied presentation with multiple risk and protective factors 2. Although the vast majority of individuals presenting with their first psychotic episode will not have an...
Article
Anterior horn syndrome
Anterior horn syndrome is a fairly generic term used to refer to flaccid paralysis and areflexia due to involvement of the anterior grey matter horns of the spinal cord. Sensation is typically preserved.
Causes of anterior horn syndrome include:
anterior spinal artery ischemia
poliomyeliti...
Article
Focal cerebral arteriopathy of childhood
Focal cerebral arteriopathy of childhood (FCA), also known as transient cerebral arteriopathy (TCA), is characteristically an acute monophasic disease, with unilateral stenosis of the distal internal carotid artery and/or the proximal middle/anterior cerebral arteries, causing infarction in the ...
Article
Miliary cerebral metastases
Miliary cerebral metastases (or carcinomatosis encephalitis ) is a rare form of cerebral metastastic disease 1.
As with the use of miliary description in other conditions, the appearances are of innumerable tiny, punctate nodules, in this case scattered throughout the brain. The nodules may b...
Article
Amaurosis fugax
Amaurosis fugax is the transient monocular loss of vision, normally lasting a few seconds to a few minutes, secondary to vascular ischemia or insufficiency.
Epidemiology
It has an incidence of 50,000 per year in the United States.
Clinical presentation
Patients present with transient monoc...
Article
Cavernous sinus contents (mnemonic)
The cavernous sinus contents (structures within the sinus proper and also in its lateral wall) and their relative positions can be recalled with the following mnemonic:
O TOM CAT
Consider a coronal view of the cavernous sinus.
'O TOM' are the first letters of components of the lateral wall of...
Article
Congenital syndromes associated with enlarged ventricles
Congenital ventriculomegaly can have a large number of syndromic associations.
Common
acrocephalosyndactylies
Apert syndrome
Pfeiffer syndrome
acrocephalopolysyndactylies
Crouzon syndrome
achondroplasia
fetal alcohol syndrome
lissencephaly
osteopetrosis
Sotos syndrome
X-linked hyd...
Article
Galassi classification of middle cranial fossa arachnoid cysts
The Galassi classification of middle cranial fossa arachnoid cysts is used to classify arachnoid cysts in the middle cranial fossa, which account for 50-60% of all arachnoid cysts 1. Galassi et al. published this classification in 1982, and at the time of writing (June 2016), it remains the most...
Article
Ophelia syndrome
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. In addition to anti-mGluR5, many other antibodies are associated with or implicated in autoimmune encephalitis in the setti...
Article
Transient global amnesia
Transient global amnesia (TGA) is a clinical syndrome with no clear etiology identified. The syndrome is transient and typically resolves within a few hours.
Epidemiology
Transient global amnesia is most common in the 60-70 year age range 8.
Associations
migraine, approximately 2.5-fold inc...
Article
Liquefactive necrosis
Liquefactive necrosis is a form of necrosis where there is transformation of the tissue into a liquid viscous mass.
Pathology
In liquefactive necrosis, the affected cell is completely digested by hydrolytic enzymes leading to a soft, circumscribed lesion which can consist of fluid with remains...
Article
Anterior meningocele
Anterior meningocele is characterized by herniation of CSF-filled sac through an anterior osseous defect.
It usually occurs in the sacral region where it is termed an anterior sacral meningocele although it can also occur in other areas like the thorax 2.
When present in the sacrum, it is oft...
Article
Yin-yang sign (solitary fibrous tumor)
The yin-yang sign is a radiologic appearance described in solitary fibrous tumor of the dura on MR.
On T2-weighted images, these tumors have two separate solid components, one that is hyperintense and one that is iso- to hypointense relative to brain parenchyma. Histologically, the former repre...
Article
Spinal epidural mass
The differential diagnosis for a spinal epidural mass includes:
epidural metastasis
epidural abscess
herniated nucleus pulposus
epidural hematoma
epidural arteriovenous malformation
epidural angiolipoma
epidural lipomatosis
extramedullary hematopoiesis
spinal schwannoma
spinal meningio...
Article
Congenital cerebral toxoplasmosis
Congenital cerebral toxoplasmosis is a manifestation of congenital toxoplasmosis and refers to development of cerebral toxoplasmosis in the fetus through maternal transmission.
Please refer to congenital toxoplasmosis for a broad discussion on epidemiology and pathology.
Radiographic features...
Article
Radionuclide shuntography
Radionuclide cisternography is a nuclear medicine imaging technique that uses 99mTc-DTPA (diethyletriaminepentaacetic acid; pentetate) injected into CSF shunt reservoirs to evaluate their patency.
Imaging is performed at 2-6 hours after injection of the radiopharmaceutical into the shunt reserv...
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