|
Kernohan's Notch
Kernohan's notch is a cerebral peduncle indentation associated with some forms of transtentorial herniation (uncal herniation). It is a secondary condition caused by a primary injury on the ''opposite'' hemisphere of the brain.#refWolf, Wolf et al, 1995 Kernohan's notch is an ipsilateral condition, in that a left-sided primary lesion (in which Kernohan's notch would be on the right side) evokes motor impairment in the left side of the body and a right-sided primary injury evokes motor impairment in the right side of the body.#refPearce, Pearce, 2006 The seriousness of Kernohan's notch varies depending on the primary problem causing it, which may range from benign brain tumors to advanced subdural hematoma. Mechanism Kernohan's notch phenomenon is a result of the compression of the cerebral peduncle, which is part of the mesencephalon, against the tentorium cerebelli due to transtentorial herniation. This produces ipsilateral hemiparesis or hemiplegia The skull is an incompressible ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerebral Peduncle
The cerebral peduncles are the two stalks that attach the cerebrum to the brainstem. They are structures at the front of the midbrain which arise from the ventral pons and contain the large ascending (sensory) and descending (motor) nerve tracts that run to and from the cerebrum from the pons. Mainly, the three common areas that give rise to the cerebral peduncles are the cerebral cortex, the spinal cord and the cerebellum. The region includes the tegmentum, crus cerebri and pretectum. By this definition, the cerebral peduncles are also known as the basis pedunculi, while the large ventral bundle of efferent fibers is referred to as the cerebral crus or the pes pedunculi. The cerebral peduncles are located on either side of the midbrain and are the frontmost part of the midbrain, and act as the connectors between the rest of the midbrain and the thalamic nuclei and thus the cerebrum. As a whole, the cerebral peduncles assist in refining motor movements, learning new motor ski ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Duret Haemorrhage
Duret haemorrhages are small linear areas of bleeding in the midbrain and upper pons of the brainstem. They are caused by a traumatic downward displacement of the brainstem. They are named after Henri Duret. Causes Duret haemorrhages are named after Henri Duret, who discovered these brainstem lesions in dogs with increased intracranial pressure. They are small linear areas of bleeding in the midbrain and upper pons of the brainstem. They are caused by a traumatic downward displacement of the brainstem with parahippocampal gyrus herniation through the tentorial notch. or acute hematoma, edema following trauma, abscess, or tumor. Pathogenesis Duret haemorrhages are haemorrhages secondary to raised intracranial pressure with formation of a transtentorial pressure cone involving the front part of the cerebral peduncles, the cerebral crura. Increased pressure above the tentorium may also involve other midbrain structures. Kernohan's notch is a groove in the cerebral peduncle which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Traumatic Brain Injury
A traumatic brain injury (TBI), also known as an intracranial injury, is an injury to the brain caused by an external force. TBI can be classified based on severity (ranging from mild traumatic brain injury TBI/concussionto severe traumatic brain injury), mechanism ( closed or penetrating head injury), or other features (e.g., occurring in a specific location or over a widespread area). Head injury is a broader category that may involve damage to other structures such as the scalp and skull. TBI can result in physical, cognitive, social, emotional and behavioral symptoms, and outcomes can range from complete recovery to permanent disability or death. Causes include falls, vehicle collisions and violence. Brain trauma occurs as a consequence of a sudden acceleration or deceleration within the cranium or by a complex combination of both movement and sudden impact. In addition to the damage caused at the moment of injury, a variety of events following the injury may result in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Watson Kernohan
James Watson Kernohan, M.D. (1896–1981) was an Irish-American pathologist born October 1, 1896 in County Antrim, Ireland. He studied medicine at Queen's University Belfast, and in 1922 he emigrated to the United States and subsequently worked as a pathologist at the Mayo Clinic in Rochester, Minnesota. Kernohan retired from active medical practice in 1962 and died May 5, 1981. Kernohan is remembered for his work in neuropathology, particularly research of spinal cord tumors, brain abscesses and metastatic brain lesions. He is credited with developing a widely used classification system for brain tumors. The eponymous ''Kernohan's notch'' is named after him, which is a groove in the cerebral peduncle caused by displacement of the brainstem against the incisura of the tentorium cerebelli in some cases of transtentorial herniation. In 1952 he published an atlas of tumor pathology titled ''Tumors of the Central Nervous System'', and with Mayo neurosurgeon Neurosurgery or neurolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arteriovenous Malformation
Arteriovenous malformation is an abnormal connection between arteries and veins, bypassing the capillary system. This vascular anomaly is widely known because of its occurrence in the central nervous system (usually cerebral AVM), but can appear in any location. Although many AVMs are asymptomatic, they can cause intense pain or bleeding or lead to other serious medical problems. AVMs are usually congenital and belong to the RASopathies. The genetic transmission patterns of AVMs are incomplete, but there are known genetic mutations (for instance in the epithelial line, tumor suppressor PTEN gene) which can lead to an increased occurrence throughout the body. Signs and symptoms Symptoms of AVM vary according to the location of the malformation. Roughly 88% of people with an AVM are asymptomatic; often the malformation is discovered as part of an autopsy or during treatment of an unrelated disorder (called in medicine an "incidental finding"); in rare cases, its expansion or a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cerebral Crus
The cerebral crus (crus cerebri) is the Anatomical terms of location, anterior portion of the cerebral peduncle which contains the motor tracts, travelling from the cerebral cortex to the pons and spine. The plural of which is cerebral crura. In some older texts this is called the cerebral peduncle but presently it is usually limited to just the anterior white matter portion of it. Additional images File:Human brain frontal (coronal) section description 2.JPG, Human brain frontal (coronal) section References External links * * NIF Search - Cerebral Crus via the Neuroscience Information Framework Brainstem {{neuroanatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oculomotor Nerve Palsy
Oculomotor nerve palsy or oculomotor neuropathy is an eye condition resulting from damage to the third cranial nerve or a branch thereof. As the name suggests, the oculomotor nerve supplies the majority of the muscles controlling eye movements (four of the six extraocular muscles, excluding only the lateral rectus and superior oblique). Damage to this nerve will result in an inability to move the eye normally. The nerve also supplies the upper eyelid muscle (levator palpebrae superioris) and is accompanied by parasympathetic fibers innervating the muscles responsible for pupil constriction ( sphincter pupillae). The limitations of eye movement resulting from the condition are generally so severe that patients are often unable to maintain normal eye alignment when gazing straight ahead, leading to strabismus and, as a consequence, double vision (diplopia). Presentation A complete oculomotor nerve palsy will result in a characteristic displacement outward (exotropia) and downward ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
