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brain herniationPressure-induced prolapse of part of the brain into adjacent spaces, which occurs when the brain is under high pressure.
Coma, paralysis, unilateral dilated pupil.
Head injury, primary or metastatic brain tumour, bacterial meningitis, brain abscess.
Cerebellar herniation, uncal (temporal) herniation, transtentorial herniation.
brain herniationNeurology A pressure-induced prolapse of part of the brain into adjacent spaces, which occurs when the brain is under very high pressure Clinical Coma, paralysis, unilateral dilated pupil Etiology Head injury, 1º or metastatic brain tumor, bacterial meningitis, brain abscess Types Cerebellar herniation, uncal–temporal herniation, transtentorial herniation of the brain
encephalon; that part of the central nervous system contained within the cranium, comprising the forebrain, midbrain and hindbrain, and developed from the embryonic neural tube. It is connected at its base with the spinal cord. The brain is a mass of soft, pinkish gray nerve tissue. For specific brain diseases see under headings relating to etiology and lesion.
common signs caused by an abscess in the brain are circling, rotation of the head, abnormal reflexes in one eye. The CSF may show evidence of infection.
see berry aneurysm.
acute or chronic insufficiency of the blood supply to the brain causes anoxia which causes clinical signs that vary with the severity of the deprivation. Acute anoxia causes muscle tremor, recumbency, convulsions and death or recovery if the anoxia is relieved soon enough. Chronic anoxia causes lethargy, weakness, blindness and sometimes convulsions. In either case there may be permanent damage.
brain cestodal cyst
brain coup lesion
a derivation from contrecoup.
irreversible coma with apnea, loss of all brainstem reflexes and absence of activity on an electroencephalogram.
relieving the pressure within the cranial vault. This may be done surgically by opening the cranium, or medically by administering hypertonic solutions of slowly metabolized materials, such as mannitol, intravenously.
an important part of a number of acute diseases, e.g. lead poisoning, encephalitis, salt poisoning in swine, polioencephalomalacia of ruminants and hypoxia due to any cause. Clinically manifested by blindness, opisthotonos, nystagmus, recumbency and tonic convulsions. Inherited in polled and horned Herefords; calves are recumbent at birth and are never able to stand but consciousness is normal. See also neuraxial edema.
brain ependymal lining
may occur with trauma, in extradural, subdural or intraparenchymal locations. They can cause progressive increase in intracranial pressure and eventually death.
intracranial hemorrhage affecting the brain usually follows traumatic injury but spontaneous hemorrhage may result from an intrinsic vascular lesion. Loss of consciousness is a common sign followed by residual signs depending on the locality and size of the hemorrhage. Ataxia and convulsions are common sequelae.
displacement of brain from the cranial vault through the foramina (tentorial notch or foramen magnum) or ventral to dural septae. The usual causes are brain edema or hemorrhage with resulting increase in intracranial pressure.
see brain anoxia (above).
see feline ischemic encephalopathy.
see brain anoxia (above).
occurs in cranial trauma that fractures the skull, causes severe acceleration or deceleration, or penetrates the skull and brain tissue.
occurs in phalaris spp. poisoning; a characteristic greenish brown color grossly of the gray matter in brainstem nuclei and spinal cord, caused by a suspected lysosomal storage of granules of pigment material; usually associated with some degree of Wallerian degeneration within spinal cord tracts.
a radiographic, magnetic or nuclear medical procedure for the detection of brain tumors, abscesses, hematomas and other intracranial lesions. Not widely used in veterinary medicine because of the expensive equipment required.
brain spongy degeneration
injury to the brain, including that caused by migrating worm larvae, will have diffuse effects including the development of edema, and local effects due to pressure by displaced bone or to hemorrhage. Initial shock, manifested as unconsciousness, is likely to be followed by residual localizing signs, e.g. facial paralysis, head rotation.
cause signs suggestive of local space-occupying lesion in the cranial cavity, including the increased intracranial pressure syndrome, blindness with disturbance of ocular reflexes, head rotation, circling and jacksonian epileptic episodes.
see third, fourth, fifth ventricle.