Chapter 16--DO NOT STUDY Flashcards
Traumatic brain injury (TBI)
a wound to the brain that results from a blow to the head, is the most common form of brain damage in people under age 40. TBI commonly results from the head making impact with other objects
what do the brains of people with multiple concussions show?
extensive, diffuse loss of cerebral tissue.
Brain damage from TBI
Trauma can disrupt the brain’s blood supply, induce bleeding (leading to increased intracranial pressure), cause swelling (leading to increased intracranial pressure), expose the brain to infection, and scar brain tissue (the scarred tissue becomes a focus for later epileptic seizures)
Concussion,
the common term for mild traumatic brain injury (MTBI)
what is chronic traumatic encephalopathy characterized by?
neurofibrillary tangles, plaques, and neuronal death. Cerebral atropy and expanded ventricles due to cell loss are typical in advanced cases.
what commonly accompanies TBI?
a loss of consciousness that may be brief (minutes) or prolonged (coma
what does the duration of unconsciousness during TBI tell you?
serves as a measure of the severity of damage, because it correlates directly with mortality, intellectual impairment, and deficits in social skills.
two behavioral effects from TBI
(1) impairment of the specific func- tions mediated by the cortex at the coup (the site of impact) or countercoup (opposite side) lesion (2) more generalized impairments from widespread trauma throughout the brain.
Movement of the hemispheres in relation to one another causes what?
tearing characterized by a loss of complex cognitive functions, including reductions in mental speed, concentration, and overall cognitive efficiency.
Traumatic brain injuries that damage the frontal and temporal lobes also tend to significantly affect what?
personality and social behavior
what is frustrating about TBI?
difficult to diagnose
N-acetylaspartate (NAA),
the second most abundant amino acid in the human brain
NAA &; TBI
People with traumatic brain injuries show a chronic decrease in NAA that correlates with the severity of the injury
chronic traumatic encephalopathy (CTE)
Progressive degenerative disease caused by multiple concussions and other closed-head injuries, characterized by neurofibrillary tangles, plaques, and cerebral atrophy and expanded ventricles due to cell loss.
magnetic resonance spectroscopy (MRS)
Modification of MRI to identify changes in specific markers of neuronal function; promising for accurate diagnosis of traumatic brain injuries.
how long does recovery from head trauma last?
may continue for 2 to 3 years and longer, but most cognitive recovery occurs in the first 6 to 9 months
recovery of memory symptoms in head trauma
Recovery of memory functions appears to be slower than recovery of general intelligence, and the final level of memory performance is lower than for other cognitive functions.
People with brainstem damage,
as inferred from oculomotor disturbance, have a poorer cognitive outcome, and a poorer outcome is probably true of people with initial dysphasias or hemiparesis as well.
what is significantly reduced after TBI?
quality of life—in social inter- actions, perceived stress levels, and enjoyment of leisure
stroke
an interruption of blood flow from either the blockage of a vessel or bleeding from a vessel.
ischemia
Lack of blood to the brain as a result of stroke.
diaschisis
Neural shock that follows brain damage in which areas connected to the site of damage show a temporary arrest of function.
neuroprotectant
Drug used to try to block the cascade of poststroke neural events.
what happens in the first seconds to minutes after ischemia?
changes begin in the ionic balance of the affected regions, including changes in pH and in the properties of the cell membrane.