Functional recovery of the brain after trauma Flashcards
what is Functional Recovery
the recovery of abilities and mental processes that have been compromised as a result of brain injury or disease
explain the study of E.B.
E.B. had his left hemisphere removed at 2½ and regained most of his language abilities –> at age 17 his language appeared almost normal in everyday life in terms of vocabulary and grammar compared against healthy controls.
This suggests that the right hemisphere – through intensive rehabilitation - compensated for many of the lost functions.
However, E.B. did not fully recover all lost language functions (there were some subtle grammatical problems; difficulties picture-naming), which suggests that some functions could not be compensated for.
what is Axon Sprouting
When an axon is damaged, its connection with a neighbouring neuron is lost.
In some cases, adjacent axons will sprout extra connections to the neuron, replacing those connections that have been destroyed.
This helps to replace function, but only if the damaged axon and the compensatory axons do a similar job.
Neuronal Unmasking
‘Dormant synapses’ are synaptic connections that exist anatomically but their function is blocked.
Under normal conditions these synapses may be ineffective because the rate of neural input to them is too low for them to be activated.
However, increasing the rate of input, as would happen when a surrounding brain area becomes damaged, can open (‘unmask’) these dormant synapses.
This opens connections to brain regions that are not normally activated, creating a lateral spread of activation, which, in time, gives way to the development of new structures.
Denervation Supersensitivity
Axons that do a similar job become aroused to a higher level to compensate for the ones that are lost.
However, it can have the consequence of over-sensitivity to messages such as pain.
Factors Affecting Recovery of the Brain After Trauma
- Age differences in functional recovery:
Deterioration of the brain in old age affects the extent and speed of recovery – older brains are essentially less plastic. - Gender differences in functional recovery:
Research suggests that women recover better from brain injury as their function is not as lateralised (females show more bilateral patterns). - Education attainment and functional recovery
what did Marquez de la Plata et al. (2008) do
following brain trauma, older patients (40+ years) regained less function in treatment than younger patients and were also more likely to decline in terms of function for the 5 years following the trauma.
what did Ratcliff do
Ratcliff et al. (2007) examined 325 patients with brain trauma for their responsiveness to cognitive skills following rehabilitation.
Results showed that women performed significantly better than men on tests of attention/working memory and language, whereas men outperformed females in visual analytic skills.
Overall, the results suggested a better recovery for women.
However, the results did not control for performance pre-injury, which could have influenced results.
Research in this area is mixed, so clear overall conclusions cannot be drawn.
what did Schneider et al., 2014: do
Schneider et al., 2014:
A study of 769 patients who suffered from head injuries and had been treated. Patients followed a rehabilitation programme and progress was monitored.
Of the 769 patients:
24% did not finish school
51% had 12-15 years of education
25% graduated from university, with an undergraduate degree
One year after the injury, 28% of the patients made a full recovery:
39% of the graduates were left free of disability vs.
10% of those who had left school early
Schneider conclusions
Patients with the equivalent of a college education were 7x more likely to make a full recovery than people who did not finish school.
The researchers argue that more educated people make more effective use of their brains, which strengthens them.
Conclusion:
People who have remained in education for longer have a greater ‘cognitive reserve’- they are less likely to be left permanently disabled after a head injury. Their brains are better able to maintain function in spite of damage, which makes them more likely to regain function following a brain trauma.
