recovery of function

the reacquisition of movement skills lost through injury

“The complex activity of the whole organism that is directed at
performing a behavioral task”

Recovery of Function

⬢ When a function is not lost, despite a brain injury, it is referred to as
a spared function.
⬢ For example, when language develops normally in children who
have suffered brain damage early in life, retained language function
is said to be spared.

Sparing of Function

“The ability to achieve task goals in the same way it was performed before
injury”, that is, using the same processes used prior to the injury

Recovery

is defined as behavioral substitution, that is, alternative behavioral
strategies are adopted to complete a task

Compensation

Recovery versus Compensation

⬢ The response to this question has changed over the years as our
knowledge about the plasticity of the CNS has changed.
⬡ For many years, the adult CNS was characterized as both rigid and
unalterable.
 Therapy directed at compensation
⬡ Recent research has shown that the adult CNS has great plasticity.

Should Therapy be Directed at Recovery of Function or Compensation?

A number of factors can affect the outcome of damage to the
nervous system as well as the extent of subsequent recovery,
including both endogenous (within the individual) and exogenous
(external to the individual) factors

Factors Affecting Recovery of Function

The age of the individual at the time of lesion affects recovery of
function.
⬢ Having a stroke at the age of 53 has a better prognosis for recovery
compared to having a stroke at the age of 76.

Effect of Stage of Development (Age)

• size of the lesion 

• speed of the lesion

Characteristics of the Lesion

Patients with smaller lesion have a greater chance of recovery

size of the lesion

Slowly developing lesions appear to cause less functional loss than
lesions that happen quickly

Speed of the lesion

⬢ A number of preinjury factors have been shown to moderate the
effect of pathology on CNS function
⬢ Preinjury exercise, environmental enrichment, and dietary
restriction are all examples of neuroprotective factors.

⬢ Preinjury exercise can protect against some of the damaging effects of
aging, neurodegeneration, and brain injury.
⬢ In animal studies, prestroke exercise was found to reduce infarct size,
although the mechanisms underlying this finding are not clear. May be
due to
⬡ an increase in exercise-induced neuroplasticity
⬡ decrease processes such as edema

Preinjury Neuroprotective Factors

In animal studies, prestroke exercise was found to reduce infarct size,
although the mechanisms underlying this finding are not clear. May be
due to

⬡ an increase in exercise-induced neuroplasticity
⬡ decrease processes such as edema

Patients who were actively engaged in a rich and varied life (preinjury
environmental enrichment) may have functional neural circuitry that is
more varied than that of restricted patients

A greater ability to reorganize the nervous system after a lesion or
simply to use alternative pathways to perform a task

⬢ Certain drugs can have profound effects on the recovery process.
⬡ Amphetamine appears to facilitate recovery following brain injury
⬡ The inhibitory neurotransmitter gamma-aminobutyric acid (GABA)
affects recovery of function
⬡ GABA agonists impeded recovery from brain damage in rat
⬡ GABA antagonists were beneficial

⬡ Administration of cholinergic agents appears to facilitate recovery.
⬡ Antihypertensive and sedative agents have been shown to slow
recovery of motor and language functions following stroke.

Postinjury Factors: Effect of Pharmacology

⬢ The hemiplegic monkeys underwent four type of postoperative training
⬡ No treatment
⬡ Massage of the involved limb
⬡ Restraint of the noninvolved limb
⬡ Restraint of the noninvolved limb + limb exercise
⬢ The last condition was the only one to show recovery

Postinjury Factors: Effect of Exercise and Training