NEW TREATMENTS IN NEUROREHAB FOUNDED ON BASIC RESEARCH, by Taub
In the past neurorehab interventions had slow progression becaz it was based on:
a.) neuroscience: influenced physical therapy school
b.) behavioral psych: influenced treatment of chronic pain
** didn’t help clinical practice too much
-however basic research from these field (understanding of neural transmission) has helped developed treatment
for numerous other disorders, ex/ parkinsons.
- after a CNS injury, the behavioral/cognitive/thrceptual deficits tend to follow a spontaneous recovery of
function. Ex of behavioral plasticity, in the 19 century they didn’t think this was possible
- however over time ppl started changing their view toward this, but spontaneous recovery was never fully
explained or experimentally researched becaz techniques were not advanced enough.
- in the 1970s, labs started showing that mammillary CNS did have the capacity to reorganize itself. Ex/
cerebral cortex reorganization aka cortical reorganization.
Article wonders if theres a relationship btwn cortical plasticity and spontaneous recovery.
From deafferentation to constraint-induced movement (CI) therapy:
A/ Basic research w/monkeys:
- when you remove the somatic sensation from a limb in a monkey the monkey doesn’t use that limb in a free
situation (deafferentation: The elimination or interruption of sensory nerve impulses by destroying or injuring
the sensory nerve fibers). Thus the ventral root is intact and motor function is possible.
- however if you induce movement of that deafferented limb by restricting movement so that they can only use
that limb for a period of days, the monkey starts to use that limb for a variety of purposes for the rest of their
life. Even if they weren’t using that limb for years before this intervention. Their movements with the limb tend
to clumsy but they are effective and extensive. Considered a substantial rehab of movement.
- you can also use training procedures:
i. Conditioned response technique: methods inspired by studies of operant conditioning. Gives a reward after
an action to strength it. NOT supported by real life situations
ii. Shaping: operant conditioning, involving small steps toward a desired behavior. Support my real life. Caused
a complete reversal of motor disability
- behavioral technique: in animals improve motor performance after neuro damage. Not enough theory or
mechanism research done to test the effectiveness of this technique on humans
B/Apossible mechanism: learned non-use.
- evidence suggests that non use of single deafferented limb is a learning phenomenon that involves a
behaviorally reinforced suppression of movement, known as learned non-use.
- this is why restraint/training techniques are effective becaz they overcome learned non-use.
C/Applicability to humans after stroke:
- strokes tend to lv pts with a permanent unilateral loss of function in an upper extremity, even tho the limb is
- Taub et al. Used both parts of the CI therapy protocol to rehab pts with chronic upper extremity hemiparesis
(Slight paralysis or weakness affecting one side of the body). They used stroke pts after 1 year becaz thats when
motor recovery usually plateaus. PP had to wear a sling on their good arm for 90% of the time for 14 days and
received training on their affected arm for 10 days, 6hours/day. The control were told they were improving even
tho they weren’t. FOUND: Tx group showed s sig. Increase in skill/quality of movement in 2 lab test and large
increase in real world arm use over a 2 week period, and showed no decrease when tested 2 years later after
treatment. CONTROL didn’t change or decline in the real world.
- most techniques involve constraining the non-affected arm, but 2 dont. Common factor of effective therapy:
repeated training of the paralyzed arm. This cud be becaz this induces cortical reorganization.
- CI therapy has proved to be effective in treating upper extremities for the chronic symptoms of stoke and acute
symptoms present 7-14 days after stroke. - effect size: a measure of effect that is adopted when diff scales are used to measure an outcome. Its usually
calculated by dividing the mean diff btwn the experimental and control groups by the stdv of the control or both
groups. Since its a standardized measure it allows us to compare/combine the effects found in diff studies of the
same phenomenon. STUDY with 300 ppl found CI therapy to have a high effect size (2.1-4.0, thus >0.8) and is
incorporated into the clinical setting
D/ Reorganization in response to treatment:
-studies indicate that the size of cortical representation of a body part in adults depends on the amount of use of
that part and that CI therapy is + associated with cortical reorganization. Such studies include:
i. Transcranial magnetic stimulation: used to induce a transient stimulation of activity in a relatively
restricted area of the brain. Ex/ focal TMS was used to map the area of the primary motor cortex
ii. Magnetic source imaging: detect magnetic field change associated w/brain activity
iii. Readiness potential: a broad negativity in the electroencephalogram