Remapping the Cortex: How Rehab Exercise does it.

Below are two studies that we recently incorporated into 2 neurologic gait cases during one of our global teleseminars on www.onlineCE.com.  You can find that lecture there in a few weeks but we have dozens of our other presentations available there presently. 

Injury to a body part starts a reorganization of the brain cortex. We know this occurs from a plethora of studies but most of them are based on injury induced changes and not from treatment-induced means.  These studies support the treatment induced changes that occur in the central nervous system, and they are profound and give us comfort and validity in our work. The findings of these studies should not be a shock to you if you are in the work of manual therapy and rehab. 

The one study used transcranial magnetic stimulation to map the cortical motor output area of a hand muscles on both sides in 13 stroke patients in the chronic stage of their illness before and after a 12-day-period of constraint-induced movement therapy.

What they found was “post treatment the muscle output area size in the affected hemisphere was significantly enlarged, corresponding to a greatly improved motor performance of the paretic limb”. As the study showed, this suggested a recruitment of adjacent brain areas. Even at 6 month follow up examinations “the motor performance remained at a high level, whereas the cortical area sizes in the 2 hemispheres became almost identical, representing a return of the balance of excitability between the 2 hemispheres toward a normal condition.”

The second study (2) looked at limb immobilization in 10 right-handed subjects with right upper extremity injury that required at least 14 days of limb immobilization. Subjects underwent 2 MRI examinations post injury, 48 hours and 16 days post immobilization. Cortical thickness of sensorimotor regions and FA of the corticospinal tracts was measured.  The findings showed “a decrease in cortical thickness in the left primary motor and somatosensory area as well as a decrease in FA in the left corticospinal tract. In addition, the motor skill of the left (noninjured) hand improved and is related to increased cortical thickness and FA in the right motor cortex.”

These studies suggest the findings are associated with skill transfer from the right to the left hand. It was suggested that immobilization induces rapid reorganization of the sensorimotor system. 

Rehab works, but everyone here on The Gait Guys already knew that. It is just nice to know the specifics of “how”.  

Please go to these articles and get the specifics for yourself. Don’t take our word for it ! 

references:

1. Stroke. 2000 Jun;31(6):1210-6.Treatment-induced cortical reorganization after stroke in humans. Liepert J1, Bauder H, Wolfgang HR, Miltner WH, Taub E, Weiller C.

2. Langer N, et al “Effects of limb immobilization on brain plasticity"Neurology 2012; 78: 182–188.