Tuesday, December 18, 2007

About the Value of Exercise after Brain Injury

Brain injury is a life changing event. Your health care provider may help you with a stay in a rehabilitation clinic for a number of weeks, where you learn how to deal with your new life. Then, you are on your own.

Christopher Reeve taught us that it is important to remain upbeat and exercise. Occupational therapy is essential. Nerve cells need stimulation for recovery and repair. Reorganization may occur. Synapses, that is the contacts between the nerve cells, may strengthen with stimulation and use. To advance recovery from hemiparesis after stroke, one novel treatment, Constraint-Induced Movement therapy, entails the temporary restraint of the functional limb while the patient is encouraged to carry out tasks with the paralyzed limb.

We understand little about the repair of broken connections between nerve cells, when, for instance, a sudden snap of the head pushes the brain so forcefully inside the skull that the long processes of the nerve cells are severed. This effect is known as axonal shear. By contrast, extensive knowledge has been gathered on the effects of ischemia, that is when the blood supply to the brain tissue is disrupted, and strategies are being developed to rescue nerve cells under this condition.

We have learned that functional recovery depends on low concentrations of the excitatory neurotransmitter glutamate in the extracellular fluid. Glutamate in high concentrations may cause nerve cells to fire electrical impulses at high rate in intense oscillations causing convulsive seizures. Moreover, too much glutamate may trigger programmed cell death.

Furthermore, free radicals need to be eliminated. Free radicals are highly reactive chemicals that can modify the molecular machinery of the cell to such extent that vital functions cease. They accumulate in high concentrations when the blood-brain barrier is breached, the brain tissue is flooded with fluid, and blood perfusion is disrupted.

Neuroprotective agents are currently tested that may help to minimize the adverse effects of glutamate and the exposure to free radicals.

In addition to medication, however, the right amount of exercise seems instrumental. Remaining passive does not help recovery. On the other hand, one should not overdo it. Too much stimulation may harm already stressed nerve cells. The keys to success are regimen and persistence. One needs to continue exercising at a steady pace, though progress seems elusive.

The tasks to be carried out appear nonsensical at first, because the goals are unattainable. Try anyways. For example, the challenge may consist of playing Tetris, although the clusters of squares disappear from view in the part of the visual field blinded by a cortical stroke cortical blindness). Frustratingly, you may not be able to track the squares, when it counts most. Keep at it! You will do better than you believe. Chances are that you will improve as the days go by, recovering visual function over time.

This is the advice I should have given a former colleague who called me one day out of the blue and asked me what could be done in such a case. Taken by surprise, I could not come up with the idea until after we had hung up. Sadly, she did not leave her number.

You may give it a try here:

  • Maggie Fox posted a report with the title "Computer exercise helps stroke victims "see" again" on Reuters today, describing a research study that demonstrates that this idea works (04/01/09).
  • Yesterday, Roni Caryn Rabin posted a report with the title "Study Raises Estimate of Paralyzed Americans" in The New York Times that according to a recent survey commissioned by the Christopher Reeve Paralysis Foundation 5.6 million Americans suffer from paralysis. In roughly 1.3 million people the cause is spinal cord injury. Stroke constitutes the most prevalent cause with 1.6 million cases (04/21/09).
  • Listen to this informative interview with Dr. Olajide Williams by Rebecca Roberts entitled "'Stroke Diaries' Provide Insight For Survivors" on NPR's Talk to the Nation today about recovery from stroke. We can still progress in recovery a very long time after the event (05/06/10).
  • This Wall Street Journal video sums up concisely the progress of research in the recovery of function after brain and spinal cord injury (10/26/10):
  • In the video below with the title "Robot legs help stroke survivor to walk again" Reuters' Stuart McDill reported yesterday on a promising application of a computer-assisted exoskeleton that may help people recover walking after a stroke (11/29/2011):
  • In their article published online by Science magazine last week, Van den Brand and others (2012) provided an appealing proof of a new concept facilitating the rapid recovery of function after spinal cord injury in paraplegic rats. The procedure entails infusion of neurotrophic substances into the cerebral motor cortex and precisely-timed electrical stimulation of the spinal cord, stimulating growth of new nerve cell connections, as well as robotics-supported physical exercise. Watch the demonstration in the video below narrated by Reuters' Jim Drury two days ago (06/02/2012):
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  1. please quit linking to NY Times

  2. Dear J:
    I try to provide references to all sources, regardless of provenance.