People with Parkinson’s disease suffer from the inability to move in the typical, apparently effortless, way. Initiating movement can become difficult and, once initiated, movement may be clumsy and require a great deal of effort.

A prominent feature of Parkinson’s disease is the death of brain cells (neurons) in a brain nucleus known as the substantia nigra (substantia is Latin for substance and nigra is Latin for black; the nucleus in the brain looks black). These neurons produce dopamine, which they use to communicate with other neurons in the brain. Replacing the dopamine lost when these cells die by taking L-dopa has been the treatment of choice for many decades. L-dopa therapy decreases the severity of the patient’s movement problems but does not cure the disease. Worse, L-dopa therapy decreases in effectiveness over the long term.

The electrical stimulation of deep brain structures (the basal ganglia) has been shown to be effective in reducing the dose of L-dopa needed by patients to maintain their ability to move. However, placing electrodes deep in the brain is a very serious matter. Exposing the brain during surgery should be avoided if possible. A research team has provided evidence that stimulating the spinal cord dorsal columns from outside the nervous system’s protective covering (the dura mater) may provide the same benefits without the dangers of open brain surgery. The research was described in the paper “Spinal Cord Stimulation Restores Locomotion in Animal Models of Parkinson’s Disease” published March 20, 2009 in Science.

This was the first paper on treating Parkinson’s disease by stimulating the spinal cord dorsal columns so we’re probably a long way off from using this therapy in humans (the experiments were performed in mice). The next step should be to try the procedure on non-human primates.