Parkinson’s disease: initiating movement

Parkinson’s disease is a slow, debilitating, degenerative neurological disease which develops as a result of the death of cells in a part of the brain known as the substantia nigra. The disease is characterized by tremor, muscle rigidity, stiffness, difficulty in bending one’s arms or legs, a loss of balance, and changes in gait—including the development of a slow shuffling walk. People with Parkinson’s disease can experience extreme difficulty in initiating voluntary movements, sometimes to the extent that they might even appear “frozen” while they are struggling in the moments before they actually begin moving.

A great deal of research in recent years has focussed on ways in which the cells in the substantia nigra might be replaced, and many (if not most) of the patents relating to Parkinson’s disease focus on biological or pharmaceutical treatments. What is proposed here, however, is far simpler — an intervention that might possibly provide immediate help to those people who have difficulty with the initiation of movement. If the proposed device worked in the way intended, it would be unlikely to pose any manufacturing difficulties, and be of relatively low cost. But first a little background …

You might remember the film “Awakenings”, starring Robert De Niro and Robin Williams. The film was based on the experiences of Dr Oliver Sacks who had written a book with the same title. In one scene in the film, patients (who did not have Parkinson’s disease but nonetheless had difficulty with initiating voluntary movement) are shown being able to walk across a patterned floor more easily than they would have been able to negotiate a homogeneously tiled floor. The patients used some of the coloured tiles as stepping stones on which to pace out their steps. It was as if the pattern provided the patient with a method of timing their steps once they had been initiated, as well as with the initiation of movement.

In the proposed device, the person with Parkinson’s disease would listen to a sound whose tonal characteristics (including amongst other things, volume, loudness variation, pitch, pitch variation, rhythm, and rhythmic variation) were set so as to maximize the person’s ability to initiate a desired movement. A triple-beat tone, for example, sounded loud-soft-soft, or high-low-low, might aid the initiation and maintenance of movement in the same way that a musician calling out “ONE-two-three ONE-two-three ONE” indicates to his or her fellow musicians when they should commence playing.

The development of the device would proceed hand-in-hand with a series of small experimental studies, and if the device were found to be of any benefit, it could be enhanced in several obvious ways including the following.

  • Many different pre-programmed tonal mixtures each suited to a different movement.
  • Analysis of an individual patient’s movement pattern could provide the appropriate parameters for walking, washing, washing up, polishing and indeed any kind of movement one wished.
  • The appropriate sound could be activated in several different ways including activation by artificial voice-recognition of a spoken command, such as “walk”, or activation by pressing a button on the device.
  • Existing music tracks could be analyzed for their rhythmic qualities to determine which tracks would provide the appropriate sound for a particular movement. That way, the person would be able to choose to listen to music rather than to a boring sound.

Obviously, sound is not the only method by which the appropriate movement-initiating stimulus could be delivered. Tactile and visual stimuli could both be used and programmed for the same kinds of variations as described above. A patient might, for example, wear a pair of spectacle frames containing coloured, light emitting diodes which pulsed in a way that was analogous to the tonal variations in an auditory stimulus.

Contributors: Mark R. Diamond