Overactive - Research Directions

Research Directions

Studies have been done with electromyography to trace skeletal muscle activity in some hyperkinetic disorders. The electromyogram (EMG) of dystonia sometimes shows rapid rhythmic bursts, but these patterns can almost always be produced intentionally. In the myoclonus EMG, there are typically brief, and sometimes rhythmic, bursts or pauses in the recording pattern. When the bursts last for 50 milliseconds or less they are indicative of cortical myoclonus, but when they last up to 200 milliseconds, they are indicative of spinal or brainstem myoclonus. Such bursts can occur in multiple muscles simultaneously quite quickly, but high time resolution must be used in the EMG trace to clearly record them. The bursts recorded for tremor tend to be longer in duration than those of myoclonus, although some types can last for durations within the range for those of myoclonus. Future studies would have to examine the EMGs for tics, athetosis, stereotypies and chorea as there are minimal recordings done for those movements. However, it may be predicted that the EMG for chorea would include bursts varying in duration, timing, and amplitude, while that for tics and stereotypies would take on patterns of voluntary movements.

In general, research for treatment of hyperkinesia has most recently been focusing on ameliorating symptoms rather than attempting to correct the pathogenesis of the disease. Therefore, now and in the future it may be beneficial to inform the learning of the disease's pathology through carefully controlled, long-term, observation-based studies. As therapies are supported by proven effectiveness that can be repeated in multiple studies, they are useful, but the clinician may also consider that the best treatments for patients can only be evaluated on a case-by-case basis. It is the interplay of these two facets of neurology and medicine that may bring about significant progress in this field.