Other causes include toxins within the brain, autoimmune disease, and infections, which include meningitis.Since the basal ganglia often have many connections with the frontal lobe of the brain, hyperkinesia can be associated with neurobehavioral or neuropsychiatric disorders such as mood changes, psychosis, anxiety, disinhibition, cognitive impairments, and inappropriate behavior.In children, primary dystonia is usually inherited genetically. Secondary dystonia, however, is most commonly caused by dyskinetic cerebral palsy, due to hypoxic or ischemic injury to the basal ganglia, brainstem, cerebellum, and thalamus during the prenatal or infantile stages of development. Chorea and ballism can be caused by damage to the subthalamic nucleus. Chorea can be secondary to hyperthyroidism. Athetosis can be secondary to sensory loss in the distal limbs; this is called pseudoathetosis in adults but is not yet proven in children. Diagnosis
Definition
There are various terms which refer to specific movement mechanisms that contribute to the differential diagnoses of hyperkinetic disorders. As defined by Hogan and Sternad, "posture" is a nonzero time period during which bodily movement is minimal. When a movement is called "discrete," it means that a new posture is assumed without any other postures interrupting the process. "Rhythmic" movements are those that occur in cycles of similar movements. "Repetitive," "recurrent," and "reciprocal" movements feature a certain bodily or joint position that occur more than once in a period, but not necessarily in a cyclic manner.Overflow refers to unwanted movements that occur during a desired movement.
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 diseases pathology through carefully controlled, long-term, observation-based studies.