cerebral palsy such as dystonia in the leg and trunk. treatment of secondary dystonia by administering levodopa in dopamine-responsive dystonia, copper chelation in wilson's disease, or stopping the administration of drugs that may induce dystonia have been proven effective in a small number of cases. physical therapy has been used to improve posture and prevent contractures via braces and casting, although in some cases, immobilization of limbs can induce dystonia, which is by definition known as peripherally induced dystonia. there are not many clinical trials that show significant efficacy for particular drugs, so medical of dystonia must be planned on a case-by-case basis. botulinum toxin b, or myobloc, has been approved by the us food and drug administration to treat cervical dystonia due to level a evidential support by the scientific community. surgery known as gpi dbs (globus pallidus pars interna deep brain stimulation) has come to be popular in treating phasic forms of dystonia, although cases involving posturing and tonic contractions have improved to a lesser extent with this surgery. a follow-up study has found that movement score improvements observed one year after the surgery was maintained after three years in 58% of the cases. it has also been proven effective in treating cervical and cranial-cervical dystonia. tics treatment of tics present in conditions such as tourette's syndrome begins with patient, relative, teacher and peer education about the presentation of the tics. sometimes, pharmacological treatment is unnecessary and tics can be reduced by behavioral therapy such as habit-reversal therapy and/or counseling. often this route of treatment is difficult because it depends most heavily on patient compliance. once pharmacological treatment is deemed most appropriate, lowest effective doses should be given first with gradual increases. the most effective drugs belong to the neuroleptic variety such as monoamine-depleting drugs and dopamine receptor-blocking drugs. of the monoamine-depleting drugs, tetrabenazine is most powerful against tics and results in fewest side effects. a non-neuroleptic drug found to be safe and effective in treating tics is topiramate. botulinum toxin injection in affected muscles can successfully treat tics; involuntary movements and vocalizations can be reduced, as well as life-threatening tics that have the potential of causing compressive myelopathy or radiculopathy. surgical treatment for disabling tourette's syndrome has been proven effective in cases presenting with self-injury. deep brain stimulation surgery targeting the globus pallidus, thalamus and other areas of the brain may be effective in treating involuntary and possibly life-threatening tics. history in the 16th century, andreas vesalius and francesco piccolomini were the first to distinguish between white matter, the cortex, and the subcortical nuclei in the brain. about a century later, thomas willis noticed that the corpus striatum was typically discolored, shrunken, and abnormally softened in the cadavers of people who had died from paralysis. the view that the corpus striatum played such a large role in motor functions was the most prominent one until the 19th century when electrophysiologic stimulation studies began to be performed. for example, gustav fritsch and eduard hitzig performed them on dog cerebral cortices in 1870, while david ferrier performed them, along with ablation studies, on cerebral cortices of dogs, rabbits, cats, and primates in 1876. during the same year, john hughlings jackson posited that the motor cortex was more relevant to motor function than the corpus striatum after carrying out clinical-pathologic experiments in humans. soon it would be discovered that the theory about the corpus striatum would not be completely incorrect. by the late 19th century, a few hyperkinesias such as huntington's chorea, post-hemiplegic choreoathetosis, tourette's syndrome, and some forms of both tremor and dystonia were described in a clinical orientation. however, the common pathology was still a mystery. british neurologist william richard gowers called these disorders "general and functional diseases of the nervous system" in his 1888 publication entitled a manual of diseases of the nervous system. it was not until the late 1980s and 1990s that sufficient animal models and human clinical trials were utilized to discover the specific involvement of the basal ganglia in the hyperkinesia pathology. in 1998, wichmann and delong made the conclusion that hyperkinesia is associated with decreased output from the basal ganglia, and in contrast, hypokinesia is associated with increased output from the basal ganglia. this generalization, however, still leaves a need for more complex models to distinguish the more nuanced pathologies of the numerous diverse hyperkinesias which are still being studied today. in the 2nd century, galen was the first to define tremor as "involuntary alternating up-and-down motion of the limbs." further classification of hyperkinetic movements came in the 17th and 18th centuries by franciscus sylvius and gerard van swieten. parkinson's disease was one of the first disorders to be named as a result of the recent classification of its featured hyperkinetic tremor. the subsequent naming of other disorders involving abnormal motions soon followed. research directions a healthy, neuropathic, and myopathic electromyogram, respectively. 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.