Movement disorders can be classified as hypokinesias and hyperkinesias.
- First, determine whether or not an involuntary movement disorder is actually present (typically worse with anxiety and diminished during sleep).
- Second, determine the nature of the involuntary movements (such as chorea, dystonia, myoclonus, and tremor) by assessing features such as rhythmicity, speed, duration, pattern, induction, complexity, and suppressibility.
Types of movement disorder
- Akinesia/bradykinesia (Parkinsonism)
- Psychomotor depression
- Freezing phenomenon
- Hypothyroid slowness
- Stiff muscles
- Essential tremor
- Tics, such as Tourette syndrome
- Hemifacial spasm
- Others including akathisia, dyskinesia, hyperekplexia, jumpy stumps, moving toes, myokymia, myorhythmia, restless legs, and stereotypy
Features distinguishing movement disorders
- Dystonic tremor
- Tardive dyskinesia
- Moving toes and fingers
- Stiff-person syndrome
- Paroxysmal dyskinesia
Speed of movements
- Myoclonus (faster) → chorea → athetosis (slower)
- Tics (suppressible) → chorea → dystonia → tremor (hard to suppress)
- Tics (complex) → stereotypies → myoclonus → akathitic movements (simple)