Approach to Movement disorders

Definitions of presentations of movement disorders:

Tremor:

  • Involuntary, rhythmic, alternating, oscillatory movements
  • There are many causes of tremor. See the list below for more details. These range from physiologic tremor, drug induced tremor, Parkinson’s disease, Essential tremor, tremor due to metabolic abnormality (CO2 retention for example), hyperthyroidism, anxiety, alcohol withdrawal, cerebellar lesions and other conditions.
  • Enhanced physiological tremor can occur with hyperthyroidism or drugs
  • Describe whether the tremor occurs at rest, or with action (on maintaining posture) or action (intension tremor when approaching a target)

Myoclonus:

  • Involuntary, sudden, brief, jerk, positive (contraction), negative (inhibition of tone).
  • Myoclonus may be part of an epilepsy syndrome such as Juvenile myoclonic epilepsy, or due to compressive lesions such as in some cases of hemifacial spasm, or due to previous injury to the brain such as with anoxic brain injury, or due to prion disease as with Creutzfeldt Jakob disease, or part of a neurodegenerative process  as in Lafora disease.

Chorea:

  • Involuntary, nonrhythmic, rapid, irregular, jerky, purposeless, unpredictable, non-sustained movement.
  • Chorea may be part of a neurodegenerative process such as Huntington’s disease, due to metabolic abnormalities as in hyperglycemia or drug induced or be part of rheumatic fever.

Ballism, Hemiballismus:

  • Ballism and hemi-ballismus are involuntary, very large amplitude, rapid movement, that involve proximal parts of the limb, and lead to flailing. It is called hemiballism if involves one whole side of the body.
  • This is often due to ischemic stroke of the subthalamic nucleus

Dystonia:

  • Dystonia is involuntary, simultaneous contraction of agonist & antagonist muscles, predictable movements, twisting or turning.
  • This may be idiopathic as in torticollis , genetic as with primary dystonias, or due to or part of other illness as with drug induced dystonias and dystonias in Creutzfeldt Jakob disease. See below for a more extensive list.

Athetosis:

  • Athetosis is involuntary, slow writhing, continuous movements; almost “dance-like”.
  • This is often accompanied by chorea and shares many causes

Tics:

  • Tics are involuntary, stereotyped, repetitive movements= motor tics/ vocalizations= phonic tics. Can be suppressed temporarily. Release provides relief to the patient.
  • Tics may be idiopathic and can occur in Tourette’s disease, or be drug induce.

Akathesia:

  • Akathesia is inability to remain still due to an inner sense of restlessness.
  • This is often drug induced.

Hyperekplexia:

  • Abnormal exaggerated startle response to sudden expected stimuli.
  • This is rare and is due to mutations in glycine receptor (GLRA1) gene. This is a type of “channelopathy”, an ion channel disorder.

Ataxia:

  • Uncoordinated or inaccurate movement not due to paresis, sensory disturbances, increased tone or involuntary movements
  • Gait: broad based, staggering & swaying, unsteady,
  • Truncal ataxia: inability to sit or stand without support
  • Dysmetria: Past-pointing,
  • Asynergia/dyssynergia
  • Intension (kinetic) tremor, postural tremor

 

Causes of Tremor:

  • Essential tremor
  • Parkinson’s disease
  • Wilson’s disease
  • Thyrotoxicosis
  • Drugs & toxins:
    • Caffeine, beta agonists, levothyroxine
    • SSRIs, lithium, valproate
    • Dopamine antagonists
    • Prednisolone,
    • Cigarettes, amfetamine,
    • CO2 retention
  • Adult onset idiopathic dystonia
  • Cerebellar disease

Causes of Oculopalatal tremor OPT formerly oculopalatal myoclonus a.k.a. palatal tremour formerly palatal myoclonus:

Causes of Parkinsonism:

 

DDx. of Parkinson’s disease:

 

Causes of tics: