2: Movement Disorders Flashcards
What is a movement disorder
Syndrome caused by excess or paucity of automatic or voluntary movements
What are 3 common movement disorders
- Essential tremor
- PD
- Restless leg syndrome
What are the 4 types of movement
- Automatic
- Voluntary
- Semi-voluntary
- Involuntary
What is automatic behaviours
Learned motor behaviours performed without conscious effort
Give an example of automatic behaviour
Walking to a familiar place
What is voluntary behaviour
Behaviour performed in response to an external stimulus
What is semi voluntary movement
Behaviour performed in response to an internal stimulus
Give two examples of semi voluntary movement disorders
- Tic
- Restless leg syndrome
What are involuntary movements
Movements that cannot be surpassed
Give 4 examples of non-supressable movement disorders
- Tremor
- Myoclonus
- Chorea
- Dystonia
How is normal control of movement divided
Central
Peripheral
What are central components of movement
- Motor cortical areas
- Basal ganglia
What are peripheral components of movement
- Motor neurone junction
- Muscle
- Spinal Cord
What pathways exist in the basal ganglia
Direct and Indirect
Explain effect of dopamine on direct pathway
Direct pathway contains D1-receptors. Hence is excited by dopamine release from corticostriatal neutrons
Explain effect of dopamine on indirect pathway
Direct pathway contains D2-receptors. Hence is inhibited by dopamine release from corticostriatal neurons
What is the role of direct pathway
Increases voluntary movement
Explain direct pathway
- Corticostriatal neurons stimulate external pallidum
- External palladium inhibits internal pallidum
- This prevents internal pallidum form inhibiting thalamus
- Excites thalamus and movement
Explain indirect pathway
Inhibits movement
Explain indirect pathway
- Corticostriatal neurons inhibit external pallidum (D2 receptors)
- This disinhibits sub thalamic nucleus
- Subthalamic nucleus stimulates the internal pallidum
- Internal pallidum inhibits thalamus, inhibiting movement
What are the two types of movement disorders
Hyperkinetic
Hypokinetic
What are 7 hyperkinetic movement disorders
- Dystonia
- Tremor
- Tic
- Myoclonus
- Akathisia
- Athetosis
- Chorea
What are 5 hypo kinetic movement disorders
- Cataplexy
- Bradykinesia
- Rigidity
- Catatonia
- Holding Tic
Define tremor
Regular, rhythmic, repetitive movements that affects one or more body parts
Define dystonia
Sustained twisting repetitive movements with prolonged abnormal posture involving groups of muscles
Define chorea
Involuntary, Irregular, Purposeless, unsustained movement that flow from one body part to another
Define myoclonus
Brief electric shock like movements arising from nervous system
What is positive myoclonus
Contraction agonist then antagonistic muscle groups
What is negative myoclonus
Transient interruption in tonic muscle tone (asterixis)
What is a Tic
Repetitive stereotyped behaviour that is difficult to control
What is akathisia
Inner restlessness
What is cataplexy
Transient loss in muscle tone due to strong emotion
Define a tremor
Rythmic involuntary movement of one or more body parts
What is the most common cause of tremor
Essential tremor
What is the inheritance pattern of essential tremor
Autosomal dominant
How does essential tremor present
- Postural tremor - worse with arms outstretched
- Head tremor
What improves essential tremor
Alcohol
Rest
What is stereotype for essential tremor patient
Young patient with sudden-onset tremor
How is essential tremor managed first line
Propanolol
What is an alternative to propranolol for managing essential tremor
Primidone
What tremor is present in Parkinson’s disease
Pill Rolling
What type of tremor is pill rolling tremor
Resting
What tremor is present in cerebellar lesion
Intention tremor
Give 4 organic causes of tremor
- Thyrotoxicosis
- CO2 retention
- Hepatic encephalopathy
- Anxiety
How are tremors broadly divided
- Action
- Resting
Are resting tremors or action tremors more common
Action tremors
What disorder is most commonly associated with resting tremor
Parkinson’s disease
What is restless leg syndrome
Spontaneous continuous lower limb movement that may be associated with parasthesia
In which gender is restless leg syndrome more common
Female
How can aetiology of restless leg syndrome be divided
Primary
Secondary
What are secondary causes of restless leg syndrome
- IDA
- DM
- ESRD
- Inflammatory: Coeliac, IBD
- Neuorlogical: anti-depressants
What are 4 risk factors for restless leg syndrome
- Pregnant
- IDA
- FH
- DM
- Uraemia
What type of movement disorder is restless leg syndrome and why
Akathisia = inner restlessness causes a desire to move leg.
Symptoms start at night and then progress to day-time
When are symptoms of restless leg syndrome worse
At rest
What investigations are ordered in restless leg syndrome
EMG
NCS
FBC - to exclue IDA
How can restless leg syndrome be managed
Stretching and walking
Dopamine agonists
