Dyskinesias Flashcards
What is a dyskinesia?
Involuntary abnormal movement
What are dyskinesia’s characterised by?
Frequency
Amplitude
Exacerbating factors - stress and fatigue
Describe rest tremor
Abolished on voluntary movement
Give a cause for rest tremor
Parkinsonism
Describe intention tremor
Irregular, large amplitude, worse at the end of purposeful acts
Give some causes of intention tremor
Cerebellar damage - MS, stroke
Describe postural tremor
Absent at rest, present on maintained posture (arms outstretched) and may persist (but is not worse) on movement
Give some causes of postural tremor
Benign essential tremor
Thyrotoxicosis
Beta- agonists
Describe re-emergent tremor
Postural tremor developing after a delay of 10 seconds
What are the causes of re-emergent tremor
Parkinson’s disease
Describe chorea
Non-rhythmic jerky, purposeless movements flitting from one place to another
Give some examples of choreas
Grimacing
Raising the shoulders
Flexing/extending the fingers
Give some causes of chorea
Huntington’s disease
Sydenham’s chorea
Which drug worsens chorea
Levodopa
What is Sydenham’s chorea
Rare complication of group A streptococcal infection
Describe hemiballismus
Large amplitude flinging hemichorea affecting proximal muscles contralateral to a vascular lesion of the subthalamic nucleus
What is the typical patient with hemiballismus
Elderly
Diabetic
What is the prognosis of hemiballismus
Recovers spontaneously over a few months
Describe athetosis
Slow, sinuous, confluent, purposeless movements (especially digits, hand, tongue and face)
Often difficult to distinguish from chorea
What causes athetosis
Cerebral palsy
What is psuedoathetosis caused by?
Severe proprioceptive loss
What are tics?
Brief, repeated, stereotyped movements often difficult to distinguish from chorea
What types of tics occur in tourettes syndrome?
Motor and vocal
What might haloperidol cause if given to people for tics?
Tardive dyskinesia
Which drugs are considered for severe tics
Clonidine or clonazepam
Describe myoclonus
Sudden involuntary focal or general jerks arising from the cord, brainstem or cerebral cortex
Which conditions is myoclonus seen in
Metabolic Neurodegenerative (lysosomal storage enzyme defects) CJD Myoclonic epilepsies (infantile spasms) Benign essential myoclonus Asterixis (metabolic flap)
Describe benign essential myoclonus
Childhood onset with frequent generalised myoclonus without progression
Often autosomal dominant
Which drugs might benign essential myoclonus respond to?
Valproate
Clonazepam
Piracetam
Describe the genetic inheritance pattern of benign essential myoclonus
Autosomal dominant
Describe asterixis
Jerking of outstretched hands
Worse when wrists extended (loss of extensor tone as there is incoordination between flexors and extensors - negative myoclonus)
What causes asterixis
Liver or kidney failure Hyponatraemia Hypercapnia Gabapentin Thalamic stroke if unilateral
What are tardive syndromes?
Delayed onset yet potentially irreversible symptoms occurring after chronic exposure to dopamine antagonists
Describe tardive dyskinesia
Orobuccolingual
Truncal
Choreiform
Describe tardive dystonia
Sustained, stereotyped muscle spasms of twisting, turning character
Describe tardive akathisia
Sense of restlessness or unease +/- repetitive, purposeless movements
How do you treat tardive dyskinesia
Gradually withdraw neuroleptics and wait 3-6 months
Tetrabenazine may help
Which antipsychotics are less likely to cause tardive syndromes
Quetiapine, olanzapine and clozapine - Atypical antipsychotics
Describe dystonia
Prolonged muscle contractions causing abnormal posture or repetitive movements
Describe idiopathic generalized dystonia
Childhood onset dystonia often starting in one leg with ipsilateral progression over 5-10yrs
What inheritance pattern is idiopathic generalized dystonia
Autosomal dominant (DYT1 deletion)
What must you exclude in idiopathic generalized dystonia
Wilsons disease
Dopa responsive dystonia
What drugs may be used to treat idiopathic generalized dystonia
Anticholinergics
Muscle relaxants
Deep brain stimulation
Describe focal dystonia
Confined to one part of the body
Idiopathic and rarely generalise
Worsened by stress
Patients might develop a geste antagoniste to try to resist the dystonic posturing
Give some examples of focal dystonias
Spasmodic torticollis - where head is pulled to one side of the body
Writers cramp
Blepharospasm - involuntary contraction of orbicularis oris
How are focal dystonia’s treated?
Injection into the overactive muscles
What is acute dystonia
Torticollis (head drawn up)
Oculogyric crisis (eyes drawn up)
Trismus (oromandibular spasm)
What causes an acute dystonia?
Staring neuroleptics and some anti-emetics (metoclopramide and Cyclizine)
How do you treat acute dystonic reactions
A dose of anticholinergic
