Dyskinetic disorders Flashcards
What are dyskinetic disorders charcterised by?
Characterised by impaired panning, control or execution of movement
What is a resting tremor?
https://www.youtube.com/watch?v=AYPzyOK2H2E
Tremor which is abolished with on voluntary movement
What is the cause of a resting tremor?
Parkinsonism
What is an intention tremor?
https://www.youtube.com/watch?v=4Sf-TuXMK64
Intention tremor is a slow (2–4 Hz) tremor during voluntary movement that develops as the limb approaches the target.
What tests would you do to assess for an intention tremor?
- Finger-to-nose test
- Heel-shin sign
Why does an intention tremor occur?
Delays in motor initiation and movement termination, and abnormalities of movement force and acceleration, contribute to intention tremor
What can cause an intention tremor?
- Intoxication – alcohol, benzodiazepine
- Cerebellar infarction
- Multiple sclerosis
- Vertebral artery dissection
- Cerebellar mass lesion – tumour, abscess, AVM
- HSV cerebellitis
- Hereditary cerebellar degeneration (Freidreich’s ataxia)
- Paraneoplastic cerebellar degeneration
What is a postural tremor?
https://www.youtube.com/watch?v=ZHUXI6OGdjo
A tremor which is absent at rest, but present on maintained posture (e.g. outstretched arms) and may persist on movement
What are causes of postural tremor?
- Benign essential tremor
- Thyrotoxicosis
- Anxiety
- B-agonists
What is chorea?
https://www.youtube.com/watch?v=1hKtmtu2pCw
Non-rhythmic, jerky, purposeless movements flitting from one place to another e.g. facial grimacing, raising the shoulders, flexing/extending fingers
What can cause choreic movements?
- Systemic disease - thyrotoxicosis, SLE, antiphospholipid syndrome, primary polycythaemia
- Genetic diseaseb - Huntingtons disease, neuroacanthocytosis
- Drugs - levodopa, OCP
- Post infection - Syndenham’s chorea
- Pregnancy
What is syndenham’s chorea?
https://www.youtube.com/watch?v=wTCnbga3sqg
A rare atuoimmune complication of group A strep infection, characterized by rapid, uncoordinated jerking movements primarily affecting the face, hands and feet. It is caused by destruction of cells in the corpus striatum of the basal ganglia
What drug can worsen chorea symptoms?
Levodopa
What is hemiballismus?
https://www.youtube.com/watch?v=1iSnmwXfN5o
Large-amplitude, flinging hemichorea (affecting proximal muscles) conttralateral to a vacular lesion of the subthalamic nucleus - often elderly diabetics
Violent swinging movements of one side of the body.
Typical causes of hemiballismus?
Usually by infection or haemorrhage in the contralateral subthalamic nucleus
What is athetosis?
https://www.youtube.com/watch?v=J_wIDm1_ax4
Slow, sinuous, confluent, puposeless movements (esp. digits, hands, face, tongue) which are often difficult to distinguish from chorea
What are causes of atheotosis?
Most common cerebral palsy
What is pseudoathetosis?
Athetosis caused by severe proprioceptive loss
What are tics?
https://www.youtube.com/watch?v=M0CBmmxufAk
Brief, repeated, sterotyped movements which patients may suppress for a while. Usually involve face and shoulders.
Eg tourette’s
What is myoclonus?
https://www.youtube.com/watch?v=bHG3GdvZOps
Sudden involuntary focal o general jerks arising from cord, brainstem or cerebral cortex