10.7 Hyperkinetic disorders Flashcards
What is a tremor
involuntary rhythmic, repetitive, oscillatory movement of body part caused by alternative contraction of agonists and antagonist muscle groups
What are the types of tremor
Resting: may disappear when asleep of relaxed
Postural: present when limb in certain position
Intention: present when moving body part to/from target, particularly when terminal exaggeration
What is an essential and dystonic tremor?
Essential: bilateral, largely symmetrical postural and kinetic tremor of hands and forearms (bimodal distribution)
Dystonic: Typically jerky, may be position and/or task specific
What are the causes of an intention tremor?
Cerebellar pathology, MS, midbrain pathology, functional
What drugs induce a rest tremor?
Dopamine antagonists Valproate Lithium Amiodarone Calcium channel blockers
What drugs induce an action tremor?
Beta agonists Anticonvulsants Thyroxine Lithium Tricyclic antidepressants Caffeine Nicotine Amphetamines
What is the treatment for an essential tremor?
1st: propanolol
2nd: primidone
What is myoclonus?
Brief, shock like, involuntary movements caused by muscular contractions (positive myoclonus) or inhibitions (negative myoclonus, asterixis)
What is restless leg syndrome, genetic basis, disease associations and treatment?
Unpleasant or uncomfortable urge to move legs particularly in the evenings and is transiently relieved by movement
Autosomal dominant
Disease associations: iron deficiency, uraemia, peripheral neuropathy, pregnancy, MS, PD
Treatment: dopamine agonists
What is periodic limb movement disorder and what is the treatment?
Involuntary limb movements during sleep with stereotyped flexion at the hips/knees, ankle dorsiflexion and great toe extension
Movements lats about 2 seconds and occur every 20-40 seconds, occur in stage 1-2 sleep and associated with excessive daytime sleepiness
Treatment - same as restless leg syndrome
What are tics
Sudden, brief, intermittent repetitive movements or vocalisations which can be voluntarily suppressed
What is the primary cause of a tic?
Tourettes - persistent evolving motor and phonic tics, age of onset
What are the secondary causes of Tics?
Huntington’s, Wilsons, CJD, Downs
Cocaine, amphetamines
Encephalitis, neurosyphilus, head traumas, stroke, neoplasm
What is the management of tics?
Education, habit reversal training, tetrabenazine, botulinium toxin
What is chorea, athetosis and ballism and what are the primary causes?
Chorea: rapid, distal dance like movements
Athetosis: writhing, random, slower
Ballism: proximal, large amplitude, flinging
Causes: huntingotns, benign hereditary chorea, neuroacanthocytosis, Wilsons
What is Huntingtons disease?
Inherited progressive neurodegenerative disoder which causes choreiform movements, psychiatric symptoms and dementia
Caused by a CAG repeat in the Huntingtin gene
What is the management of drug induced disorders?
Taper/withdraw offending agent
Tetrabenazine
Small dose dopamine agonist
What is dystonia?
A movement disorder characterised by sustained or intermittent muscle contractions causing abnormal, often repetitive movements, postures or both
Typically patterned, twisting and may be tremulous
Often initiated or worsened by voluntary action and associated with overflow muscle activation
How does Botulinum toxin work?
Blocks ACh release, resulting in chemo-deneration
