Clinical Movement Disorders 1: Hyperkinetic Disorders Flashcards
What is a ballism and why does it generally occur?
Sudden flinging movements of an entire limb, usually due to a lesion in the subthalamic nucleus
Usually unilateral (hemiballismus)
What is chorea vs athetosis?
Chorea - “dance” - sudden, brisk, usually distal movements (i.e. dancing)
Athetosis - Typically more proximal, snake-like, writhing movements. Slower than choreiform movements.
What causes Huntington disease? Include inheritance and chromosome.
Autostomal dominant trinucleotide repeat disorder of chromosome 4 “Huntin 4 food”. CAG repeat disorder >30 will express disease.
Caudate loses
Ach
GABA
(Striatal neurons are GABAnergic and cholinergic)
Give four examples of dysimmune chorea.
- Sydenham’s chorea -post-strept
- anti-NMDA receptor encephalitis - usually presents with chorea
- Chorea gravidarum - occurring in pregnancy
- Lupus - due to anticardiolipin Abs
Give an example of toxic chorea.
Over-medicated Parkinson’s disease - “peak dose dyskinesia”
or:
CO poisoning - very rate
What is the definition of dystonia and what can change it? Where does it occur most frequently?
Continuous or near-continuous involuntary contraction of muscles with abnormal posture, which is often stimulus-modulated (changes with touch or action, present more in certain actions)
- Most frequently cervical
What does it mean for dystonia to be focal, segmental, or generalized?
Focal - Affecting a limb or part of a limb
Segmental - Affecting multiple muscles innervated by same spinal cord segments
Generalized - affecting whole body, or a hemidystonia
What is the most common cause of genetic dystonia?
Wilson’s disease - copper in the basal ganglia
What is torticollis, blepharospasm, and Writer’s cramp and what causes them? What type of dystonia is the third?
Torticollis - cervical dystonia
Blepharospasm - spasm of orbicularis oculi muscle, making it difficult to see
Writer’s cramp - motor program problem -> task-specific dystonia
Give three examples of toxic dystonia.
- Acute dystonia to neuroleptics
- Tardive dyskinesia - chronic D2 blockade
- Tetanus - loss of GABA and glycine from Renshaw cells in spinal cord
Where are the three characterizing features of a tremor?
- Rhythm - fast vs slow (they are always regular)
- Morphology - flexion vs extension, pillrolling, etc
- Circumstance when tremor is greatest - resting, postural, or action
What type of tremor is essential tremor, and what is the frequency? Is it unilateral or bilateral?
High-frequency tremor (8-12 Hz), postural tremor (worsens with sustained posture)
Onset is BILATERAL, although it may be asymmetric
How is essential tremor inherited?
Familial -> autosomal dominant
How is essential tremor treated?
Drugs: Nonselective beta blockers + primidone
Self-medication: Transient suppression by alcohol
Thalamic deep brain stimulation if severe and refractory
What causes Wilson’s disease and what three tests are used to definitely test for it with high sensitivity?
Autosomal recessive loss of copper-transporting ATPase on chromosome 13
- Serum ceruloplasmin - decreased in most
- 24-hour urine copper - increased in most
- Slit-lamp exam - Check for Kayser-Fleischer rings - present in 90% with neurologic presentation
What are the features of a tic?
Stereotypic, reptitive, may be volitionally suppresses, have premontory urges
Generally more complex han myoclonus
Simple tic: simple movement
complex: gestures which may appear purposeful
What two psychiatric conditions is Tourette syndrome associated with it, and what is the diagnostic criteria?
Associated with OCD and ADHD
Multiple motor and 1+ vocal tics persisting for >1 year
What are the features of myoclonus?
Sudden, focal, localized muscle contraction
It is recurring but not regular, and may be generalized or segmental
(i.e. hiccups or jerks)
Where do myoclonus jerks originate from and what are they frequently seen in?
Originate from any part of CNS (cortex, brainstem, spinal cord)
Frequently seen in metabolic abnormalities -> renal or liver failure
What is asterixis? When does it often happen?
“negative myoclonus” - Intermittent lapses in postural tone -> not truely rhythmic
Flapping of hands when trying to hold extension is an example
-> Happens often in Wilson’s disease (along with dystonia) and hepatic encephalopathy
Is ataxia a motor deficit? Common features?
Yes -> deficit of motor function due to sensory or cerebellar lesion Common features: -dyscoordination -dysmetria (overshoot/undershoot) -dysdiadochokinesis
What is the most common hereditary ataxia in the Western world? What causes it?
Friedreich’s ataxia
- Trinucleotide repeat “GAA”
- Frataxin gene - iron binding protein in mitochondria causing free radical damage - chromosome 9
-> damage to multiple spinal cord tracts, ataxia with hypertrophic cardiomyopathy
What are some other autosomal recessive / nutritionally related ataxia other than Friedreich’s?
- Ataxia-telangectasia (DNA repair problem)
- Ataxia with vitamin E deficiency - spinocerebellar degeneration
- Abetalipoproteinemia - Vitamin E deficiency
- Refsum disease - accumulation of branched fatty acids from lack of peroxisome genesis
What are the autosomal dominant ataxias of concern?
Mostly spinocerebellar ataxias (SCAs) for which you should do a gene panel for
