Term
| What are the major types of tremors and how are they classified? |
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Definition
1) Resting (limb supported against gravity)
2) Action
- Postural (Physiological or Essential)
- Kinetic
- Task-specific |
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Term
| What are the defining features of an Essential Tremor? |
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Definition
Most common tremor requiring treatment (both postural and kinetic)
1) Bilateral action tremor, involving upper limbs
2) Can be isolated head tremor (if no dystonia)
3) No other neurological abnormalities
**Supported by family history (autosomal dominant), if tremor reduced with OH-, and lasting more than 3 years** |
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Term
A patient presents with a bilateral action tremor of the upper limbs that is improved when he uses alcohol.
It has been occurring for 5 years in the absence of any other neurological issues.
What is the pathophysiology/treatment of this condition? |
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Definition
This is an Essential Tremor (bilateral tremor w/o other neuro issues)
1) Pathophysiology is speculated to involve ION perhaps as a central oscillator.
2) Beta Adrenergic blockers (Propranolol)
- crosses BBB with side effects of fatigue, impotence and depression
- contraindicated with asthma, heart block or bradycardia
3) Anti-convulsent (Primidone)
- Deoxybarbiturate metabolizied to phenobarbital and phenylthymalonimide (more effective then phenobarbital)
- Side effects of somnolence (titrate slowly!)
4) Surgery- lesion ventral intermediate nucleus (Vin) of thalamus for contralateral tremor, Gamma Knife or DBS |
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Term
A patient presents with slow (2-4 hz) tremors during action and increasing as targets are approached.
They occur irregularly but not at rest.
What is the pathophysiology/treatment of this condition? |
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Definition
Cerebellar Tremor (Intentional) seen is MS, Wilson's and after Cerebellar stroke
1) Cerebellar outflow tracts are lesioned
2) DBS of Vim thalamus has been 70% effective for MS (but its progressive and treatments are NOT GREAT) |
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Term
| What is the difference between juvenile-onset and adult-onset primary dystonia? |
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Definition
1) Child
-Starts in lower body
- Becomes generalized
- Often inherited
2) Adult
- Focal (can progress to segmental, but not generalized)
- Commonly sporadic |
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Term
| What are the major types of adult-onset primary dystonia? |
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Definition
Co-contraction of agonist/antagonist muscles
- Cervical
- Blepharospasm (eye closure or blinking from peri-ocular muscles)
- Oromandibular (Meige's syndrome)
- Laryngeal
- Task-specific |
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Term
What genetic form of Dystonia occurs in 90% of Ashkenazi jews with primary dystonia?
What is known about it? |
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Definition
DYT1 ("CAG mutation") of Torsin A
- Tends to start in foot and spread to whole body, exhibiting reduced penetrance.
1) Encodes AAA+ ATPase, which is molecular chaperone in protein folding, membrane fusion and vesicle trafficking
2) Torsin A is highly concentrated in SNpc (DA input to striatum) |
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Term
Which Dystonia presents as generalized dystonia in early childhood with parkinsonian symptoms (bradykinesia and rigidity)?
What mutations cause this condition and how is it treated? |
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Definition
DYT5-Dopa-responsive dystonia (DRD)
1) Commonly Autosomal Dominant mutation in GTP cyclohydrolase involved in THB synthesis (co-factor for tyrosine hydroxylase)
- Less commonly AR mutation in TH itself.
2) Improved with L-dopa therapy (sometimes misdiagnosed as Cerebral Palsy) |
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Term
| Explain what is known about the basic pathophysiology underlying Dystonia? |
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Definition
Thought to involve BG, but details unclear!
-Was thought to involve Gpi inhibition, but Gpi lesioning is actually therapeutic!
- Can occur anywhere
- May involve "pattern" of pallidal-thalamic activities during voluntary movement, where thalamus-muscle synchronization overflows to other muscle groups as well. |
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Term
| What treatments are available for Dystonia? |
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Definition
Chemodenervation (Botulism) and DBS are MAINSTAY
1) Botulinum toxin injected into affected muscles causing chemodenervation (every 3-6 months)
2) Pharmacological
- Anti-Ach in high doses
- Benzos
- Tetrabenazine (DA depletion)
- L-DOPA (for DYT5)
3) Surgical
- DBS in GPi (not thalamus, as with tremor) takes weeks to emerge at high levels of stimulation (also unlike tremor) |
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Term
| How does DBS treatment differ for Essential Tremor and Dystonia? |
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Definition
1) Works quickly at low levels in Vim thalamus for Tremor
2) Works slowly at high levels of stimulation in Gpi for Dystonia |
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Term
True or False:
DBS treatment to the ventral intermediate nucleus of the thalamus for essential tremor reduces the frequency and the amplitude of the tremor. |
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Definition
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Term
A patient presents with a resting tremor that is distractible.
What kind of tremor is this most likely to be? |
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Definition
Psychogenic.
Unlike PD, where the tremor is not distractible. |
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