Essential Tremor

Question 1

Tremor of ET vs Tremor of PD

Answer 1

Question 2

Lead-pipe rigidity

Answer 2

Velocity-independent resistance felt throughout range of motion (unlike cogwheel rigidity)

Question 3

Physiologic tremor

Answer 3

A very low-amplitude (8-12Hz) tremor that is rarely visible to the naked eye.

It is present in individuals while maintaining posture or movement and is nonpathologic.

It is enhanced by stress, caffeine, and thyroid dysfunction.

Question 4

ET often onsets around age ___

Answer 4

ET often onsets around age 45

Question 5

ET is most often seen in the ___, but may appear in ___

Answer 5

ET is most often seen in the hands/wrists, but may appear in the legs, head, and even voice

Question 6

___ can dramatically decrease essential tremor in about 50% of cases, making it a very useful sign.

Answer 6

Improvement with low doses of ethanol (glass of beer or wine) can dramatically decrease essential tremor in about 50% of cases, making it a very useful sign.

Question 7

While ET is a clinical diagnosis, the following should be considered/performed when working up ET:

Answer 7

• Full neurologic examination (and if abnormal, MRI)
• Consider Parkinson’s
• Consider thyroid dysfunction
• Consider dystonia
• Consider Wilson’s

Question 8

ET is typically an ___ disorder

Answer 8

ET is typically an autosomal dominant disorder

Question 9

Stroke-induced mimic of essential tremor

Answer 9

Purely kinetic and intention tremors are sometimes caused by infarcts of cerebellar output tracts or damage to the red nucleus

These are often more highly specific in context than essential tremor: such as tremor ONLY when writing.

Question 10

Best way to differentiate ET from idiopathic PD or other parkinsonian disorders

Answer 10

¹²³I-FP-CIT SPECT (or DaT scan)

Will show asymmetric basal ganglia uptake, indicating diminished dopamine transporter density in the striatum and a diagnosis of a parkinsonian disorder.

Question 11

Mainstays of ET therapy

Answer 11

• Conservative: Adequate rest, reduce caffeine intake, stress-coping strategies
• Pharmacologic:
  
  • Beta blockers (propranolol)
    
    • Asthma and hypotension are relative contraindications
  • Anti-seizure medications (primidone and topiramate)
    
    • Second-line after beta blockers
    • Lower dose than used for epilepsy
    • Initiate at low doses and increase slowly, otherwise may induce ataxia and nausea
  • Anxiolytics (diazepam or alprazolam)
    
    • For those whose symptoms are exacerbated by anxiety
• Interventional:
  
  • Botox injection
    
    • For voice tremors
  • Deep brain stimulation
    
    • For medically refractory disease
    • Preexisting psychiatric disease is a contraindication

Question 12

With regards to laterality, essential tremor is almost always ___, while the PD tremor is often ___.

Answer 12

With regards to laterality, essential tremor is almost always bilateral, while the PD tremor is often asymmetric.

However, because it effects fine motor actions, patients with ET may feel as though it affects their dominant hand more.

Question 13

Features of a “cerebellar tremor”

Answer 13

• Always occurs as an intention tremor
• Hypermetria will be present on finger-nose-finger