Essential tremor (N)

Question 1

Define essential tremor.

Answer 1

Progressive, mainly symmetrical, rhythmic, involuntary oscillation movement disorder of the hands and forearms, that is usually absent at rest and present during posture and intentional movements

Question 2

What are the causative factors for essential tremor? (3)

Answer 2

• ageing
• genetics
• environmental toxins

Question 3

What is the most common cause of essential tremor?

Answer 3

Positive family Hx - autosomal dominant condition

Question 4

What demographics are most often affected in essential tremor?

Answer 4

Binomial distribution - teens and elderly

Question 5

What areas of the brain are involved in essential tremor? (3)

Answer 5

• cerebellum
• brainstem
• thalamus

Question 6

What has been reported to abolish essential tremor?

Answer 6

Acute cerebellar stroke

Question 7

What type of tremor is essential tremor?

Answer 7

Action tremor

Question 8

What are some types of action tremor (low yield)? (9)

Answer 8

• essential tremor
• enhanced physiological tremor - present equally in outstretched arms and legs - thyrotoxicosis, hypoglycaemia etc
• Parkinson’s disease - resting tremor alongside rigidity, bradykinesia, postural instability
• adult-onset idiopathic dystonia - tremor irregular and jerky
• Wilson’s disease - dystonia, dystonic tremor and/or resting tremor
• cerebellar outflow tremor - irregular tremor with goal-directed movements, ataxic component, other cerebellar signs e.g. slurred speech, eye findings, abnormal gait
• Holme’s tremor - irregular, coarse proximal upper extremity tremor with large amplitude
• orthostatic tremor - rare, not visible, cannot stand still
• psychogenic tremor - distractibility, suggestibility and trainability

Question 9

What are the clinical features of essential tremor? (6)

Answer 9

• bilateral upper limb action tremor - with absence of other neurological signs (cerebellar signs e.g. ataxia, dystonia, parkinsonism)
• worse with sustained voluntary movements (i.e. when arms outstretched), stress or anxiety
• problems with fine motor tasks
• involves - hands (90%), head (30%), voice (15%)
• may be accompanied by an intention tremor or resting tremor
• improves with alcohol consumption, BZs, barbiturates or gabapentin (drugs affecting GABA systems)

Question 10

What examinations do you do for essential tremor?

Answer 10

Cranial nerves, upper and lower limb neurological exams

Question 11

What are some risk factors for essential tremor? (3)

Answer 11

• advanced age
• family Hx
• environmental toxins - organochloride pesticides, lead, mercury, beta-carboline alkaloids

Question 12

What type of diagnosis is essential tremor?

Answer 12

Clinical diagnosis - no first-line investigations

Question 13

What scans can we do for essential tremor?

Answer 13

Head CT or MRI - only when there is a focal neurological sign

Question 14

What scan can differentiate essential tremor from Parkinson’s disease?

Answer 14

SPECT Scan (Single-Photon Emission Computed Tomography) - normal putamen value (Parkinson’s would be different)

Question 15

What are the differential diagnoses for essential tremor? (6)

Answer 15

• Parkinson’s disease - would see DANISH symptoms
• dystonia
• Wilson’s disease - resting and action tremor, Kayser-Fleischer rings, abnormal LFTs
• enhanced physiological tremor
• drug-induced tremor
• psychogenic tremor

Question 16

How do we manage essential tremor if it is mild and there is no dysfunction?

Answer 16

Observation

Question 17

What is the management of essential tremor if dysfunction/embarrassment?

Answer 17

• 1st line: propranolol (CI in asthma) or primidone
• 2nd line: gabapentin

Question 18

What other management techniques are there for essential tremor? (3)

Answer 18

• deep brain stimulation - if drugs have no effect
• focused ultrasound thalamotomy with MRI guidance
• gamma knife thalamotomy

Question 19

What are some complications of essential tremor?

Answer 19

Deep brain stimulation related paraesthesia/dysarthria/gait disorder

Question 20

Describe the prognosis of essential tremor.

Answer 20

Persistent and progressive condition - many people only mildly affected and do not seek medical treatment