Essential tremor

Question 1

Definition

Answer 1

AKA benign essential tremor = progressive tremor affecting predominantly the upper limb

Question 2

Character

Answer 2

Absent at rest
Occurs in posture and with movement
- without neurological signs or symptoms

Question 3

Aetiology

Answer 3

Unknown

Question 4

Epidemiology

Answer 4

Advanced age >70
FHx
Caucasian
Exposure to environmental toxins:
- organochlorine pesticides,
- lead,
- mercury,
- beta-carboline alkaloids

Question 5

Signs

Answer 5

Improvement with sedation:
- Alcohol
- Benzodiazepines
- Barbiturates
- Gabapentin

Question 6

Symptoms

Answer 6

Hand tremor:
- Upper limb
- Worse on movement and posturing
- Bilateral
Head or voice tremor
Difficulty performing fine motor tasks:
- writing,
- eating,
- dressing

Question 7

Assessment

Answer 7

Movement Disorder Society:
1. Isolated tremor syndrome of bilateral upper limb action tremor
2. At least 3 years’ duration
3. With or without tremor in other locations (e.g., head, voice, or lower limbs )
4. Absence of other neurological signs , such as dystonia, ataxia, or parkinsonism.

Question 8

Diagnosis

Answer 8

Dx of exclusion
Urine
- 24-hour urinary copper: Wilson’s disease
Bloods
- TFTs: hyperthyroidism
- U&Es: electrolyte disturbance
- LFTs: hepatic failure can cause tremor
- Serum caeruloplasmin : Wilson’s disease
Imaging
Consider doing:
- Tremor physiology tests: can differentiate ET and Parkinson’s disease

Question 9

Iatrogenic considerations

Answer 9

Lithium
Hx of poisoning
Alcohol withdrawal

Question 10

Treatment

Answer 10

Mild disease:
- Observation

Moderate disease:
FIRST LINE:
- Propranolol MC
- Primidone
SECOND LINE:
- Gabapentin
- Benzodiazepines

Treatment-resistant disease: third-line (surgical)
- Deep brain stimulation: nucleus ventralis intermedius (VIM) of the thalamus
- MRI-guided thalamotomy

Question 11

Complications

Answer 11

Deep brain stimulation can be associated with the following complications:
- Paraesthesia
- Dysarthria
- Gait disorder