Tremor is a neurological symptom and a neurological sign. It can be due to primary disorders of the nervous system or secondary nervous system dysfunction due to systemic disease. Tremors can also be physiologic and certain substances such a caffeine or circumstances such as anxiety can exaggerate physiological tremors.
Clinical features:
- Involuntary, rhythmic, alternating, oscillatory movements
- There are many causes of tremor. See the list below for more details. These range from physiologic tremor, drug induced tremor, Parkinson’s disease, Essential tremor, tremor due to metabolic abnormality (CO2 retention for example), hyperthyroidism, anxiety, alcohol withdrawal, cerebellar lesions and other conditions.
- Enhanced physiological tremor can occur with hyperthyroidism or drugs
- Describe whether the tremor occurs at rest, or with action (on maintaining posture) or action (intension tremor when approaching a target)
Investigatiosn to consider:
- FBC, complete metabolic panel including LFTs
- Thyroid function tests
- ABG: if CO2 retention is suspected
- MRI brain: if Wilson disease is suspected
- If < 40 y.o. serum ceruloplasmin: <20 mg per decilitre +/-slit lamp examination
- DAT SPECT (123I-FP-CIT SPECT) “DaTSCAN”: if atypical or to distinguish between esstential tremor and Parkinson disease
- Fragile X PCR: fragile X tremor ataxia syndrome
Causes of Tremor:
- Essential tremor
- Parkinson’s disease
- Wilson’s disease
- Thyrotoxicosis
- Drugs & toxins:
- Caffeine, beta agonists, levothyroxine
- SSRIs, lithium, valproate
- Dopamine antagonists
- Prednisolone,
- Cigarettes, amfetamine,
- CO2 retention
- Adult onset idiopathic dystonia
- Cerebellar disease (see ataxia)
Causes of Oculopalatal tremor OPT formerly oculopalatal myoclonus a.k.a. palatal tremour formerly palatal myoclonus:
- Essential palatal tremor
- Brainstem infarct
- Brainstem hemorrhage
- Severe brainstem trauma
- Multiple sclerosis
- Posterior fossa tumours
- Posterior circulation AVM
- Posterior circulation aneurysm
- Brainstem Cavernous malformations
- Behcet’s disease
- Progressive ataxia and palatal tremour PAPT
Causes of Parkinsonism:
- Idiopathic a.k.a. Parkinson’s disease formerly paralysis agitans
- Postencephalitic parkinsonism a.k.a. encephalitis lethargica, rare
- Anoxic brain injury e.g. cardiac arrest
- Drugs:
- Antipsychotics: Phenothiazines, butyrophenones e.g. haloperidol & others
- Metoclopramide
- Reserpine
- Tetrabenazine
- Toxins:
- Manganese dust, carbon disulfide, severe CO poisoning, welding fumes
- MPTP
- Other neurological disorders:
- Diffuse Lewy body disease
- Wilson’s disease
- Parkinson plus syndromes:
- Progressive supranuclear palsy a.k.a. Steele-Richardson-Olszewski disesase
- Multiple system atrophy MSA:
- Shy-Drager syndrome
- Striatonigral degeneration, rare:
- Olivopontocerebellar degeneration
- Basal ganglia calcification
- Cortical basal ganglionic degeneration
- Creutzfeldt-Jakob disease