Differentials
Common
Parkinson disease (PD)
History
unilateral or asymmetric rest tremor, slowed movements, stiffness, micrographia, drooling, difficulty turning over in bed, difficulty with buttons and utensil use, shuffling gait, and decreased arm swing; history of hyposmia, history of rapid eye movement sleep behavior disorder
Exam
masked facies (reduced facial animation), hypophonia, unilateral or asymmetric rest tremor (may be pill rolling), slow or low-amplitude finger taps and hand grips, rigidity, difficulty standing from chair, shuffling gait, stooped posture, decreased arm swing, retropulsion on pull-back testing, stooped posture
1st investigation
- dopaminergic agent trial:
positive response to L-dopa or other dopaminergic agent (dopamine agonist). The diagnosis of PD is made clinically, and in cases without atypical features, no additional diagnostic testing is indicated. Warranted if atypical features or unclear clinical diagnosis. In tremor-predominant disease, doses as high as 1200 mg of levodopa may need to be reached before concluding lack of efficacy.
Other investigations
- head MRI scan:
normal image in most patients
More - functional neuroimaging (e.g., PET or single-photon emission CT):
decreased basal ganglia presynaptic dopamine uptake
Dementia with Lewy bodies
History
fluctuating cognition, cognitive impairment, and parkinsonism occurring within 1 year of each other, visual hallucinations (not related to dopaminergic therapy) and delusions, sensitivity reactions to neuroleptics
Exam
muscle rigidity, stooped posture, cogwheel rigidity, shuffling gait, impairment on cognitive testing
1st investigation
- none:
clinical diagnosis
Enhanced physiologic tremor
History
tremor noticed in situations of stress, anxiety, or excessive caffeine use; absence of neurologic disease
Exam
anxious appearance; fine high-frequency postural and kinetic tremor that occurs in arms, legs, and voice but not the head
1st investigation
- none:
clinical diagnosis
More
Hypoglycemia (enhanced physiologic tremor)
History
history of diabetes or glucose intolerance, history of insulin use
Exam
sympathoadrenal or neuroglycopenic symptoms; action tremor
1st investigation
- serum glucose:
low
Other investigations
- thyroid function test:
normal
More
Thyrotoxicosis (enhanced physiologic tremor)
History
weight loss, diaphoresis (excessive sweating), heat intolerance, palpitations, anxiety
Exam
diaphoresis, tachycardia, enlarged thyroid gland; action tremor
1st investigation
- serum TSH, free T3, free T4:
TSH: low; free T3: high; free T4: high
Other investigations
Alcohol withdrawal (enhanced physiologic tremor)
History
history of alcohol misuse
Exam
tremulousness, seizures, delirium, hallucinations, spider angiomata, gynecomastia, enlarged liver, signs of autonomic hyperactivity, no alcohol for 6 hours produces intention tremor; hypertension; tachycardia
1st investigation
- CBC:
elevated MCV
- liver function tests:
elevated gamma-GT
Other investigations
- thyroid function test:
normal
More
Essential tremor or essential tremor plus
History
tremor mainly affects hands, shaky handwriting or utensil use; positive family history; tremors may improve with alcohol use
Exam
postural and/or kinetic tremors of hands, tremors may also involve head and voice; essential tremor occurs in the absence of other neurologic signs; if subtle neurologic signs such as impaired tandem gait, subtle body posturing suggestive of dystonia, or mild memory impairment are present, then essential tremor plus is the more appropriate classification
1st investigation
Other investigations
Drug-induced tremor
History
occurs following ingestion of certain drugs; rest tremors can be caused by dopamine receptor blockers such as neuroleptics, atypical antipsychotics, antinausea agents (metoclopramide, prochlorperazine, promethazine), and calcium-channel blockers (flunarizine, cinnarizine) or dopamine depletors (tetrabenazine); action tremors are common following treatment with antidepressants (serotonin-reuptake inhibitors, tricyclics, monoamine oxidase inhibitors), mood stabilizers (lithium), antiepileptic drugs (valproic acid), cardiac drugs (amiodarone), immunosuppressants (cyclosporine, tacrolimus, corticosteroids), asthma drugs (albuterol, theophylline), and stimulants (amphetamines); tremor occurs in a reasonable time frame following drug ingestion
Exam
rest or action tremor
1st investigation
- none:
clinical diagnosis
Other investigations
- thyroid function test:
normal
More
Uncommon
Multiple system atrophy
History
lightheadedness and syncope, erectile dysfunction, urinary dysfunction, dysarthria, gait difficulty, slow movements, rest tremor, lack of coordination, early postural instability
Exam
orthostatic hypotension, parkinsonism, ataxia, hyperreflexia, shuffling or ataxic gait
1st investigation
- none:
clinical diagnosis
More
Progressive supranuclear palsy
History
frequent falls, visual problems, axial rigidity, dysarthria, dysphagia, personality and cognitive change, rest tremor
Exam
supranuclear gaze palsy, dysarthria, "surprised" facial expression, axial rigidity, bradykinesia, frontal release signs, cognitive impairment, marked gait instability
1st investigation
- none:
clinical diagnosis
More
Cortical basal degeneration
History
asymmetric rest tremor; disorder of skilled, learned, purposeful movement; dystonic limb posturing; alien limb phenomenon
Exam
parkinsonism (rest tremor, rigidity, bradykinesia, postural instability), limb apraxia, dystonia, spontaneous and reflex focal myoclonus, rigidity
1st investigation
- none:
clinical diagnosis
Toxin-induced tremor
History
history of toxic exposure to the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) (heroin addicts), carbon monoxide, manganese (may be seen in welders or in patients receiving parenteral nutrition), methanol, or cyanide
Exam
parkinsonism (rest tremor, rigidity, bradykinesia, and postural instability)
1st investigation
- none:
clinical diagnosis
Other investigations
- head MRI scan:
shows high signal intensity on T1-weighted images in the globus pallidus in patients actively exposed to high levels of endogenous or iatrogenic manganese, as with intravenous hyperalimentation and cirrhosis, or with environmental-industrial exposure such as with welding, smelting, or manganese mining; may show bilateral globus pallidus lesions in carbon monoxide poisoning
Postencephalitic parkinsonism
History
was common in 1920s but has now virtually disappeared; occurred as a sequel to lethargic encephalitis within a variable period, from days to many years, after the acute process
Exam
parkinsonism (rest tremor, rigidity, bradykinesia, postural instability)
1st investigation
- none:
clinical diagnosis
Other investigations
Pheochromocytoma (enhanced physiologic tremor)
History
headache, sweating, palpitations
Exam
hypertension, tachycardia, action tremor
1st investigation
- 24-hour urine collection for catecholamines, metanephrines, normetanephrines:
high
- serum free metanephrines, normetanephrines:
high
Other investigations
- thyroid function test:
normal
More
Cerebellar tremor (multiple sclerosis, trauma, or stroke)
History
complaints of incoordination, imbalance, family history of cerebellar ataxia, history of multiple sclerosis, head trauma, stroke, or cerebellar hemorrhage
Exam
coarse irregular kinetic tremor generated proximally, abnormal finger-to-nose testing and heel-to-shin testing, dysdiadochokinesis, wide-based ataxic gait, dysarthria (speech problems)
1st investigation
- head MRI scan:
may see signs of cerebellar atrophy, or may suggest demyelinating disease in multiple sclerosis, or show changes consistent with stroke, trauma, or hemorrhage
Other investigations
- thyroid function test:
normal
More
Fragile X tremor ataxia syndrome
History
occurs in upper limbs, age >60 years, more common in men, gait ataxia, may be a family history of premature ovarian failure in females and/or intellectual disability (fragile X syndrome) in males
Exam
intention tremor, ataxic gait, often have acquired cognitive impairment especially executive dysfunction
1st investigation
- head MRI scan:
middle cerebellar peduncle hyperintensities
Other investigations
- genetic testing:
positive fragile X premutation in FMR1 gene
- thyroid function test:
normal
More
Orthostatic tremor
History
tremor in legs that occurs on standing, accompanied unsteadiness, tremor disappears on sitting or walking
Exam
high-frequency tremor of legs when standing
1st investigation
- none:
clinical diagnosis
Primary writing tremor
History
tremor of hand only when writing
Exam
hand tremor when writing only
1st investigation
- none:
clinical diagnosis
Other investigations
- thyroid function test:
normal
More
Dystonic tremor
History
tremor in a body region (usually head or neck, but may be limb) often with a directional pulling or jerking quality
Exam
often irregular head and neck tremor with a jerky, directional quality; patient may use a sensory trick (geste antagoniste) to relieve or diminish tremor; tremor may be very sensitive to task-specific or positional factors e.g., may disappear at a specific position (‘null point’)
1st investigation
- none:
clinical diagnosis
Other investigations
- brain MRI:
normal in most cases
More
Wilson disease
History
tremor, dysarthria, incoordination, dystonia, gait abnormalities, psychiatric changes, <40 years of age, hepatitis or cirrhosis
Exam
Kayser-Fleischer rings, tremor, dysarthria, dystonia, ataxia
1st investigation
- serum ceruloplasmin:
<18 mg/dL suggests Wilson disease
- 24-hour urine copper:
>100 micrograms indicates disease
- liver function tests:
abnormal
- slit-lamp exam:
Kayser-Fleischer rings, greenish deposits as an arc across the outer rim of the top of the cornea
- head MRI scan:
bilateral T2 hyperintensities in any or all of basal ganglia, thalamus, or midbrain; hypointensities can also be seen
Other investigations
- liver biopsy:
liver copper >250 micrograms/g
- thyroid function test:
normal
More
Rubral tremor
History
history of stroke or central nervous system insult such as multiple sclerosis; uncontrollable coarse tremor
Exam
tremor of arm with equal rest, action, and intention components
1st investigation
- head MRI scan:
may show damage to the red nucleus or cerebellothalamic pathways
Other investigations
- thyroid function test:
normal
More
Functional (psychogenic) tremor
History
sudden onset of tremor, history of anxiety or depression, history of sexual or child abuse
Exam
tremor that is distractible or can be entrained to a new frequency; may be associated with other nonorganic signs such as give-way weakness; nonanatomic sensory exam; astasia-abasia (inability to either stand or walk in a normal manner)
1st investigation
- none:
clinical diagnosis
Other investigations
- thyroid function test:
normal
More
Use of this content is subject to our disclaimer