History

Fact Explanation
Tremulous upper/lower extremities. Shaky head movement ET is generally recognized as due to cerebellar system dysfunction and the presence of several types of structural-anatomical changes in the cerebellum. [2] Shaky legs/feet is less common. Other affected body parts may include eyelids and trunk. Head movement in an up-and-down or side-to-side motion. Tremors worsen with voluntary movement, stress, anxiety, excitement, emotional upset, fatigue and cold temperatures. Improvement in tremor is witnessed on alcohol consumption. [3]
Difficulty performing tasks [1] Performing tasks such as writing,brushing, dressing up, sewing, eating or drinking is difficult due to the kinetic tremor of the hands. [3]
Trembling voice when speaking [1] Larynx (voice box) is affected. [1]
References
  1. TOY Eugene C., SIMPSON Ericka P. , PLEITEZ Milvia, ROSENFIELD David, TINTNER Ron. CASEFILES: Neurology. 2nd ed. McGraw-Hill Medical. 2007.
  2. LOUIS Elan D., FAUST Phyllis L., VONSATTEL Jonh-Paul G.. Purkinje cell loss is a characteristic of essential tremor. Parkinsonism & Related Disorders [online] 2011 July, 17(6):406-409 [viewed 18 May 2014] Available from: doi:10.1016/j.parkreldis.2011.05.004
  3. CHOU Kelin L.. Diagnosis and management of the patient with tremor : Medicine and Health. Rhode Island. May 2004 [viewed 15 May 2014] Available from: http://med.brown.edu/neurology/articles/kc13504.pdf

Examination

Fact Explanation
Positive family history [4] 50-70% of the ET patients have been found to have a positive family history - Autosomal dominant inheritance. [4]
Regular tremor [3] Regular tremor on out-stretched hands and also on finger-to-nose maneuver is observed. Bilateral persistent symmetrical postural or kinetic tremors. [3] Generally recognized as due to cerebellar system dysfunction and the presence of several types of structural-anatomical changes in the cerebellum. [1]
Mild regular “waviness” seen when writing or drawing spirals [2] Caused because of the hand tremor due to cerebellar system dysfunction [1]
"Ratchety” quality [2] "Ratchety" quality felt in the tone of the controlateral arm when performing voluntary movement with one hand. [2] Generally recognized as due to cerebellar system dysfunction and presence of several types of structural-anatomical changes in the cerebellum. [1]
References
  1. LOUIS Elan D., FAUST Phyllis L., VONSATTEL John-Paul G.. Purkinje cell loss is a characteristic of essential tremor. Parkinsonism & Related Disorders [online] 2011 July, 17(6):406-409 [viewed 18 May 2014] Available from: doi:10.1016/j.parkreldis.2011.05.004
  2. TOY Eugene C., SIMPSON Ericka P., PLEITZ Milvia, ROSENFIELD David, TINTNER Ron. CASEFILES: Neurology. 2nd edition. New York: McGraw-Hill Medical. 2007.
  3. CHOU Kelin L.. Diagnosis and management of the patient with tremor. Medicine and Health: Rhode Island, May 2004 5(87) 135-138. [viewed 15 May 2014] Available from: http://med.brown.edu/neurology/articles/kc13504.pdf
  4. DENG Hao, LE Weidong, JANKOVIC Joseph. Genetics of essential tremor. Brain (2007),130, 1456 ^1464 [viewed 18 May 2014] Available from: doi:10.1093/brain/awm018

Differential Diagnoses

Fact Explanation
Enhanced physiologic tremor A low-amplitude, high-frequency tremor at rest and asymptomatic during action. Anxiety, stress, and certain medications and metabolic conditions enhance this tremor. For such patients further testing is not needed since tremor goes away on elimination of the cause. [4]
Drug-and Metabolic-induced tremors a) Perform a comprehensive medication review (prescribed and over-the-counter medications). Many medications can cause or exacerbate tremor. Therefore on revealing of the suspected medication that cause the tremor, advice the patient to discontinue it. b) To rule out various metabolic causes of tremor, perform an initial work-up of tremor of blood testing for hepatic encephalopathy, hypocalcemia, hypoglycemia, hyponatremia, hypomagnesemia, hyperthyroidism, hyperparathyroidism, and vitamin B12 deficiency. [2] [4]
Wilson Disease Considered in young patients (< 50 years) with an action tremor. [1] Manifests with a "wing-beating" tremor [3] Useful screening tests; serum ceruloplasmin and a slit-lamp examination for Kayser-Fleischer ring. However, patients with Wilson’s disease usually present with dysarthria, dystonia, and parkinsonism and very rarely present with isolated action tremor. [1]
Parkinson Disease Considered in older patients. (>60 years) 1) PD is clinically characterized by the classic triad of rest tremor, bradykinesia and rigidity. [3] 1) Rest tremor dampens with action in PD, whereas in ET it is generally a postural/kinetic tremor that dampens upon rest. [1] 2) The tremor with PD usually appears after a latent period of several seconds, while there is a sudden onset of tremor in ET. [6] 3) Patients with PD rarely have a tremor of the head or voice but may have a leg. lips, chin, jaw or tongue tremor (usually at rest). [3] 4) PD is associated with a stooped posture, slow movement, a shuffling gait, speech problems other than tremor, and sometimes memory loss while ET does not have other health problems. [6]
Task- or position-specific tremors Tremor occurs specifically during a particular task or posture but not when performing any other task with the same hand. (Eg: writing) [7]
Dystonia Isolated head tremor in ET must be excluded from head tremor seen in patients with cervical dystonia. ET: rhythmic, regular oscillations Cervical dystonia: irregular oscillations, tilting of the head or chin, and varying intensity with position changes. [1]
Psychogenic tremor Abrupt onset, spontaneous remission, changing tremor characteristics, and extinction with distraction. [2] [5]
Cerebellar tremor Presents with a disabling, low-frequency, slow intention or postural tremor. Other neurologic signs include dysmetria (overshoot on finger-to-nose testing), dyssynergia (abnormal heel-to-shin testing and/or atraxia), and hypotonia. Multiple sclerosis (MS) is the most common cause. Other causes include tumors, ischemic or haemorrhagic strokes, alcoholic cerebellar degeneration, vitamin E deficiency or paraneoplastic syndromes. [2] [4]
Multiple system atrophy (MSA) Presents with a postural, resting or, both tremors; and Parkinsonian features. [8]
References
  1. BHIDAYASIRI R. Differential diagnosis of common tremor syndromes Postgrad Med J [online] 2005 Dec, 81(962):756-762 [viewed 18 May 2014] Available from: doi:10.1136/pgmj.2005.032979
  2. LEEHEY MA. Tremor: diagnosis and treatment. Primary Care Case Rev. 2001;4:32–39.
  3. CHOU Kelin L. Diagnosis and management of the patient with tremor: Medicine and Health. Rhode Island, [online] May 2004 5(87) 135-138. [viewed 15 May 2014] Available from: http://med.brown.edu/neurology/articles/kc13504.pdf
  4. CRAWFORD Paul, ZIMMERMAN Ethan E. Differentiation and Diagnosis of tremor. Am Fam Physician. 2011 Mar 15;83(6):697-702. [online] [viewed15 May 2014] Available from: http://www.aafp.org/afp/2011/0315/p697.html
  5. GUPTA A, LANG AE. Psychogenic movement disorders. Curr Opin Neurol. 2009;22(4):430–436.
  6. TOY Eugene C., SIMPSON Ericka, PLEITZ Milvia, ROSENFIELD David, and TINTNER Ron. CASEFILES: Neurology. 2nd ed. McGraw-Hill Medical. 2007.
  7. BAIN Peter G. The Management of tremor.J Neurol Neurosurg Psychiatry 2002;72(Suppl I):i3–i9 [online] [viewed 16 May 2014] Available from: http://jnnp.bmj.com/content/72/suppl_1/i3.full.pdf
  8. GILMAN S, WENNING GK, LOW PA, BROOKS DJ, MATHIAS CJ, TROJANOWSKI JQ, WOOD NW, COLOSIMO C, DüRR A, FOWLER CJ, KAUFMANN H, KLOCKGETHER T, LEES A, POEWE W, QUINN N, REVESZ T, ROBERTSON D, SANDRONI P, SEPPI K, VIDAILHET M. Second consensus statement on the diagnosis of multiple system atrophy Neurology [online] 2008 Aug 26, 71(9):670-676 [viewed 18 May 2014] Available from: doi:10.1212/01.wnl.0000324625.00404.15

Investigations - for Diagnosis

Fact Explanation
Tremor focused neurological examination Clinical criteria for ET (MDS consensus statement Deuschl et al., 1998): INCLUSION CRITERIA: *A bilateral, largely symmetric, postural or kinetic tremor which involves both hands and forearms, and is visible and persistent. *Additional/isolated tremor in the head, but absence of abnormal posturing. EXCLUSION CRITERIA:  *Other abnormal neurological signs (especially dystonia). *Presence of known causes of enhanced physiologic tremor.   *Historical or clinical evidence of psychogenic tremor.   *Convincing evidence of sudden onset or step-wise deterioration.   *Isolated voice, tongue, chin, leg tremor. *Isolated position- or task-specific tremor. [1]
Electromyography or accelerometry Assess tremor frequency, rhythmicity, and amplitude. *Differentiate between ET and PK: a tremor frequency below 5.5 Hz suggests PD; a tremor frequency above 6 Hz suggests ET. *When orthostatic tremor is suspected EMG is needed to confirm the diagnosis - typical high-frequency (13–18 Hz) EMG pattern appearing after a short period of standing. [2]
Lab test: Standard electrolyte panel, R/o metabolic disturbances (most common: hypoglycemia) [2]
Lab test: Thyroid function tests Recommended in patients with an action tremor. R/o thyroid diseases (most common: hyperthyroidism) [2]
Lab test: Serum ceruloplasmin Considered in patients with an unexplained tremor and under 55 years of age. R/o Wilson disease [2]
MRI of the head Indicated if the tremor has an acute onset or a stepwise progression. Also for exclusion of inflammatory (including multiple sclerosis) and structural lesions and Wilson disease. [2]
Single-photon emission CT (SPECT) scanning using ioflupain 123 I (DaTSCAN) to rule out parkinsonism. [2]
Screen for drugs of abuse and alcohol consuption Alcohol overuse and withdrawal can cause tremor. Conversely, small amounts of alcohol can temporarily relieve essential tremor and hence can be a clue to the diagnosis. [2]
References
  1. BUIJINK AW, CONTARINO MF, KOELMAN JH, SPEELMAN JD, VAN ROOTSELAAR AF. How to Tackle Tremor - Systematic Review of the Literature and Diagnostic Work-Up Front Neurol [online] :146 [viewed 18 May 2014] Available from: doi:10.3389/fneur.2012.00146
  2. CRAWFORD Paul, ZIMMERMAN Ethan E. Differentiation and Diagnosis of Tremor. Am Fam Physician. [online] 2011 Mar 15;83(6):697-702. [viewed May 18 2014] Available from: http://www.aafp.org/afp/2011/0315/p697.html

Investigations - Followup

Fact Explanation
Adjusting of medication doses may be needed over time. Because essential tremor is a slowly progressive disorder there may be lose of benefit and adverse reactions on long term use. [1]
Follow-up with family members. During follow-ups of the patient, since essential tremor is familial it is appropriate to make family members aware of it and examine them as well when suspected of an ET.
References
  1. RAJPUT AH, RAJPUT A. Medical Treatment of Essential Tremor J Cent Nerv Syst Dis [online] :29-39 [viewed 18 May 2014] Available from: doi:10.4137/JCNSD.S13570

Management - General Measures

Fact Explanation
Avoid caffeine and smoking To prevent induction of tremors. [2]
Get enough sleep Tremors disappear during sleep. [3]
Alcohol (30ml) 1-2 drinks. Drinking should not be recommended as a treatment for non-alcoholics but this can be used an alternative for intermittent tremor control in those who consume alcohol. [1]
Use of larger utensil handles or wrist weights [4] Helps in coping with kinetic tremor of the hands
References
  1. RAJPUT AH, RAJPUT A. Medical Treatment of Essential Tremor J Cent Nerv Syst Dis [online] :29-39 [viewed 18 May 2014] Available from: doi:10.4137/JCNSD.S13570
  2. LOUIS Elan D., FAUST Phyllis L., VONSATTEL Jonh-Paul G. Essential Tremor. N Engl J Med [online] 2001 September, 345(12):887-891 [viewed 18 May 2014] Available from: doi:10.1056/NEJMcp010928
  3. TOY Eugene C., SIMPSON Ericka P., PLEITZ Milvia, ROSENFIELD David, TINTNER Ron. CASEFILES: Neurology. 2nd edition. New York:McGraw-Hill Medical. 2007.
  4. PUSCHMANN A, WSZOLEK ZK. Diagnosis and Treatment of Common Forms of Tremor Semin Neurol [online] 2011 Feb, 31(1):65-77 [viewed 18 May 2014] Available from: doi:10.1055/s-0031-1271312

Management - Specific Treatments

Fact Explanation
First line drugs [5] Beta-adrenergic blockers- Propranolol: 40-320mg/d ) - a better choice for younger patients than older patients because of serious adverse effects (dizziness, confusion, memory loss) in older adults. Contraindicated for use in patients with asthma, diabetes, cardiac conduction block or heart failure. (Primidone is preferable for those patients.) [1] Anti-convulsants- Primidone: (50-1000mg twice a day) - drug of choice for older adults. [1] Contraindicated in patients with hypersensitivity to phenobarbital and porphyria.
Second line drugs [5] Benzodiazepines- Alprazolam(0.125–0.5 mg/d): Effective in patients whose tremor is frequently aggravated by anxiety or other stressors. Clonazepam(0.5-4mg twice a day): Helpful in patients who failed other first and second lines of therapy. GABA analogs- Gabapentin (100-3600mg three times a day): Low effectiveness in patients who have failed primidone or propranol. Pregabalin (25-75mg twice a day): Low dosage is recommended because doses past 300mg have increased incidence of side effects. Anti-convulsants- Topiramate (25-400mg twice a day): Most effective second-line agent and can be used in patients not responding to propranolol and primidone. Botulinum toxin - useful in the treatment of head and voice tremor. Given once every 3 months : for head tremor - 50 units to 400 units for voice tremor - 0.6 to 14 units [2]
Third line drugs (mostly suitable for patients who are not candidates for surgical therapy.) [5] Calcium channel blockers- Nimodipine (30mg four times a day): May be considered in patients who have failed other commonly used medications. Atypical neuroleptic agents- Clozapine(25-75mg/d): May be considered in medically refractory ET if other nonpharmacological options are either contraindicated or not desired by the patients.
Surgical management Indicated in rare cases where patients have disabling and medically refractory tremor; and also useful in reducing head and voice tremor. Deep brain stimulation (DBS) : Can be performed bilaterally with fewer side effects than thalamotomy. [1] Thalamotomy (Rest tremor gets completely suppressed) [3] [4]
References
  1. CHOU Kelin L. Diagnosis and management of the patient with tremor: Medicine and Health. Rhode Island. [online] May 2004 5(87) 135-138. [viewed 15 May 2014] Available from: http://med.brown.edu/neurology/articles/kc13504.pdf
  2. RAJPUT AH, RAJPUT A. Medical Treatment of Essential Tremor J Cent Nerv Syst Dis [online] :29-39 [viewed 18 May 2014] Available from: doi:10.4137/JCNSD.S13570
  3. FYTAGORIDIS A, SANDVIK U, ASTROM M, BERGENHEIM T, BLOMSTEDT P. Long term follow-up of deep brain stimulation of the caudal zona incerta for essential tremor. J Neurol Neurosurg Psychiatry. Dec 28 2011
  4. BöTZEL K, TRONNIER V, GASSER T. The Differential Diagnosis and Treatment of Tremor Dtsch Arztebl Int [online] 2014 Mar, 111(13):225-236 [viewed 18 May 2014] Available from: doi:10.3238/arztebl.2014.0225
  5. HEDERA P, CIBULčíK F, DAVIS TL. Pharmacotherapy of Essential Tremor J Cent Nerv Syst Dis [online] :43-55 [viewed 18 May 2014] Available from: doi:10.4137/JCNSD.S6561