Editing Essential tremor (section)

{{short description|Movement disorder that causes involuntary tremors}}
{{cs1 config|name-list-style=vanc|display-authors=6}}
{{Infobox medical condition
| name          = Essential tremor
| synonyms      = Idiopathic tremor
| image         = File:Spiral drawing of Essential Tremor patient.svg
| caption       = [[Archimedean spiral]] drawings by a man with a [[Anatomical terms of location#Medial and lateral|unilateral]] essential tremor. The spiral on the left was drawn by the subject using the left hand, and the one on the right using the right hand.
| pronounce     =
| field         = [[Neurology]]
| symptoms      =
| complications =
| onset         = Any age, but typically after 40
| duration      =
| types         =
| causes        = Unknown
| risks         = Family history, exposure to particular [[toxin]]s<ref name=pmid17679670/>
| diagnosis     = Based on symptoms<ref name="hopkinsmedicine"/>
| differential  = [[Cerebellar tremor]], [[Dystonia|dystonic tremor]], [[multiple sclerosis]], [[Parkinson's disease]]<ref name="BMJ">{{cite journal | vauthors = Bhidayasiri R | title = Differential diagnosis of common tremor syndromes | journal = Postgraduate Medical Journal | volume = 81 | issue = 962 | pages = 756–762 | date = December 2005 | pmid = 16344298 | pmc = 1743400 | doi = 10.1136/pgmj.2005.032979 }}</ref>
| prevention    =
| treatment     = Medications, surgery<ref name=Abboud/>
| medication    = [[Beta blocker]]s, [[primidone]], anti-epileptics, [[topiramate]], [[gabapentin]], [[levetiracetam]], [[benzodiazepines]]<ref name=Abboud/>
| prognosis     =
| frequency     = Annual incidence of 23.7 per 100,000 (2010)<ref name="NCBI1">{{cite journal | vauthors = Zesiewicz TA, Chari A, Jahan I, Miller AM, Sullivan KL | title = Overview of essential tremor | journal = Neuropsychiatric Disease and Treatment | volume = 6 | pages = 401–408 | date = September 2010 | pmid = 20856604 | pmc = 2938289 | doi = 10.2147/ndt.s4795 | doi-access = free }}</ref>
| deaths        =
}}

'''Essential tremor''' ('''ET'''), also called '''benign tremor''', '''familial tremor''', and '''idiopathic tremor''', is a medical condition characterized by involuntary rhythmic contractions and relaxations ([[neural oscillations|oscillations]] or twitching movements) of certain muscle groups in one or more body parts of unknown cause.<ref>{{DorlandsDict|eight/000110470|tremor}}</ref> It is typically symmetrical, and affects the arms, hands, or fingers; but sometimes involves the head, vocal cords, or other body parts.<ref name=Abboud>{{cite journal | vauthors = Abboud H, Ahmed A, Fernandez HH | title = Essential tremor: choosing the right management plan for your patient | journal = Cleveland Clinic Journal of Medicine | volume = 78 | issue = 12 | pages = 821–828 | date = December 2011 | pmid = 22135272 | doi = 10.3949/ccjm.78a.10178 | s2cid = 58374 | doi-access = free }}</ref> Essential tremor is either an ''action'' (intention) tremor—it intensifies when one tries to use the affected muscles during voluntary movements such as eating and writing—or it is a ''postural'' tremor, which occurs when holding arms outstretched and against gravity. This means that it is distinct from a [[Tremor#Categories|resting tremor]], such as that caused by [[Parkinson's disease]], which is not correlated with movement.<ref name="news-medical.net">{{cite web |title=LINGO1 variant responsible for essential tremors and Parkinson's disease |url=http://www.news-medical.net/news/20090902/LINGO1-variant-responsible-for-essential-tremors-and-Parkinsons-disease.aspx |publisher=news-medical.net |date=2 September 2009 |access-date=27 October 2014}}</ref> Unlike Parkinson's disease, essential tremor may worsen with action.

Essential tremor is a [[progressive disease|progressive]]<ref name="UF Health">{{cite web | vauthors = Shukla AW |title=Essential Tremor Information |url=https://movementdisorders.ufhealth.org/for-patients/movement-disorder-information/essential-tremor-information/ |website=Unified Health |access-date=17 June 2018}}</ref><ref name="NORD">{{cite web |vauthors=Louis ED |title=Essential Tremor |url=https://rarediseases.org/rare-diseases/essential-tremor/ |publisher=National Organization for Rare Disorders |access-date=17 June 2018}}</ref><ref name="NCBI2">{{cite journal | vauthors = Gironell A, Ribosa-Nogué R, Gich I, Marin-Lahoz J, Pascual-Sedano B | title = Severity stages in essential tremor: a long-term retrospective study using the glass scale | journal = Tremor and Other Hyperkinetic Movements | volume = 5 | pages = 299 | year = 2015 | pmid = 25793146 | pmc = 4361372 | doi = 10.7916/D8DV1HQC | doi-broken-date = 25 February 2025 }}</ref> [[neurological disorder]], and the most common [[movement disorder]]. Though not life-threatening, it can certainly be debilitating. Its onset is usually between 40 and 50 years of age, but it can occur at any age.<ref>{{cite web |title=Tremor |url=https://www.ninds.nih.gov/health-information/disorders/tremor |website=National Institute of Neurological Disorders and Stroke}}</ref> The cause is poorly understood. Diagnosis is made by observing the typical pattern of the tremor coupled with the exclusion of known causes of such a tremor. There is currently no medical test available to identify an essential tremor.

While essential tremor is distinct from Parkinson's disease, which causes a resting tremor, essential tremor is nevertheless sometimes misdiagnosed as Parkinson's disease.<ref name=Abboud/> Some patients have been found to have both essential tremors and resting tremors.<ref name=Abboud/>

Treatments for essential tremor include medications, typically given sequentially to determine which provides the most efficacy with least side effects. ''Clostridium botulinum'' toxin (Botox) injections and ultrasound are also sometimes used for cases refractory to medications.