Editing Essential tremor (section)

==Diagnosis==
Usually, the diagnosis is established on clinical grounds. Although ET was long considered a single-symptom illness, recent studies have shown that some patients also experience other additional motor symptoms and non-motor features.<ref name=":6">{{cite journal | vauthors = Louis ED, Lenka A | title = The Olivary Hypothesis of Essential Tremor: Time to Lay this Model to Rest? | journal = Tremor and Other Hyperkinetic Movements | volume = 7 | pages = 473 | date = 13 July 2017 | pmid = 28966877 | pmc = 5618117 | doi = 10.7916/D8FF40RX | doi-broken-date = 25 February 2025 }}</ref> According to recent medical literature, besides isolated essential tremor, there are two additional classifications: 'ET plus' and 'ET-PD.' 'ET plus' is diagnosed when patients show cognitive impairments or other motor symptoms like [[ataxia]], [[dystonia]], or resting tremor. 'ET-PD' is used for those who meet the criteria for both ET and [[Parkinson's disease]].<ref name="The Pathophysiology and Treatment o">{{cite journal | vauthors = Kosmowska B, Wardas J | title = The Pathophysiology and Treatment of Essential Tremor: The Role of Adenosine and Dopamine Receptors in Animal Models | journal = Biomolecules | volume = 11 | issue = 12 | pages = 1813 | date = December 2021 | pmid = 34944457 | pmc = 8698799 | doi = 10.3390/biom11121813 | doi-access = free }}</ref> The clinical features of tremor in a patient include medical history (such as age of onset, family history, progression over time, and exposure to drugs or toxins), tremor characteristics (like which parts of the body are affected, when the tremor occurs, and its frequency), and any associated signs (such as signs of systemic illness, neurological signs, and soft signs). For some types of tremors, additional tests like recording tremor frequency, imaging for [[lesion]]s, receptor imaging, and biomarkers in blood or tissue may help identify the cause.<ref>{{cite journal | vauthors = Bhatia KP, Bain P, Bajaj N, Elble RJ, Hallett M, Louis ED, Raethjen J, Stamelou M, Testa CM, Deuschl G | title = Consensus Statement on the classification of tremors. from the task force on tremor of the International Parkinson and Movement Disorder Society | journal = Movement Disorders | volume = 33 | issue = 1 | pages = 75–87 | date = January 2018 | pmid = 29193359 | pmc = 6530552 | doi = 10.1002/mds.27121 }}</ref> Tremors can start at any age, from birth through advanced ages (senile tremor).<ref>{{cite journal | vauthors = Louis ED, Dure LS, Pullman S | title = Essential tremor in childhood: a series of nineteen cases | journal = Movement Disorders | volume = 16 | issue = 5 | pages = 921–923 | date = September 2001 | pmid = 11746623 | doi = 10.1002/mds.1182 | s2cid = 30848508 }}</ref><ref>{{cite journal | vauthors = Bain PG, Findley LJ, Thompson PD, Gresty MA, Rothwell JC, Harding AE, Marsden CD | title = A study of hereditary essential tremor | journal = Brain | volume = 117 ( Pt 4) | issue = 4 | pages = 805–824 | date = August 1994 | pmid = 7922467 | doi = 10.1093/brain/117.4.805 }}</ref> Any [[voluntary muscle]] in the body may be affected, although the tremor is most commonly seen in the hands and arms and slightly less commonly in the [[neck]] (causing the person's head to shake), [[tongue]], and legs. A resting tremor of the hands is sometimes present.<ref name=pmid8334571/><ref>{{cite journal | vauthors = Cohen O, Pullman S, Jurewicz E, Watner D, Louis ED | title = Rest tremor in patients with essential tremor: prevalence, clinical correlates, and electrophysiologic characteristics | journal = Archives of Neurology | volume = 60 | issue = 3 | pages = 405–410 | date = March 2003 | pmid = 12633153 | doi = 10.1001/archneur.60.3.405 | doi-access = free }}</ref> Tremor occurring in the legs might be diagnosable as orthostatic tremor. Tremors in the lower limbs are quite rare in ET and are more likely to indicate Parkinson's disease.<ref>{{cite journal | vauthors = Rajalingam R, Breen DP, Chen R, Fox S, Kalia LV, Munhoz RP, Slow E, Strafella AP, Lang AE, Fasano A | title = The clinical significance of lower limb tremors | journal = Parkinsonism & Related Disorders | volume = 65 | pages = 165–171 | date = August 2019 | pmid = 31201091 | doi = 10.1016/j.parkreldis.2019.06.007 | hdl-access = free | hdl = 20.500.11820/fcbc5316-6d53-418f-ba3a-a73208c6f186 }}</ref>

ET occurs within multiple neurological disorders besides Parkinson's disease. This includes [[migraine]] disorders, where co-occurrences between ET and migraines have been examined.<ref name="Correlation between essential tremo"/>