Editing Essential tremor (section)

==Pathophysiology==
Essential tremor is one of the most prevalent and poorly-understood neurological disorders.<ref name=disorder>{{cite journal | vauthors = Louis ED, Vonsattel JP | title = The emerging neuropathology of essential tremor | journal = Movement Disorders | volume = 23 | issue = 2 | pages = 174–182 | date = January 2008 | pmid = 17999421 | pmc = 2692583 | doi = 10.1002/mds.21731 }}</ref> Clinical, physiological and imaging studies point to involvement of the [[cerebellum]] and/or [[cerebellothalamocortical]] circuits.<ref name=disorder/> The traditional model for essential tremor, the olivary hypothesis, suggests that ET is caused by abnormal electrical activity in the [[inferior olivary nucleus]]. This activity makes neurons fire in a regular, [[Synchronization|synchronized]] way, which then disrupts signals to the [[cerebellum]] and leads to [[tremor]]s.<ref>{{cite journal | vauthors = Louis ED | title = Re-thinking the biology of essential tremor: from models to morphology | journal = Parkinsonism & Related Disorders | volume = 20 Suppl 1 | issue = 1 | pages = S88–S93 | date = January 2014 | pmid = 24262197 | doi = 10.1016/S1353-8020(13)70023-3 }}</ref> However, recent studies, especially those examining brain tissue, propose a new hypothesis that ET may be a [[neurodegenerative disease]] focused in the cerebellum, differing from the old theory<ref name=":6" />'''.''' Changes in the cerebellum could also be mediated by alcoholic beverage consumption. [[Purkinje cell]]s are especially susceptible to ethanol [[excitotoxicity]].<ref name="pmid20721919">{{cite journal | vauthors = Mostile G, Jankovic J | title = Alcohol in essential tremor and other movement disorders | journal = Movement Disorders | volume = 25 | issue = 14 | pages = 2274–2284 | date = October 2010 | pmid = 20721919 | doi = 10.1002/mds.23240 | s2cid = 39981956 }}</ref> Impairment of Purkinje synapses is a component of cerebellar degradation that could underlie essential tremor.<ref name="pmid20721919" /> Some cases have [[Lewy bodies]] in the [[locus ceruleus]].<ref>{{cite journal | vauthors = Louis ED | title = Essential tremors: a family of neurodegenerative disorders? | journal = Archives of Neurology | volume = 66 | issue = 10 | pages = 1202–1208 | date = October 2009 | pmid = 19822775 | pmc = 2762114 | doi = 10.1001/archneurol.2009.217 }}</ref><ref name="'Essential tremor' or 'the essentia"/><ref name=pmid18025031>{{cite journal | vauthors = Louis ED, Faust PL, Vonsattel JP, Honig LS, Rajput A, Robinson CA, Rajput A, Pahwa R, Lyons KE, Ross GW, Borden S, Moskowitz CB, Lawton A, Hernandez N | title = Neuropathological changes in essential tremor: 33 cases compared with 21 controls | journal = Brain | volume = 130 | issue = Pt 12 | pages = 3297–3307 | date = December 2007 | pmid = 18025031 | doi = 10.1093/brain/awm266 | doi-access = free }}</ref> ET cases that progress to Parkinson's disease are less likely to have had cerebellar problems.<ref name=pmid26336614>{{cite journal | vauthors = Ghika A, Kyrozis A, Potagas C, Louis ED | title = Motor and Non-motor Features: Differences between Patients with Isolated Essential Tremor and Patients with Both Essential Tremor and Parkinson's Disease | journal = Tremor and Other Hyperkinetic Movements | volume = 5 | pages = 335 | year = 2015 | pmid = 26336614 | pmc = 4548968 | doi = 10.7916/D83777WK | doi-broken-date = 25 February 2025 }}</ref> Recent neuroimaging studies<ref>{{cite journal | vauthors = Benito-León J, Sanz-Morales E, Melero H, Louis ED, Romero JP, Rocon E, Malpica N | title = Graph theory analysis of resting-state functional magnetic resonance imaging in essential tremor | journal = Human Brain Mapping | volume = 40 | issue = 16 | pages = 4686–4702 | date = November 2019 | pmid = 31332912 | pmc = 6865733 | doi = 10.1002/hbm.24730 }}</ref> have suggested that the efficiency of the overall brain functional network in ET is disrupted.

In 2012, the [[National Toxicology Program]] concluded that sufficient evidence exists of an association between blood lead exposure at levels >10 μg/dl and essential tremor in adults, and limited evidence at blood lead levels >5 μg/dl.<ref name=NTP2012>{{cite report | title = NTP monograph on health effects of low-level lead | issue = 1 | pages = xiii, xv–148 | date = June 2012 | pmid = 23964424 | url = https://ntp.niehs.nih.gov/ntp/ohat/lead/final/monographhealtheffectslowlevellead_newissn_508.pdf | publisher = U.S. Department of Health and Human Services | author = National Toxicology Program |s2cid=25344446 }}</ref>