Editing Huntington's disease (section)

===Clinical===

[[File:Huntington.jpg|thumb|upright|alt=Cross section of a brain showing undulating tissues with gaps between them,  two large gaps are evenly spaced about the centre.| [[Coronal plane|Coronal]] section from an [[MRI]] [[brain scan]] of a patient with HD, showing [[atrophy]] of the heads of the [[caudate nucleus|caudate nuclei]], enlargement of the frontal horns of the [[lateral ventricles]] (hydrocephalus ''ex vacuo''), and generalized cortical atrophy<ref>{{cite web |vauthors=Gaillard F |title=Huntington's disease |url=http://www.radpod.org/2007/05/01/huntingtons-disease/ |date=1 May 2007 |work=Radiology picture of the day |publisher=www.radpod.org |access-date=24 July 2009 |url-status=dead |archive-url=https://web.archive.org/web/20071022134552/http://radpod.org/2007/05/01/huntingtons-disease/ |archive-date=22 October 2007}}</ref>]]

A [[physical examination]], sometimes combined with a [[psychological examination]], can determine whether the onset of the disease has begun.<ref name="lancet07" />  Excessive unintentional movements of any part of the body are often the reason for seeking medical consultation.  If these are abrupt and have random timing and distribution, they suggest a diagnosis of HD.  Cognitive or behavioral symptoms are rarely the first symptoms diagnosed; they are usually only recognized in hindsight or when they develop further.  How far the disease has progressed can be measured using the unified Huntington's disease rating scale, which provides an overall rating system based on motor, behavioral, cognitive, and functional assessments.<ref name="pmid19111470">{{cite journal | vauthors = Rao AK, Muratori L, Louis ED, Moskowitz CB, Marder KS | title = Clinical measurement of mobility and balance impairments in Huntington's disease: validity and responsiveness | journal = Gait & Posture | volume = 29 | issue = 3 | pages = 433–436 | date = April 2009 | pmid = 19111470 | doi = 10.1016/j.gaitpost.2008.11.002 }}</ref><ref>{{cite web |url=http://huntingtonstudygroup.org/tools-resources/uhdrs/ |title=Unified Huntington's Disease Rating Scale (UHDRS) |access-date=14 April 2009 |work=UHDRS and Database |publisher=HSG |date=1 February 2009 |url-status=live |archive-url=https://web.archive.org/web/20150811064639/http://huntingtonstudygroup.org/tools-resources/uhdrs/ |archive-date=11 August 2015}}</ref> [[Medical imaging]], such as a [[CT scan]] or [[magnetic resonance imaging|MRI scan]], can show atrophy of the caudate nuclei early in the disease, as seen in the illustration to the right, but these changes are not, by themselves, diagnostic of HD. [[Cerebral atrophy]] can be seen in the advanced stages of the disease. [[Functional neuroimaging]] techniques, such as [[functional magnetic resonance imaging]] (fMRI) and [[positron emission tomography]] (PET), can show changes in brain activity before the onset of physical symptoms, but they are experimental tools and are not used clinically.<ref name="lancet07" />