Cranio-Facial Changes The In Patients With Huntington Disease, A Review Article

Huntington's disease (HD) is a rare autosomal dominant sever and usually fatal chronic neurodegenerative illness with prevalence of 5.96 to 13.7 per 100000. The primary pathology is the precipitation of huntingtin protein in the neurons due to the presence of multiple CAG repeat in the N terminal of the HTT gene on the short arm of chromosome 4. Classically this is well known to primarily affect the caudate nucleus the largest of the basal ganglia. This manifests radiologically by shrinkage of the caudate nucleus with secondary dilatation of ventricular system. This however cannot explain the fact that the HD patients show a multitude of psychiatric and cognitive symptoms in addition to chorea. But it may be explained by the recent studies that show the basal nuclei are involved in limbic and emotional control in addition to their motor function. In order to review evidence of structural basal ganglia changes and their relation to clinical manifestations in patients with HD we conducted a web based search for published literature in the topic using pubmed and google scholar. The review of the literature showed that the initial changes in HD happen in the caudate nucleus. Other parts of the striatum such as the putamen and globus pallidus are also affected, particularly following disease progression, with additional proof of thalamic changes. Such structural changes, in the striatum, for example, have been associated with specific cognitive deficits including attention, working memory and executive functions. Interestingly studies reported that MRIs are able to detect these changes long before clinical manifestation of HD. We concluded that most of the components of the basal ganglia are reduced in size in HD. This volume reduction is evident years before the onset of the disease. The magnitude of volume reduction is directly related to the severity of the disease. These changes may be used to predict the onset and prognosis of disease and to monitor the response to treatment.