Huntington’s chorea is a genetic disease with progressive course of development leading to disorder in the execution of voluntary movements, and the emergence of uncontrolled impervious to the will of others. Disorder in intellectual functions associated with delay and a general difficulty in mental activity, memory, attention and concentration also occur in all described cases of the disease. Last but not least are the changes in the emotional-affective sphere as apathy, irritability, depression, and others that may be present in the early stages of the disease.
The disease is autosomal dominant mode of inheritance. This means that each patient has at least one parent who is also affected by the disease. The sick in turn can also transmit the disease to their offspring, this possibility is 50%. Some factors such as late onset of the disease, early death of a parent or carriers of intermediate variants of interference can cause difficulty in assessing family history. The disease onset is between 35- and 44 years of age. In 25 percent of cases, symptoms appear after 50, while others, even after 70 years. Described is the juvenile form of the disease with onset before 20 years of age.
The disease is due to a genetic mutation in the gene localized in the short arm of chromosome 4, which is responsible for the production of a protein called huntingtin. Consequently, to develop a selective degeneration of neurons in the so-called striatum in the brain, which is visible and neuroimaging.
Early stage – there are clumsiness and awkwardness in carrying out movements. There are changes in eye movements associated with difficult tracking of a moving object with the advent of sakadi, hard fixation of sight and others. Often the first sign is the emergence of apathy, irritability, anxiety, depression, delusions and thought disorder in activity;
Intermediate stage – appear involuntary muscle contractions-dystonia. Trochaic Hyperkinesias for specific clinical symptom. Represent stranded, fast, rhythmic movements that can cover the head, shoulder, limbs and gradually cover all muscle. Can occur unintentionally mugging, stretching the lips, frequently flashing, lifting the shoulder retraction of head, limb movement and others. Appears so-called. “Dancing gait”, which is a serious problem in walking associated with narushnie body balance. Trochaic Hyperkinesias intensified in emotions and disappear during sleep. At this stage increases the difficulty in implementation and intentional, volitional movements. They start harder, perform more slowly, impaired control of power and speed. Especially difficult is the execution of fine movements. And problems occur speech – disatriya. Weight loss and generalized weakness may also be monitored.
Late stage – there is rigidity – abnormally increased muscle tone, bradykinesia – difficulty in initiation and continuation of a movement. Self gait becomes impossible. Problems with speech intensified to prevent such. Problems occur and swallowing – dysphagia, a choking hazard. Weight significantly decreased. At this stage, patients are completely dependent on foreign aid.
Violations in intellectual functions associated mostly with mental activity, the possibility of organizing and planning tasks easy distraction and concentration, as well as psychiatric disorders – personality changes, mood disorders, behavioral the changes apathy, aggression, increased appetite and sexual optionally, alcohol dependence and the like, may occur at any time of the progression of the disease.
The diagnosis is based on clinical, family history, as well as the confirmation by neuroimaging techniques brain, where there is a characteristic atrophy of the striatum. Molecular genetic analysis proves the presence of the genetic mutation. It is essential to conduct prenatal and pre-implantation diagnosis to objectify the presence or absence of genetic mutations in the developing fetus.