ILLNESS (CHOREA) OF GENTINGTON Illness of Gentington — the hereditary disease which is characterized by the progressing degeneration of neurons of a striatum and bark of a great brain and shown a combination of a chorea and other extrapyramidal disturbances to dementia.
Etiology and pathogeny.
The gene mutation on the 4th chromosome coding protein gentingtin is an etiology of Gentington. Disturbance of synthesis of this protein predetermines selective damage of neurons basal gangliyev, first of all a kernel having a tail and a shell (in total forming a striatum), and also some zones of bark. However mechanisms of this process remain badly studied. The choreic hyperkinesia is connected with excess activity of dofaminergichesky system and can decrease under the influence of the neuroleptics which are blockers of dopamine receptors. The disease is transmitted but autosomal dominantly to type, at the same time the pathological gene possesses very high penetrance, and by 70 years the illness is shown practically at all its carriers. Children inherit a disease from one of parents with probability of 50%.
The illness of Gentington can be shown practically at any age, but a thicket between 35 and 55 years. Awkwardness, concern, forgetfulness or oppressed mood can be the first symptoms. In process of progressing of a disease there is more explicit a choreic hyperkinesia which is characterized fast, chaotic, replacing each other, but reductions of muscles of extremities, irregular on time and amplitude. Gradually the hyperkinesia generalizutsya, involving face muscles and trunks. The involuntary movements can remind intentional grimacing an aping and deliberate grimaces. Hesitating of these movements, patients quite often aim to give to these aimless movements visibility of purposeful acts that can externally look as excessive airs and graces. Gait becomes unstable, "dancing", sometimes slowed down, strained. At late stages of a disease other extrapyramidal syndromes — muscular dystonia, an akineziya, rigidity, and also postural instability with frequent falling join. Finally the patient appears to the confined to the bed or a wheelchair. Owing to involvement of muscles of a throat and a throat develop the heavy dysarthtia complicating communication with the patient, and in the subsequent and a dysphagy which can lead to disturbance of food and aspiration. Mental disturbances quite often precede motive and are shown as cognitive (disturbance of attention, memory easing, slowness of thinking), and emotional and personal frustration (apathy, a depression, a tendency to self-isolation, irascibility, impulsiveness, sometimes maniacal states). Gradually at patients dementia develops, however because of slowness of thinking and the muffled speech its degree is quite often exaggerated. Meanwhile ability to understand and remember told remains a long time therefore it is important to be careful, talking about the patient at his presence. At an initial stage of a disease at patients the heavy depression which can lead to suicide attempts develops. At a late stage psychotic disturbances with nonsense and hallucinations are frequent, and also the incontience of urine and a calla is noted. Patients die at the phenomena of a cachexia and deep weak-mindedness. The lethal outcome comes in 10 — 17. Approximately in 10% of cases the disease begins till 20 flyings (a juvenile form of an illness of Gentington). Heavier and rapid current, and also dominance in a clinical picture not of a chorea, and an akineziya and rigidity is characteristic of it.
Diagnosis is based on existence of the family anamnesis and a characteristic clinical picture. Now the diagnosis can be confirmed by means of methods of molecular genetics which allow to reveal a disease gene at patients and their relatives long before emergence of the first symptoms, and also to carry out prenatal diagnosis. But it is necessary to consider that diagnosis of a disease at a preclinical stage for lack of a real opportunity to prevent or at least to slow down its approach can cause the hardest spiritual wounds. In prevention of distribution of a disease the crucial role belongs to medicogenetic consultation.
Now there is no opportunity to prevent progressing of a disease, and treatment has purely symptomatic character. For reduction of a hyperkinesia use neuroleptics, for example Sulpiridum (eglonyl) or a haloperidol, Reserpinum, benzodiazepines (clonazepam, lorazepam). Though these drugs also reduce a hyperkinesia, they not always improve an athletic ability of patients, and also can lead to side effects, strengthening symptoms of parkinsonism or causing drowsiness, block and apathy. At a depression amitriptyline or other antidepressants are shown. At an akinetikorigidny form apply antiparkinsonichesky means (levodopa drugs, dopamine agonists, amantadin, cholinolytics), but their effect is usually small. A part is played by the physiotherapy exercises directed to the prevention of contractures and deformations, maintenance of skills of movement. The nurse has to monitor food of patients, help them with observance of the hygienic mode, watch their behavior, warn possible injuries. At suicide statements it is necessary to inform immediately treating or the doctor on duty and to organize continuous supervision over the patient. At a late stage prevention of decubituses, contractures, control of regular bladder emptying and intestines are important.