Ataxia spinocerebeloasa
Ataxiile ataxiilor spinocerebeloase part of autosomal dominant group.
Ataxia type 1 spinocerebeloasa
And formerly called "olivopontocerebeloasa atrophy, is characterized by the appearance of a cerebellar ataxii the trunk and limbs, with the appearance of disorders of balance and walking, slowness in initiating voluntary movements. Speech is impaired can occur dysarthria and dysphagia, tremor of the head and torso and oculomotor nerve paresis. In extrapyramidal symptoms, meet rigidity, tremor and parkinsonian facies property. Achilean rotulian reflexes and are altered, the rest does not change the other reflexes. Sphincter disorders frequently occur with urinary and faecal loss. Dementia, if it occurs, is usually moderate.
Necropsy examination of the brain reveals a marked reduction of the ventral half of the bridge, the cerebellum shows atrophy relatively large areas, and the eminent Olivara ventral bulb is missing. Histologically it is found to reduce the number of cells in the granular layer, demyelination processes and middle cerebellar peduncle, cerebellar hemispheres. Pontine nuclei are found at a large loss of cells. In the nuclei of skeletal, putamen were found in degenerative changes and loss of pigment cells in the black substance.
Spinocerebeloasa ataxia type 1 is located on a defect on chromosome 6p22-P23.
Spinocerebeloasa ataxia type 2
This type of ataxia has been described for the population of Cuba and may begin at age 2 years, but have seen cases when the disease started at the age of 65. Spinocerebeloasa ataxia type 2 is caused by a defect located on chromosome 12q23-Q24.
Machado-Joseph disease or ataxia type 3 spinocerebeloasa
In terms of symptoms, this disease is classified into three types.
In type I disease symptoms usually appear within the first two decades of life.
This is manifested by a slow walk and stiff, with widening support base. Lower limb spastic movements occur.
Disease type II (or type ataxia) is the most common type of disease and is manifested by dysarthria, gait ataxia and extremities. Onset of symptoms occurs between 20 and 40 years, linking spasticity, rigidity and dystonia, oftalmopareze and vertical gaze deficits.
Ataxia type III or type-amyotrophic develops between 50 and 70 years and includes disorders like dysarthria and ataxia pancerebeloase gait and extremities. Tendon reflexes are diminished or even absent. Genetic defect disease Machado-Joseph is on chromosome 14q24-Q32.
Other less important forms of autosomal dominant ataxii are transmitted - Spinocerebeloasa ataxia type 4 whose fault is on chromosome 16q24-ter - Ataxia type 5 spinocerebeloasa defect on chromosome 11 - Spinocerebeloasa ataxia type 6 - Dentatorubropalidoluisiana atrophy, the disease is caused by CAG triplet rehearsal on chromosome 12p12-ter - Spinocerebeloasa ataxia type 7 with retinal degeneration syndrome is caused by abnormalities on chromosome 3p12-p2
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