Spinal cerebellar ataxia (SCA) is caused by degenerative atrophy of the cerebellum, brainstem and spinal cord, and generally develops in adolescence and adulthood, with progressive worsening of the disease. Patients with spinal cerebellar ataxia mainly exhibit drunkenness, staggering walk, imbalance of movement, slurred speech, and choking on food and water.
In general, the patient’s mental ability] is abnormal. Because the patient walks like a penguin, it is also called “penguin family”. The causes of spinal cerebellar ataxia include tumor, trauma, inflammation, and genetics. Genetics has identified seven genes that are responsible for the disease due to abnormal amplification of the CAG trinucleotide repeat sequence in the gene, resulting in the formation of an abnormally extended polyglutamine peptide chain within the encoded protein, which resembles a long tail that causes abnormal changes in the functional metabolism of the protein, resulting in neuronal cell death. The longer this abnormal long tail is and the earlier the age of onset, the faster the disease progresses.
I. Clinical manifestations of spinal cerebellar ataxia
1. Early manifestation is possible. There is a sense of instability in walking gait, a sense of vertigo, especially when walking in the field paths, road irregularities are particularly obvious, easy to hit the wall or door frame; muscle pain and stiffness in both legs, clumsy movements; hands fine movement, such as end soup, end tea when there is shaking, soup, tea and other easy to spill out of the container; writing word line irregularity, handwriting than before scribble, word line spacing is not equal, sometimes the nib can be seen through the paper; speech than before not Fluent speech, tongue knotted, easy to choke when eating or drinking.
2. Main clinical manifestations. Nystagmus, blurred vision; lack of fluent diction, choking on water, swallowing difficulties; increased muscle tone of the limbs, active or hyperactive tendon reflexes (especially the double lower limbs), positive pathological signs; clumsy and slow movements of the upper limbs, poor alternating movements; stiffness of the lower limbs, unstable walking or standing, waddling gait.
Second, the etiology and pathogenesis of spinal cerebellar ataxia.
Lesions of the cerebellum can be caused by a variety of conditions, commonly including.
1, primary or metastatic tumors.
2, vascular such as cerebellar infarction, cerebellar hemorrhage, etc.
3, inflammatory such as acute cerebellitis, cerebellar abscesses, etc.
4, toxic such as alcoholism, food, drugs, harmful gas poisoning, etc.
5, side effects of drugs, such as anti-epileptic drugs.
6, demyelinating diseases, such as multiple sclerosis
7, congenital underdevelopment, dysplasia or other congenital malformations of the cerebellum.
8, endocrine disorders, cerebellar calcification.
9, degenerative brain function degeneration, such as multi-system atrophy
10, trauma.
11, hereditary, such as hereditary spinal cerebellar ataxia.
The prevalence of these diseases is about 2-17/100,000, accounting for about 10-15% of the genetic diseases of the nervous system.
Patients tend to develop the disease in adulthood, and current research suggests that the disease is mostly due to abnormal amplification of the CAG trinucleotide repeat sequence within the coding region of the causative gene resulting in the formation of an abnormally extended polyglutamine peptide chain within the coding protein, which is like a long tail that causes abnormal changes in the functional metabolism of the protein, which in turn causes cell death and cerebellar degeneration and atrophy . The longer the CAG repeats will result in a longer post-translational long tail, and the earlier the age of onset, the more rapidly the disease will progress.