Spinocerebellar ataxia (SCA)

[Kevin5697]

This may be in the wrong forum. If it is I apologize.

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Last Friday, May 1, I had a CT/CAT Scan as a first step in finding out what is going on with my balance/speech and coordination issues. Also on the 7th I had an appointment with a neurologist to interperate and explain the CT. On the CT 'movie' going down from the top of my head everything looks normal until you get to my cerebellum. The CT Scan rulled out either a stroke or tumor. It also rulled an anurism . My Cerebellum is showing signs of shrinkage or atrophy, thus the problems with my balance, speech and uncoordination of my left arm. The nurologist put me through a series of motor skill test and also a 'DWI' type test. I failed all of them miserably. The doctor believes but is not certain I have:
Spinocerebellar Ataxia (SCA) but will not know for sure until I have an MRI of the brain and cervical spine and also a DNA blood test.
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As I understand it through my limited research, SCA is either genetic or enviromental (possible exposure to chemicals etc.) or trauma to the area. I hope and pray that it isn't genetic as I'd hate to think my son and grandson will also have this disease. As far as I know no one in my fathers family has had SCA. I'm not sure about my mothers family. She died when I was 2-3 years old and all of her brothers and sisters have passed away.

As spinocerebellar ataxia is a progressive disease and I have only been exhibiting symptoms for approx. 6 months I am curious to find out how agressive SCA is.

Since there is no treatment or cure, is there anything that is done for life quality and easing the burden on family members?

If I do NOT have spinocebellar ataxia what other condition could I have with my symptoms?

Thanks,

Kevin

[Jordanna Joaquina, MS, CGC]

As you may have learned from your research, there are currently over 25 identified types of hereditary spinocerebellar ataxia (SCA), which are characterized by slowly progressive gait issues and are often associated with poor coordination of hands, speech, and eye movements. Atrophy of the cerebellum occurs frequently.

The different types of SCA are classified by their mode of inheritance (the manner in which the condition is passed down) as well as the gene (or gene area) involved. Most types of SCA have a symptom onset in adulthood (30's or 40's) and are inherited in an autosomal dominant manner. Disease progression is extremely variable and can range from 1 to 40 years.

In autosomal dominant conditions, a mutation in a single gene copy is sufficient to cause the disease. A person with an autosomal dominant SCA has a 50% chance of passing on their mutation to each child they have. In most cases of autosomal dominant SCA, an affected person has an affected parent, but in some cases, an affected person is the first one in their family to be affected.

To complicate matters, some types of autosomal dominant SCA are caused by an expansion of a DNA segment of three nucleotides (the building blocks of DNA) that are repeated multiple times. These repeats are called CAG trinucleotide repeats. These repeats can expand as they are passed from one generation to the next. A larger repeat number is typically associated with an earlier onset of disease symptoms and more severe disease. This genetic phenomenon is called anticipation.

Genetic testing for hereditary spinocerebellar ataxia is typically performed in a stepwise fashion. Testing usually begins with the more common types of SCA and is performed in groups. Testing for the less common types of SCA may depend on multiple factors, such as a person's ethnic background (some types occur more frequently in certain ethnic backgrounds) and/or other distinguishable symptoms, such as the presence of tremors, dementia, or learning disabilities. Clinical testing is not yet available for all of  the classified types of SCA and as such, not everyone with a hereditary SCA has an identifiable mutation.

As you mentioned, there are acquired, non-genetic causes (such as vitamin deficiencies and tumors) as well and other diseases (such as some mitochondrial diseases and multiple sclerosis) which can cause ataxia. Genetic testing results as well as other tests results, such as your MRI, will help your neurologist in making an accurate diagnosis.

As you know, there is currently no cure or effective treatment for spinocerebellar ataxia. Treatment is supportive and may include canes, walkers, and wheelchairs for balance issues; use of special devices that assist with handwriting, buttoning, and holding eating utensils; speech therapy and/or computer-based devices for individuals with speech issues.

In order to provide a complete risk assessment, it would be important to talk with a genetic counselor who could review your family history and genetic testing results in detail and provide you with more detailed risk information. You can find a genetic counselor through the National Society of Genetic Counselors website or through companies like mine, AccessDNA.

It sounds like you are going through a lot right now, and we wish you the best with all of your upcoming tests.

[Kevin5697]

Thank you so much for the reply. I am scheduled for an MRI and genetics blood work this coming Monday, May 18th. I was told that I will have to sign my life away in wavers and will also have a counselor which is mandatory per ins. co. that I visit with.

I and my family have braced for and are expecting the worse but are hoping that what ever I have isn't quite as severe and is treatable.

If you could provide sources for I could read etc. for further info on this disease I would greatly appreciate it.

Thank you,

Kevin