Hi Cathy,
I am so sorry to hear about your sister.
There is one thing I hope the doctors have considered, and that is gluten sensitivity as a possible cause for cerebellar ataxia (intolerance to gluten found in wheat, rye, barley). Some studies say it may be responsible for up to 40% of idiopathic cerebellar ataxia, and possibly even some forms of hereditary ataxia.
Do you know if your sister has been tested specifically for antigliadin antibodies? The reason this is so important is that some people with ataxia and antigliadin antibodies have improved on a gluten free diet. Unfortunately, sometimes existing damage may be permanent, but the progression may be slowed or stopped with gluten free diet. The studies can be found below.
Much of the research on this has been done by
Dr. Marios Hadjivassiliou from the UK , but there are others who have found similar results. I know that Dr. Hadjivassiliou works with other doctors who have contacted him, so if your sister's doctors needed to know more in regard to appropriate testing they could try to contact him.
In particular, you may want to look at these articles of his:
Autoantibody targeting of brain and intestinal transglutaminase in gluten ataxia, Feb 2006
Cerebellar abnormalities on proton MR spectroscopy in gluten ataxia, July 2005 - free full text
Dietary treatment of gluten ataxia. Sept 2003 - free full text
Gluten ataxia in perspective: epidemiology, genetic susceptibility and clinical characteristics. Mar 2003 - free full text
The humoral response in the pathogenesis of gluten ataxia. Apr 2002
Clinical, radiological, neurophysiological, and neuropathological characteristics of gluten ataxia. Nov 1998
Gluten sensitivity as a neurological illness. May 2002 - free full text
The Neurology of Gluten Sensitivity: Science vs. Conviction -
Choreic syndrome and coeliac disease: a hitherto unrecognised association, Apr 2004
Also check out these pages of The Gluten File:
The Neurological Manifestations of Gluten Sensitivity
Gluten Ataxia
This may be a long shot~ but I just want to be sure that the doctors have considered this....because it may provide for a glimmer of hope. Here is a page about
Diagnostic Testingfor celiac disease/ gluten sensitivity... but I would recommend contacting Dr. H. directly because I know there are other tests he'd likely recommend in regard to gluten ataxia.
Cara