Table 2.

Clinical profiles of gluten ataxia and anti-GAD65 Ab-associated cerebellar ataxia.

	Gluten Ataxia	Anti-GAD65 Ab-associated Cerebellar Ataxia
Clinical profile
Time course	Insidious and chronic	Insidious and chronic or subacute
Age and sex	50s, female (55%)	60s, female (mostly)
Main symptoms of cerebellar involvement	Gait ataxia. Limb ataxia and nystagmus are mild and less frequent (60-70%)	Gait ataxia. Limb ataxia and nystagmus are mild and less frequent (60-70%)
Associated neurological symptoms	Cortical myoclonus, neuropathy	Stiff person syndrome, epilepsy
Abnormality in cerebrospinal fluid	Generally none	Sometimes; CSF oligoclonal bands
Cerebellar atrophy on MRI	Present depending on duration of ataxia. The vermis is primarily involved. The degree of atrophy is mild relative to ataxia	Present depending on duration of ataxia The vermis is primarily involved. The degree of atrophy is mild relative to ataxia
Clues for diagnosis Neurological features suggestive the need for further investigations on autoimmunity:   • 40-60s, female   • Gait ataxia with dominant vermian atrophy   • Atrophy on MRI is milder relative to the severity of ataxia
	Gluten Ataxia	Anti-GAD65Ab-associated Cerebellar Ataxia
Autoimmune background
Trigger of autoimmunity	Gluten ingestion	Unknown
HLA	Type DQ2 or DQ8	-
Well characterized autoantibodies	Anti-gliadin (IgG/IgA) Anti-TG2, TG6	Anti-GAD65Ab (high titer) usually exceeds the levels seen in type 1 diabetes mellitus by 100-fold
Associated autoimmune diseases	Coeliac disease (47%)	Type 1 diabetes mellitus, autoimmune thyroid diseases, pernicious anemia