Table 1.

Clinical characteristics of 30 patients with PACA. Cerebellar atrophy was rated as 1 = mild, 2 = moderate, 3 = severe with a mean score for vermian atrophy 1.44 vs hemispheric atrophy of 1. This demonstrates the preferential involvement of the vermis in PACA. IDDM insulin dependent diabetes mellitus, PA pernicious anaemia, SPS stiff person syndrome, SLE systemic lupus erythematosus

Average age at onset of ataxia	56 years (range 18 to 83)
Average age at the time of this report	63 years (range 20 to 86)
Average duration of ataxia	7 years (range 2 to 20)
additional autoimmune diseases	100% (10 thyroid disease, 5 IDDM, 4 PA, 3 Sjogren’s, 2 SPS, 1 SLE, 1 scleroderma, 1 RA, 1 Crohn’s, 1 myositis, 1 vitiligo)
CSF oligoclonal bands	5/10 (50%)
auto-antibodies	26/30 (87%) (12 thyroid peroxidase, 5 low level anti-GAD, 4 intrinsic factor, 3 anti-Ro, 1 ANA/dsDNA, 1 centromere, 1 anti-CCP)
Subacute presentation	21/30 (70%)
Acute presentation	4/30 (13%)
Gait ataxia	100%
Abnormal vermian NAA/Cr	100% (mean NAA/Cr ratio 0.82)
Degree of vermian atrophy	1.44 (1 mild, 2 moderate, 3 severe)
Degree of hemispheric atrophy	1