Background Wegener Granulomatosis (WG) and psoriasis are two rheumatologic diseases in which neurological involvement is quite rare.

Case history A 72-years-old male, diagnosis of WG since 1999. Since 2003 he presented simple verbal tics, four limbs involuntary movements. The cognitive profile was in line with an amnestic mild cognitive impairment. Hyperkinetic syndrome improved with low dosages of Tetrabenazine. A 67-years-old woman presented with choreic movements mainly at the left limbs and painful swelling left wrist. Neuropsychological evaluation showed a mild frontal dysfunction. Within 4 months diagnosis of psoriasis was made. Methylprednisolone was given with improvement of chorea, instead tetrabenazine was stopped for parkinsonism. Genetic tests for HD, HDL2, SCA-17 and research for acanthocytis were negative. FDG-PET showed right caudo-putaminal hypermetabolism in the first patient and bilateral basal ganglia hypermetabolism in the second patient. Brain MRI didn't show any significant alteration in both patients. CSF examination, iron and cupper sieric values were in the normal range. Sieric anti-basal ganglia antibodies (ABGA) showed auto-antigen of 45 kDa.

Conclusions ABGA positivity has been described during autoimmune diseases such as Sydenham Chorea, ADEM and PANDAS‏ and post-mortem studies showed perivascular infiltration by lymphocytes in the basal ganglia. Striatal hypermetabolism on FDG-PET with chorea associated with SLE and primary antiphospholipid syndrome has been reported probably (1,2) due to autoantibodies vs basal ganglia neurons. The ABGA positivity does not imply a pathogenetic relationship, however the concomitant striatal hypermetabolism in our cases could extend the spectrum of chorea associated with autoimmune diseases.