Table 3 Case box 2

A 54-year-old male was transferred to our department due to severe dysarthrophonia, double vision, nystagmus and ataxia in the last 7 weeks. The onset of symptoms was subacute over a few days. Brain MRI revealed an early cerebellar atrophy, consistent with aggressive course of subacute cerebellar degeneration. Routine CSF-analysis revealed 9 lymphocytic cells/μl, an elevation of total protein levels to 57.5 g/ml and CSF-specific oligoclonal immunoglobulin G (IgG) bands. Initial standard serum screening for antineuronal Abs was negative. Extensive analysis demonstrated autoantibodies against neurochondrin (titer of 1:1,000) in serum and autoantibodies against Delta/Notch-like Epidermal Growth Factor-Related Receptor isolated in CSF only (titer of 1:100). The following comprehensive diagnostic work-up including PET-CT detected a hypermetabolic area in the left parotid gland, diagnosed as Warthin´s tumor after biopsy. Other reasons for a paraneoplastic origin were not detected. First-line therapies, including steroid pulse (5 g of methylprednisolone), immunoadsorption (8 cycles) and IVIG (1 g/kg body weight) were non-effective and the patient deteriorated further. Due to a severe gait ataxia the patient could not walk without a both-sided assistance anymore. Severe nystagmus, double vision and dysarthrophonia made communication almost impossible. For symptomatic treatment, fampridine (20 mg per day) was started, resulting in a slight improvement of the dysarthrophonia only. Following, we performed a therapy cycle with bortezomib which surprisingly led to substantial improvement several days after therapy initiation. One week later the patient was able to walk without help and even climb stairs again. In a follow-up investigation two months later all symptoms had substantially improved. Neurochondrin- and DNER-Abs in serum were negative