Hashimoto's encephalopathy (HE) is a presumed autoimmune disorder associated with
anti-thyroid autoantibodies and signs and symptoms of
encephalopathy. A sub-type of HE is associated with
cerebellar dysfunction and
ataxia. Immunosuppressive therapy, particularly
corticosteroid treatment, is utilized in the majority of cases. Short-term
apheresis has been reported with variable patient responses. Here we report the case of a 72 year-old female with an ∼15 year history of cerebellar type HE that had profound improvement in symptoms after long-term
apheresis treatment over an ∼2 year period. Following an induction phase, twice-weekly maintenance
apheresis of 1 plasma volume reversed long-standing severe
gait ataxia that had required a walker, as well as mild
cognitive symptoms. This paralleled reductions in anti-thyroid antibody levels. Holidays from
apheresis lasting several weeks and/or reductions in maintenance
apheresis frequency to once per-week resulted in re-expression of
ataxia and
cognitive impairments along with a rise in anti-thyroid antibody levels. An
apheresis dose-effect was observed whereby parallel rise and fall in both symptomatology and antibody levels would mirror duration between
apheresis intervals. To our knowledge, this is the first report of profound therapeutic benefit and a dose-response relationship to long-term
apheresis in cerebellar-type HE. This case suggests that maintenance
apheresis be considered in responsive patients, particularly in those with
contraindications to medical immunosuppression.