Cerebellar hypoperfusion found in most patients with anti-NF155 antibody-positive nodopathy

IntroductionAnti–neurofascin-155 (NF155) antibody-positive nodopathy is a distinct autoimmune neuropathy characterized by sensory ataxia, tremor, and poor response to intravenous immunoglobulin (IVIg). Although classically considered a peripheral disorder, central nervous system (CNS) involvement has been suggested, but functional neuroimaging correlates remain unclear.MethodsWe retrospectively analyzed seven male patients with NF155 antibody-positive nodopathy. Clinical and electrophysiological assessments were performed, and all patients underwent brain perfusion single-photon emission computed tomography (SPECT) using 123I-IMP iodoamphetamine. Imaging data were processed using three-dimensional stereotactic surface projection (3D-SSP) and compared to an age-matched database. Cerebellar hypoperfusion was defined as regional z-scores ≤ −2.0.ResultsThe mean patient age was 39.0 ± 12.9 years, and mean disease duration was 5.0 ± 3.9 years. Tremor was documented in all patients at some point during the disease course and was predominantly postural or kinetic. Cerebellar hypoperfusion was identified in six patients (86%), involving the cerebellum bilaterally in most cases, with variable degrees of asymmetry across individuals. No correlation was found between hypoperfusion and disease duration or age.ConclusionCerebellar hypoperfusion was frequently observed in this single-center case series of anti-NF155 antibody-positive nodopathy. These findings are descriptive and hypothesis-generating, and compatible with a possible association between cerebellar perfusion abnormalities and tremor. Larger prospective studies are warranted to validate these observations and explore their clinical implications.