Clinical and laboratory features of juvenile-onset anti-NF155 autoimmune nodopathy

BACKGROUND: Neurofascin 155 autoimmune nodopathy (NF155 AN) is a recently recognised immune-mediated neuropathy distinct from chronic inflammatory demyelinating polyneuropathy. While adult-onset cases have been increasingly reported, the juvenile-onset form remains poorly characterised. METHODS: We retrospectively analysed 36 patients with NF155 AN, focusing on detailed characterisation of 16 juvenile-onset cases. Their clinical and laboratory data were reviewed. RESULTS: Juvenile-onset patients presented with sensorimotor neuropathy characterised by distal predominant weakness, tremor and sensory ataxia. Motor symptoms were the presenting feature in 75% of patients, which significantly differed from the adult cases (p=0.0015). Postural tremor was more frequent in juvenile patients (94%), while cranial nerve involvement was less common (19%). Electrophysiologically, absent compound muscle action potentials in lower limbs were significantly more prevalent in juvenile patients (peroneal: 78%; tibial: 66%; p