CNTN1 and nephrotic syndrome: An anti-paranodal protein antibody (anti-CNTN1, anti-Caspr1, and anti-NF155) should be tested in patients complaining of sensorimotor impairment, often with acute/subacute onset, severe disability, ataxia, tremor, respiratory failure, and cranial nerve involvement, associated with nephrotic syndrome and very high CSF protein levels.