The participants provided their written informed consent to participate in this study

The participants provided their written informed consent to participate in this study. underwent plasmapheresis therapy, although the treatments efficacy was limited. To gain a deeper understanding of Comp the disease, we conducted a comprehensive literature review, identifying 52 cases of CNTN1 antibody-positive nodopathy to date, with a tremor prevalence of 26.9%. Additionally, we found that the average CSF protein level in CNTN1 antibody-positive nodopathy was 2.57 g/L, with 87% of patients exhibiting a CSF protein level above 1.5 g/L. Conclusion We present a rare case of recurrent CNTN1 antibody-positive nodopathy. Our findings indicate a high prevalence of tremor (26.9%) and elevated CSF protein levels among patients with CNTN1 antibody-positive nodopathy. Keywords: contactin-1, nodopathy, CIDP, tremor, ataxia 1.?Introduction Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is the most common form of chronic inflammatory neuropathy, characterized by segmental demyelination. Beyond demyelinating or axonal damage, recent studies introduced a concept termed nodopathy, referring to microstructural alterations limited to the nodal and paranodal regions, potentially leading to significant nerve dysfunction (1, 2). In patients with CNTN1 antibody positivity, paranodal destruction and axo-glial disjunction have been documented. The cell adhesion molecule neurofascin-186 (NF186) anchors voltage-gated sodium channels at the node, while the glial protein neurofascin-155 (NF155), along with axonal proteins contactin-1 (CNTN1) and contactin-associated protein-1 (CASPR1), constitutes an axoglial complex in the paranodal region ( Figure?1 ) (3). Therefore, CIDP cases with NF155 and CNTN1 antibodies might exhibit similar pathophysiology and clinical manifestations, including distal Cefmenoxime hydrochloride dominant symptoms and axonal degeneration, differing from the typical CIDP symptoms of proximal and distal muscle weakness with less pronounced axonal degeneration (4). Open in a separate window Figure?1 Diagram of the antibody complex in the Ranvier node region. Approximately 10% of CIDP patients exhibit autoantibodies against nodal and paranodal proteins, with anti-NF155 antibodies present in 4%C18% of patients and antibodies against CNTN1, CASPR1, and the CNTN1-CASPR1 complex reported in 1%C7% of patients (5). Querol et?al. described the characteristics of neuropathy with CNTN1 antibody as including older age at onset, GuillainCBarre syndrome-like acute onset of weakness, sensory ataxia, and early axonal involvement (6), noting a higher prevalence of tremor among those with positive antibodies. The response to corticosteroids and intravenous immune globulin (IVIG) was suboptimal (3). Given the distinct clinical presentations between typical CIDP and nodopathy, their pathogenic mechanisms might be different. Here, we report a case of recurrent CNTN1 antibody-positive nodopathy and discuss the possible mechanisms of tremor and ataxia, and the CSF Cefmenoxime hydrochloride characteristics, to deepen our understanding of the disease. 2.?Case presentation 2.1. First episode 2.1.1. Medical history and physical examination On 15 December 2010, a 45-year-old woman was admitted to our hospital with primary complaints of numbness in the upper limbs and weakness in the lower limbs, persisting Cefmenoxime hydrochloride for 5 months. Neurological examination revealed that the Medical Research Council (MRC) grade ( Table?1 ) for the upper limbs was normal, while the MRC grade for the lower limbs was grade 2. Deep-tendon reflexes across all four limbs were weak. She had a medical history of nephrotic syndrome but no family history of hereditary conditions or infectious diseases. Table?1 Medical research council (MRC) scale for muscle examination. studies have shown that CNTN1 antibodies can disrupt the interaction between the CNTN1/Caspr1 Cefmenoxime hydrochloride complex and NF155, altering the structure of the Ranvier node region and contributing to symptoms of CNTN1-related CIDP (34). Second, Yumako Miura and colleagues found that CNTN1 is widely expressed in dorsal root ganglion neurons (14). Additionally, the dorsal root ganglias bloodCnerve barrier is more permeable, allowing CNTN1 antibodies to infiltrate sensory neurons and axons, which may explain sensory ataxia (35). The patient being double-positive for CNTN1 and GT1a and GQ1b antibodies complicates the diagnosis. Given that ataxia is a prevalent sign of MillerCFisher syndrome, associated with GT1a and GQ1b antibodies (36), it raises the question of.