Berini, Sarah E.

Abstract Introduction/Aims Carpal and cubital tunnel syndrome (CTS, CuTS) are common among patients with hereditary neuropathy with liability to pressure‐palsies (HNPP) and Charcot–Marie‐Tooth type 1A (CMT1A) and may impact quality of life. We aimed to evaluate the utility of nerve decompression surgeries in these patients. Methods Medical records were reviewed for patients with PMP22 mutations confirmed in Mayo Clinic laboratories from January 1999 to December 2020, who had CTS and CuTS and underwent surgical decompression. Results CTS occurred in 53.3% of HNPP and 11.5% of CMT1A, while CuTS was present in 43.3% of HNPP and 5.8% of CMT1A patients. CTS decompression occurred in 10‐HNPP and 5‐CMT1A patients, and CuTS decompression with/without transposition was performed in 5‐HNPP and 1‐CMT1A patients. In HNPP, electrodiagnostic studies identified median neuropathy at the wrist in 9/10 patients and ultrasound showed focal enlargements at the carpal and cubital tunnels. In CMT1A, median and ulnar sensory responses were all absent, and the nerves were diffusely enlarged. After CTS surgery, pain, sensory loss, and strength improved in 4/5 CMT1A, and 6/10 HNPP patients. Of clinical, electrophysiologic and ultrasound findings, only activity‐provoked features significantly correlated with CTS surgical benefit in HNPP patients (odds ratio = 117.0:95% confidence interval, 1.94 > 999.99, p = 0.01). One CMT1A and one HNPP patient improved with CuTS surgery while 2 HNPP patients worsened. Discussion CTS symptom improvement post‐surgery can be seen in CMT1A and (less frequent) in HNPP patients. CuTS surgery commonly worsened course in HNPP. Activity‐provoked symptoms in HNPP best informed benefits from CTS surgery.

Systemic sclerosis (SSc) is characterised by non-inflammatory vasculopathy, autoimmunity and widespread fibrosis. While the presence of antineutrophil cytoplasmic antibodies (ANCAs) has been reported in SSc, their association with ANCA-associated vasculitis is exceedingly rare. Myeloperoxidase ANCA is more common than proteinase-3 ANCA, and glomerulonephritis is the most common clinical presentation of ANCA-associated vasculitis in SSc. ANCAs have been associated with the adverse disease outcomes in SSc, including higher mortality per recent reports. A 65-year-old man with diffuse cutaneous SSc for 6 years presented with new-onset peripheral neuropathy. Workup revealed a positive proteinase-3 and cytoplasmic ANCA, and histopathology confirmed an inflammatory vasculitic neuropathy. The patient was successfully treated with rituximab. Our case highlights the importance of checking ANCA in SSc at baseline, given the risk of disease-related complications, even years later. Tissue biopsy is often warranted for confirmation of vasculitis and prompt treatment can optimise long-term outcomes.

See article on pages 643–649 in this issue.