Assessment of diagnostic criteria for multifocal motor neuropathy in patients included in the Italian database.

BACKGROUND AND PURPOSE: This study aimed to assess the diagnostic criteria, ancillary investigations and treatment response using real-life data in multifocal motor neuropathy (MMN) patients. METHODS: Clinical and laboratory data were collected from 110 patients enrolled in the Italian MMN database through a structured questionnaire. Twenty-six patients were excluded due to the unavailability of nerve conduction studies or the presence of clinical signs and symptoms and electrodiagnostic abnormalities inconsistent with the MMN diagnosis. Analyses were conducted on 73 patients with a confirmed MMN diagnosis and 11 patients who did not meet the diagnostic criteria. RESULTS: The European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) diagnostic criteria were variably applied. AUTHOR: When applying the American Association of Electrodiagnostic Medicine criteria, an additional 17% of patients fulfilled the criteria for probable/definite diagnosis whilst a further 9.5% missed the diagnosis. In 17% of the patients only compound muscle action potential amplitude, but not area, was measured and subsequently recorded in the database by the treating physician. Additional investigations, including anti-GM1 immunoglobulin M antibodies, cerebrospinal fluid analysis, nerve ultrasound and magnetic resonance imaging, supported the diagnosis in 46%-83% of the patients. Anti-GM1 immunoglobulin M antibodies and nerve ultrasound demonstrated the highest sensitivity. Additional tests were frequently performed outside the EFNS/PNS guideline recommendations. CONCLUSIONS: This study provides insights into the real-world diagnostic and management strategies for MMN, highlighting the challenges in applying diagnostic criteria.

Regular assessment of serum vascular endothelial growth factor levels to monitor POEMS syndrome.

BACKGROUND: To investigate the utility of regular serum VEGF (sVEGF) levels assessment in the monitoring of POEMS syndrome. METHODS: We retrospectively reviewed data of 30 patients with POEMS syndrome whose sVEGF was tested regularly every 6 months. sVEGF levels after treatment were measured and correlated with disability (Overall Neuropathy Limitations Scale, ONLS), clinical impairment (measured with the modified Clinical Response Evaluation Scale, mCRES), and relapse-free survival. The ability of sVEGF to predict disease flares during remission and refractory disease was also analysed. RESULTS: Patients with normalised serum VEGF levels (< 1000 pg/ml) at 6 months showed prolonged relapse-free survival (at 3-year 94% for complete VEGF response, 57% partial, 0% none, p < 0.001) and greater later clinical improvement (median ΔmCRES complete VEGF response -5 vs partial -4, p = 0.019, and vs no VEGF response -2, p = 0.006). After remission, the sensitivity of 6-month sVEGF monitoring in predicting clinical relapse was 58% with a specificity of 100%. In patients refractory to treatment, the sensitivity in predicting further clinical worsening was 15%. In addition, in 25% of the patients in remission and 16% of those refractory to therapy, sVEGF levels only increased at the time of relapse. CONCLUSIONS: Regular sVEGF assessment is a valid biomarker in the prediction of disease reactivation in POEMS syndrome and was particularly useful during the phase of remission.