Pathological spontaneous activity as a prognostic marker in chronic inflammatory demyelinating polyneuropathy

Area of Science:

• Neurology
• Clinical Electrophysiology

Background:

• Monitoring chronic inflammatory demyelinating polyneuropathy (CIDP) progression is challenging due to poor correlation between nerve conduction studies and functional disability.
• The prognostic and disease activity value of pathological spontaneous activity (PSA) in needle electromyography (EMG) within different CIDP subgroups has not been longitudinally analyzed.

Purpose of the Study:

• To determine if pathological spontaneous activity (PSA) serves as a prognostic marker or a marker of disease activity in a cohort of patients with CIDP.
• To longitudinally correlate PSA occurrence with clinical disability and CIDP subtypes.

Main Methods:

• Retrospective analysis of 127 patients with CIDP spectrum disorder over a mean of 57 months.
• Assessment of pathological spontaneous activity (PSA) including fibrillations and positive sharp waves at diagnosis, new occurrences, and continuous presence.
• Correlation of PSA with the Inflammatory Neuropathy Cause and Treatment Overall Disability Sum Score (INCAT-ODSS) and CIDP subtype.

Main Results:

• Pathological spontaneous activity (PSA) was present at diagnosis in 49.6% of CIDP patients.
• More frequent PSA was significantly associated with higher INCAT-ODSS at last follow-up.
• Continuous and new PSA occurrences correlated with greater disability, atypical phenotypes, and increased need for treatment escalation.

Conclusions:

• Pathological spontaneous activity (PSA) is associated with increased disability and more frequent in atypical CIDP variants.
• Electromyography (EMG) examination, specifically assessing PSA, is an adequate marker for monitoring CIDP disease progression.
• EMG evaluation should be incorporated into the routine management of CIDP patients.