The cerebrospinal fluid in myasthenia gravis

Area of Science:

• Neurology
• Clinical Chemistry

Background:

• Myasthenia gravis (MG) is a neuromuscular disease affecting voluntary muscle function.
• Cerebrospinal fluid (CSF) analysis is used to diagnose and monitor neurological conditions.

Purpose of the Study:

• To investigate CSF parameters in patients with myasthenia gravis.
• To determine if there is evidence of intrathecal immunoglobulin G (IgG) synthesis in MG patients.
• To assess the impact of blood contamination on CSF analysis.

Main Methods:

• Collected CSF samples from 46 myasthenia gravis patients and 50 controls.
• Measured leucocyte count, total protein, albumin, and IgG concentration in CSF.
• Evaluated CSF for signs of intrathecal IgG synthesis.
• Simulated iatrogenic blood contamination to assess its effect on CSF composition.

Main Results:

• Mean leucocyte count, total protein, IgG, and albumin concentrations were slightly higher in MG patients than controls.
• No evidence of intrathecal IgG synthesis was found in any patient.
• CSF findings were generally normal, with slight abnormalities attributed to comorbidities or blood contamination.
• Even minor, undetectable blood contamination significantly increased CSF albumin and the albumin/serum albumin ratio.

Conclusions:

• CSF analysis in myasthenia gravis patients typically shows normal or near-normal results.
• Intrathecal IgG synthesis is not a characteristic feature of myasthenia gravis.
• Blood contamination is a critical confounding factor in CSF analysis, affecting albumin levels and ratios.