Related Experiment Video
Updated: Oct 3, 2026
Comprehensive Autopsy Program for Individuals with Multiple Sclerosis
Published on: July 19, 2019
[Contribution of biology to diagnosis of multiple sclerosis]
1Laboratoire d'Immunologie Cellulaire et INSERM U 546, Hôpital Pitié-Salpêtrière, Paris, France.
Insights
Cerebrospinal fluid analysis, particularly for intrathecal IgG synthesis, is crucial for diagnosing multiple sclerosis (MS). While common in MS, this test indicates nervous system inflammation rather than being specific to the disease.
Area of Science:
- Neurology
- Immunology
- Clinical Diagnostics
Context:
- Cerebrospinal fluid (CSF) analysis is the sole biological test within the diagnostic criteria for Multiple Sclerosis (MS).
- Intrathecal IgG synthesis detection via isoelectric focusing is recommended for all CSF analyses in suspected MS cases.
- This immunological marker is present in approximately 95% of MS patients.
Purpose:
- To evaluate the role and utility of cerebrospinal fluid analysis in the diagnosis and management of Multiple Sclerosis.
- To determine the significance of intrathecal IgG synthesis as a diagnostic and potentially prognostic marker.
- To provide guidance on the systematic application of CSF analysis in different MS phenotypes and related neurological conditions.
Summary:
- Intrathecal IgG synthesis, detected in most MS cases, signifies nervous system inflammation but lacks MS specificity.
- CSF analysis is advised for primary progressive MS, most monosymptomatic demyelinating syndromes, and other forms based on clinical context and MRI findings.
- Current CSF analysis does not offer prognostic criteria for MS; its value in atypical forms lies in differential diagnosis.
Impact:
- Highlights the importance of CSF analysis, especially intrathecal IgG synthesis, in the diagnostic workflow for MS.
- Emphasizes the need for careful interpretation of CSF findings, recognizing their inflammatory but non-specific nature.
- Informs clinical practice regarding the strategic use of CSF analysis for MS diagnosis and the exclusion of other neurological disorders.
Abstract:
The analysis of the cerebrospinal fluid is the only biological test included in the diagnostic criteria for MS. A search for intrathecal IgG synthesis by isoelectrofocussing should always be performed when the cerebrospinal fluid is analyzed for a possible diagnosis of MS. Intrathecal IgG synthesis is detected in about 95 p. 100 of MS cases. However, it is not specific for MS and only signs the inflammatory nature of the nervous system lesions. In our opinion, analysis of the CSF should be proposed systematically for primary progressive MS, in most cases of monosymptomatic demyelinating syndromes, and according to the clinical context and the result of the MRI analyses in the remaining forms. To date, no prognostic criteria can be drawn from the analysis of the CSF. Other biological tests can be performed in order to eliminate other diagnosis. These tests only have a great interest in atypical forms of the disease.
