Mode
Text Size
Log in / Sign up

Verbal fluency is significantly impaired in multiple sclerosis and neuromyelitis optica spectrum disordersSpeech Fluency Linked to Cognitive Function in MS and NMOSD

AI-generated summary of the cited source, checked by automated accuracy review. How we work

Key Takeaway
Note that impaired verbal fluency serves as a potential marker for cognitive dysfunction in MS and NMOSD.

This meta-analysis synthesized data from 69 studies to evaluate verbal fluency, specifically phonemic and semantic domains, in patients with multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOSD). The analysis compared these patient populations against healthy controls and evaluated differences between MS subtypes.

The synthesis revealed significantly worse performance in the MS group for both phonemic fluency (SMD -0.82; 95% CI -0.94 to -0.71) and semantic fluency (SMD -0.81; 95% CI -0.95 to -0.68) compared to healthy controls. Similarly, patients with NMOSD showed significantly worse phonemic (SMD -0.49; 95% CI -0.73 to -0.26) and semantic fluency (SMD -0.57; 95% CI -0.85 to -0.29) than healthy controls. No significant differences were found between MS and NMOSD patients in either phonemic or semantic categories.

Additionally, the analysis noted that progressive forms of MS showed poorer performance in both phonemic (SMD -0.43; 95% CI -0.13 to -0.73) and semantic (SMD -0.55; 95% CI -0.32 to -0.79) fluency compared to relapsing-remitting forms. These findings suggest that verbal fluency may be a clinically relevant marker of cognitive dysfunction in these conditions, potentially aiding the identification of patients for targeted rehabilitation.

How this fits prior evidence

This meta-analysis addresses a gap in characterizing cognitive markers in neuroinflammatory conditions. While previous evidence noted that optical coherence tomography shows significantly reduced retinal measurements in neuromyelitis optica spectrum disorder compared to multiple sclerosis, this study provides data on cognitive outcomes specifically in both MS and NMOSD populations. It confirms that both groups exhibit significant deficits in verbal fluency compared to healthy controls.

A large review of 69 studies looked at how well people with multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOSD) could perform on verbal fluency tasks. These tests measure how easily a person can produce words based on specific sounds or meanings.

The findings showed that individuals with MS and NMOSD performed significantly worse on these speech tasks than healthy people. Specifically, both phonemic and semantic fluency were lower in those with these conditions. The study also found that people with progressive forms of MS had harder time with verbal fluency than those with relapsing-remitting forms.

While the data shows a clear link between speech performance and cognitive function, it is important to remember this is an observational summary of existing research. These results suggest that testing verbal fluency could help doctors identify patients who might need specific cognitive support. You should speak with your healthcare provider to discuss what these findings mean for your personal care plan.

What this means for you:
Lower verbal fluency scores are linked to cognitive challenges in people with MS and NMOSD.

Common questions

What is verbal fluency?

Verbal fluency refers to how easily a person can produce words during a test. This includes phonemic fluency, which involves producing words starting with specific sounds, and semantic fluency, which involves producing words related to a specific category or meaning.

How does MS affect speech performance?

The study found that people with multiple sclerosis performed significantly worse on both phonemic and semantic fluency tasks compared to healthy individuals. Additionally, those with progressive forms of MS showed poorer performance than those with relapsing-remitting forms.

Is there a difference between MS and NMOSD in these tests?

The research found no significant difference in verbal fluency scores when comparing people with multiple sclerosis to those with neuromyelitis optica spectrum disorders. Both groups showed similar levels of difficulty compared to healthy controls.

Study Details

Study typeMeta analysis
EvidenceLevel 1
PublishedJul 2026
View Original Abstract ↓
BACKGROUND: Cognitive impairment is common in people with multiple sclerosis and neuromyelitis optica spectrum disorders. Verbal fluency in particular has been receiving increasing attention over the last couple of years. OBJECTIVE: This meta-analysis summarizes the existing evidence from previous studies on verbal fluency in people with multiple sclerosis and neuromyelitis optica spectrum disorders. METHODS: The MOOSE guidelines for meta-analyses of observational studies were followed. A systematic literature search was conducted in MEDLINE, Scopus, and the Cochrane Library from January 1990 to March 2025. Sixty-nine (69) studies were included in the synthesis. RESULTS: People with multiple sclerosis performed significantly worse than healthy controls in both phonemic ( = 50, SMD -0.82, 95% CI -0.94 to -0.71, I 68%,  < 0.00001) and semantic fluency ( = 46, SMD -0.81, 95% CI -0.95 to -0.68, I 80%,  < 0.00001). Similar results were observed in people with neuromyelitis optica spectrum disorders for phonemic ( = 5; SMD -0.49, 95% CI -0.73 to -0.26, I 27%,  < 0.0001) and semantic fluency ( = 7, SMD -0.57, 95% CI -0.85 to -0.29, I 48%,  < 0.0001). No significant differences in performance were found between the two clinical entities for either phonemic ( = 5, SMD -0.01, 95% CI -0.21 to -0.19, I 0%,  = 0.92) or semantic fluency ( = 5, SMD -0.01, 95% CI -0.39 to -0.41, I 58%,  = 0.97). Analysis within the group of people with multiple sclerosis indicated poorer performance in those with the progressive forms than in those with relapsing-remitting multiple sclerosis in both phonemic ( = 10, SMD -0.43, 95% CI -0.13 to -0.73, I 81%,  = 0.005) and semantic fluency ( = 10, SMD -0.55, 95% CI -0.32 to -0.79, I 64%, < 0.00001). CONCLUSIONS: Verbal fluency may be a clinically relevant marker of cognitive dysfunction in multiple sclerosis and neuromyelitis optica spectrum disorders. Routine testing may help identify patients who could benefit from targeted cognitive rehabilitation interventions.
Free Newsletter

Clinical research that matters. Delivered to your inbox.

Join thousands of clinicians and researchers. No spam, unsubscribe anytime.