Can Multiple Sclerosis (MS) affect speech?

Speech Disorders in Multiple Sclerosis

Yes, Multiple Sclerosis (MS) commonly affects speech, with approximately 40% of MS patients experiencing dysarthria characterized by disorders of voice intensity, quality, articulation, and intonation. 1

Speech Impairments in MS

MS can cause several types of speech disorders:

• Dysarthria: The most common speech disorder in MS, typically presenting as a mixed spastic-ataxic dysarthria 1

  • Characterized by slow articulation and imprecise consonant pronunciation
  • Changes in voice quality (harshness, hoarseness)
  • Reduced pitch and loudness control
  • Monotonous speech patterns

• Temporal speech features affected: 2

  • Slower speech and articulation rate
  • More frequent and longer pauses during speech
  • Difficulty with speech tasks requiring higher cognitive effort

• Specific speech system impairments: 3

  • Phonation system: Changes in speech rate, longer pause durations, lower volume
  • Articulation system: Lack of muscle synchronization, inaccurate pronunciations (especially of vowels)
  • Prosody: Monotonous speech lacking normal intonation patterns

Prevalence and Impact

• Speech disorders occur in approximately 56% of MS patients, though severity is generally mild 4
• Even patients with minimal neurological disability (EDSS < 2.0) can show subclinical speech impairments 4
• Speech disorders significantly impact quality of life and communication abilities 3

Relationship to MS Disease Progression

• Speech disorders reflect the severity of neurological involvement in MS 4
• Decreased articulation rate correlates with overall MS disability as measured by the Expanded Disability Status Scale (EDSS) 4
• Speech impairments may serve as potential biomarkers for disease progression 5

Underlying Neurological Mechanisms

• Speech disorders in MS result from demyelination affecting:

  • Pyramidal tracts (causing spastic components)
  • Cerebellar pathways (causing ataxic components)
  • Combined pyramidal-cerebellar involvement produces the most common speech phenotype 4

• The strongest correlation exists between irregular oral diadochokinesis (rapid repetitive movements) and upper limb function as measured by the 9-Hole Peg Test 4

Management Approaches

For MS patients with speech disorders:

• Speech and language therapy is strongly recommended to improve functional communication 6

• Therapy should focus on:

  • Articulation exercises
  • Breath control techniques
  • Voice modulation training
  • Compensatory strategies for clearer speech

• Alternative communication methods may be beneficial when speech is severely affected:

  • Gestures
  • Writing
  • Visual aids
  • Augmentative and alternative communication devices 7

Clinical Implications

• Early identification of speech changes may help in monitoring disease progression
• Regular assessment of speech function should be part of comprehensive MS management
• Speech disorders may precede other neurological symptoms, serving as early indicators of disease activity
• Speech therapy interventions should be initiated promptly when speech changes are identified

Speech disorders in MS are significant but often underrecognized manifestations that can substantially impact patients' quality of life and communication abilities. Early identification and appropriate speech therapy interventions are essential components of comprehensive MS management.