Diagnosis and Rehabilitation of Dysphonia After Spinal Cord Injury: A Systematic Review

Patients with spinal cord injury (SCI) frequently experience dysphonia, leading to communication difficulties, social participation restrictions, and reduced quality of life. In the absence of consensus guidelines, we conducted a systematic review to synthesize evidence on diagnostic tools and rehabilitation protocols for dysphonia after SCI, with the aim of informing clinical practice and future research.

Six biomedical, rehabilitation, and speech pathology databases were searched, along with reference lists of relevant studies. Inclusion criteria were as follows: adults with acquired SCI of any etiology, studies reporting dysphonia assessments or rehabilitation protocols, and designs ranging from randomized controlled trials (RCTs) to case reports (English only). Two reviewers independently screened studies, extracted data, and assessed risk of bias (RoB) and level of evidence (LoE) using design-specific tools and Oxford Centre for Evidence-Based Medicine criteria. Dysphonia assessments-including instrumental, acoustic, perceptual, and self-reported measures-were summarized as frequencies and percentages; rehabilitation protocols were described narratively. The review was registered in the International Prospective Register of Systematic Reviews (CRD42024561809).

From 626 unique records, 18 studies were included (total n = 303; mean age 39 years; 79.3% male), comprising 4 RCTs (LoE 2) and 14 observational or case studies (LoE 3-4). Most studies focused on cervical SCI with varied etiologies and American Spinal Injury Association Impairment Scale grades (A-D). RoB was generally low to moderate. Dysphonia assessments included instrumental evaluations (83%, mainly spirometry or plethysmography of lung volumes, pressures, and flows), acoustic analyses (83%, most commonly maximum phonation time and sound pressure level), perceptual measures (78%, using heterogeneous tools), and patient questionnaires (67%, mainly the Voice Handicap Index extended and short forms [VHI/VHI-10]). Reported rehabilitation protocols included the use of speech valves for ventilated patients, glossopharyngeal breathing, abdominal binding, and neurologic music therapy.

Current research on dysphonia after SCI remains limited and methodologically heterogeneous. Evidence supports combining spirometry, indirect laryngoscopy, acoustic and perceptual analyses, and VHI-10 for comprehensive assessment. Among rehabilitation approaches, abdominal binding and neurologic music therapy show the most consistent benefits. High-quality, large-scale studies with longer follow-up are needed to standardize diagnostic and rehabilitation protocols and improve voice outcomes in this underexplored field.