Speech disorders like dysarthria are a common and disabling symptom of Friedreich’s ataxia (FA), but they are largely ignored in clinical trials. More research is needed to develop better ways of assessing and intervening to address them, a review study reports.
It also suggests various assessment tests and treatment approaches that may help patients with these communication difficulties.
The study “Speech and Language Disorders in Friedreich Ataxia: Highlights on Phenomenology, Assessment, and Therapy” was published in the journal The Cerebellum.
Difficulties with speech and language, while common in FA, have no effective treatments and significantly impact patients’ quality of life and their ability to communicate and participate in society.
These problems are well-described in other neurodegenerative illnesses, but their characterization in FA is still quite incomplete.
Knowing the characteristics, methods used for evaluation, and therapeutic approaches used to tackle speech and communication difficulties in FA is key for improving patient care.
To address this gap, researchers reviewed current literature to collect available data on the characteristics, assessment, and treatment of speech and language disorders in people with Friedreich’s ataxia.
The review revealed that people with this disease often have dysarthria — affecting up to 84% to 100% of patients and often within the first two years of disease onset.
It seems to arise due to impairments in the central nervous system (brain and spinal cord) involved in the motor control of speech (the cerebellar and pyramidal brain regions), as well as peripheral factors such as neuromuscular weakness and postural complications.
Despite high variability in the severity and type of speech difficulties, patients’ voices share common characteristics that include roughness, breathiness, and strain, associated with poor pitch control in continuous speech and sustained vowels.
In addition to dysarthria, language impairments like problems with verbal fluency or hearing difficulties can further hamper communication — difficulties “whose specific recognition is fundamental to personalize treatments,” the researchers wrote.
Evaluation of speech and language problems in FA “is a challenging field,” they noted. It relies to date on different clinical and instrumental tools; a scale specific for FA is not yet available.
Both classical tests and new technologies can improve the accuracy of speech evaluations and indicate speech parameters that could be a potential source of disease biomarkers.
Electromyography (that measures electrical activity of muscles) and motion analysis of the tongue and the orofacial and respiratory muscles are among examples of tests that could offer greater insights into the characteristics of dysarthria in FA patients, the study noted. Others include perceptual and acoustic analysis of vocal recordings (e.g., to measure jitter, shimmer, and signal-to-noise ratio) and mathematical models.
Despite the importance of speech and language to patients’ well-being, “the problem is almost neglected from a therapeutic perspective,” the researchers stressed. “Clinical trials in FRDA do not consider speech and language as primary outcomes.”
According to the team, two approaches seem the “most reliable therapeutic options to be validated in future trials.”
One is tailored speech training, which has been investigated in multisystemic ataxia with good clinical results, encouraging the application of this approach to other ataxias, including FA.
Another promising treatment approach is noninvasive neuromodulation using transcranial magnetic stimulation or direct current stimulation (passing a strong brief electrical current through an insulated wire coil placed on the skull). Studies suggest this approach is effective for easing motor disturbances in people with ataxias and speech disorders.
“In conclusion, the assessment and treatment of language and speech disorders in FRDA [Friedreich’s ataxia] are still largely unmet issues, towards which scientific research should be oriented urgently, in order to improve patients’ quality of life,” the authors concluded.
They also highlighted the “scarcity of studies in this field,” and the need for further efforts to improve the management of these difficulties for patients.