Worldwide, it is estimated that a person receives a diagnosis of dementia every three seconds, and 78 million people are projected to be affected by dementia by 20301. Despite these staggering figures, current infrastructures to provide proactive and longitudinal medical care to this population are frequently insufficient. Between 50–80% of dementia cases go undocumented in primary care in high income countries2, a statistic that only rises in countries classified as low to middle income1–3. In the words of the World Health Organization (WHO) Director General, dementia is a “looming… public health disaster, ‘a tidal wave’”3,4.
Dementia is classified as young onset when it occurs before the age of 655–7. A recent systematic review by Hendriks et al. (2023) determined that approximately 370,000 people worldwide are diagnosed with young-onset dementia per year. While a much smaller percentage, the prevalence of young-onset dementia and far-reaching societal implications are significant. Young-onset dementias, ranging from Alzheimer’s disease to frontotemporal dementia to Parkinson’s disease, insidiously disrupt mechanisms of communicative competence8–19 and therefore warrant speech and language intervention. Primary progressive aphasia (PPA) is a distinctive subtype of young-onset dementia syndromes that selectively impacts functions of speech and language at the milder stages of the condition20–22. Identifying the onset of PPA, or its milder stages, poses significant challenges due to the relative complexity and rarity of the condition20–22. In the absence of a one-to-one correspondence between presentation and underlying pathology, PPA can present as one of three established variants (semantic, nonfluent, and logopenic) or heterogeneously, where symptomatology and evolution of presentation can vary starkly20–22. Despite these differences, the functional impact of PPA encompasses all variants: a fundamental change and progressive loss to communicative ability.
The capacity to communicate is an imperative feature of the human experience. A behavioral approach to the care of people living with PPA (PwPPA) is paramount to enhance, maintain, or compensate for communication loss. Presently, there is no curative treatment publicly available for this condition22. Speech and language therapy is the primary intervention that can slow down the behavioral impact of symptoms, which immediately impacts positive engagement, participation, and quality of life. Such intervention has been shown to maintain communication abilities for longer through both compensatory and restitutive approaches23–25. Early referral to speech and language therapy is imperative to optimize possible improvements, maintenance, and compensation for decline in linguistic capacity faced by PwPPA26–29. Speech-language therapists/pathologists (SLT/Ps) are recognized as central specialists in the care of PwPPA with roles in the diagnosis and coordinated care of the condition22,27,28, 30, 31. Kate Swaffer, founder of Dementia Alliance International (DAI), and person living with the semantic variant of PPA, has spoken publicly about the pressing need for SLT/Ps to be consistently integrated in the care of those living with the condition.
“People with dementia who will almost all have language and speech changes, need proactive speech pathology after diagnosis, not just a speech pathologist to attend when we can no longer swallow well nearer to the end of life… this is how I have managed to still speak as well as I do.”32.
Despite this need, there remains a consequential gap in the number of people living with dementia who qualify for speech and language therapy and those that receive this service27,33,34. Evidence demonstrates that PwPPA must begin speech and language intervention as early as possible to avoid the risk of not benefitting from impairment-based or functional interventions26,33. Furthermore, as highlighted by Swaffer (2019), people living with early-onset dementias, such as PPA, and their families seek support to optimize participation and quality of life outcomes, which is bolstered by appropriate and timely access to SLT/P intervention31,35. Perhaps more critically, beyond gaps in referrals, SLT/Ps report limited confidence and feel underprepared for working with PwPPA34,36,37.
Table 1
A description of the best practice principles for speech-language therapists/pathologists working with primary progressive aphasia (Volkmer, Cartwright, Ruggero et al., 2023).
Principle | Applications |
Knowing people deeply | Understanding a person’s values, environment, and systems of support to explain a diagnosis, tailor collaborative and person-centered plans of care, and provide informational counseling |
Preventing disasters | Providing timely specialist referrals and anticipatory care |
Practical issues | Working with person and the people who surround them to identify possible barriers to enhance long-term management and deliver accessible and comprehensive care |
Professional development | Refining personal understanding, skills, practices, and role in service provision |
Connectedness | Connecting to other service providers or peer groups to optimize interdisciplinary support |
Barriers and limitations | Identifying and advocating to address gaps, limitations, and failures in diagnoses, management, referrals, and interdisciplinary care |
Peer support and mentorship towards a shared understanding | Providing training and peer mentorship to ensure ongoing education and improvement of practice |
In response to these concerns, a group of international expert clinician-academic SLT/Ps worked collaboratively to establish best-practice principles to guide SLT/P services for PwPPA and their families38. The consensus process culminated in a set of seven best practice principles visualized in the form of the “Clock Model”. With the aim of promoting autonomy and person-centered care, these principles represent concepts of “Knowing people deeply,” “Preventing disasters,” “Practical issues,” “Professional development,” “Connectedness,” “Barriers and limitations,” and “Peer support and mentoring towards a shared understanding” (see Table 1). The principles provide a framework for the essential components of SLT/P intervention and can be used to guide clinical decision-making, care coordination and service development in the SLT/P field. Further, use of the principles can be extended to the professional development, training and education needs of the current and future SLT/P workforce. Utilizing the principles of the aforementioned aspects of SLT/P practice has the potential to close the current gap between the expressed need for SLT/P services by PwPPA and their families, and the readiness of SLT/Ps to provide best-practice care and innovation in the PPA field.
Furthermore, the best practice principles can guide the development of educational modules and training tools for future and current SLT/Ps seeking to provide consistent and evidence-based care for PwPPA. They can also serve as a starting point for maximizing the care for communication loss available to the broader spectrum of dementias. There are significant translational applications of this work on PPA as communication challenges are experienced across neurodegenerative conditions39,40 and people with non-language led dementias and their families identify SLT/Ps as essential in providing them with the relevant support41. While PPA is currently the only recognized language-led dementia syndrome, enhancing current SLT/P education, training, and services will allow us to upskill capacity within the profession and generalize these skills to a broader population. This is especially relevant as the functional impact of language impairment in dementia has yet to be fully characterized40: while decline in linguistic function in progressive conditions is well-documented42,43, the clinical relevance of these changes, and how these can be addressed through SLT/P intervention, remains to be widely recognized.
To develop a relevant and viable resource, gaps in current educational opportunities and exposure to aspects of the PwPPA care continuum must be addressed. As such, the aim of this study was to investigate a more global perspective on SLT/P confidence in enacting the roles and responsibilities within each of these principles, as well as clinical prioritization and ranking of basic competencies when working with PwPPA. To accomplish this, we conducted a survey to explore the experiences of SLT/Ps working with PwPPA with reference to their clinical settings, educational experiences, clinical decision-making, and self-reported areas of need in current practices of care.