Bulbar dysfunction (BD) presents as dysphagia and dysarthria, which may lead to weight loss, impaired communication, orofacial pain and aspiration pneumonia. Bulbar dysfunction in MND is a negative prognostic indicator of survival, requires careful monitoring and necessitates well-timed multidisciplinary interventions; referral to speech-language pathology (SLP), neuropsychology, feeding tube placement, augmentative communication devices etc. Pseudobulbar affect (PBA) manifests in disproportionate emotional responses to minimal or non-contextual stimulus. BD and PBA develop in a range of neurological conditions but are pathognomonic of motor neuron diseases (MNDs) with considerable diagnostic, management and quality of life (QoL) implications.
As reported by patients and their families, BD and PBA constitute one of the most burdensome clinical symptoms, with considerable QoL and social ramifications. Feedback from patient advocacy groups, our shared clinical experience and research highlighted the high incidence of misdiagnoses, delay in interventions and limited awareness for both BD and PBA. Considerable academic and clinical gaps persist in our understanding of the aetiology and propagation of these symptoms, especially in the mid- to late-stages of MND. There is a striking lack of consensus in definitions, validated screening tools, diagnostic criteria, and research into the social and QoL implications. The meaningful integration of research findings in BD and PBA internationally is hindered by differences in terminology, screening practices, access to multidisciplinary interventions, cultural factors, sex, and differences in health care systems in different geographical regions.
The applicants of this consortium propose a robust, multi-site, multimodal, study to evaluate biological underpinnings and QoL impact of BD and PBA in MND. The presence and severity of bulbar (speech and swallowing) dysfunction will be evaluated using a validated algorithm based on acoustic and kinematic parameters / features. A purpose-designed neuroimaging protocol will be implemented to evaluate the cortical, white matter, brainstem, cerebellar and muscle components of bulbar function. Using patient reported outcome measures (PROMS), patient and caregiver perspectives on the impact of BD & PBA will be monitored. A comprehensive battery of neuropsychological tests, mood, affect, QoL questionnaires will be administered to map the incidence, clinical associations, longitudinal evolution and social sequelae of bulbar and pseudobulbar impairment. The interactions between PBA and affective state, executive dysfunction and cognitive disinhibition will be specifically evaluated. A transnational comparison approach will be utilised to document cultural and healthcare system differences in management of BD and PBA. An ethical framework will be provided to subsume and evaluate data in a conceptual context. The work will lead to an improved understanding of the aetiology and impact BD & PBA and the establishment and cross-validation of best practice recommendations. Ultimately, the project will raise public awareness of the clinical, social and QoL impact of BD & PBA.
The applicants are not only passionate about clinical MND care, but they also have complementary research expertise in neuropsychology, speech pathology, social science and neuroimaging. They believe that achieving the objectives of this project is directly relevant to precision individualised patient care and meaningful caregiver support.
