Development of a patient-specific dyspnoea questionnaire in motor neurone disease (MND): the MND dyspnoea rating scale (MDRS).

Motor neurone disease (MND) is a progressive, unremitting and fatal disease. Respiratory dysfunction is common and a significant cause of morbidity. The relationship between subjective dyspnoea and objective measures of lung function have been unexplored in MND. Increasing interest in the specific treatment of respiratory symptoms in MND has highlighted the need for simple, reliable and valid measures to quantify the degree of dyspnoea in this condition. Several generic questionnaires have been developed to rate subjective breathlessness but are inappropriate for use in MND patients as they often assess dyspnoea by exercise-limitation. As yet, there are no published disease-specific measures to assess dyspnoea in MND. In order to accurately and reproducibly measure the subjective experience of dyspnoea in this patient group, we have developed and validated a novel patient-specific dyspnoea questionnaire, the MND dyspnoea rating scale (MDRS). It comprises three domains covering dyspnoea, emotion and mastery and is valid for use in MND patients at all stages of disease progression. In our cohort of 40 unselected patients with MND we have shown that the patients subjective experience of dyspnoea is closely related to emotion and psychological control over the disease. Dyspnoea is not related to objective measures of lung function such as vital capacity, irrespective of limb or bulbar presentation. In conclusion, vital capacity, although useful prognostically, is only one aspect of respiratory function in MND. The MDRS is a reliable and valid tool to rate subjective dyspnoea in MND.