Presentation of motor neuron disease in a patient with weight loss and acute-on-chronic respiratory failure.

A previously fit and well 72-year-old man was referred to the acute medical unit with acute shortness of breath and confusion. He had presented 6 months earlier to his General Practitioner with a 6-month history of weight loss and lethargy. Despite CT imaging and extensive blood tests, no cause was found. He was having ongoing outpatient investigations, including a respiratory review leading up to his admission; the deterioration in his condition also coincided with the implementation of the COVID-19 lockdown. On admission, he was found to be in acute-on-chronic type 2 respiratory failure; examination revealed scattered fasciculations. Further inpatient electromyography (EMG) and nerve conduction study (NCS) confirmed motor neuron disease (MND). This case highlighted the importance of considering neuromuscular causes for acute respiratory failure in acute presentations and demonstrated the challenges in the diagnosis of MND in those presenting atypically with non-specific symptoms and the limitations of remote consultations in complex cases.