An Observational Study in People With Amyotrophic Lateral Sclerosis to Validate Tidal /End-Tidal CO2, Measured by the N-Tidal C™ Against Directly Measured PaCO2 and to Determine the Ease of Home Use of the Device

This is a prospective, observational study of patients attending Royal Papworth Hospital's weekly MND clinic. If a patient decides to participate in the study, they will continue to receive all normal care. Researchers will ask permission to review the results of any medical investigations and tests previously undertaken, by looking in medical records and will collect new data prospectively. There will be two groups of patients recruited:

A).Hospital Questionnaire Monitoring Group (12 months) for up to 200 patients who will:

i) Have four routine hospital based assessments (every 3 months, standard care) ii) Above usual care: completion of the ALSFRS-R questionnaire at each clinic (4 in total. The ALSFRS-R (Amyotrophic Lateral Sclerosis Functional Rating Score-Revised) measures range of difficulties that people with MND can have in their daily lives. The results from this questionnaire help to measure the severity of MND symptoms, and how fast the disease is progressing. B). Home Device Monitoring Group (12-24 months) for 30 patients These participants patient will be given a portable monitoring device (called the N-Tidal C) to record their breathing pattern in clinic and at home and have: i) Four to six routine hospital based assessments (every 3 months, standard care). At the discretion of the investigator this may be at each clinic visit up to a total of 24 months ii) Completion of an ALSFRS-R symptom questionnaire at each visit (4-6 in total). At the discretion of the investigator this may be at each clinic visit up to a total of 24 months iii) Telephone consultation 2 weeks after commencing home monitoring to validate correct and safe use of the device (1 in total) iv) Completion of a supervised N-Tidal C breath record at each clinic visit (4 to 6 total). At the discretion of the investigator this may be at each clinic visit up to a total of 24 months v) Completion of a weekly symptom diary (up to 52 in total). At the discretion of the investigator this may continue up to 24 months vi) Home monitoring with N-Tidal C for 75 seconds, up to 3 times per day (up to study finish). SA 02 introduced an additional modified breath holding manoeuvre for home monitoring patients in clinic.

The range of 4 to 6 assessments covers the eventuality that participants may start in group A and transfer to group B as their condition changes. This will be determined by the treating doctor and will be based upon their lung function, limb weakness and whether they (or a carer) are able to use the device. During the home monitoring trial, data collected by the N-Tidal C device will be downloaded at each clinic visit, to check that the device is correctly recording data. Researchers will not be able to analyse the data collected by the device.

Only the information obtained from the standard measurements (standard care) will be used to decide when a patient needs help with their breathing at night time by starting a ventilator. A patient participating in the Home Monitoring Group will continue to use their N-Tidal C device to record their daytime breathing up to 3 times per day, after they start using a ventilator.