Ratios regarding pulmonary function tests, hours using non-invasive ventilation (NIV) and months of evolution. Panel A - Vital capacity (VC) in a percentage of the normal values, PaCO2 in mmHg and hours of NIV use. Panel B - Maximal static respiratory pressures at the mouth: maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) are expressed as a percentage of the normal values. Tests show a worsening of the pulmonary function, maintaining normocapnia. The NIV duration was increased to full-time NIV for 16 months before death. During the last few months, VC was non-measurable, and MIP and MEP were zero or non-measurable.