Postpolio syndrome

ADVANCE magazine has an interesting article about Postpolio syndrome, focusing on respiratory disturbances:

Disordered breathing is among the most misdiagnosed and misunderstood symptoms polio survivors face later in life. Too often their breathlessness and inefficient coughs are misdiagnosed as asthma or chronic obstructive pulmonary disease. For many aging polio survivors, it largely has been up to them to initiate their care and educate their doctors on the medical literature.

One-third to one-half of polio survivors experience new or increased weakening and pain in the muscles later in life. This typically occurs 10 to 40 years after recovering from original polio. This weakening can affect the diaphragm and breathing muscles, causing such disorders as obstructive sleep apnea, central sleep apnea, pneumonia, pulmonary restriction, shallow breathing, pneumonia, and diffuse muscle twitching during sleep.

He warns that split-night sleep studies are not appropriate for polio survivors I agree with this; home testing is not appropriate either.

Polio survivors should be given portable volume-pressure ventilators to use with nasal interfaces for ventilatory assistance rather than CPAP or bilevel positive airway pressure, Dr. Bach said. Polio survivors do not benefit from the expiratory positive pressure, he said, and it detracts from the positive inspiratory pressure in assisting the inspiratory muscles.
I disagree, many do have some element of obstructive sleep apnea and benefit from BiPAP. Typically these patients do require a wide differential between the EPAP and IPAP.

A few patients still use the iron lung, a form of negative pressure ventilation. Negative pressure ventilation can predispose to or worsen obstructive sleep apnea, but is very effective in some patients with postpolio syndrome.