Table 1

 Clinical characteristics of the 22 patients

Clinical featuresAllRRMSPMSNMO
*p<0.01, refers to comparison of NMO with progressive MS group; †unresponsive (5 patients with PMS and 1 with NMO unresponsive as a result of sepsis, 1 patient with RRMS and 1 with NMO unresponsive as a result of brainstem (pontine) inflammation, 2 patients with PMS and status epilepticus); ‡2 patients with NMO and 4 with progressive MS had a necropsy, all were consistent with the clinical diagnosis.
EDSS, expanded disability status scale; MS, multiple sclerosis; NA, not applicable; NMO, neuromyelitis optica; PImax, maximal inspiratory pressure; PMS, progressive multiple sclerosis; RRMS, relapsing remitting multiple sclerosis.
Sex (F:M)14:81:010:73:1
Age at onset of disease35 (12–57)1332 (12–57)40 (37–43)
EDSS before admission or relapse (median (range))8.5 (2.0–9.5)38.5 (6–9.5)3.5 (2.0–8.0)*
Type of ventilatory support
    Mechanical ventilation only9072
    Ventilation and tracheostomy9171
    Tracheostomy only4031
Time from onset to mechanical ventilation/tracheostomy (median years (range))17.5 (0.5–32)919 (8–32)2.5 (0.5–5)*
Duration of ventilation (median days (range))8.5 (1–65)108 (1–27)50 (5–65)
Age (years) at time of ventilatory support (median (range))50 (22–81)2251 (27–81)43 (38–56)
Indication for ventilation/tracheotomy
    Respiratory failure only13103
    Airway protection only (seizure or coma)†413
Underlying cause
    Aspiration pneumonia120102
    Mucous plugging121101
    Mechanical respiratory failure (PImax ⩽25 cm H2O)8044
Follow up
    Survival: time to death or last follow up (months)16 (0–91)1722 (0–91)22 (0–60)
    Median time to death after start of ventilation (months) (n = 17)22 (0–91)NA22 (0–91)5 (0–39)
    Died within 6 months of ventilatory support8062
    Survived >3 years after discharge10172
EDSS at discharge (median (range))9.0 (7.5–9)8.59 (7.5–10)9 (8.5–10)
Dead at last follow up17014‡3‡