A nationwide survey of ALS patients on trachoestomy positive pressure ventilation (TPPV) who developed a totally locked-in state (TLS) in Japan

Abstract

We conducted a nationwide survey of ALS patients on tracheostomy positive pressure ventilation (TPPV) who had developed a totally locked-in state (TLS) during the period from August to November 2006, in Japan. TLS occurred in 89 of 709 (13%) ALS patients on TPPV. On the second investigation, 29 of 41 patients with TLS showed complete palsy of more than two voluntary motor systems out of 4 motor systems [respiratory, pontine and medullar (bulbar), limb and external ocular motor systems] successively during a certain six months. The conventional classification of ALS based on the initial symptoms (bulbar, upper limb and lower limb type) was not found to be useful for predicting the onset of TLS. Seventy percent the patients developed TLS within 5 years after the start of TPPV. Thirty-seven (90%) patients finally developed total ophthalmoplegia at the onset of TLS, while one patient eventually developed complete bulbar palsy. One of 11 ALS patients with TLS, whom we experienced at Tokyo Metropolitan Neurological Hospital, also eventually showed complete palsy of the pontine (bulbar) motor system (inability to pull back the jaw). Due to the fact that TLS is a state of complete palsy of the voluntary motor systems for communication, which may occur during the course of ALS in around 15% of patients, further clinical investigation of TLS including cognition is thus considered to be essential for improving the palliative care of ALS patients on TPPV.