[Patient education--support--help with decisions: ethical aspects in treatment of amyotrophic lateral sclerosis].
Patients with amyotrophic lateral sclerosis (ALS) develop progressive, degenerative loss of muscle function while retaining mental capacity. This implies special problems of patient information, which should be phase-adapted and patient centered. The difficult task of the physicians requires to provide sufficient information, to enable shared decision-making, without leaving the patient alone. Respiratory failure due to loss of muscle function is often the limiting problem. However, the possible option of ventilatory support opens the question when to stop treatment. It is most important to differentiate between intended mercy-killing and foregoing treatment due to the patient's wish. Discontinuation of treatment is morally justifiable, even required, if the patient refuses further treatment. Advance directives may be helpful to make decisions according to patients' preferences in time.