At the age of 44 years, this now 57-year-old woman noticed myalgia and difficulty walking, progressing over weeks. Two weeks after the first complaints, lifting the arms became troublesome too. CK activity was found to be > 10,000 U/L. TSH was normal. A diagnosis of myositis was made, and prednisone was started at a dose of 60 mg daily (body weight 80 kg). CK decreased, but the complaints worsened. Six weeks after disease onset, she was presented at our hospital. She was otherwise healthy, apart from well-controlled Graves disease with orbitopathy at the age of 31 years.

A 20-year-old previously healthy man suddenly noticed that he was unable to run. The next day he could not climb the stairs and lost strength in his arms. He was admitted to hospital, and over the next hours he progressively lost muscle power in his arms and legs. Swallowing was progressively impaired, and he noticed minor tingling in both hands and feet. He had had a minor upper respiratory tract infection a week prior to admission.

A previously healthy, very active 68-year-old man, who usually cycled over 100 km several times a week, noticed progressive tingling in his feet and lower legs that increased over several weeks. This was followed by progressive weakness in the arms and legs exceeding a period of eight weeks. After three months of progression, weakness became so severe that he could not even walk without help. He did not use drugs or drink alcohol.

A 50-year-old man was initially seen by a rheumatologist because he had crooked fingers on the left hand and painful cramps. No rheumatological abnormalities were found. In the next three years, he developed severe atrophy and weakness of the left hand, and could not hold a glass of water. There were no sensory complaints. His GP considered motor neuron disease.