In 22 patients with idiopathic Parkinson's disease we observed a sudden worsening of motor symptoms and severe akinesia during hospitalization because of infectious diseases, bone fractures, surgery for gastrointestinal tract diseases, and iatrogenic causes. Of these patients, 12 recovered completely, 6 had a partial recovery, and 4 died. Treatments included subcutaneous apomorphine/lisuride infusion and dantreolene (with a creatine phosphokinase level higher than 200 IU). In all patients a definite refractoriness to therapy was shown with a transient lack of response to apomorphine.