 Two clinical trials have been performed in ALS patients with s.c. administration of IGF-I indicating a possible beneficial effect, and a third clinical trial is in progress. Methionyl growth hormone mGH showed no effect on survival, disease progression and muscular strength. MGH was administered at a fixed dose and peripheral production of IGF-I appeared to be normal. We propose a double-blind trial of Growth Hormone GH as add-on therapy to Riluzole, with an individually regulated dose based on the peripheral response of IGF-I. Aim of our study is to determine if the add-on of GH to treatment with Riluzole is able to reduce neuronal loss in the motor cortex of ALS patients. As secondary objectives, effect of GH on mortality, QoL, and motor function will be assessed. 