The effect of the nervous system on the cellular invasion into the inflammatory field was studied by the "skin window" technique. One-hundred twelve patients with different neurological disorders and 146 healthy persons were examined. Invasion by macrophages was delayed in Charcot-Marie-Tooth disease, in amyotrophic lateral sclerosis, after section of the brachial plexus, in gross lesions of the brain stem and diencephalon, and in lesions of the frontobasal, frontopolar, and insular regions.