A number of the problem areas in the field of autism are specifically addressed in this volume, which uses the tools of neurological analysis. One is whether autism is mostly a single disease entity, as originally described by Kanner, or is a large syndrome of multiple diseases as postulated in this book. Such a finding has implications for research, diagnosis and treatment. In what ways are autism and Asperger syndrome related? Has autism been increasing in recent years; does a sophisticated historical review of its prevalence rates suggest that autism has never been a rare disorder? A topic of special interest is whether autism is reversible. One chapter looks at the natural course of those diseases which have a transient autistic phase, while another chapter reviews the possibility and reports of reversible autistic behavior. There is an in-depth discussion of the neurological signs and symptoms that can be found in children with autism and Asperger syndrome; these include abnormal cranial circumference, epilepsy, changes of muscle tone, stereotypies and mutism. (The Appendix includes a form specifically designed for the neurological examination of patients with autism and Asperger syndrome.) Which of the components of the neural networks of the brain are impaired causing the presentation of autistic symptoms? Of particular interest is the dysfunction of the cerebellum and its circuits. Regarding treatment, parents often are overwhelmed by the amount of available information, since treatment issues are far from settled. In addition to the medical/educational therapies available today, this book also contains a detailed evaluation of alternative therapies.