This issue of Physical Medicine and Rehabilitation Clinics of North America is devoted to "Difficult to Treat Pain Syndromes," and is edited by Adam L. Schreiber, DO of the Jefferson Medical College of Thomas Jefferson University. Articles in this issue will include: Carpal Tunnel Syndrome Diagnosis; Non-surgical Treatment of Carpal Tunnel Syndrome; Parsonage Turner Syndrome Diagnosis and Treatment; Trochanteric Pain Syndrome Diagnosis and Treatment; Complex Regional Pain Syndrome Diagnosis and Treatment; Discogenic Spine Pain Syndrome Diagnosis and Treatment; Failed Back Surgery Syndrome Diagnosis and Treatment; Myofascial Pain Syndrome Diagnosis and Treatments; Opioid Syndrome Diagnosis and Treatment; Spinal Cord Pain Syndrome Diagnosis and Treatment; Cerebral Vascular Accident Hemishoulder Pain Syndrome Diagnosis and Treatment; and Cancer Pain Syndromes.