Chronic Pain in Neurotrauma: Implications on Spinal Cord and Traumatic Brain Injury

Abstract

Long-lasting and persistent pain is a frequent consequence of spinal cord and brain injury. Several studies point to a significantly high proportion of patients who experience pain following the trauma. This chapter gives a brief overview of the prevalence, types of persistent pain, animal models that study pain outcomes, and the pertinent mechanisms that underlie the development of neuropathic pain following traumatic spinal cord and brain injury.Traumatic brain injury (TBI) and spinal cord injury (SCI) impose a high personal, social, and economic burden of disability. Although not as common as low back pain, TBI and SCI combined might have an equivalent economic impact mainly because of the young age of patients, the severity of the associated disability, and the major limitations on daily activity (Ma et al., 2014). Research-based estimates of the prevalence of persistent pain are variable and high in patients with SCI and TBI. Most studies indicate that about two-thirds of patients with either SCI or TBI will experience pain after the injury (Nampiaparampil, 2008; Siddall et al., 2003; Stormer et al., 1997; Uomoto and Esselman, 1993). Pain is consistently rated as one of the most difficult problems associated with these types of injuries (Nepomuceno et al., 1979; Rintala et al., 1998; Stensman, 1994; Westgren and Levi, 1998), hinders the ability to participate in rehabilitation programs (Widerstrom-Noga et al., 1999), and is difficult to treat. Chronic pain delays the acquisition of an optimal level of activity (Nicholson Perry et al., 2009) and independence and adversely affects the patients’ mood (Kennedy et al., 1997; Stroud et al., 2006).This chapter reviews and summarizes both clinical and experimental studies that focus on chronic pain after TBI and SCI. The emphasis will be in particular on the prevalence of chronic pain in patients with TBI and SCI. We highlight the specific types of pain that occur after injury. A survey of the different experimental animal models of brain and spinal cord injury evaluating pain as an outcome will be discussed. Finally, we will address the mechanisms responsible for the development of chronic pain following SCI and TBI.