TABLE 5

Problems of the CNS That Are Sources of Pain or Have Features That Include Pain Behaviors

ProblemFeatures and Comments
Central neuropathic painSymptoms include pain localized to the gastrointestinal tract, such as pain triggered by distention of the gastrointestinal tract (suggested by pain associated with tube feedings or intestinal gas, with relief after a bowel movement or flatus)
Pain features can occur spontaneously and with no trigger, described by adults as “shock-like”
Attributable to impairment of the spinothalamic tract and thalamus
Visceral hyperalgesiaAltered threshold to pain generation in response to a stimulus in the gastrointestinal tract
Attributable to sensitization of visceral afferents as well as central sensitization in the CNS
Autonomic dysfunction (dysautonomia)Features that suggest dysautonomia: skin flushing, hyperthermia, pain localized to the gastrointestinal tract, retching, bowel dysmotility, general discomfort, agitation, tachycardia, sweating, arching, stiffening
Dysautonomia can be a source of discomfort, and pain can trigger the features that occur with dysautonomia
DystoniaInvoluntary sustained or intermittent muscle contractions cause twisting and repetitive movements, abnormal postures, or both
Children with secondary dystonia attributable to severe alterations of the CNS may also be at risk of central neuropathic pain
Pain can trigger and worsen features of dystonia
Paroxysmal autonomic instability with dystoniaInvolves features of both autonomic dysfunction and dystonia
Indicates altered function of the CNS areas that regulate autonomic function and movement
Pain can trigger and worsen the observed features
SpasticityVelocity-dependent increase in muscle tone that results in muscles that are resistant to movement
Spasticity is often not painful but can result in musculoskeletal pain over time
Muscle spasmsSudden involuntary contraction of a muscle or group of muscles; associated features can include arching, stiffening, tremors, and clonus
Pain behaviors can indicate pain from muscle spasms or indicate pain from another source as the trigger for muscle spasms
DeliriumDisturbance of consciousness with an acute onset over hours to days and a fluctuating course
Features include disordered thinking, change in cognition, inattention, altered sleep-wake cycle, change in arousal, and psychomotor disturbances