Descriptive Psychopathology: The Signs and Symptoms of ...

266 Section 3: Examination domainsChronic pain can be understood as an expression of neuronal plasticity at thelevels of the nociceptor neurons, spinal cord, and brain. Faced with repeated stimulifrom an injury, the brain compensates by adjusting its responses to it. At somepoint the adjustment is sustained even if the injury resolves. 61 The patient is nothistrionic or malingering, rather a form of long-term learning has taken place.The underlying process in plasticity initially involves nociceptor and spinal cordmicroglia sensitization. This is reported in inflammatory disease, diabetes andinjury. 62 Long-term potentiation of dorsal horn neurons occurs, and underliessuch experiences as tactile allodynia and sensory hyperalgesia. 63 “On” and “off”cells in the rostral ventromedial medulla that modulate the transmission of painbecome “stuck” in the “on” position leading to further sensitization. 64 Pain-specificthalamic nuclei then become sensitized, effecting the cortical perception of pain. 65Anterior cingulate cortex metabolism increases in response to painful stimulationand thalamic input. 66 The somatosensory cortex reorganizes to accommodate theincreased input, highlighting the sensitization of involved body areas. 67 Thus, whatappears to be chronic pain of psychological origin is more likely the result ofCNS sensitization leading to hypersensitivity. A co-occurring intense emotionalstate as part of a mood or anxiety disorder exacerbates pain hypersensitivity,but the resolution of the emotional state may not resolve the chronic pain.Perceptual disturbances associated with migraineAlthough migraine is classified as a headache disorder, it is a complex syndromethat also includes perceptual, autonomic and other neurologic disturbances. Theperceptual features of migraine may be misunderstood as conversion disorder orhysteria, malingering, or as part of borderline personality disorder resulting inthe sufferer being denied appropriate treatment. Patients with cluster headacheare so fearful of future attacks that they may threaten suicide to avoid the painfulexperiences. This risk is high when headache control is poor and the threatmisinterpreted as manipulative. Patients with migraine are also most likely toexperience severe but treatable headache after ECT.The psychopathology of migraine is similar to that of seizure disorder, and thetwo conditions co-occur in patients and their first-degree relatives. 68 In migrainethe visual phenomena are commonly experienced in the peripheral visual field,while in seizure disorder perceptual symptoms are experienced centrally. 69 Sixtypercent of migraineurs report a prodrome of several minutes, hours or days thatinclude non-melancholic depression, irritability, fatigue, drowsiness, sluggishness,photo- and phono phobia, hyperosmia, neck stiffness, feeling cold, feelingthirsty, a change in appetite, and abdominal distress.About 20% of migraine sufferers report an aura of minutes to an hour thatimmediately precedes the headache. Auras include visual phenomena such as