Page 204 Guide to Pain Management in Low-Resource Settings

192 Maija Haanpää and Aki Hietaharju

to central reorganization in the cerebrum, which ex- burning pain, but aching, pricking, and lacerating pain
plains the peculiar phenomenon of pain experienced is also common. Central poststroke pain is most often
in the missing part of the body. In some patients, phan- constant and spontaneous, but in rare cases it may be
tom limb pain is maintained by stump pain (a periph- paroxysmal and allodynic (i.e., evoked by touch, ther-
eral pain at the site of amputation). Phantom limb pain mal sensation, or emotions). Hyperesthesia is a com-
is more likely to occur if the individual has a history of mon fi nding in sensory examination. In a hemisphere
chronic pain before the amputation and is less likely if lesion, there is abnormal sensation on the contralateral
the amputation is done in childhood. side of the face, trunk, and limbs, and accompanying
Phantom pain is often similar to the pain felt motor paresis if the pyramidal tract is aff ected. In a low
before the amputation, and in addition, the patient may brainstem lesion, there is a crossed pattern in the sen-
experience nonpainful phantom phenomena, such as a sory changes: they are located ipsilaterally in the face
twisted leg. and contralaterally in the trunk and limbs due to dam-
Graded motor imagery and mirror therapy age of the ipsilateral trigeminal sensory nucleus and the
are novel and inexpensive approaches that have been crossed spinothalamic tract, respectively.
shown to reduce pain and disability in patients with
phantom limb pain. In graded motor imagery, patients Is all pain neuropathic in patients
go through three phases. First, they assess images who have had a stroke?
of their limbs in various positions. Th e second phase
consists of imagining moving the limbs in a smooth Nociceptive pain is also very common in patients who
and painless manner. Finally, patients end up by actu- have had a cerebrovascular lesion. It most often aff ects
ally mimicking the movement. In mirror therapy, pa- the shoulder and is related to changed dynamics due to
tients are instructed to use the mirror in such a way motor weakness on the aff ected side. Possible causes are
that the refl ected image of the intact limb seems to subluxation of the glenohumeral joint, rotator cuff tear,
appear in the place of the amputated or aff ected ex- soft tissue injury due to inappropriate handling of the
tremity. Th e mirror image produces an illusion of two patient, and spasticity of the shoulder muscles.
“healthy” limbs, and movement of the healthy limb
may ameliorate the phantom limb pain. Both of these
What are the characteristics
therapies aim at activation of cortical networks that
subserve the aff ected limb. of central pain after traumatic
brain injury?
What is the defi nition of central Traumatic brain injury occurs when a sudden, blunt, or

poststroke pain? penetrating trauma causes brain damage. Th e preva-
lence of central pain in patients with traumatic brain
All neuropathic pain directly caused by cerebrovascu- injury is not known. Chronic pain in these patients is
lar lesion (i.e. infarct or hemorrhage), independent of almost exclusively unilateral, and the most common
where the lesion is located, is called central poststroke qualities are pricking, throbbing, and burning. A curi-
pain. It was previously called thalamic pain according to ous feature is the manifestation of pain in body regions
the typical location of the lesion, but it can also be due that are not associated with local or spinal injury. Th ese
to cortical (parietal cortex), subcortical, internal capsule painful regions exhibit very high rates of pathologically
(posterior limb), or brainstem lesion. evoked pain (allodynia and hyperpathia). Th e most fre-
quently reported painful body regions are the knee area,
What are the clinical features of shoulders, and feet. Neuronal hyperexcitability has been
central poststroke pain? suggested as a contributing factor to the chronic pain.
Treatment of central pain in patients with traumatic
In the majority of patients, central poststroke pain is brain injury is challenging, because most of these pa-
a contralateral hemi-pain, not always including the tients are also suff ering from cognitive defi cits and emo-
face, but it may also be restricted to part of the upper tional distress, and neuropathic pain may overlap with
or lower extremity. Th e most common pain quality is pain of psychogenic origin.