Page 383 Guide to Pain Management in Low-Resource Settings

Appendix: Glossary 371

Spondylolisthesis in the cerebellar region) or due to pulsatile compres-
Forward movement of one of the vertebrae of the spine sion by the cerebellar artery that causes brief attacks
in relation to an adjacent vertebra, most often at the of severe pain in the lips, cheeks, gums, or chin on one
level of L5/S1. Simple “functional” X-ray (lateral view side of the face. Only a symptom complex including
in full extension and full fl exion of the spine) may dem- attack-like pain of less than 2 minutes, no neurological
onstrate spondylolisthesis. Only a major forward move- defi cits, absent or minor chronic pain, and typical trig-
ment (>25–50% of the vertebral length) is an indication ger factors should be diagnosed as trigeminal neural-
for surgery. gia. Carbamazepine is still considered to be the drug of
fi rst choice. If drug therapy fails, trigeminal neuralgia
Substance P is one of the few pain syndromes where surgery is in-
Substance P is a member of the tachykinin family of dicated (Janetta surgery).
neuropeptides that is expressed in sensory neurons.
World Health Organization
It works as a stimulatory neurotransmitter or neuro-
modulator when it is released centrally, and as a proin- An agency of the United Nations established in 1948
fl ammatory mediator when it is released peripherally. to further international cooperation in improving
It activates the neurokinin-1 receptor, a major factor in health conditions. Although the World Health Or-
central sensitization. ganization (WHO) inherited specifi c tasks relating
to epidemic control, quarantine measures, and drug
Withdrawal syndrome standardization from the Health Organization of the

Th e abrupt cessation of a repeatedly or continuously ad- League of Nations (which was set up in 1923) and
ministered opioid agonist, or the administration of an from the International Offi ce of Public Health at Par-
antagonist, typically results in withdrawal syndrome. is (established in 1909), the WHO was given a broad
Signs and symptoms include sweating, tachycardia, hy- mandate under its constitution to promote the attain-
pertension, diarrhea, hyperventilation, and hyperrefl ex- ment of “the highest possible level of health” by all
ia. See also the entry on “Dependence”. people. WHO defi nes health positively as “a state of
complete physical, mental, and social well-being and
Tolerance
not merely the absence of disease or infi rmity.” Th e
Tolerance is the need for progressively increasing doses
cancer pain management recommendations of the
of an agonist to maintain the same eff ect (e.g., analge- WHO (the analgesic ladder) have had a major eff ect on
sia). In chronic pain, the need for increasing doses of
the rate of opioid prescriptions to patients with cancer
opioids can be due to alterations in receptor functioning and HIV-related pain, mainly in countries belonging to
(e.g., coupling to G proteins, second messengers) and/
the Organization for Economic Co-operation and De-
or to increasing painful stimulation (e.g., by a growing velopment (OECD). Unfortunately, Eastern European
tumor), among other reasons. Tolerance is fortunately
countries and many low-resource countries continue
not common in patients who have opioid-sensitive pain. to have only very restricted opioid delivery rates to
In patients seeking opioid treatment for mood stabiliza-
cancer patients, which should be considered a health
tion, tolerance is frequent. Th erefore, in patients with emergency. Th e Pain and Policy Study Group of the
nonmalignant pain and nonprogressing disease, the re-
WHO is investing a lot of eff ort to infl uence this situ-
peated need for dose escalation (typically every 4 to 8 ation by advising government authorities and health
weeks, when tolerance to the sedating and euphoric
care workers on legislative, educational, and treat-
eff ects of opioids develops) should be a warning sign ment changes necessary to be able to provide adequate
for “inadequate” opioid use, and the opioid medication
amounts of opioids to patients in need. For further in-
should be gradually discontinued. formation see their website for a lot of relevant facts
Trigeminal neuralgia regarding opioids in most countries of the world.

A disorder of the trigeminal nerve in its root area (e.g.,
secondary trigeminal neuralgia due to malignant masses