Breakthrough pain in malignant and non-malignant diseases: a review of prevalence, characteristics and mechanisms.
Breakthrough pain or transient worsening of pain in patients with an ongoing steady pain is a well known feature in cancer pain patients, but it is also seen in non-malignant pain conditions with involvement of nerves, muscles, bones or viscera. Continuous and intermittent pain seems to be a general feature of these different pain conditions, and this raises the possibility of one or several common mechanisms underlying breakthrough pain in malignant and non-malignant disorders. Although the mechanisms of spontaneous ongoing pain and intermittent flares of pain (BTP) may be difficult to separate, we suggest that peripheral and/or central sensitization (hyperexcitability) may play a major role in many causes of BTP. Mechanical stimuli (e.g. micro-fractures) changes in chemical environments and release of tumour growth factors may initiate sensitization both peripherally and centrally. It is suggested that sensitization could be the common denominator of BTP in malignant and non-malignant pain.
Svendsen
Kristina B
KB
Danish Pain Research Center, University Hospital of Aarhus, Noerrebrogade 44, Building 1A, 8000 Aarhus, Denmark. kristina@akhphd.au.dk
Andersen
Steen
S
Arnason
Sigurdur
S
Arnér
Staffan
S
Breivik
Harald
H
Heiskanen
Tarja
T
Kalso
Eija
E
Kongsgaard
Ulf E
UE
Sjogren
Per
P
Strang
Peter
P
Bach
Flemming W
FW
Jensen
Troels S
TS
D006801:Humans; D010146:Pain / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology*; D010147:Pain Measurement; D015995:Prevalence; D020886:Somatosensory Disorders / Q000503:physiopathology