Fibromyalgia – physiological aspects

Eva Kosek, MD., PhD., Assistant Professor

Department of Clinical Neuroscience, Karolinska Institute and Stockholm Spine Center, Stockholm, Sweden.

Lausanne 2008-05-22

Fibromyalgia - ACR 1990 criteria.

• History of widespread pain > 3 months

• Pain in at least 11 of 18 tender points on digital palpation.

Wolfe et al., 1990

CWP + TP =FMS (0.5-4%)

Female/male ratio 10:1

CWP (10-11%)Female/male ratio 1½:1

TP count - a crude screening tool for disturbed sensory processing?

Clauw and Crofford 2003

Increased pain sensitivity to all tested modalities

0 35 40 45 50

Temp. (°C)

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VA

S r

atin

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FM. pat. max. pain FM. pat. contralat. to max pain Controls `max. pain´ Controls contralat. to `max. pain´

Pressure pain Heat pain

Kosek et al 1995, 1996

Subjectively similar pain intensity:Similar central nervous system activation in both groups.

Same intensity of pressure stimulation:More pronounced and bilateral CNS activation in FM patients compared to healthy controls.

Evidence of enhanced transmission/processing of painful stimuli

Gracely et al., 2002

Left amygdala

Nucleus accumbens

Right dorsal ACC

Lower my-opioidreceptor bindning capacity in patients with fibromyalgia

Harris et al. 2007

Abnormal concentrations of pain related transmittor substances in the cerebrospinalfluid (i.e., serotonin, SP, glutamate)

Russell et al. 1992, 2002Sarchielli et al. 2007

FMS patients have increased sensitivity to somatosensory

stimuli independently of emotional factors – indicating

augmentation of pain transmission and/or processing.

Future Challenges

• Develop clinically useful diagnostic tools to detect facilitation, central sensitisation/disinhibition in individual patients

• Further development of new treatments targeting these CNS-abnormalities

• Investigate the possibilities of secondary prevention