Relationship between pain symptoms and referred sensory and trophic changes in patients with gallbladder pathology.

The relationship was investigated between algogenic potential of gallbladder pathology and occurrence/extent of sensory and trophic changes in the referred area. Five groups of subjects were studied, with: symptomatic gallbladder calculosis (3-20 colics); asymptomatic calculosis; symptomatic gallbladder shape abnormality (8-18 colics); asymptomatic shape abnormality; normal gallbladder/no symptoms. At the cystic point (CP) and contralaterally, all underwent measurement of: pain thresholds to electrical stimulation of skin, subcutis and muscle; thickness of subcutis and muscle via ultrasounds. Contralaterally to CP, all thresholds were not significantly different in the five groups. At CP, subcutis and muscle thresholds were significantly lower in symptomatic vs asymptomatic patients and/or normals (0.0001<P< 0.05). In symptomatic cases, at CP compared to contralaterally, subcutis and muscle thresholds were significantly lower (0.0001<P<0.02), subcutis thickness was significantly higher and muscle thickness significantly lower (0.006<P<0.02). Subcutis and muscle thresholds at CP in symptomatic patients were significantly and inversely correlated linearly to the number of colics (P<0.0004; P<0.0001). Patients with symptomatic calculosis were re-evaluated after 6 months; those not presenting further colics showed a significant increase in subcutis and muscle thresholds at CP, while those who continued presenting colics showed a further significant threshold decrease (0.01<P<0.05); tissue thickness did not vary. Referred hyperalgesia and altered trophism from the gallbladder only occur in painful pathology, their extent being modulated by the amount of perceived pain. The results suggest different mechanisms by which visceral nociceptive inputs trigger sensory vs trophic changes in the referred area.