Regional cerebral blood flow in patients with orally localized somatoform pain disorder: a single photon emission computed tomography study.

AIM: Somatoform pain disorder is characterized by persistent and chronic pain at one or more sites without an associated general medical condition and in which psychological factors are thought to play a role. This study aimed to investigate the pathological features of somatoform pain disorder localized to the oral region by single photon emission computed tomography (SPECT). METHODS: Ten patients (nine females and one male; average age 55.0 ± 14.4 years) having somatoform pain disorder with oral symptoms participated. SPECT was performed using N-isopropyl-4-[(123) I] iodoamphetamine intravenous injections, and regional cerebral blood flow (rCBF) was assessed by three-dimensional stereotactic surface projections. We also selected 12 healthy individuals (seven females and five males; average age 61.8 ± 13.2 years) to act as controls. RESULTS: Both the patient and control groups showed no atrophy or infarction on CT or magnetic resonance imaging. The patient group showed higher rCBF in the subcortical area, especially in the thalamus and cingulate gyri, than the control group. In contrast, the patient group showed lower rCBF in the bilateral frontal and occipital lobes as well as in the left temporal lobe. CONCLUSIONS: These results suggest that the biological process involved in somatoform pain disorder of the oral region is characterized by changes in limbic and cortical functions. The finding that somatoform pain disorder with oral symptoms is associated with brain functional changes will help to develop treatment regimes for this disorder and clarify the underlying pathology.

Oral cenesthopathy examined by Rorschach test.

Experience of abnormal pains and unusual sensations in the mouth without a somatic base, for example abnormal mucus secretion, pulling sensation on the jaw or teeth, or a vibrating sensation, is termed 'oral cenesthopathy'. Psychological factors were investigated in terms of cognitive functions and personality tendencies, using Rorschach test in 28 patients with this condition (three men and 25 women). In oral cenesthopathy patients (i) the processing of new information is inefficient; (ii) the necessary resources for social adaptation are lacking, emotional control is inadequate, and uncomfortable emotions are expressed less; and (iii) with regard to interpersonal interaction, less interest is shown in others, trust in others is diminished, and they tend to have a higher Coping Deficit Index.