Regional cerebral blood flow in patients with orally localized somatoform pain disorder: a single photon emission computed tomography study.
OBJECTIVE
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.
Karibe
Hiroyuki
H
Department of Pediatric Dentistry, School of Life Dentistry, Nippon Dental University, Tokyo, Japan. h-karibe@tky.ndu.ac.jp
Arakawa
Ryosuke
R
Tateno
Amane
A
Mizumura
Sunao
S
Okada
Tomoo
T
Ishii
Takashi
T
Oshima
Katsuo
K
Ohtsu
Mitsuhiro
M
Hasegawa
Isao
I
Okubo
Yoshiro
Y
D000328:Adult; D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging; D002560:Cerebrovascular Circulation / Q000502:physiology*; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D020367:Iofetamine; D008297:Male; D008875:Middle Aged; D009055:Mouth / Q000000981:diagnostic imaging*; D010146:Pain / Q000000981:diagnostic imaging*; D010147:Pain Measurement; D019275:Radiopharmaceuticals; D013001:Somatoform Disorders / Q000000981:diagnostic imaging*; D015899:Tomography, Emission-Computed, Single-Photon
D019275:Radiopharmaceuticals; D020367:Iofetamine