Gastroparesis (GP), defined as delayed gastric emptying in the absence of any mechanical obstruction, is a challenging clinical condition, mainly because of limited treatment options. Studies in animal models of delayed gastric emptying as well as patients with gastroparesis revealed depletion or ultrastructural changes of interstitial cells of Cajal (ICC) in the gastric tissue, recently termed ICC-opathy. ICC are the pacemakers of the gastrointestinal tract and are involved in the transmission of the neuronal signaling to the smooth muscles. Therefore, lack of ICC could be one explanation of delayed gastric emptying in gastroparetic patients. How frequently ICC changes are observed in gastroparesis is not yet clear. In this review, the data on gastric ICC counts and morphology in animal models and patients with gastroparesis are discussed.
Gastric Emptying ; Gastrointestinal Tract ; Gastroparesis* ; Humans ; Interstitial Cells of Cajal ; Models, Animal ; Muscle, Smooth ; Neurons

BACKGROUND/AIMS: Nausea, an unpleasant symptom of diabetic gastroparesis (DMGP), has been reported to be alleviated by needleless transcutaneous electrical acupuncture (TEA). Our study was designed to utilize electroencephalography (EEG) and electrogastrography (EGG) recordings to investigate the central and peripheral responses of TEA in the treatment of nausea in DMGP patients. METHODS: Eleven DMGP subjects underwent simultaneous EEG and EGG testing while grading the severity of nausea following 30-minute intervals of: (1) baseline, (2) visual stimulation (VS) to provoke more nausea, (3) active VS together with TEA, and (4) TEA alone, and a final 15-minute recording without any intervention. RESULTS: The nausea score was increased to 5.9 ± 1.5 with VS (P < 0.05, vs 3.5 ± 1.0 at baseline), then reduced to 3.5 ± 1.2 with VS plus TEA, and to 2.5 ± 1.3 with TEA alone, while it continued at a score of 2.9 ± 1.0 post TEA (all significant, P < 0.05, vs VS without TEA). The mean percentage of normal gastric slow waves was decreased to 60.0 ± 5.7% with VS (P < 0.05, vs 66.6 ± 4.5% at baseline), then improved to 69.2 ± 4.8% with VS plus TEA, and maintained at 70 ± 3.6% with TEA alone. During initial VS, EEG signals showed right inferior frontal activity as the prominent finding, but during VS with TEA, left inferior frontal activity predominated. CONCLUSIONS: In DMGP, TEA improves gastric dysrhythmia and ameliorates nausea. TEA treatment of nausea provoked by VS resulted in a change of dominance from right to left inferior frontal lobe activity. These data provide new understandings of peripheral and central mechanisms for nausea, and potential future directions for DMGP treatment approaches.
Acupuncture* ; Electroencephalography ; Frontal Lobe ; Gastroparesis* ; Humans ; Nausea* ; Ovum ; Photic Stimulation ; Tea