ABSTRACT
Tinnitus refers to the perception of abnormal sound in the absence of external sound stimulation. It can have an impact on a person's mood, memory, attention, and mental state, although the mechanism of tinnitus is still unclear. In recent years, the research on the central neural mechanism of tinnitus has attracted the attention of scholars.Functional magnetic resonance imaging （fMRI）,as an effective imaging technology, has been actively employed in this field. This paper provides a systematic summary of studies on the central neural mechanism of tinnitus by fMRI in recent years,revealed the changes of functional connections among tinnitus-related neural networks,such as auditory network,limbic system,default mode network and salience network. The central neural mechanism of tinnitus involves multiple networks that interact with each other. By understanding this mechanism, we hope to develop more targeted prevention and treatment strategies to help patients alleviate long-term tinnitus.
Subject(s)
Humans , Tinnitus/diagnostic imaging , Magnetic Resonance Imaging/methods , AttentionABSTRACT
Objective:To detect the abnormalities within the functional connectivity (FC) of the prefrontal cortex (PFC) in patients with overactive bladder (OAB) and to explore its central pathogenesis.Methods:Seven OAB patients (OAB group, 6 females, mean age 47.6±16.0 years) and 13 healthy controls [HC] (HC group, 10 females, mean age 49.9±9.2 years) were prospectively enrolled from August to December 2020. All subjects underwent rs-fNIRS scanning synchronized with urodynamic monitoring, and two rs-fNIRS scans were performed when the bladder was empty and when the desire to void was strong/urodynamic monitoring indicated detrusor hyperactivity (DO). The Pearson's correlation coefficients (r value, i. e., FC value) between time series of the 22 channels were calculated, and a 22×22 FC matrix for each subject was obtained. A paired-sample t-test ( P<0.05, FDR corrected) was used to compare the difference in FC values between the HC group and the OAB group when the bladder was empty and the desire to void was strong. A two-sample t-test ( P<0.05, FDR corrected) was used to compare the group differences in FC values between OAB and HC groups. Results:In this study, 7 patients were included in the OAB group, including 1 male and 6 female. The mean age was (47.6±16.0) years old. In HC group, 13 healthy subjects were included, including 3 males and 10 females. The mean age was (49.9±9.2) years. There was no significant difference in baseline data between the two groups, including age, sex composition, years of education, handedness and urgency score at the second scan ( P>0.05). Residual urine volume in both groups was less than 10 ml. The OABSS score, 3-day urine diary parameters (frequency of urination/24 h, frequency of urinary incontinence/24 h, frequency of urgency/24 h) and maximum detrusor pressure during urine storage in OAB group were significantly higher than those in HC group, with statistical significance ( P<0.01). The average urination volume/time, bladder capacity at first sensation and maximum bladder capacity in OAB group were significantly lower than those in HC group, and the differences were statistically significant ( P<0.01). In the process of bladder filling to strong desire to void, the detrusor pressure in HC group was stable without DO, and 6 cases in OAB group had DO. Compared to empty bladder state, healthy subjects with strong desire to void showed significantly increased FC within PFC in 5 Brodmann area (BA9, BA10, BA44, BA45, BA46)and 13 edges, such as the BA9(left dorsolateral prefrontal cortex [DLPFC]: ch 4, 5, 7 and right DLPFC: ch 3), BA10(left frontopolar area: ch 12, 21 and right frontopolar area: ch 10, 18), BA44(left pars opercularis Broca's area: ch 15), BA45(left pars triangularis: ch 22), BA46(left DLPFC: ch 6, 14); significantly decreased FC in 3 brain regions (BA9, BA10 and BA46) and 2 edges, such as the BA9(left DLPFC: ch 7), BA10(left frontopolar area: ch21 and right frontopolar area: ch 17), BA46(right DLPFC: ch 9). There was no significant difference in FC within PFC between OAB and HC groups with empty bladder. However, during the strong desire to void state, the FC within PFC in OAB patients was significantly abnormal when compared with HC. OAB patients showed significantly increased FC within PFC in 4 brain regions (BA9, BA10, BA45 and BA46) and 4 edges, such as the BA9(right DLPFC: ch 1 and left DLPFC: ch 7), BA10(right frontopolar area: ch 17), BA45(left pars triangularis: ch 22), BA46(right DLPFC: ch 9, 16); significantly decreased FC in 3 brain regions (BA9, BA10 and BA46) and 4 edges, such as the BA9 (right DLPFC: ch 3 and left DLPFC: ch 4), BA10(left frontopolar area: ch 12, 21), BA46(left DLPFC: ch 14) Conclusion:Compared with HC group, the PFC in OAB group showed significant abnormalities, which may lead to "dyssynergia" of PFC internal functions, result in frontal lobe dysfunction, involving sensory integration, motivation drive, emotional control and decision whether to urinate or not, etc., leading to urinary control dysfunction, which manifested as typical clinical symptoms of OAB. Our findings contribute to the understanding of the central pathogenesis of OAB and may provide a theoretical basis for the emergence of targeted brain therapy in the future.
ABSTRACT
To further investigate the application of positron emission tomography (PET) technology in acupuncture research field, with "PET" and "acupuncture" as keywords, the related literature published from 1997 to 2018 was searched in PubMed, CNKI and WANFANG database; then the literature was classified and analyzed. The results showed that in clinical and experimental studies, whether in physiological or pathological conditions, PET technology has verified the specificity of acupoints, bidirectional regulation of acupoints, and the clinical effect of -arrival from the level of brain functional activity. It has deeply revealed the central mechanism underlying that acupuncture has multi-target, multi-channel and multi-level overall effects. The purpose of this study is to provide objective scientific basis for acupuncture research, and then potentially guide the clinical practice.
Subject(s)
Acupuncture Points , Acupuncture Therapy , Positron-Emission TomographyABSTRACT
The contents about the central action mechanisms of needling Zusanli (ST 36) were sorted by summarizing the relevant literatures published in the past 10 years, and it was found that: by comparing acupuncture at Zusanli (ST 36), other acupoints or sham points, most studies showed that Zusanli (ST 36) had relatively specific characteristics in the brain function response; studies on the central action mechanisms of Zusanli (ST 36) were mainly focused on sequelae of cerebral apoplexy, pain, gastrointestinal diseases, weight loss and drug addiction withdrawal and so on; acupuncture manipulations, stimulation methods, individual differences, stimulation quantity, and stimulation duration, etc. could also induce different brain function responses; acupuncture at Zusanli (ST 36) had an after-working effect, also called long-term effect, but with poor repeatability. So, it was suggested that the future studies should focus on the factors that affect the clinical efficacies and experimental results, including the compatibility effects of the acupoints, reproducibility of research results, sample size, acupuncture methods, long-term effects and disease entities.
ABSTRACT
Nitric oxide (NO), a diffusible gas, is produced in the central nervous system, including the spinal cord dorsal horn and the trigeminal nucleus, the first central areas processing nociceptive information from periphery. In the spinal cord, it has been demonstrated that NO acts as pronociceptive or antinociceptive mediators, apparently in a concentration-dependent manner. However, the central role of NO in the trigeminal nucleus remains uncertain in support of processing the orofacial nociception. Thus, we here investigated the central role of NO in formalin (3%)-induced orofacial pain in rats by administering membrane-permeable or -impermeable inhibitors, relating to the NO signaling pathways, into intracisternal space. The intracisternal pretreatments with the NO synthase inhibitor L-NAME, the NO-sensitive guanylate cyclase inhibitor ODQ, and the protein kinase C inhibitor GF109203X, all of which are permeable to the cell membrane, significantly reduced the formalin-induced pain, whereas the membrane-impermeable NO scavenger PTIO significantly enhanced it, compared to vehicle controls. These data suggest that an overall effect of NO production in the trigeminal nucleus is pronociceptive, but NO extracellularly diffused out of its producing neurons would have an antinociceptive action.