Cortico-NRM influences on trigeminal neuronal sensation

We tested the idea that migraine triggers cause cortical activation, which disinhibits craniovascular sensation through the nucleus raphe magnus (NRM) and thus produces the headache of migraine. Stimulation of the dura mater and facial skin activated neurons in the NRM and the trigeminal nucleus. Stimulation of the NRM caused suppression of responses of trigeminal neurons to electrical and mechanical stimulation of the dura mater, but not of the skin. This suppression was antagonized by the iontophoretic application of the 5-HT_1B/1D receptor antagonist GR127935 to trigeminal neurons. Migraine trigger factors were simulated by cortical spreading depression (CSD) and light flash. Activity of neurons in the NRM was inhibited by these stimuli. Multiple waves of CSD antagonized the inhibitory effect of NRM stimulation on responses of trigeminal neurons to dural mechanical stimulation but not to skin mechanical stimulation. The cortico-NRM-trigeminal neuraxis might provide a target for a more universally effective migraine prophylactic treatment.     

Evaluation of Fetal Growth and Fetal Well-Being

This article reviews the actual knowledge and future developments of ultrasound techniques for the evaluation of fetal growth and well-being. Sonography allows the visualization of the fetus in utero and is utilized worldwide for the evaluation of fetal growth and well-being. Fetal biometry assessment is performed in the second half of pregnancy when deviations of fetal growth can be best recognized through alterations of fetal abdominal circumference growth. Doppler velocimetry of utero-placental vessels identifies alterations of placental perfusion and is valuable in the assessment of fetal brain, heart, and liver perfusion, thus being utilized in the timing of delivery. Recently, three-dimensional ultrasound evaluation of fetal organs and placenta is being developed.     

Southampton needle sensation questionnaire: development and validation of a measure to gauge acupuncture needle sensation

OBJECTIVE: The specific sensations (deqi) generated during acupuncture are thought to be important for a positive clinical outcome, particularly when treating pain. It is important to be able to measure these sensations and discriminate between deqi and pain. A greater understanding of this will greatly aid researchers who wish to conduct mechanistic studies of acupuncture. Previous questionnaire designs failed to consider patient experience and, hence, may have been flawed. The aim of this study was to generate and validate a new sensation questionnaire, that was able to discriminate between pain and deqi, taking into account patient experience and expert opinions. DESIGN: The questionnaire was designed following qualitative interviews with patients, literature review, and consultation with experts. The questionnaire was piloted and then validated. It was successfully completed by 227 patients and analyzed using factor analysis and partial correlation. SETTING: Patients were recruited via the physical therapy department at Southampton General Hospital and from private practice clinics in and around the Southampton area. SUBJECTS: The subjects were patients receiving acupuncture for any condition. RESULTS: Two (2) factors were clearly demonstrated: "Aching deqi" (7 items) which suggested deqi with pain and "Tingling deqi" (7 items) suggesting deqi only. One (1) item related solely to pain and 2 further items did not load into any factor. CONCLUSIONS: The final questionnaire is presented containing 17 items and is shown to be a valid, rigorous, soundly grounded, and patient-centered measure, capable of accurately recording deqi. We suggest that analysis should include a partial correlation of certain sensations against a pain visual analogue scale to ascertain how painful each sensation was, particularly if the questionnaire is to be used in a context in which pain and deqi need to be separated or their relationship clarified.     

Awareness of temperature and pain sensation

Evoked potentials (EPs) to radiant or contact heat pain stimuli reflect the synchronization of brain activity to noxious inputs. However, we do not know how they relate to conscious awareness (AW) of a sensation. In healthy volunteers, we determined the time of AW for thermal noxious and non-noxious sensory inputs and examined its correlation to parametric measures of vertex EPs. Subjects had to report the position of the hand of a Libet's clock at the moment they perceived either a laser or a thermode stimulus. AW was determined after subtracting the position of the clock hand at the moment of stimulus delivery from the one reported by the subject, in ms. Subjects estimated AW in all single trials, including those in which no EPs could be identified. Mean AW was estimated earlier than the corresponding EP latency for both types and intensities of stimuli. There was a weak but significant negative correlation of AW to EPs amplitude, which was higher than the correlation of AW to EPs latency. Our results indicate that the timing of AW is influenced by the subjective relevance of sensory inputs. This feature could be used for the analysis of cognitive aspects of pain processing. PERSPECTIVE: This article presents a way to measure the subjective awareness of the sensation induced by a noxious heat stimulus, either radiant or contact, in healthy human subjects. This method could be used for the analysis of cognitive aspects of pain processing.     

Psychophysical properties of female genital sensation

Provoked vestibulodynia (PVD) is characterized by the presence of vulvar touch and pain hypersensitivity. Pain with vaginal distension, which motivates treatment seeking and perpetuates distress, is frequently reported with PVD. However, the concordance between the perception of vulvar and vaginal sensation (ie, somatic and visceral genital sensations, respectively) remains unstudied in healthy women, as well as in clinical populations such as PVD. To evaluate the static and dynamic (time-varying) properties of somatic and visceral genital sensation, women with PVD (n = 14) and age- and contraceptive-matched healthy controls (n = 10) rated varying degrees of nonpainful and painful genital stimulation. Somatic (vulvar) mechanical sensitivity to nonpainul and painful degrees of force were compared to visceral (vaginal) sensitivity to nonpainful and painful distension volumes. Results indicated that healthy women showed substantial individual variation in and high discrimination of vulvar and vaginal sensation. In contrast, PVD was associated with vulvar allodynia and hyperalgesia, as well as vaginal allodynia. Modeling of dynamic perception revealed novel properties of abnormal PVD genital sensation, including temporal delays in vulvar touch perception and reduced perceptual thresholds for vaginal distension. The temporal properties and magnitude of PVD distension pain were indistinguishable from vaginal fullness in healthy controls. These results constitute the first empirical comparison of somatic and visceral genital sensation in healthy women. Findings provide novel insights into the sensory abnormalities that characterize PVD, including an experimental demonstration of visceral allodynia. This investigation challenges the prevailing diagnostic assessment of PVD and reconceptualizes PVD as a chronic somatic and visceral pain condition.     

Fetal Monitoring

The severe risk situations characterized by fetal growth retardation are outlined. The small fetus, whether growth retarded or severely premature, is best delivered where both fetal monitoring and newborn resuscitation are available. The moderate risk fetus can be monitored at home base with clinical skills described in this article.     

Fetal Surgery

As prenatal diagnosis has become increasingly sophisticated and as technological advances have enhanced the range of diagnostic capabilities, invasive therapies have developed from our expanded understanding of the natural history and pathophysiology of structural anomalies. This article presents a comprehensive review of the treatment options currently available for the entire spectrum of fetal diagnoses that are potentially surgically correctable. The current indications, contraindications, and outcomes for shunting procedures, open fetal surgery, and fetoscopic surgeries are reviewed.     

Fetal imaging

Presently, MRI is an adjunct to prenatal sonography. It provides information that can aid in the diagnosis of fetal anomalies, affect prenatal counseling and management of the pregnancy, and guide prenatal intervention and delivery planning. With further advances in technology, particularly shorter scan times and better image resolution, the applications for fetal imaging are likely to increase.     

Fetal Megacystis

The purpose of our retrospective observational series was to determine whether the sonographic characteristics of fetal megacystic bladders can be used to reliably establish the most likely diagnosis in fetuses with this condition. The sonographic records of pregnant patients referred to our institutions over a 10‐year period who were found on initial 2‐dimensional sonography to be carrying fetuses with megacystis were examined for evidence of a keyhole sign, bladder thickness, amniotic fluid index, and fetal sex. When available, 3‐/4‐dimensional sonography, Doppler angiography, tomographic ultrasound imaging, virtual organ computer‐aided analysis, and automatic volume calculation were used as part of the detailed fetal anatomic survey. Twenty fetuses with megacystis were identified. Seventeen were male; 2 were female; and 1 had ambiguous genitalia. All male fetuses with megacystis originally had a diagnosis of prune belly syndrome. The diagnosis for 10 male fetuses with a keyhole sign was changed to megacystis secondary to posterior urethral valves. The fetus with ambiguous genitalia had prune belly syndrome. One of the female fetuses had a diagnosis of urethral atresia, and the diagnosis for the other female fetus was megacystis‐microcolon‐intestinal hypoperistalsis syndrome. In conclusion, in fetuses with megacystic bladders, it is possible to distinguish between cases with prune belly syndrome, posterior urethral valves, urethral atresia, and megacystis‐microcolon‐intestinal hypoperistalsis syndrome by a detailed anatomic survey using 2‐ and 3‐/4‐dimensioinal sonographic techniques.     

Fetal surgery

Fetal surgery has emerged from the realm of medical curiosity into an exciting, multidisciplinary specialty now capable of improving patient outcomes for a wide variety of diseases. Recent advances allow prenatal providers to both accurately diagnose and treat many fetal anomalies while maintaining maternal safety. As the initial postnatal health care providers to the majority of these newborns, neonatologists need to be familiar with some of the more recent state-of-the-art procedures currently being used. In this review, the authors discuss the prenatal evaluation process and various operative approaches (ie, open hysterotomy, fetoscopy, and percutaneous) to conduct fetal surgery. They then analyze the effectiveness of some of the more established and experimental prenatal therapies that are being performed for a number of fetal anomalies, including twin-twin transfusion syndrome, thoracic malformations, airway obstruction, congenital diaphragmatic hernia, myelomeningocele, and aortic valve stenosis.     

Fetal Imaging

Given that practice variation exists in the frequency and performance of ultrasound and magnetic resonance imaging (MRI) in pregnancy, the Eunice Kennedy Shriver National Institute of Child Health and Human Development hosted a workshop to address indications for ultrasound and MRI in pregnancy, to discuss when and how often these studies should be performed, to consider recommendations for optimizing yield and cost effectiveness, and to identify research opportunities. This article is the executive summary of the workshop.