Predominant recurrence polarity among 928 adult international bipolar I disorder patients

Baldessarini RJ, Undurraga J, Vázquez GH, Tondo L, Salvatore P, Ha K, Khalsa H‐MK, Lepri B, Ha TH, Chang JS, Tohen M, Vieta E. Predominant recurrence polarity among 928 adult international bipolar I disorder patients. Objective: To test the hypothesis that patients with bipolar disorder (BPD) differ demographically and clinically within subgroups based on the predominant‐polarity of major recurrences. Method: We tested factors for association with predominantly (≥2 : 1) depressive vs. mania‐like episodes with 928 DSM‐IV type‐I BPD subjects from five international sites. Results: Factors preliminarily associated with predominant‐depression included: electroconvulsive treatment, longer latency‐to‐BPD diagnosis, first episode depressive or mixed, more suicide attempts, more Axis‐II comorbidity, ever having mixed‐states, ever married, and female sex. Predominant‐mania was associated with: initial manic or psychotic episodes, more drug abuse, more education, and more family psychiatric history. Of the 47.3% of subjects without polarity‐predominance, risks for all factors considered were intermediate. Expanding the definition of polarity‐predominance to ≥51% added little, but shifting mixed‐states to ‘predominant‐depression’ increased risk of suicidal acts from 2.4‐ to 4.5‐fold excess over predominant‐mania–hypomania, and suicidal risk was associated continuously with increasing proportions of depressive or mixed episodes. Conclusion: Subtyping by predominant‐polarity yielded predictive associations, including the polarity of first episodes and risk of suicide attempts. Such subtyping may contribute to improve planning of clinical care and to biological studies of BPD.     

Preserved emotional awareness of pain in a patient with extensive bilateral damage to the insula,anterior cingulate,and amygdala

Functional neuroimaging investigations of pain have discovered a reliable pattern of activation within limbic regions of a putative “pain matrix” that has been theorized to reflect the affective dimension of pain. To test this theory, we evaluated the experience of pain in a rare neurological patient with extensive bilateral lesions encompassing core limbic structures of the pain matrix, including the insula, anterior cingulate, and amygdala. Despite widespread damage to these regions, the patient’s expression and experience of pain was intact, and at times excessive in nature. This finding was consistent across multiple pain measures including self-report, facial expression, vocalization, withdrawal reaction, and autonomic response. These results challenge the notion of a “pain matrix” and provide direct evidence that the insula, anterior cingulate, and amygdala are not necessary for feeling the suffering inherent to pain. The patient’s heightened degree of pain affect further suggests that these regions may be more important for the regulation of pain rather than providing the decisive substrate for pain’s conscious experience.     

Determination of torque-limits for human and cat lumbar spine specimens during displacement-controlled physiological motions

Background contextQuadruped animal models have been validated and used as biomechanical models for the lumbar spine. The biomechanics of the cat lumbar spine has not been well characterized, even though it is a common model used in neuromechanical studies.PurposeCompare the physiological ranges of motion and determine torque-limits for cat and human lumbar spine specimens during physiological motions.Study design/settingBiomechanics study.Patient sampleCat and human lumbar spine specimens.Outcome measuresIntervertebral angle (IVA), joint moment, yield point, torque-limit, and correlation coefficients.MethodsCat (L2–sacrum) and human (T12–sacrum) lumbar spine specimens were mechanically tested to failure during displacement-controlled extension (E), lateral bending (LB), and axial rotation (AR). Single trials consisted of 10 cycles (10 mm/s or 5°/s) to a target displacement where the magnitude of the target displacement was increased for subsequent trials until failure occurred. Whole-lumbar stiffness, torque at yield point, and joint stiffness were determined. Scaling relationships were established using equations analogous to those that describe the load response of elliptically shaped beams.ResultsIVA magnitudes for cat and human lumbar spines were similar during physiological motions. Human whole-lumbar and joint stiffness magnitudes were significantly greater than those for cat spine specimens (p<.05). Torque-limits were also greater for humans compared with cats. Scaling relationships with high correlation (R² greater than 0.77) were established during later LB and AR.ConclusionsThe current study defined “physiological ranges of movement” for human and cat lumbar spine specimens during displacement-controlled testing, and should be observed in future biomechanical studies conducted under displacement control.     

Exaggerated heart rate oscillations during two meditation techniques.

We report extremely prominent heart rate oscillations associated with slow breathing during specific traditional forms of Chinese Chi and Kundalini Yoga meditation techniques in healthy young adults. We applied both spectral analysis and a novel analytic technique based on the Hilbert transform to quantify these heart rate dynamics. The amplitude of these oscillations during meditation was significantly greater than in the pre-meditation control state and also in three non-meditation control groups: i) elite athletes during sleep, ii) healthy young adults during metronomic breathing, and iii) healthy young adults during spontaneous nocturnal breathing. This finding, along with the marked variability of the beat-to-beat heart rate dynamics during such profound meditative states, challenges the notion of meditation as only an autonomically quiescent state.     

Interoceptive awareness declines with age

Aging has been shown to increase sensory thresholds for a variety of exteroceptive and proprioceptive stimuli. However, the influence of aging on interoceptive awareness has received relatively little empirical attention. Here we report an inverse association between aging and interoception, as indexed by the ability to sense the heartbeat at rest. In a group of 59 participants ranging in age from 22 to 63 years, age inversely predicted heartbeat detection ability, both within and across several measurement sessions. On average, age accounted for 30% of the variance in heartbeat detection accuracy. Other attribute variables including body mass index and sex were not related to heartbeat detection ability. These findings provide clear empirical evidence that interoception, much like exteroception and proprioception, declines with age.     

Effects of metoprolol on heart rate in patients with digitalis treated chronic atrial fibrillation

Adequate control of ventricular rate in patients with chronic atrial fibrillation (AF) may not be achieved with digitalis alone. In the present study the additional effect of two different doses (50 mg and 50 + 50 mg) of oral metoprolol, a new selective β-blocking agent, on ventricular rate in patients with longstanding AF has been studied. A decrease in the mean ventricular rate during rest and during exercise at various work loads was observed after both doses. The effect was more pronounced at the highest work load of 80 W, both after 50 mg (p < 0.002) and after 50 + 50 mg (p < 0.01) of the drug. A high initial heart rate at rest or during exercise was reduced more by the drug than a lower one. Exercise tolerance was reduced in 2 patients. These results suggest that patients with AF in whom satisfactory control of heart rate cannot be achieved with digitalis alone may benefit from addition of individualized metoprolol therapy.     

Cutaneous adverse reactions associated with calcium channel blockers

The calcium channel blockers, nifedipine, verapamil, and diltiazem, are widely used for the treatment of cardiovascular disease. In spite of their widespread use, little data about the frequency and spectrum of cutaneous reactions associated with these agents have been published. Based on reports provided to the FDA's Division of Epidemiology and Drug Surveillance, and the American Academy of Dermatology's Adverse Drug Reaction Reporting System, it appears that the frequency of adverse cutaneous events associated with these drugs is low, but that occasionally severe reactions are associated with the use of these drugs. Among the more serious reactions associated with the calcium channel blockers are toxic epidermal necrolysis with diltiazem, Stevens-Johnson syndrome and erythema multiforme, which have been associated with all three drugs in this class, and exfoliative dermatitis, which has also been reported with all three agents. Most serious reactions associated with these agents occur within two weeks of initiating drug therapy. These findings suggest that calcium channel blockers are occasional causes of a wide spectrum of cutaneous reactions and should be considered as possible causative factors in patients who develop adverse cutaneous reactions while using these drugs.     

Standards for the Uniform Reporting of Hypertension in Adults Using Population Survey Data: Recommendations From the World Hypertension League Expert Committee

Surveillance and monitoring of cardiovascular risk factors including raised blood pressure are critical to informing efforts to prevent and control cardiovascular disease. Yet, many countries lack the capacity for adequate national surveillance. Furthermore, hypertension indicators are often reported in different ways, which hampers the ability to compare and assess progress. In order to encourage standardized hypertension surveillance reporting, the World Hypertension League assembled an Expert Committee to develop a standard set of core indicators, definitions, and recommended analyses. The recommended core indicators are: (1) blood pressure distribution, (2) prevalence of hypertension, (3) awareness of the condition, (4) antihypertensive drug treatment, and (5) control of hypertension based on drug therapy. Each of these can be reported overall and by age group and sex, with crude and age‐standardized changes tracked over time in order to assess the impact of instituted policies and programs for hypertension prevention and control. An expanded list of indicators can also facilitate tracking of hypertension prevention and control efforts. Widespread adoption of these indicators and analyses could benefit all those conducting and analyzing hypertension surveys and will facilitate hypertension surveillance efforts.     

Encoding of compressive stress during indentation by group III and IV muscle mechano-nociceptors in rat gracilis muscle

The mechanical state encoded by group III and IV muscle afferents, putative mechano-nociceptors, during indentation was examined using an isolated muscle-nerve preparation in a rat model. Gracilis muscle and its intact innervation were surgically removed from the medial thigh of the rat hindlimb and placed in a dish containing rodent synthetic interstitial fluid. The tendons of the muscle were coupled to an apparatus that could stretch and apply compression to the muscle. Using a standard teased-nerve preparation, the neural responses of single mechanically sensitive group III or IV afferents were identified. Afferents were classified as mechano-nociceptors on the basis of their graded response to noxious levels of compressive stress (or strain) as well as, in some cases, their polymodal response to noxious thermal stimuli. Mechano-nociceptors (n = 13) were stimulated using controlled compressive stress (10-30 kPa) or strain (40-80%) while simultaneously measuring displacement and force by compressing the muscle between a flat cylinder and a hard platform. Linear regression was used to evaluate the relationships between neural response and mechanical stress, force, strain, and displacement. The mean neural response (threshold: 1.1 +/- 0.4 kPa; sensitivity: 0.5 +/- 0.1 Hz/kPa; means +/- SE) was significantly and substantially more highly correlated with compressive stress than force, strain, or displacement. The data from this study support the hypothesis that muscle nociceptors stimulated by indentation encode compressive stress rather than force, strain, or displacement.