Cerebellar subjects show impaired coupling of reach and grasp movements

We examined how cerebellar deficits in isolated reaching or grasping movements contribute to abnormalities in a combined reach and grasp movement, and whether people with cerebellar damage show abnormalities in the spatiotemporal relationships of reach and grasp movements. We studied subjects with cerebellar damage and matched controls as they performed a combined reach and grasp, an isolated reach, and an isolated grasp. These movements were performed under slow-accurate and fast speed conditions. Subjects were also tested for their ability to correctly estimate the target size based on visual information. We measured the three-dimensional position of the index finger, thumb and wrist joint during all tasks. Results showed that cerebellar subjects overestimated the target size to a greater extent than did controls. During movement testing, cerebellar subjects were impaired on isolated reach and isolated grasp. However, they did not worsen parameters of reach or grasp movements during the combined reach and grasp. Instead there were distinct deficits in the coupling of the reach and grasp movement. Compared with controls, cerebellar subjects showed abnormalities in the sequence of the reach and grasp movement and highly variable timing of peak grip aperture. In the slow-accurate condition, cerebellar subjects decomposed the reach and grasp movement into separate reach then grasp components, and produced multiple peaks in grip aperture. In the fast condition, cerebellar subjects did not decompose, produced a single peak grip aperture, and dropped the target more often. These results indicate that cerebellar damage can cause a specific breakdown in the coupling of reach and grasp movements. The cerebellum may be involved in combining reach and grasp movements into a single motor program.     

Pulmonary protective mechanisms in human infants

The flow of oral and nasal secretions into the pharynx is a recognized source of pulmonary aspiration during sleep in infants and adults alike. Such aspiration probably accounts for many cases of bacterial pneumonia. In infants, swallowing occurs frequently in sleep, and the rate of swallowing appears to be far greater than that of the sleeping adult. Such swallowing during sleep appears to be the major mechanism whereby oral and nasal secretions are transported to the digestive tract. Certain aspects of those swallows, such as "swallow-breaths" and their coordination with the respiratory cycle, have been documented. A brief period of airway closure is always seen during such nonfeeding swallows. Nonfeeding swallows are usually seen during mixed and obstructive apneic spells in preterm infants. The underlying reflex mechanisms responsible for such swallows during apnea are unclear. During ordinary postfeeding regurgitation, upper airway closure and swallowing occur in close temporal sequence. These events appear to be major mechanisms of airway protection during regurgitation. In certain infants, regurgitation and prolonged apnea often occur simultaneously. The mechanism underlying their association is unclear but may involve laryngeal chemoreceptors.     

Laser injuries of the eye.

With the increasing use of lasers in the military and industry, a moderate number of significant retina injuries have occurred. These injuries have been due to lasers in the visible and near-infrared spectrum primarily, with a pulse duration in the nanosecond range. Use of lasers in the ophthalmic community has resulted also in structural damage to the cornea, lens, IOL, and retina. Because we have no proven treatment for most injuries to the retina, we must continue to strongly emphasize the use of wavelength-specific protective goggles to try to prevent future eye injuries.     

Motor performance benefits of matched limb imitation in prosthesis users

Our previous work demonstrated that the action encoding parietofrontal network, which is crucial in planning and executing motor tasks, is less active in prosthesis users who imitate movements of intact actors (mismatched limb) versus prosthesis users (matched limb). Such activation could have behavioral consequences in prosthesis users rehabilitating with intact therapists. The goal was to identify behavioral effects of matched versus mismatched limb action imitation in naïve users of prostheses. Intact subjects donned a specially adapted prosthetic device to simulate the wrist and forearm movement that transradial amputees experience. While electrogoniometry was recorded, non-amputated prosthesis users (NAPUs) observed and imitated demonstrations of a skillful motor task performed by either an intact actor or NAPU. We hypothesized that NAPUs would elicit less motion variability when performing matched versus mismatched imitation. Matched imitation resulted in a significant decrease in shoulder motion variability compared with mismatched imitation. The matched group also developed elbow motion patterns similar to the NAPU demonstrator, while the mismatched group attempted patterns similar to the intact demonstrator. This suggests a behavioral advantage to matched imitation when adapting to a prosthetic device, as it yielded more consistent movements and facilitated development of new motor patterns. Further, these results suggest that when prosthesis users are faced with the impossible task of imitating movements of an intact hand, they perform this action with greater variability and poorer technique. This work has implications on how prosthetic device operation is conveyed to persons with amputation as their clinical interactions often involve mismatched limb imitation.     

Reports of Injury Risks and Reasons for Choice of Sleep Environments for Infants and Toddlers

Objective

Compare mothers’ reports of injuries for infants and toddlers sleeping with crib-bumpers/mesh-liners/no-barriers and reasons for these sleep environment choices.

Methods

A cross-sectional survey of mothers subscribing to a parenting magazine and using crib bumpers (n?=?224), mesh liners (n?=?262), and no barriers (n?=?842). Analyses of four possible injuries (face-covered, climb-out/fall, slat-entrapment, hit-head) including multivariate logistic regression adjusted for missing data/demographics and Chi squared analyses of reasons for mothers’ choices.

Results

Maternal reports of finding infants/toddlers with face covered had 3.5 times higher adjusted odds (aOR) for crib bumper versus mesh liner use. Breathing difficulties and wedgings were reported for infants/toddlers using crib bumpers but not mesh liners. Climb-outs/falls showed no significant difference in aORs for crib bumpers versus no-barriers and mesh liners versus no barriers. Reports of slat-entrapment were less likely for mothers using crib bumpers and mesh liners than using no barrier (aOR?=?.28 and .32). Reports of hit-heads were less likely for crib bumpers vs no barrier (aOR?=?.38) with no significant difference between mesh liners versus no barrier use. Mothers using crib bumpers and mesh liners felt their choice prevented slat-entrapment (89%, 91%); 93.5% of crib bumper users felt their choice prevented hit-heads. Significantly more mesh liner than crib bumper users chose them because “There is no suffocation risk” (64.1% vs. 40.6%), while 83.6% of no-barrier users chose them because “I was concerned about suffocation risk.”

Conclusions for Practice

Mothers appeared to be more concerned about preventing minor risks than suffocation. Understanding reasons for mothers’ use of barriers/no-barriers is important in tailoring counseling for mothers with infants/toddlers.

     

Inflammation and Vascular disease: the role of C-reactive protein

Inflammation is an important component of active atherosclerotic disease. C-reactive protein (CRP)is a non-specific inflammatory marker that is increased in inflammatory conditions. Newer more sensitive assays (high sensitivity CRP) can detect the low levels of inflammation associated with vascular disease. CRP levels can give further risk assessment to individuals beyond predictions from traditional risk factors. This measurement is most useful in helping to discriminate risk in intermediate risk patients such as metabolic syndrome patients. Exercise and weight loss have been shown to significantly lower CRP levels. Lipid lowering therapies, especially with the statin class of medications, also lower CRP levels. A reduction in inflammation may be an important component of plaque stabilization and contribute to cardiovascular risk reduction.     

Characteristics of individuals meeting criteria for new onset panic attacks following exposure to a typhoon

The association between trauma exposure and panic attacks has received increased attention over the past decade, with mounting evidence suggesting an overlapping etiologic pathway. This study examined the incidence of new onset panic attacks in 775 Vietnamese individuals in the 2–3 months following Typhoon Xangsane. Pre-typhoon (Wave 1) and post-typhoon (Wave 2) assessments were conducted, allowing for consideration of factors occurring prior to the typhoon in addition to typhoon-relevant responding. Of the 775 participants, 11.6% (n=90) met criteria for lifetime panic attack pre-typhoon and 2.8% (n=22) met post-typhoon panic attack criteria. Individuals with pre-typhoon panic were significantly older and reported less education compared to the no-panic group. Individuals in both panic groups were more likely to screen positive on a Wave1 psychiatric screening measure, endorse greater typhoon exposure and prior traumatic event exposure and were significantly more likely to meet DSM-IV criteria for posttraumatic stress disorder (PTSD) and major depression (MDD) post-typhoon compared with persons reporting no history of panic attacks. Pre and post-typhoon panic exhibited similar patterns across variables and both panic conditions were associated with the development of PTSD and MDD, suggesting that persons experiencing panic attacks may represent a vulnerable population in need of early intervention services.