Reflex sympathetic dystrophy in cervical spinal cord injury patients

Sixty consecutive patients admitted to the spinal cord injury unit at a Downey, California medical center were evaluated for hand and upper extremity pain. Patients averaged nine months postinjury and had an average age of 37 years. Seven patients (11.7%) complained of diffuse hand pain, swelling, and stiffness. All patients with complaints were evaluated with three-phase radionuclide scintigraphy. Six of those seven patients had scintigrams consistent with reflex sympathetic dystrophy (RSD), an overall incidence of 10%. Three of these six patients were treated with stellate ganglion blocks, which gave relief of symptoms and allowed return to their rehabilitation program. An awareness of RSD as a cause of pain in spinal cord injured patients should lead to earlier recognition and treatment.     

Internal vascularity of the scaphoid in cadavers after insertion of the Herbert screw

This article describes the effects of various operative exposures for insertion of the Herbert screw on the internal vascularity of the scaphoid. Vessels supplying the proximal 70% to 80% of the scaphoid were intact in all specimens except one, which had a combined palmar and dorsal. approach. Vessels supplying the tubercle and the distal 20%-30% were disrupted in five of 18 specimens undergoing the palmar approach. The palmar approach did not disrupt the significant dorsal blood supply, and the dorsal approach was safe provided care was taken to preserve the visible dorsal vascular leash.     

Reflex sympathetic dystrophy in brain-injured patients.

One-hundred consecutive patients were prospectively evaluated on admission to our Brain Injury Unit for signs and symptoms of reflex sympathetic dystrophy (RSD) in the upper extremity. Patients averaged 4 months postinjury and had an average age of 29 years. Thirteen patients had clinical signs and symptoms of RSD and were then evaluated with standard radiographs and 3-phase radionuclide scintigraphy. Twelve of 13 patients had 3-phase bone scans (TPBS) consistent with RSD (12% overall incidence). RSD was present exclusively in the spastic upper extremity. There were 9 patients with hemiparesis and 3 with quadraparesis. There was a significantly higher (P < 0.01) incidence of associated upper extremity injury in the group with RSD (75%). All patients had a mean Rancho Cognitive Level of V and initial Glasgow Coma Scores less than 8. Patients who developed RSD had lower Glasgow Coma Scores than the non-RSD patients. Brain-injured patients often display agitation, hyperalgesia, disuse or neglect of the RSD-involved extremity. In addition, these patients are often cognitively unable to vocalize complaints of pain. Undiagnosed RSD in these patients can result in a significant delay in rehabilitation and possible loss of the use of an otherwise functional upper extremity.     

Posture, Place, and Mood Effects on Ambulatory Blood Pressure

Ambulatory blood pressure was studied as a function of posture, place, and mood in 131 subjects classified according to race, gender, and hypertensive status. The effect of posture was significant and explained a substantial proportion of within-subject variability. After controlling for posture, significant place and mood effects were observed when subjects were sitting but not when they were standing. Home vs. work differences in both systolic and diastolic blood pressure were significantly greater in Whites than in Blacks. Similar differences in systolic blood pressure were greater in mild hypertensive than in normotensive subjects. The results of this study underscore the need to control for effects of posture when interpreting ambulatory blood pressure readings.     

Predicting Home and Work Blood Pressure Measurements from Resting Baselines and Laboratory Reactivity in Black and White Americans

The relationship between blood pressure in the laboratory (both at rest and in response to laboratory tasks) and ambulatory blood pressure at home and at work was evaluated. One hundred nineteen normotensive and unmedicated mild-moderate hypertensive black and white females and males participated in laboratory blood pressure monitoring at rest and during four challenging tasks (structured interview, video game, bicycle exercise, and cold pressor test) as well as ambulatory blood pressure monitoring while at home and at work. Baseline blood pressure taken while subjects were at rest was the strongest predictor of ambulatory systolic blood pressure (r = .64) and diastolic blood pressure (r = .77) at work. Among reactivity tasks the strongest predictors of ambulatory blood pressure in the total population were the structured interview and the video game (both psychological tasks) followed by the cold pressor test. Racial comparisons, however, determined that the cold pressor test predicted diastolic blood pressure significantly better for blacks (r = .73) than for whites (r = .40), suggesting a possible difference in blood pressure regulation.     

Control strategies in directing the hand to moving targets

Summary We have evaluated the use of visual information about the movement of a target in two tasks tracking and interceptions — involving multi-joint reaching movements with the arm. Target velocity was either varied in a pseudorandom order (random condition) or was kept constant (predictable condition) across trials. Response latency decreased as target velocity increased in each condition. A simple model that assumes that latency is the sum of two components — the time taken for target motion to be detected, and a fixed processing time — provides a good fit to the data. Results from a step-ramp experiment, in which the target stepped a small distance immediately preceding the onset of the ramp motion, were consistent with this model. The characteristics of the first 100 ms of the response depended on the amount of information about target motion available to the subject. In the tracking task with randomly varied target velocities, the initial changes in hand velocity were largely independent of target velocity. In contrast, when the velocity was predictable the initial hand velocity depended on target velocity. Analogously, the initial changes in the direction of hand motion in the interception task were independent of target velocity in the random condition, but depended on target velocity in the predictable condition. The time course for development of response dependence was estimated by controlling the amount of visual information about target velocity available to the subject before the onset of limb movement. The results suggest that when target velocity was random, hand movement started before visual motion processing was complete. The response was subsequently adjusted after target velocity was computed. Subjects displayed idiosyncratic strategies during the catch-up phase in the tracking task. The peak hand velocity depended on target velocity and was similar for all subjects. The time at which the peak occurred, in contrast, varied substantially among subjects. In the interception task the hand paths were straighter in the predictable than in the random condition. This appeared to be the result of making adjustments in movement direction in the former condition to correct for initially inappropriate responses.     

Eye position signals in human saccadic processing

Summary 1. We studied saccades to briefly flashed targets in 8 human subjects. The target flash occurred (i) during smooth pursuit (ramp-flash), (ii) just before a saccade to another target (step-flash), or (iii) during steady fixation (flash only). All lights were extinguished after the target flash so that smooth pursuit or saccadic eye movements occurred during the interval of complete darkness between the target flash and the saccade to it. We compared these saccades to those made without intervening eye movement (flash only), and quantified the extent to which the saccadic system compensated for the change in eye position that occurred during the dark interval. 2. Saccades to control flashes were reasonably accurate (mean gain 0.87) and consistent. Compensation for the intervening eye movement in the ramp-flash and step-flash paradigms was highly variable from trial to trial. On average, subjects compensated for 27% of the intervening pursuit eye movement on ramp-flash trials and for 58% of intervening saccadic movement on step-flash trials. 3. Multiple regression analysis showed that the variability did not depend on factors such as variations in underlying saccadic gain, response latency, timing of stimuli or size of the required response. We conclude that this variability is intrinsic to saccadic responses that require the use of an eye position signal. 4. These results show that an eye position signal is available to the saccadic system but that this signal has low fidelity. The high variability and low fidelity of the eye position signal suggest that the saccadic system does not normally operate in spatial coordinates, which require the use of an accurate eye position signal, but rather in retinal coordinates.     

Lifestyle modification and weight reduction among low-income patients with the metabolic syndrome: the CHARMS randomized controlled trial

Although weight is an important intervention target among patients with metabolic syndrome, few trials have recruited low-income minority populations. The Community Health and Risk-reduction for Metabolic Syndrome randomized controlled trial aimed to examine the effects of a lifestyle intervention on weight and metabolic syndrome components among low-income minority adults. We randomized 120 adults with metabolic syndrome to standard medical care (N = 60) or a lifestyle intervention (N = 60). Using an intent-to-treat approach, we found significant intervention effects on weight [B = ?0.452; SE = 0.122; 95 % confidence intervals (CI) ?0.653 to ?0.251) and glucose levels at 6-months (B = ?0.522, SE = 0.234, 95 % CI ?0.907 to ?0.138). These changes were maintained through the 12-month assessment. No significant effects were observed on insulin resistance or other metabolic syndrome components. Our intervention was successful in achieving modest but significant weight loss and reduction in fasting glucose among low-income minority subjects with metabolic syndrome.     

Arterial patterns of the deep and superficial palmar arches

The vascular patterns of the palmar arches and their interconnecting branches present a complex and challenging area of study. Improvements in microsurgical techniques have made a better understanding of vascular patterns and vessel diameters more important. Forty-five fresh limbs from cadavers were amputated at the level of the midhumerus. Ward's red latex or Batson's compound was injected under pressure to visualize the arterial system in the hand. After hardening of the injected material, the skin, subcutaneous tissues, and tendons were removed. The specimens were digested in concentrated potassium or sodium hydroxide leaving the bony elements and a cast of the arterial system. The superficial palmar arch is most easily classified into two categories: complete or incomplete. An arch is considered to be complete if an anastomosis is found between the vessels constituting it. An incomplete arch has an absence of a communication or anastomosis between the vessels constituting the arch. Complete superficial palmar arches were seen in 84.4% of specimens. In the most common type, the superficial arch was formed by anastomosis between the superficial volar branch of the radial artery and the ulnar artery. This was seen in 35.5% of specimens. In 31.1%, the arch was formed entirely of the ulnar artery. Incomplete superficial arches were seen in 15.5% of specimens. In 11.1%, the ulnar artery forms the superficial arch but does not contribute to the blood supply to the thumb and index finger. The deep palmar arch was found to be less variable with 44.4% formed by an anastomosis between the deep volar branch of the radial artery and the inferior deep branch of the ulnar artery. Injection followed by chemical debridement allows direct visualization and measurement of the arches and the smaller arterial branches that are visualized poorly with other techniques. Based on the vessel measured, vessels of the superficial and deep arches are of sufficient size to allow microvascular repair, although repair of the communicating branches, the dorsal carpal rete, and its branches, probably is not feasible because of their small size.