Relationship between cognition and functional outcomes after dysvascular lower extremity amputation: a prospective study.

OBJECTIVE: The aim of this study was to examine associations between a cognitive screen and four neuropsychologic tests administered at both 6 wks and 4 mos after amputation and five functional outcomes measured 12 mos after lower extremity amputation. DESIGN: This study includes a prospective cohort from four medical centers. Participants were primarily male Veterans experiencing their first lower extremity amputation as a result of complications of diabetes mellitus or peripheral arterial disease. Of those eligible, 87 (64%) enrolled; 75 (86%) were retained at 12 mos. Measures included demographic/health information, four neuropsychologic measures, the Locomotor Capability Index-5, the Gronigen Activity Restriction Scale, prosthetic use, community participation, and social integration. RESULTS: Better performance on the Short Portable Mental Status Questionnaire at 4 mos was associated with greater 12-mo mobility and social integration. Better attention and working memory abilities 6 wks after amputation were associated with increased 12-mo prosthetic wear; and at 4 mos after amputation, with greater 12-mo mobility. Better verbal memory at 6 wks was associated with greater 12-mo social integration and community participation as well as increased prosthetic wear. CONCLUSIONS: These findings highlight the potential value in including a brief, formal cognitive assessment in addition to a general mental status screen. Specific domains of cognitive function are differentially associated with functional outcomes and may inform amputation rehabilitation decisions.

Prevalence and 1-year course of alcohol misuse and smoking in persons with lower extremity amputation as a result of peripheral arterial disease.

OBJECTIVE: The aim of this study was to describe prevalence of alcohol misuse and smoking among individuals with amputations as a result of peripheral arterial disease before surgery and 12 mos after surgery, changes in these behaviors over time, and factors associated with change. DESIGN: This is a prospective cohort study of 75 veterans experiencing their first major unilateral amputation. Measures included demographic and general health information, Alcohol Use Disorders Identification Test, smoking behaviors, and social support. RESULTS: Sixteen percent of the participants reported engaging in alcohol misuse at presurgical baseline; and 13% at 12 mos after amputation. Thirty-seven percent of the participants were categorized as smokers at baseline; this number dropped to 29% at 12 mos after amputation. Among those who decreased drinking and quit smoking, there was a trend indicating greater social support. CONCLUSIONS: The participants endorsed drinking and smoking behaviors at levels consistent with other types of disability and with veterans using the Veterans Health Administration for their health care. Even with a variety of health concerns, after amputation, most of the smokers and those engaging in alcohol misuse continued to smoke and drink at their preamputation rate. The presence of social support may encourage health behavior change and is an important area for future research and intervention.

Changes in cognitive function from presurgery to 4 months postsurgery in individuals undergoing dysvascular amputation.

OBJECTIVE: To describe cognition among individuals with new amputations at 3 time points: presurgical, 6 weeks postamputation, and 4 months postamputation. DESIGN: Prospective cohort. SETTING: Medical centers. PARTICIPANTS: Referred sample Veterans who were primarily men (N=80) experiencing their first lower extremity amputation as a result of complications of diabetes mellitus or peripheral arterial disease. Patients were screened for the absence of gross cognitive impairment using the Short Portable Mental Status Questionnaire (SPMSQ). Of those 87 individuals who were eligible, 64% enrolled; 29 were enrolled presurgically and have cognitive data for all 3 time points, and 58 were enrolled postamputation. Eighty of the 87 individuals enrolled by 6 weeks remained enrolled at 4 months. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Demographic and general health information, general mental status (SPMSQ), and 4 brief, well-established neuropsychological measures. RESULTS: Most mean neuropsychological test scores fell in the low average or average range. For most participants, overall cognitive status improved from pre- to postsurgery and then remained stable between 6 weeks and 4 months. There were significant improvements between pre- and postsurgical test scores in verbal learning and memory, and these remained unchanged between 6 weeks and 4 months. Better 4 month cognitive performance was associated with higher perceived general health. CONCLUSIONS: Overall cognitive performance is poorest presurgically. Though there is improvement between pre- and postamputation, cognition appears generally stable between 6 weeks and 4 months.

Multiple traumatic limb loss: a comparison of Vietnam veterans to OIF/OEF servicemembers.

Multiple-limb loss due to war-theater injuries results in a unique group of servicemembers requiring intensive rehabilitation and diverse prosthetic devices. This article compares the Vietnam and the Operation Iraqi Freedom/Operation Enduring Freedom (OIF/OEF) groups with war-theater-associated multiple-limb loss to document significant changes in health status, prosthetic-device use, and long-term prognosis. During 2007 and 2008, a national survey queried 73 Vietnam veterans and 61 OIF/OEF servicemembers sustaining multiple-limb loss. Average years since limb loss are 39 for Vietnam veterans and 3 for OIF/OEF servicemembers. Self-rated health status was excellent or very good in 38.9% of the Vietnam group and 60.7% of the OIF/OEF group (p = 0.01). More of the OIF/OEF group than the Vietnam group reported performing high-impact aerobic activities, 18% versus 3% (p = 0.005). The OIF/OEF group currently uses more diverse prosthetic-device types than the Vietnam group. Based on Vietnam veterans' 39-year experience, the long-term prognosis for OIF/OEF servicemembers with multiple-limb loss is an active, fulfilling life. The healthcare team caring for these patients should carefully address proper prosthesis fit and maintenance of good health and function.

Arousal and attention deficits in patients with tinnitus.

We investigated the effects of tinnitus on measures of arousal and attention at various levels of the neuraxis to derive a profile of the pathophysiology of tinnitus. Individuals with tinnitus of at least 6 months' duration (14 male, 15 female) and healthy controls (14 male, 21 female) were tested for arousal and habituation to repetitive stimulation at the brainstem-thalamus level by measuring the P50 potential, a scalp-recorded, auditory-evoked response, using pairs of click stimuli. We used the psychomotor vigilance task, a reaction-time test, to assess attentional processes mediated by thalamocortical functions. We then correlated deficits in arousal and attention, as measured by these tests, with perceived tinnitus severity. Results showed no difference between tinnitus patients and controls in level of arousal or habituation to repetitive sensory stimulation, as measured by the amplitude of the P50 potential and the ability to suppress a second, closely paired stimulus, respectively. However, reaction-time assessments showed that patients with tinnitus have attentional deficits relative to controls (p = .02). We found no significant correlation between sleep disturbance or tinnitus severity and reaction-time testing.

Stimulation of the semicircular canals via the rotary chair as a means to test pharmacologic countermeasures for space motion sickness.

OBJECTIVE: Space motion sickness is currently treated pharmacologically with the empiric use of the H1 antihistamine promethazine, but use of this intervention is limited by the side effect of significant sedation. This creates a dilemma, as full cognition is particularly important during the same conditions likely to exacerbate the symptoms of space motion sickness. Using overstimulation of the semicircular canals with a rotary chair as a paradigm for space motion sickness, we evaluated four medications, commonly used for the treatment of terrestrial motion sickness and vertigo, for their efficacy in alleviating the simulated symptoms of space motion sickness. STUDY DESIGN: Randomized, prospective, double-blind study. SETTING: Tertiary referral center. PATIENTS: Healthy male and female volunteers, 18 years of age or older, without history of neurologic or psychiatric disorders, and with no known allergies or any previous adverse reactions to the drugs used. INTERVENTIONS: Lorazepam 1 mg, meclizine 25 mg, promethazine 25 mg, scopolamine 0.4 mg, or placebo. MAIN OUTCOME MEASURE: The ability of each treatment to control the nausea and vomiting associated with our paradigm for space motion sickness was evaluated by measuring time of rotation pre- and posttreatment and time of symptom onset pre-and posttreatment. RESULTS: Only scopolamine effected a mean change in duration of rotation that reached statistical significance when compared with placebo (p <0.008), with a greater than 40% increase in rotation time. Results with promethazine were not statistically significant. CONCLUSION: Results showed a rank order of efficacy of scopolamine > promethazine > placebo > meclizine > lorazepam. Scopolamine significantly increased rotation time, but none of the treatments resulted in a significant delay to onset of symptoms.

Effects of drug countermeasures for space motion sickness on working memory in humans.

Space motion sickness (SMS) is a problem during the first 72 h of space flight and during transitions from different gravity environments. There currently are no effective drug countermeasures for SMS that also accommodate the retention of optimal cognitive function. This creates a dilemma for astronauts because cognitive skills are particularly important during gravity transitions (e.g., take-off and landing). To quantify the cognitive side effects of potential drug countermeasures, an automated delayed matching-to-sample (DMTS) procedure was used to assess visual working memory before and after drug countermeasures (meclizine 25 mg, scopolamine 0.4 mg, promethazine 25 mg, or lorazepam 1 mg, given orally approximately 45 min prior to testing) and/or the induction of SMS by vestibular stimulation in a rotary chair (spinning). Sixty-seven normal healthy volunteers (mean age, in years, 26.6+/-4.8 S.D.; 24 females and 43 males) each participated in two test sessions, one 'off' drug and one 'on' drug. Spinning by itself significantly decreased task accuracy (Acc) and choice response speed, especially at longer recall delays. Meclizine alone had no effect on Acc or speed with or without spinning. Scopolamine alone decreased Acc, and with spinning, slowed speed. Promethazine alone had no adverse effect, but combined with spinning, decreased Acc and speed. Lorazepam alone decreased speed, and with spinning, decreased Acc. The data suggest that, at clinically useful doses, the rank order of the drugs with the best cognitive profiles is meclizine>scopolamine>promethazine>lorazepam.

Developmental aspects of timing behavior in children.

This research examined the association of age, sex, and intelligence on the performance of a time production (temporal response differentiation, TRD) task. Variations of this task have been used extensively with both animals and humans to study factors that affect aspects of timing ability. The participants in this study (720 children, ages 5 to 13 years) were required to hold down a response lever for at least 10 s, but no more than 14 s, to receive a nickel. Older children made more correct lever holds and exhibited less variability in the duration of their lever holds than did the younger children. Boys and girls performed similarly on this task, whereas children with higher IQs made more correct lever holds. Young children with below average IQs exhibited increased variability in lever hold duration compared with young children with average and above average IQs. The results of this study illustrate that both age and intelligence influence timing ability. The use of this timing task in children, which also has been widely used in animal models, provides unique opportunities for interspecies comparisons.

Stimulant medication improves recognition memory in children diagnosed with attention-deficit/hyperactivity disorder.

The effect of stimulant medication on recognition memory was examined in 18 children with attention-deficit/hyperactivity disorder (ADHD). Recognition memory was assessed using a delayed matching-to-sample task at 6 delays ranging from 1 to 32 s. Each child was tested on 2 separate occasions, once 60 to 90 min after taking stimulant medication and the other at least 18 hr after taking medication. Children performed significantly better on medication than off. Stimulant administration significantly increased accuracy and the number of nickel reinforcers earned. Decreases in observing response latency and correct choice response latency occurred after taking stimulant medication. The results indicate that stimulant medication improved recognition memory for children with ADHD.

An overview of assistive technology for persons with multiple sclerosis.

Multiple sclerosis (MS) is a progressive neurologic disease clinically characterized by episodes of focal disorder of the cranial nerves, spinal cord, and the brain. MS affects a significant number of young adults, and they most often face a future of progressive functional losses as more of their central nervous system and cranial nerves are affected. As the disease progresses, they have new impairments with accompanying limitations in activities, restrictions to their participation in life, and compromised quality of life. Assistive technology includes any item that is used to maintain or improve functional capabilities. The rehabilitation healthcare provider has many opportunities to intervene with assistive technologies to decrease activity limitations and participation restrictions. The purpose of this article is to (1) review the impairments and associated activity limitations and participations restrictions experienced by persons with MS, (2) provide an overview of high- and low-tech assistive technologies appropriate for persons with MS, (3) discuss funding opportunities for assistive technologies, (4) review current studies of assistive technology used for persons with MS and discuss future research directions, and (5) consider assistive technology as an intervention for disability prevention.