PubMed Health⌕ Search

Biomedical subjects

Lawrence R Robinson

Publications and source records attributed to Lawrence R Robinson.

At least 19 recordsLinked to original sources
PubMed2006

Preamputation pain and acute pain predict chronic pain after lower extremity amputation.

UNLABELLED: Although previous research suggests that preamputation pain is a risk factor for pain after amputation, little is known about the association between acute postsurgical pain and chronic amputation-related pain. The current prospective study examined the associations of preamputation pain and acute postamputation pain with chronic amputation-related pain. The sample consisted of patients with lower limb amputation (N = 57) who provided both preamputation and postamputation data during a 2-year study period. Preamputation pain intensity and duration were assessed before amputation; acute phantom limb pain (PLP) and residual limb pain (RLP) intensity were assessed on postsurgical days 4 and 5. Acute PLP intensity was the only significant independent predictor of chronic PLP intensity at 6 and 12 months after amputation, whereas preamputation pain intensity was the only significant predictor of chronic PLP intensity at 24 months. Similarly, acute RLP was found to be the best overall predictor of chronic RLP. Other variables (age, gender, level and etiology of amputation, amount of postsurgical pain medication, and duration of preamputation pain) were not associated with chronic pain. These results suggest that higher levels of pain either before or soon after amputation might help to identify individuals at greatest risk for chronic pain problems and most in need of early, intensive pain interventions. PERSPECTIVE: This study suggests that both preamputation pain and acute pain soon after amputation might be associated with bothersome chronic pain. The results support further research on acute pain mechanisms and the effectiveness of early interventions aimed at preventing or managing amputation-related pain.

Acute Disease↗
PubMed2006

Electromyographic studies in mdx and wild-type C57 mice.

The electromyographic (EMG) characteristics of human Duchenne muscular dystrophy (DMD) have been well-described. However, to our knowledge, no prior needle electromyographic (EMG) studies of motor unit morphology have been undertaken in muscles from the mdx mouse, an animal that is genetically homologous to DMD. There are significant phenotypic differences between the human and murine dystrophic conditions, bringing into question whether the mdx mouse is an appropriate animal model for DMD. This study was done in order to characterize the EMG findings in mdx mice, compared to normal wild-type mice, and to assess for similarities to DMD. The tibialis anterior and gastrocnemius/soleus muscles from 34 mice (16 C57 wild-type and 18 mdx), divided into four age groups (3, 12, 18, and 24 months), were examined. Wild-type muscles showed normal insertional activity and no abnormal activity at rest. Motor unit action potential (MUAP) parameters were characterized. In contrast to wild-type muscles, mdx muscles showed increased insertional activity, abnormal spontaneous potentials, and the presence of complex repetitive discharges (CRDs). MUAPs showed increased numbers of phases (4.0 +/- 0.6, P < 0.001) and duration (7.1 +/- 1.2 ms, P < 0.02), as well as late components (15%). These EMG data indicate that mdx muscles display EMG characteristics similar to those found in muscles from boys with DMD, lending credence to the mdx mouse as an animal model for this disease. The data obtained in this study indicate a potential role for EMG as an in vivo, objective measurement tool that could be used longitudinally to monitor the effects of therapeutic interventions in mdx mice. This is important as there are few objective measures of muscle function in murine models that do not require killing the animal.

Action Potentials↗
PubMed2006

Clinically significant change in pain intensity ratings in persons with spinal cord injury or amputation.

OBJECTIVE: To examine the clinical significance of changes in chronic pain in 2 disability groups: spinal cord injury and lower limb amputation. METHODS: A reanalysis of 2 controlled clinical trials for pain in persons with disabilities. Eighty-two persons with spinal cord injuries and 34 persons with amputations provided pretreatment and posttreatment ratings of pain intensity on 0 to 10 numerical rating scales. After treatment, participants also rated the meaningfulness of any changes in pain they experienced. RESULTS: An average decrease of 1.80 points on the 0 to 10 numerical rating scales and percent decreases of about 36% corresponded to reports of a meaningful change in pain. There was no significant difference between samples, and also no differences due to gender or treatment condition. Age and pretreatment pain, however, were associated with the amount of pain decrease rated as meaningful. The change in pain intensity rated as meaningful was greater for older participants and participants with higher levels of pretreatment pain. Consistent with previous research, percent change scores were less biased by pretreatment pain than were absolute change scores. DISCUSSION: These findings are generally consistent with similar findings in other pain populations, and, in light of previous research, support an approximate 33% decrease in pain as a reasonable standard for meaningful change across chronic pain conditions. Percent change scores may be more useful for comparing the effects of pain treatments across samples or conditions because they are less biased by pretreatment pain level.

Adult↗
PubMed2005

Use of the AAEM guidelines in electrodiagnosis of ulnar neuropathy at the elbow.

OBJECTIVE: The goal of this study was to determine if practice patterns in Washington State were altered by the development and publication of the American Association of Electrodiagnostic Medicine practice parameter for electrodiagnosis of ulnar neuropathy at the elbow. DESIGN: Medical records from 350 workers' compensation patients who underwent surgery for ulnar neuropathy at the elbow in Washington State were reviewed for the consistency of the electrodiagnosticians' report and the practice parameter. Statistical analysis (chi2 or Fischer's exact test) compared prepublication and postpublication patterns of test use. RESULTS: Thirty-one percent of the 153 studies (n = 47) were not consistent with American Association of Electrodiagnostic Medicine guidelines before its publication vs. 34% of the 138 studies (n = 47) after publication. This was not a statistically significant change (P = 0.63). CONCLUSION: Evaluation of the usefulness and dissemination of the guidelines is warranted. The practice parameter may need to be simplified and educational efforts extended to improve provider use of new guidelines.

Adult↗
PubMed2004

Which motor nerve conduction study is best in ulnar neuropathy at the elbow?

There is debate regarding how best to utilize ulnar motor nerve conduction velocity (MNCV) to identify ulnar neuropathy at the elbow (UNE). We used receiver operator characteristic (ROC) curves to compare absolute across-elbow MNCV with MNCV difference between elbow and forearm segments (VDIF) when recording from abductor digiti minimi (ADM) and first dorsal interosseous (FDI) muscles. Also, we determined how their utility was impacted by low amplitudes of compound muscle action potentials (CMAPs). We studied 85 subjects with UNE and 77 subjects with carpal tunnel syndrome but without clinical evidence of UNE. The UNE group was divided into three subgroups based on CMAP amplitude. At 95% specificity, MNCV sensitivities were 80% at ADM and 77% at FDI, and VDIF sensitivities were 51% at ADM and 38% at FDI. The ROC curves showed MNCV to be superior to VDIF across all amplitude subgroups; however, confidence intervals overlapped when amplitude was high.

Adult↗
PubMed2004

Trial of amitriptyline for relief of pain in amputees: results of a randomized controlled study.

OBJECTIVE: To evaluate whether amitriptyline is more effective than placebo in improving phantom limb pain or residual limb pain. DESIGN: Randomized controlled trial of amitriptyline for 6 weeks. SETTING: University hospital. PARTICIPANTS: Thirty-nine persons with amputation-related pain lasting more than 6 months. INTERVENTION: Six-week trial of amitriptyline (titrated up to 125 mg/d) or an active placebo (benztropine mesylate). MAIN OUTCOME MEASURES: Analyses were conducted to examine whether there was a medication group effect on the primary outcomes (average pain intensity) and secondary outcome measures (disability, satisfaction with life, handicap). RESULTS: No significant differences were found between the treatment groups in outcome variables when controlling for initial pain scores. CONCLUSIONS: Our findings do not support the use of amitriptyline in the treatment of postamputation pain.

Adult↗
PubMed2004

Somatosensory evoked potentials in coma prognosis.

SEPs provide useful prognostic information regarding outcome after coma. Use of the summary data presented here should allow clinicians caring for these patients to provide families with a greater degree of certainty regarding outcome than previously has been available.

Brain Injuries↗
PubMed2004

Clinical utility of the flick maneuver in diagnosing carpal tunnel syndrome.

OBJECTIVE: To determine the utility of the flick maneuver (flicking motion of hands and wrists when most symptomatic) in the clinical evaluation of carpal tunnel syndrome (CTS). DESIGN: Review of standardized data collection on 142 subjects referred for electrodiagnostic evaluation of possible CTS at a university hospital electrodiagnostic clinic. Subjects were first clinically evaluated with the flick, Phalen, and Tinel maneuvers. Subsequently, they all underwent nerve conduction studies. Electrodiagnostic results were used as the gold standard for patient group assignments. Sensitivities, specificities, and predictive values for individual and combined clinical tests were determined. McNemar chi square values were calculated to determine whether one test identified more patients with CTS. The sensitivities of clinical maneuvers were also evaluated in relation to electrodiagnostic severity of CTS. RESULTS: Of the 142 subjects, 67% had CTS. The sensitivities of the flick, Tinel, and Phalen signs were 37%, 27%, and 34%, respectively. False-positive results ranged from 8% (Tinel) to 26% (flick and Phalen). Positive predictive values for the flick, Tinel, and Phalen maneuvers were 74%, 87%, and 73%, respectively, and negative predictive values were 37%, 39%, and 35%. McNemar chi square results revealed that the flick maneuver detected more subjects with CTS than the Tinel sign. With increasing electrodiagnostic severity, the sensitivity of all clinical tests tended to improve slightly. CONCLUSION: The flick sign is of limited clinical utility in diagnosing CTS, with low sensitivity and specificity.

Adult↗
PubMed2003

Use of somatosensory-evoked potentials and cognitive event-related potentials in predicting outcomes of patients with severe traumatic brain injury.

OBJECTIVE: This study was performed to evaluate the usefulness of somatosensory-evoked potentials (SEPs) and cognitive event-related potentials (ERPs) in predicting functional outcomes of severe traumatic brain injury patients. DESIGN: Prospective study of 22 patients with severe traumatic brain injury. Demographic information, Glasgow Coma Scale, and electrophysiologic measurements were recorded. Functional outcomes, as quantified by the Glasgow Outcome Scale-Extended, were obtained. RESULTS: Bilateral absence of median nerve SEP was strongly predictive of the worst functional outcome. The specificity and positive predictive value of absent SEP for predicting death or persistent vegetative state at 6 mo after traumatic brain injury were as high as 100%. If the definition of unfavorable outcome was expanded to include Glasgow Outcome Scale-Extended 1-4, absence of ERP was equivalent to the absence of SEP in specificity and positive predictive value. On the other hand, normal ERPs showed higher sensitivity and negative predictive value for prognosticating the best outcomes compared with normal SEPs. If the definition of favorable outcome was expanded to include Glasgow Outcome Scale-Extended 5-8, ERP was still superior to SEP for prognosticating good outcome. Interestingly, the highest sensitivity and negative predictive value for favorable outcomes were associated with the presence of any discernible waveform. CONCLUSIONS: Although median nerve SEP continues to make reliable prediction of ominous outcome in severe traumatic brain injury, the addition of the speech-evoked ERPs may be helpful in predicting favorable outcomes. The strength of the latter test seems to complement the weakness of the former.

Adolescent↗
PubMed2003

Predictive value of somatosensory evoked potentials for awakening from coma.

OBJECTIVES: A systematic review of somatosensory evoked potentials performed early after onset of coma, to predict the likelihood of nonawakening. The pooled results were evaluated for rates of awakening, confidence intervals, and the possibility of rare exceptions. DATA SOURCES: Forty-one articles reporting somatosensory evoked potentials in comatose patients and subsequent outcomes, from 1983 to 2000. STUDY SELECTION: Studies were included if they reported coma etiology, age group, presence or absence of somatosensory evoked potentials, and coma outcomes. DATA EXTRACTION: We separated patients into four groups: adults with hypoxic-ischemic encephalopathy, adults with intracranial hemorrhage, adults and adolescents with traumatic brain injury, and children and adolescents with any etiologies. Somatosensory evoked potentials were categorized as normal, abnormal, or bilaterally absent. Outcomes were categorized as persistent vegetative state or death vs. awakening. DATA SYNTHESIS: For each somatosensory evoked potential result, rates of awakening (95% confidence interval) were calculated: adult hypoxic-ischemic encephalopathy: absent 0% (0%-1%), abnormal 22% (17%-26%), normal 52% (48%-56%); adult intracranial hemorrhage: absent 1% (0%-4%), present 38% (27%-48%); adult-teen traumatic brain injury: absent 5% (2%-7%), abnormal 70% (64%-75%), normal 89% (85%-92%); child-teen: absent 7% (4%-10%), abnormal 69% (61%-77%), normal 86% (80%-92%). CONCLUSIONS: Somatosensory evoked potential results predict the likelihood of nonawakening from coma with a high level of certainty. Adults in coma from hypoxic-ischemic encephalopathy with absent somatosensory evoked potential responses have <1% chance of awakening.

Adolescent↗
PubMed2002

Cognitions, coping and social environment predict adjustment to phantom limb pain.

Biopsychosocial models of chronic pain hypothesize a role for psychological and environmental factors in adjustment to chronic pain. To test the utility of such models for understanding phantom limb pain, 61 persons with recent amputations were administered measures of average phantom limb pain intensity, pain interference, depression, pain coping use, pain cognitions and appraisals, and social environmental variables 1 month post-amputation, and the measures of pain intensity, pain interference, and depression again 5 months later. Multiple regression analyses showed that the psychosocial predictors made a statistically significant contribution to the concurrent prediction of average phantom limb pain, pain interference, and depression at the initial assessment, and a significant contribution to the prediction of subsequent change in pain interference and depression over the course of 5 months. The results support the utility of studying phantom limb pain from a biopsychosocial perspective, and identify specific biopsychosocial factors (e.g., catastrophizing cognitions, social support, solicitous responses from family members, and resting as a coping response) that may play an important role in adjustment to phantom limb pain.

Adaptation, Psychological↗
PubMed2002

Occult maxillary sinusitis as a cause of fever in tetraplegia: 2 case reports.

Common causes of fever in tetraplegia include urinary tract infection, respiratory complications, bacteremia, impaired autoregulation, deep vein thrombosis, osteomyelitis, drug fever, and intra-abdominal abscess. We report 2 acute tetraplegic patients who presented with fever of unknown origin. After extensive work-up, they were diagnosed with occult maxillary sinusitis. A search of current literature revealed no reports of sinusitis as a potential source of fever in recently spinal cord--injured patients. Patients with tetraplegia, especially in the acute phase of spinal cord injury, often undergo nasotracheal intubation or nasogastric tube placement, which may result in mucosal irritation and nasal congestion. All of the previously mentioned factors, in combination with poor sinus drainage related to supine position, predispose them to developing maxillary sinusitis. The 2 consecutive cases show the importance of occult sinusitis in the differential diagnosis of fever in patients with tetraplegia.

Adult↗
PubMed2002

Tourniquet obliteration of exercise-induced sensory nerve conduction augmentation.

OBJECTIVE: We previously discovered that minimally suprathreshold sensory nerve action potential amplitudes increased during isometric muscle contraction. In this study, the hypothesis was that the exercise-induced response could be blocked with a tourniquet. METHODS: A total of 21 healthy male and female subjects were recruited from the medical center. Baseline and postevent serial sural nerve recordings were made in the leg of 16 healthy subjects under the following conditions: (1) blood pressure cuff inflation at the arm, (2) isometric muscle contraction in the hand, and (3) conditions 1 and 2 combined. RESULTS: Results showed there was a 2.9 microV increase in the sural nerve response 5 min after muscle contraction compared to baseline at rest. The exercise-induced sensory response was largely obliterated by the blood pressure cuff with exception of the 1-min postexercise recording. CONCLUSION: In conclusion, the results show a tourniquet placed on the proximal arm blocks the effect of the muscle contraction of the hand on the minimally suprathreshold sensory sural nerve conduction recording in the ankle. The likely reason for this is the interruption of a thus far unidentified circulating factor. The clinical implication is the discovery of a sensory regulatory mechanism controlled by the motor system.

Action Potentials↗
PubMedDate not supplied

A two-year longitudinal study of social support following amputation.

PURPOSE: (1) To describe one aspect of social support, social integration, longitudinally for 2 years following lower limb amputation and (2) to explore the impact of social support on depression, pain interference, life satisfaction, mobility, and occupational functioning. METHOD: Eighty-nine adults recruited from consecutive admissions to an orthopaedic surgery service completed telephone interviews 1, 6, 12 and 24 months following amputation surgery. Dependent variables included the Social Integration (SI) sub-scale of the Craig Handicap Assessment and Reporting Technique (CHART) and the Multidimensional Scale of Perceived Social Support (MSPSS). RESULTS: There was a high level of SI among most persons following lower limb amputations that was relatively unchanged in the 2 years following surgery. However, mean levels of SI were lower in this group compared to a sample without disabilities. MSPSS scores were highly variable, ranging from almost no support to the maximum amount of support. MSPSS was an important concurrent predictor of pain interference, life satisfaction, and mobility, controlling for demographic and amputation-related factors. Baseline MSPSS predicted mobility and occupational functioning 6 months post-amputation, controlling for demographic and amputation-related factors. CONCLUSIONS: Findings suggest that interventions aimed at improving the quality of social relationships after amputation may facilitate participation in activities.

Activities of Daily Living↗