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Biomedical subjects

Henry L Lew

Publications and source records attributed to Henry L Lew.

32 records · Page 2Linked to original sources
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↗
PubMed2003

Sagittal plane loading response during gait in different age groups and in people with knee osteoarthritis.

OBJECTIVE: To investigate the gait patterns and the sagittal ground reaction forces in different age groups and in people with knee osteoarthritis. DESIGN: Motion analysis and force platform data were collected for a total of 55 female subjects capable of independent ambulation. Subjects were divided into three groups consisting of the control group, the elderly group, and the osteoarthritis knee group. Gait parameters of walking velocity, cadence, step length, stride time, single- and double-support time, and sagittal ground reaction forces were obtained during comfortable walking speed. Gait analysis was performed in a tertiary hospital's gait laboratory. Variables were analyzed using a univariate repeated-measures analysis of variance. Statistical significance was set at a value of P < 0.05. RESULTS: The osteoarthritis knee group had slower walking velocity, lower cadence, and longer stride time as compared with the elderly and young control groups (P < 0.05). In ground reaction force studies, the first peak time, expressed in percentage of gait cycle, was significantly longer in the osteoarthritis knee group (20.8 +/- 3.2) as compared with the elderly (17.8 +/- 2.0) and young control groups (17.1 +/- 1.8, P < 0.01). The force during time of minimal midstance was larger in the osteoarthritis knee group (90.9 +/- 5.3) as compared with the elderly and young control groups (P < 0.05). The second peak force was significantly smaller in the osteoarthritis knee group as compared with the young control group (P < 0.01). The force change in the midfoot region in the osteoarthritis knee and elderly groups revealed more loading force onto the midfoot region during midstance as compared with the young control group (P < 0.01). CONCLUSION: Gait parameters in the elderly and osteoarthritis knee patients were characterized by slower walking velocity, lower cadence, shorter step length, longer stride time, and longer double-support time. Less heel contact and push-off forces were noticed in these two groups, with more loading force onto the midfoot during midstance.

Adult↗
PubMed2003

Measurement of forefoot varus angle by laser technology in people with flexible flatfoot.

OBJECTIVE: The purpose of this study was to measure the forefoot varus angles in subjects with and without flexible flatfoot (FF) by using laser foot-scanning technology. DESIGN: In the rehabilitation laboratory of a tertiary medical center, 70 subjects with FF, ranging in age from 10 to 50 yr, were recruited. The control group consisted of 30 volunteers without clinical evidence of FF. A total of 100 positive casts were obtained by having their subtalar joints kept in a neutral position. The plantar surface of the positive cast was scanned by a Yeti 3D Foot Scanner. A straight line was drawn between the first and fifth metatarsophalangeal joints. The forefoot varus angle was measured from this line in relation to the line parallel to the ground. RESULTS: The mean forefoot varus angle was calculated to be 5.01 +/- 4.51 degrees in our FF subjects, and 1.23 +/- 1.96 degrees in the control group. Significant statistical difference in forefoot varus angle was noted between these two groups. CONCLUSIONS: The laser foot-scanning technique offers fast and accurate measurement of the forefoot varus angles. An average forefoot varus angle of approximately 5 degrees was observed in subjects with FF, which was significantly greater than the subjects without FF. Therefore, we recommend the concept of incorporating adequate forefoot posting at the medial forefoot area of an insole in treating people with FF.

Adolescent↗
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

Treatment of detrusor-sphincter dyssynergia by pudendal nerve block in patients with spinal cord injury.

OBJECTIVE: To study the effects of pudendal nerve block with phenol on detrusor-sphincter dyssynergia in patients with spinal cord injury (SCI). DESIGN: Before-after trial performed by using a consecutive sample. SETTING: Rehabilitation hospital affiliated with a medical school. PATIENTS: Twenty-two male SCI patients (mean age, 46.3+/-11.9y; mean duration postinjury, 2.7y) with voiding dysfunction resulting from external urethral sphincter hypertonicity. INTERVENTION: Pudendal nerve block with 5% phenol solution under the guidance of electric stimulator. MAIN OUTCOME MEASURES: Outcomes were measured using (1) postvoid residual volume, maximal detrusor pressure, leak point pressure, bladder volume at the first uninhibited contraction, maximal bladder capacity, and urethral pressure profile; (2) rectoanal rest and squeeze pressures; and (3) quality of life measures for urination, quantified by the Quality of Life Index (QLI). Changes in bowel habit or autonomic dysreflexia were recorded. RESULTS: The mean decrease in postvoid residual volume was 242.8mL (mean decrease, 66%) after treatment (P<.001). The mean reduction in leak point pressure and maximal detrusor pressure were 37.1cmH(2)O and 43.3cmH(2)O, respectively (P<.05). The mean QLI significantly improved from -.74+/-.38 to.42+/-.47 (P<.001). The rectoanal pressures showed no significant difference. No complaints of fecal incontinence or other complications were noted after treatment. CONCLUSION: Pudendal nerve block performed by using 5% phenol solution was safe, easy to perform, and effective as a treatment for detrusor-sphincter dyssynergia in selected patients with SCI.

Adult↗
PubMed2002

Rehabilitation of a patient with heat stroke: a case report.

The recent death of a famous football player raised public awareness of the fatal nature of heat stroke, which is actually the third leading cause of death among American athletes. We present a typical case of heat stroke to illustrate its clinical manifestation and recovery process; risk factors, treatment options, and the importance of prevention are also discussed. Although heat stroke is not a common admission diagnosis for inpatient rehabilitation, physiatrists need to be aware of its pathophysiology, rehabilitation management, and prevention.

Adult↗
PubMed2002

Influence of medical comorbidities and complications on FIM change and length of stay during inpatient rehabilitation.

OBJECTIVE: This study was performed to evaluate the influence of medical problems on functional outcome measures of patients admitted for comprehensive inpatient rehabilitation. DESIGN: In this retrospective database review of patients, demographic information, length of stay, FIM scores at admission and discharge, and FIM efficiency were collected and analyzed. Preexisting comorbidities and acute medical complications of all patients were identified, tabulated, and analyzed. RESULTS: A total of 175 patients were categorized into three major groups. In the postorthopedic surgery group, the presence of preexisting medical comorbidities did not significantly affect admission or discharge FIM scores. In contrast, traumatic brain injury patients with preexisting medical comorbidities had a tendency to be admitted and discharged with lower FIM scores. However, traumatic brain injury patients with acute medical complications still made reasonable functional improvement during their extended stay, so that their FIM efficiency was adequately maintained. In the cerebrovascular accident group, almost all patients had preexisting medical issues. CONCLUSIONS: The rehabilitation population is diverse, and functional outcome measures for distinct disease entities may be differentially affected by factors such as preexisting medical comorbidities and acute medical complications. Except for life-threatening medical emergencies, rehabilitation patients may benefit by staying on the acute rehabilitation unit, where both medical management and a comprehensive rehabilitation program are provided with continuity.

Aged↗
PubMedDate not supplied

Prognostic value of evoked and event-related potentials in moderate to severe brain injury.

Clinicians are often expected to project patients' clinical outcomes to allow effective planning for future care. This can be a challenge in patients with moderate to severe traumatic brain injury (TBI) who are often unable to participate reliably in clinical evaluations. With recent advances in computer instrumentation and signal processing, evoked potentials and event-related potentials show increasing promise as powerful tools for prognosticating the trajectory of recovery and ultimate outcome from the TBI. Short- and middle-latency evoked potentials can now effectively predict coma outcomes in patients with acute TBI. Long-latency event-related potential components hold promise in predicting recovery of higher order cognitive abilities.

Brain Injuries↗
PubMedDate not supplied

Event-related potential in facial affect recognition: potential clinical utility in patients with traumatic brain injury.

Traumatic brain injury (TBI) frequently leads to deficits in social behavior. Prior research suggests that such deficits may result from impaired perception of basic social cues. However, these social-emotional deficits have not been studied electrophysiologically. We measured the P300 event-related potential (ERP), which has been shown to be a sensitive index of cognitive efficiency, in 13 patients with a history of moderate to severe TBI and in 13 healthy controls. The P300 response was measured during detection of 30 pictures of angry faces (rare target) randomly distributed among 120 neutral faces (frequent nontarget). Compared to control subjects, the TBI group's P300 responses were significantly delayed in latency (p = 0.002) and lower in amplitude (p = 0.003). TBI patients also showed slower reaction times and reduced accuracy when manually signaling their detection of angry faces. Coefficients of variation (CV) for the facial P300 response compared favorably to those of many standard clinical assays, suggesting potential clinical utility. For this study, we demonstrated the feasibility of studying TBI patients' P300 responses during the recognition of facial affect. Compared to controls, TBI patients showed significantly impaired electrophysiological and behavioral responses while attempting to detect affective facial cues. Additional studies are required for clinicians to determine whether this measure is related to patients' psychosocial function in the community.

Affect↗
PubMedDate not supplied

Key characteristics of walking correlate with bone density in individuals with chronic stroke.

Several recent studies of ambulatory stroke survivors have shown decreased bone mineral density (BMD) in the lower limbs and an elevated risk of hip fracture. Because bone mass is linked to skeletal loading, weight-bearing activities of daily living such as walking are considered critically important for maintenance of femoral BMD in ambulatory individuals. Little is known about the relationships between walking characteristics, skeletal loading, and bone maintenance in individuals who have experienced a stroke. This study determined whether certain gait-related parameters correlate with proximal femoral BMD in ambulatory individuals with poststroke walking deficits. We analyzed data from 33 individuals with chronic stroke and found that a recently introduced metric, the Bone Density Index, which incorporates body weight, number of steps per day, and ground reaction force magnitude, predicted proximal femoral BMD better than other commonly measured demographic and gait-related parameters that we examined.

Age Factors↗