Biomedical subjects

David R Collins

Publications and source records attributed to David R Collins.

10 recordsLinked to original sources

PubMed2006

Is there an indication for ETV in young infants in aetiologies other than isolated aqueduct stenosis?

OBJECTIVES: The objective was to determine whether endoscopic third ventriculostomy (ETV) has a role in the management of obstructive hydrocephalus in aetiologies other than idiopathic aqueduct stenosis (AS) in infants. MATERIALS AND METHODS: In addition to reviewing the literature, we performed a retrospective analysis of our endoscopy database, which was established in 1998, and analysed the outcome results of all cases of ETV in those under 1 year of age which were performed between 1998 and 2003. We included cases of idiopathic AS in the outcome analysis as a benchmark of successful outcome. Successful outcome was assessed by resolution of the presenting clinical features and shunt freedom. RESULTS: Aetiologies that were identified included, in addition to idiopathic AS, suprasellar arachnoid cysts, AS in association with post-haemorrhagic hydrocephalus (PHH), post-infectious hydrocephalus (PIH), tumour-related hydrocephalus and a heterogenous group including Dandy-Walker malformation and other developmental anomalies. Suprasellar arachnoid cysts had a 100% outcome success. Idiopathic AS had a 50% outcome success and the successful outcome of PHH cases was poor at 18%. A statistical analysis revealed no effect of age at the time of ETV on the outcome in the aetiological groups. CONCLUSIONS: The definitive initial neurosurgical management of suprasellar arachnoid cysts causing significant hydrocephalus is ETV, whereas that for PHH and PIH is probably that of a ventriculo-peritoneal shunt placement. We speculate that there may be a sub-group of AS cases, termed pure or idiopathic AS, which have a higher rate of successful outcome that may be durable from a younger age. The role of repeat ETV is controversial.

Age Factors↗

PubMed2006

Increasing ankle strength to improve gait and function in children with cerebral palsy: a pilot study.

PURPOSE: This pilot study was designed to determine whether increases in ankle strength could improve gait and function in children with spastic diplegia. METHODS: Data were obtained from 12 children with spastic diplegia who were assigned randomly to a dorsiflexor group, a plantarflexor group, a dorsi- and plantarflexor group, or a control group. Training group subjects participated in a 12-week strength program using an isokinetic dynamometer. RESULTS: The majority of subjects increased their strength in the trained muscles; the strength of untrained muscles was unchanged. The Gross Motor Function Measure (GMFM) walk-run-jump dimension and a quality of life measure (ie, Peds QL) improved significantly for the entire training group. Gait speed was not significantly increased for the entire training group but varied among training groups. Gait kinematics significantly improved or showed trends for improvement for the entire training group. CONCLUSION: This pilot investigation indicates that ankle strength increases may lead to improved function, gait speed, and quality of life in children with spastic diplegia.

Adolescent↗

PubMed2006

Effect of selective dorsal rhizotomy in the treatment of children with cerebral palsy.

OBJECT: In this investigation the authors compared impairment and functional outcomes between two groups of children with cerebral palsy (CP): one group underwent selective dorsal rhizotomy (SDR) followed by intensive physical therapy (PT), and the other group underwent the latter only (PT group). Data from an age-matched group of children without disability (nondisabled [ND] group) were also collected. METHODS: Data pertaining to the 68 children with CP were collected before any intervention and again 8 and 20 months afterwards. Data regarding the 40 children in the ND group were collected in a single session. CONCLUSIONS: Although patients in both groups with CP were weaker than those in the ND group, they did have strength gains. Gait speed in the SDR-PT group was slower than that in the ND group preoperatively but not at 20 months postoperatively. Gait speed in the PT group remained slower than that in the ND group. The pre- to postoperative change in the Gross Motor Abilities Estimate score was significantly greater in the SDR-PT group than in the PT-only group. An effective treatment for children with CP, SDR offers gains in strength, gait speed, and overall gross motor function.

Adolescent↗

PubMed2006

The effects of feedback self-consistency, therapist status, and attitude toward therapy on reaction to personality feedback.

Individuals' reactions to interpersonal feedback may depend on characteristics of the feedback and the feedback source. The present authors examined the effects of experimentally manipulated personality feedback that they--in the guise of therapists--e-mailed to participants on the degree of their acceptance of the feedback. Consistent with Self-Verification Theory (W. B. Swann Jr., 1987), participants accepted feedback that was consistent with their self-views more readily than they did feedback that was inconsistent with their self-views. Furthermore, the authors found main effects for therapist's status and participant's attitude toward therapy. Significant interactions showed effects in which high-status therapists and positive client attitudes increased acceptance of self-inconsistent feedback, effects that were only partially mediated by clients' perceptions of therapist competence. The present results indicate the possibility that participants may be susceptible to self-concept change or to self-fulfilling prophecy effects in therapy when they have a positive attitude toward therapy or are working with a high-status therapist.

Adolescent↗

PubMed2005

Gender differences in pattern of hip and lumbopelvic rotation in people with low back pain.

BACKGROUND: Findings from previous studies suggest gender may affect the pattern of hip and lumbopelvic motion during a multi-segmental movement. To date, no studies have examined movement patterns and low back pain symptom behavior during hip lateral rotation. METHODS: Forty-six people (27 males and 19 females) with low back pain were examined. Three-dimensional kinematic data and low back pain symptoms were recorded during active hip lateral rotation. Percent of maximum lumbopelvic rotation was calculated for each 10% increment of maximum active hip lateral rotation. FINDINGS: Men exhibited a greater percent of maximum lumbopelvic rotation (mean 49.3, SD 13.3) during the first 60% of hip lateral rotation than women (mean 36.2, SD 16.4) (P < 0.01). Nineteen (70.4%) of the men and seven (36.8%) of the women had pain with the hip lateral rotation test (P = 0.02). INTERPRETATION: Men exhibited more lumbopelvic rotation in the early part of hip lateral rotation than women, and hip lateral rotation was more likely to be associated with symptoms in men than women. Greater lumbopelvic motion, earlier in hip lateral rotation, may make men more vulnerable to low back pain associated with hip lateral rotation. Factors that contribute to these gender differences should be investigated further.

Adult↗

PubMed2005

Human movement coordination implicates relative direction as the information for relative phase.

The current studies explore the informational basis of the coupling in human rhythmic movement coordination tasks. Movement stability in these tasks is an asymmetric U-shaped function of mean relative phase; 0 degrees is maximally stable, 90 degrees is maximally unstable and 180 degrees is intermediate. Bingham (2001, 2004a, 2004b) hypothesized that the information used to perform coordinated rhythmic movement is the relative direction of movement, the resolution of which is determined by relative speed. We used an experimental paradigm that entails using a circular movement to produce a linear motion of a dot on a screen, which must then be coordinated with a linearly moving computer controlled dot. This adds a component to the movement that is orthogonal to the display. Relative direction is not uniquely defined between orthogonal components of motion, but relative speed is; it was therefore predicted that the addition of the component would only introduce a symmetric noise component and not otherwise contribute to the U-shape structure of movement stability. Results for experiment 1 supported the hypothesis; movement that involved the additional component was overall less stable than movement that involved only the parallel component along which relative direction can be defined. Two additional studies ruled out alternative explanations for the pattern of data in experiment 1. Overall, the results strongly implicate relative direction as the information underlying performance in rhythmic movement coordination tasks.

Adult↗

PubMed2005

Perceptual coupling in rhythmic movement coordination: stable perception leads to stable action.

Rhythmic movement coordination exhibits characteristic patterns of stability, specifically that movements at 0 degrees mean relative phase are maximally stable, 180 degrees is stable but less so than 0 degrees, and other coordinations are unstable without training. Recent research has demonstrated a role for perception in creating this pattern; perceptual variability judgments covary with movement variability results. This suggests that the movement results could be due in part to differential perceptual resolution of the target movement coordinations. The current study used a paradigm that enabled simultaneous access to both perception (between-trial) and movement (within-trial) stability measures. A visually specified 0 degrees target mean relative phase enabled participants to produce stable movements when the movements were at a non-0 degrees relationship to the target being tracked. Strong relationships were found between within-trial stability (the traditional movement measure) and between-trial stability (the traditional perceptual judgment measure), suggestive of a role for perception in producing coordination stability phenomena. The stabilization was incomplete, however, indicating that visual perception was not the sole determinant of movement stability. Rhythmic movement coordination is intrinsically a perception/action system.

Adolescent↗

PubMed2005

Orthopedic surgery after selective dorsal rhizotomy for spastic diplegia in relation to ambulatory status and age.

OBJECT: A retrospective study was performed to determine the following: 1) whether children who walk independently after selective dorsal rhizotomy (SDR) undergo fewer subsequent orthopedic operations than those who walk with assistance; and 2) the effect of age at SDR on the rate of orthopedic operations. METHODS: The cases of 158 children with spastic diplegia who were 2 to 14 years of age when they underwent SDR were followed over a 5- to 9-year period. Patients were grouped by age at the time of SDR as follows: 2 to 3 years (Group 1), 4 to 7 years (Group 2), and 8 to 14 years (Group 3). Follow-up data showed that children in all age groups who walked independently after SDR underwent fewer orthopedic operations than did children who walked with assistance. Overall rates of orthopedic surgery 5 to 9 years after SDR at last follow up were 24% for independent walkers and 51% for assisted walkers. Two-way categorical analysis (age group by ambulation) yielded a highly significant effect of ambulation (p = 0.0003). Children in Group 1 needed the fewest orthopedic operations at follow-up evaluation. In the older age groups (Groups 2 and 3), those who walked independently at the time of SDR underwent fewer orthopedic operations after SDR than did walkers who required assistance (p = 0.01). CONCLUSIONS: These data are of value in advising parents about the likelihood of orthopedic surgery based on the child's gait status both at the time of SDR and at follow-up evaluation. Orthopedic surgery is more likely in patients destined to be nonambulators.

Activities of Daily Living↗

PubMed2005

Endoscopic third ventriculostomy: an outcome analysis of primary cases and procedures performed after ventriculoperitoneal shunt malfunction.

OBJECT: The authors analyzed the role of endoscopic third ventriculostomy (ETV) as a primary treatment for hydrocephalus and also as an alternative to shunt revision for malfunctioning and infected ventriculoperitoneal (VP) shunts. METHODS: A retrospective analysis of clinical notes, operation records, and magnetic resonance imaging procedures before and after ventriculostomy was performed to determine the success or failure of ETVs in 170 patients who underwent a primary ETV and in 63 patients who underwent an ETV for shunt malfunction (secondary ETV). The patients' data were derived from an endoscopy database inaugurated in 1998. Of the 63 patients with shunt malfunctions, 49 patients (78%) had mechanical malfunction only and 14 patients (22%) had both infection and malfunction. Seventy-four percent (126 of 170) of patients in the primary ETV group and 70% (44 of 63) of patients in the secondary ETV had a successful outcome at the time of analysis. The success rate for ETVs in cases involving a mechanical shunt malfunction alone was 67% (33 of 49) compared with 79% (11 of 14) in those cases involving an infected shunt. The origin of the hydrocephalus in the primary and shunt malfunction groups was evaluated as a factor contributing to the success of the ETV. In the primary group, patients with a history of intraventricular hemorrhage (IVH) and meningitis as a cause for hydrocephalus had a poor rate of success after the ETV--27% (four of 15) and 0% (none of two), respectively. This pattern was not seen in the series involving shunt malfunction after the ETV, with 71% (five of seven) and 75% (three of four) of cases having a hydrocephalus origin of IVH and meningitis, respectively, in which a successful outcome was attained. A two-way mixed-model analysis of variance yielded a significant effect for origin (p = 0.011), a significant interaction between group and origin (p = 0.028), and a marginally nonsignificant effect of group (p = 0.0686). More than 95% of failures were evident within 1 month of the ETV in both groups. Complications were minimal in both groups, and there were no procedure-related deaths. CONCLUSIONS: An ETV is a safe procedure with few complications and a high success rate in both primary and secondary groups. An ETV to address shunt malfunction, unlike a primary ETV, is not particularly origin specific. A bonus is its success in dealing with infected shunts. Most failures will be evident early, but long-term follow up is vital.

Adolescent↗

PubMed2004

Effect of selective dorsal rhizotomy on need for orthopedic surgery for spastic quadriplegic cerebral palsy: long-term outcome analysis in relation to age.

OBJECT: The authors performed a long-term evaluation of gait status to determine the frequency with which orthopedic operations for cerebral palsy are conducted before and after selective dorsal rhizotomy (SDR) and the relation between pre- and post-SDR orthopedic surgery and age. METHODS: Fifty-two patients with spastic quadriplegia were prospectively followed for 5 to 9 years. All children were evaluated and underwent SDR at St. Louis Children's Hospital. Preoperative scores for gait function and details of previous orthopedic procedures were recorded for two age groups: those 2 to 5 (Group 1) and those 6 to 14 years of age (Group 2). Data were collected from parents who completed a questionnaire a mean of 7.5 years after SDR. Relations between gait status and the number/type of pre- and post-SDR orthopedic procedures, rate of improvement after SDR, benefit of operation according to parents, and return of spasticity were analyzed. Forty-nine percent of patients in Group 1 and 25% of those in Group 2 had improved gait scores. The interaction between pre- or post-SDR time frame and walking mode was statistically significant (p = 0.004). Among those children who had not undergone orthopedic surgery before SDR, the incidence of surgery post-SDR was higher in the older children (Group 2) than the younger children (Group 1 [70% compared with 34%]). Parents of 75% of the Group 1 patients and 88% of the Group 2 patients felt that their children benefited from SDR. CONCLUSIONS: The results of this study highlight the effect of SDR on gait status in children with spastic quadriplegic cerebral palsy. The percentage of patients needing orthopedic operations was not as high as reported previously. Parents indicated that SDR was beneficial to their children.

Adolescent↗