Altered integrated locomotor and cognitive function in elite athletes 30 days postconcussion: a preliminary study.

OBJECTIVE: To begin to understand changes in locomotor navigation in elite athletes following concussion. METHODS: Clinical measures and gait analysis were undertaken on average 37.33 days (SD = 4.8) postconcussion for 6 athletes as well as for a control group of athletes matched for age, sex, and team. The locomotor task consisted of walking at a self-selected speed along an unobstructed or obstructed path with and without a visual interference task. The trends for 4 dependent variables were described (2 for gait behavior and 2 for cognitive behavior). A principal component analysis was used to reduce data to root sources of variance among these variables. General group differences were tested with Wilcoxon matched-pairs tests on factorial scores. RESULTS: Athletes with concussion were symptom free at the time of testing and their neuropsychological test results were not different from those of athletes in the control group. However, when the laboratory data between paired groups were compared, descriptive analyses suggested potential group differences in navigating the obstacle. The simultaneous Stroop task appeared to present difficulty for both groups. A significant group effect was found on the component of the factorial analysis that was highly loaded with both gait and cognitive variables (minimum clearance, Stroop task errors, and cognitive dual-task costs), generally supporting the descriptive analyses by suggesting that athletes with concussion do not navigate the targeted complex environments like the control group. CONCLUSIONS: Athletes with concussion appear to still show navigational deficits in environments well after being considered fully recovered according to current return-to-play protocols. Although still preliminary and requiring further study, the present findings suggest that functional assessment within complex environment contexts could be considered before sending athletes back to play following a concussion, even in the absence of postconcussion symptoms or with normal clinical outcomes.

[Comparison of different techniques of hemodialysis vascular access flow evaluation: blood temperature monitoring thermodilution and doppler debimetry]. / Comparaison des mesures des débits d'abords vasculaires pour hémodialyse obtenues par méthode de thermodilution utilisant le module Blood Temperature Monitoring et par débimétrie doppler.

BACKGROUND: Access blood flow measurements are considered useful indicators for thrombosis prevention. It was the purpose of this study to compare measurements of access blood flow by two different techniques: duplex doppler and BTM thermodilution. METHODS: Patients included must be on chronic hemodialysis on arterioveinous vascular access. They must be in a unit fit with hemodialysis generator equipped with BTM tool. The measurements of access blood flow were made during the first hour of the hemodialysis session. A measurement with each technique was performed for each patient. RESULTS: Fifteen patients were included: seven men and eight women, average age 60.8 ± 9.2 years, average weight 76 ± 16 kg, duration on hemodialysis therapy 6.6 ± 6.1 years. Access blood flow was native fistula (14 patients) and a prothetic access (one patient). Average access blood flow was 1088 ± 586 mL/mn (doppler) and 1094 ± 570 mL/mn (BTM). Comparison of access flows obtained by the BTM and doppler techniques showed a strong linear relationship. The average time to perform a measure was six minutes for the doppler technique and five minutes for the BTM technique. No adverse effect was observed in our study. CONCLUSION: Our study shows a strong correlation between the two techniques (doppler and BTM) for the measurement of hemodialysis access blood flow. The BTM access blood flow measurement technique is fast, economic and made during the hemodialysis session by the nurse.

[Active WHO class IV lupus nephritis in a patient treated with etanercept for a psoriasic arthritis]. / Néphropathie lupique stade IV chez une patiente traitée par étanercept pour un rhumatisme psoriasique.

INTRODUCTION: Drug-induced lupus nephritis in patients treated with TNF α inhibitor is a rare adverse effect. Anti-TNF α therapies are commonly associated with the induction of auto-antibodies, whereas anti-TNF α-induced lupus is rare, most frequently involving arthritis and cutaneous lesions. However, several renal involvement has been reported. OBSERVATION: A 26-year old woman with a history of psoriasic arthritis treated with TNF α inhibitor (etanercept) presented with a biopsy-proved class IV lupus nephritis. The diagnosis of drug-induced lupus nephritis was probable and anti-TNF α therapy was discontinued. Standard lupus nephritis therapy was then started with prednisolone pulses and mycophenolate mofetil (MMF). Two weeks later, a septic shock following a leg cellulitis was caused by Pseudomonas aeruginosa and had a fatal evolution despite MMF withdrawal, adapted antibiotherapy and large wound excision. DISCUSSION: Our therapy was not different than for other class IV lupus nephritis. Our observation highlights two points: first the attributability to etanercept in lupic manifestations in our patient and second the therapeutic strategy in this particular case of drug-induced lupus. CONCLUSION: We reported a possible first case of IV lupus nephritis induced by anti-TNF α with a fatal evolution.

[Use of a brain-computer interface by a patient with a craniocerebral injury]. / Utilisation d'une interface cerveau-ordinateur par un client présentant un traumatisme craniocérébral.

BACKGROUND: There is limited knowledge concerning the effectiveness of computer access modes. This article presents a case report of a client with a serious traumatic brain injury who, four years after his accident, tried a brain-computer interface (Cyberlink software). PURPOSE: To examine the client's computer performance (keyboard and mouse tasks) and the degree of realisation of three occupations (written communication, interpersonal relations and leisure). METHODS: A training over 16 weeks (2 x per week) and a follow-up at 3 months were completed. The activation of the computer with Cyberlink was tested with lateral movements of the eyes, relaxation waves, waves of activation of the brain and facial musculature. FINDINGS: After 8 weeks of training with Cyberlink, no improvements were noted in the use of the keyboard and the mouse. The trial of another interface (tactile screen) finally made the optimization of mouse functions possible. IMPLICATIONS: The endurance and memory problems were circumvented with a long, repetitive and flexible training of the computer use.

Modality-specific, multitask locomotor deficits persist despite good recovery after a traumatic brain injury.

OBJECTIVE: To study the effects of sensory modality of simultaneous tasks during walking with and without obstacles after moderate to severe traumatic brain injury (TBI). DESIGN: Group comparison study. SETTING: Gait analysis laboratory within a postacute rehabilitation facility. PARTICIPANTS: Volunteer sample (N=18). Persons with moderate to severe TBI (n=11) (9 men, 3 women; age, 37.56+/-13.79 y) and a comparison group (n=7) of subjects without neurologic problems matched on average for body mass index and age (4 men, 3 women; age, 39.19+/-17.35 y). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Magnitudes and variability for walking speeds, foot clearance margins (ratio of foot clearance distance to obstacle height), and response reaction times (both direct and as a relative cost because of obstacle avoidance). RESULTS: The TBI group had well-recovered walking speeds and a general ability to avoid obstacles. However, these subjects did show lower trail limb toe clearances (P=.003) across all conditions. Response reaction times to the Stroop tasks were longer in general for the TBI group (P=.017), and this group showed significant increases in response reaction times for the visual modality within the more challenging obstacle avoidance task that was not observed for control subjects. A measure of multitask costs related to differences in response reaction times between obstructed and unobstructed trials also only showed increased attention costs for the visual over the auditory stimuli for the TBI group (P=.002). CONCLUSIONS: Mobility is a complex construct, and the present results provide preliminary findings that, even after good locomotor recovery, subjects with moderate to severe TBI show residual locomotor deficits in multitasking. Furthermore, our results suggest that sensory modality is important, and greater multitask costs occur during sensory competition (ie, visual interference).

Can measures of cognitive function predict locomotor behaviour in complex environments following a traumatic brain injury?

PRIMARY OBJECTIVE: To determine the relationships between clinical measures of executive function and attention, and laboratory measures of anticipatory locomotor adaptations with dual tasks following a TBI. METHODS AND PROCEDURES: Ten people with moderate or severe TBI were compared to 10 healthy subjects for neuropsychological measures in the clinic, as well as locomotor patterns and reading time in the laboratory for adapted Stroop tasks (Bar and Word) during unobstructed and obstructed walking. MAIN OUTCOMES AND RESULTS: As previously found 1 (Vallee M, McFadyen BJ, Swaine B, Doyon J, Cantin JF, Dumas D. Effects of environmental demands on locomotion after traumatic brain injury. Archives of Physical Medicine Rehabilitation 2006;87:806--813) during the locomotor activities, subjects with TBI walked slower, had higher clearance margins and took longer to read during the Stroop tasks than healthy subjects. In general, subjects with TBI also showed deficits in executive functions and attention. Significant relationships were specifically observed between scores on Trail Making B and clearance margins for subjects with TBI, but not for healthy subjects. Alternatively, significant relationships between clinical scores on Stroop and dual task Stroop reading times were obtained for healthy subjects but not for subjects with TBI. CONCLUSIONS: These results suggest that measures of executive functioning and attention may be associated to locomotor behaviour in complex environments following a moderate to severe TBI.

Effects of environmental demands on locomotion after traumatic brain injury.

OBJECTIVE: To determine the effects of increasingly demanding environments related to simultaneous visual tasks and physical obstructions on the locomotor ability of people with traumatic brain injury (TBI). DESIGN: Group comparison study. SETTING: Gait analysis laboratory within a postacute rehabilitation facility. PARTICIPANTS: Volunteer sample of 9 people (8 men, 1 woman; age, 39.3+/-13.0y) with moderate to severe TBI and a comparison group of 9 subjects without neurologic problems matched for age and sex (8 men, 1 woman; age, 39.7+/-12.3y). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Reading times for the Stroop bar and Stroop word tasks, walking speeds, stride lengths, and obstacle clearance margin. RESULTS: The TBI group was slower than the control group in performing the Stroop bar task during sitting (P=.002), and while avoiding the narrow obstacle (P=.05), and in performing the Stroop word task while avoiding the wide obstacle (P=.019). Despite their relatively normal gait speeds on level ground, subjects with TBI walked more slowly than control subjects for the narrow (P=.024) and the wide (P=.019) obstacle conditions and for the most complex dual task (P=.042). Greater lead-limb clearance margins were observed for the TBI group than for control subjects for all conditions whereas no differences were found for the trail limb except at the far end of the wide obstacle. CONCLUSIONS: Despite their good recovery of locomotor function, with respect to normal level walking speeds and ability to avoid obstacles, subjects with moderate and severe TBI showed residual deficits in relation to greater difficulties in dealing with environments that challenge their locomotor and attentional abilities. The use of such naturally based dual tasks may help identify some of the environmental obstructions to social participation after TBI.