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Biomedical subjects

B Bussel

Publications and source records attributed to B Bussel.

At least 37 records · Page 2Linked to original sources
PubMed1999

Functional anatomy of neuropsychological deficits after severe traumatic brain injury.

BACKGROUND: Neurobehavioral disorders after severe traumatic brain injury (TBI) are poorly correlated with focal lesions detected by structural neuroimaging techniques such as CT scan or MRI. OBJECTIVE: To explore the relationships between regional cerebral glucose metabolism at rest, as measured by PET, and neurobehavioral status after severe TBI at the subacute stage. METHODS: Thirteen patients without focal structural lesion on MRI were studied. Neuropsychological assessment included tests of memory, attention and speed of information processing, and executive functions, and a global neurobehavioral assessment. Regional cerebral glucose metabolism at rest was measured with (18F)-fluorodeoxyglucose and PET. RESULTS: A close link was found between cognitive and behavioral disorders and decreased cortical metabolism in prefrontal and cingulate cortex. Tests of memory and executive functions significantly correlated with regional metabolism in the mesial and lateral prefrontal cortex and the cingulate gyrus. Behavioral disorders correlated significantly with mesial prefrontal and cingulate metabolisms. CONCLUSION: These results suggest a predominant role of prefrontal and cingulate dysfunction in cognitive and behavioral disorders of patients with severe traumatic brain injury, even in the absence of focal structural lesion of the brain. Further cognitive functional activation research using PET or functional MRI might help clarify the relative contributions of both areas to dysfunction.

Adolescent↗
PubMed1999

Effects of intrathecal clonidine injection on spinal reflexes and human locomotion in incomplete paraplegic subjects.

We studied the effect of the intrathecal (i.t.) injection of clonidine (30, 60 and 90 microg) on the polysynaptic spinal reflexes (PSR) elicited by electrical stimulation of flexor reflex afferents (FRA), monosynaptic reflex and gait of 11 subjects with spinal cord injuries. The effect of clonidine administration on gait velocity, stride amplitude and duration was measured in eight subjects who were able to walk. Five subjects were able to walk after intrathecal injection of clonidine and three were not able to stand up. Three subjects improved their gait velocity after clonidine administration; one (S6) increased his stride amplitude; the two others decreased their cycle durations. The tibialis anterior seemed to be more regularly activated during gait. Spasticity was reduced dramatically (P<0.0001) after i.t. clonidine injection, but there was no statistically significant difference in the soleus H reflex (no effect on Hmax/Mmax). Clonidine administration decreased the amplitude of the early PSR (90-120 ms, N=4) and the threshold and maximal integrated EMG corresponding to the late response (140-450 ms, N=7). This effect was dose dependent (30, 60 and 90 microg). Placebo injection (N=4) caused no change. The changes in spinal reflexes, with a large reduction in spasticity, no change in motoneurone excitability and a large decrease in PSR, suggest that clonidine acts at a premotoneuronal level, possibly by presynaptic inhibition of group II fibres. The increase in gait velocity in three subjects could have been due to reduced spasticity or activation of spinal circuitry.

Adrenergic alpha-Agonists↗
PubMed1999

Contribution of D-Dimer determination in the exclusion of deep venous thrombosis in spinal cord injury patients.

UNLABELLED: Deep vein thrombosis (DVT) is a common complication of paraplegia despite prophylactic anticoagulant therapy. The diagnosis relies primarily on ultrasonography or phlebography; these investigations are difficult, expensive and can be time-consuming in paraplegic patients. STUDY DESIGN: To evaluate the usefulness of coagulation activation markers in excluding a diagnosis of DVT, D-Dimers, thrombin-antithrombin complexes, prothrombin fragments (F1+2) and activated factor VIIa. OBJECTIVES: To improve the diagnosis of deep venous thrombosis in paraplegic patients. SETTING: This collaborative work was done at Raymond Poincaré Hospital, Garches, France. METHODS: To evaluate the usefulness of coagulation activation markers in excluding a diagnosis of DVT, D-Dimers (D-Di), thrombin-antithrombin (TAT) complexes, prothrombin fragments (F1+2) and activated factor VIIa (FVIIa), were determined in a prospective study of 67 consecutive patients with paraplegia or tetraplegia. Doppler ultrasonography and/or phlebography of the lower limbs and D-Di, TAT, F1+2 level determination were systematically done in each patient at admission to our rehabilitation unit. RESULTS: Despite prophylactic low molecular weight heparin therapy, six of the 67 patients developed DVT diagnosed by radiologic explorations. D-Di levels measured by a reference ELISA (Asserachrom D-Di, Diagnostica Stago) or a new rapid automated turbidimetric test (STA-Liatest D-Di) were greater than 500 ng/ml in all DVT patients and in 40 non-DVT patients, of whom most had urinary tract infections, osteomas, or pressure sores. D-Di values were normal in only 21/67 patients (31%). The negative predictive value of D-Di in our study was 100% since all DVT patients had D-Di values greater than 500 ng/ml. TAT and F1+2 levels were not correlated with D-Di levels but also had a negative predictive value of 100%. Comparison of D-Di levels obtained using the two tests showed that results of the reference ELISA were closely correlated to those of the new rapid automated turbidimetric. TAT, F1+2, and factor VIIa are not useful for measuring hypercoagulability in paraplegic or tetraplegic patients since no rapid tests for determining these parameters are available. CONCLUSION: D-Di levels determined using an ELISA or a new rapid automated turbidimetric test have a good negative predictive value for DVT in paraplegic or tetraplegic patients and may reduce the need for Doppler ultrasonography and/or phlebography by 31%.

Adolescent↗
PubMed1999

Carbamazepine in agitation and aggressive behaviour following severe closed-head injury: results of an open trial.

Ten patients presenting agitation and anger outbursts at various stages following a severe closed head injury, were treated in a prospective open trial with carbamazepine, with doses ranging from 400 to 800 mg per day, during 8 weeks. Group analysis demonstrated a statistically significant improvement of a score made up from six target items from the neurobehavioural rating scale. Improvement mainly concerned irritability and disinhibition. A statistically significant improvement was also found with the Agitated Behaviour Scale. Social functioning, as assessed by family or staff ratings of the Katz Adjustment Scale, also significantly improved. No modification of global cognitive functioning was found with the Mini Mental Status Examination. Individual analysis demonstrated that the beneficial effect was important in five cases, moderate in three patients and negligible in two cases. It is concluded that carbamazepine might help to reduce agitated behaviour in brain-injured patients. However, response to treatment demonstrated an important inter-individual variability.

Adult↗
PubMed1999

[Validation of procedures of rehabilitation after cerebrovascular accident].

There are several methodological difficulties in the assessment of the effectiveness of rehabilitation in stroke patients. Obviously, double-blind studies are not possible, and only single-blind procedures can used. It is difficult to control for non specific effects, such as spontaneous recovery, patient's and therapist's motivation, social environment. It is necessary to assess the effect non only at the level of impairments, but also on disability and handicap. However, there are now accumulating data in the literature suggesting that stroke rehabilitation has a significant, although mild, effectiveness. Patients treated in specialized stroke rehabilitation units obtain a better outcome, in terms of independence in daily-life activities, than those treated in general wards. They also have shorter hospitalisation durations and are more frequently able to return home. Treatment effectiveness is related to intensity and duration of rehabilitation, and also to stroke severity. Patients with moderate impairments seem to benefit more from treatment than patients with mild or severe deficits. However, significant improvements can still be obtained in very severe cases, and even late (up to two years) post stroke. Similarly, rehabilitation of cognitive deficits (aphasia and unilateral neglect) has also been found efficient in most studies, even if the beneficial effect is relatively small. Aphasic patients treated by speech therapists improve more than patients treated by non specialized therapists or by family members who received a short training. One limitation of neglect rehabilitation is the inconsistent generalisation of treatment effects to daily-life situations. These data are encouraging but further research is needed to find out what precisely works, and how, in the "black box" of rehabilitation.

Functional Laterality↗
PubMed1998

Side effects of chronic intrathecal baclofen on erection and ejaculation in patients with spinal cord lesions.

OBJECTIVE: Assess modifications of sexual function in men treated with intrathecal baclofen for spinal spasticity. DESIGN: Prospective before-after trial. SETTING: A rehabilitation department of a university hospital; follow-up was on an outpatient basis. PATIENTS: A convenience sample of nine consecutively recruited men with spinal cord injury or multiple sclerosis who were receiving intrathecal baclofen by an implantable pump; average follow-up was 44.4 months. MAIN OUTCOME MEASURES: A questionnaire focusing on: libido; ability to sustain reflexive and psychogenic erections; rigidity, evaluated by a visual analog scale; maximum duration of erection; possibility of ejaculation. RESULTS: Libido and the ability to obtain psychogenic or reflexogenic erections were not modified. However, eight patients reported a decrease of erection rigidity and/or duration. Ejaculation was possible in three cases before implantation. It disappeared in two patients, and was more difficult to obtain in the last one. It reappeared after treatment withdrawal. No differences were found between multiple sclerosis and spinal cord injured patients. CONCLUSION: Intrathecal baclofen may compromise erection and ejaculation. This effect is reversible. Patients should be informed of this effect.

Adult↗
PubMed1998

Intrathecal clonidine for refractory detrusor hyperreflexia in spinal cord injured patients: a preliminary report.

PURPOSE: We assessed the urodynamic effect of various doses of intrathecal clonidine on refractory detrusor hyperreflexia in spinal cord injured patients. MATERIALS AND METHODS: Doses of 15, 30 or 45 microg. intrathecal clonidine or placebo were given to 5 chronic complete spinal cord injured patients with detrusor hyperreflexia. Two cystometries were performed before and 5, 30, 60, 90, 120 and 180 minutes after each injection. RESULTS: A statistically significant dose dependent decrease in detrusor hyperreflexia was observed in each patient without significant side effect. CONCLUSIONS: Intrathecal clonidine may represent a conservative reversible treatment for detrusor hyperreflexia via a subcutaneous programmable pump, like that used for baclofen, for spasticity. The long-term efficacy needs to be evaluated.

Adrenergic alpha-Agonists↗
PubMed1998

Dysprosody after severe closed head injury: an acoustic analysis.

OBJECTIVES: Neurological speech disorders (dysarthria and dysprosody) are known to be frequent sequelae after severe closed head injury. These disorders may dramatically alter communicative intent and accentuate social isolation. The aim was to provide an instrumental evaluation for prosodic production in a group of patients with severe closed head injury and to determine the correlations between prosodic production and neurobehavioural status. METHODS: Fifteen patients, at the subacute stage after severe closed head injury, were studied and compared with 11 controls, matched for age, sex, and duration of education. Each subject was required to read aloud a French sentence "Je m'en vais samedi matin" (I am leaving saturday morning) under six different prosodic intonations (neutral, affirmation, interrogation, happiness, sadness, anger). The recorded sentences were analysed using a sound signal analysis software (Signalyse) allowing the measurement of signal intensity and fundamental frequency. Statistical analyses were carried out using repeated measures analysis of variance (ANOVA). RESULTS: Patients with closed head injury were significantly less able than controls to modulate speech output (pitch and intensity) according to prosodic context. This deficit was particularly pronounced for the intonation feature of anger, question, and statement. No consistent correlations could be found between prosodic production and cognitive or behavioural data. CONCLUSIONS: Acoustic analysis of pitch and intensity may show impairments of prosodic production after severe closed head injury, which may be useful in rehabilitation planning. This impairment does not seem to reflect the eventual cognitive and behavioural deficits of the patients, but rather a specific disorder of modulation of speech output.

Adolescent↗
PubMed1997

[Increase of the contraction of the stance soleus muscle in human does not delay the swing phase in step elicited by forward fall].

In this study it was examined in man whether tension increase in the extensor muscles of the stance foot delays the stance to swing transition, as suggested by some observations made in cats. Steps reproducibly elicited by forward fall were studied. Increase in muscle tension was obtained by electrical stimulation of the tibial nerve during the last third of the first step stance phase with trains of five rectangular pulses, 1 ms in duration, at 20 Hz, whose intensity was sufficient for eliciting maximal responses in the stance Soleus muscle (e.m.g. M responses). Trials with and without electrical simulation were randomly carried out in five healthy subjects who had consented to take part in the experimentation. The stance to swing transition was characterized by the time of activation of the Tibialis anterior muscle of the stance foot and by the time of clearance of this foot from the ground. It was found that maximal contractions of the stance Soleus muscle did not change these times. Thus, in contradiction to some observations made in spinal and decerebrated cats, tension increase in the stance Soleus in man during steps elicited by a forward fall does not delay the transition to the swing phase.

Accidental Falls↗
PubMed1997

Endothelial fibrinolytic reactivity and the risk of deep venous thrombosis after spinal cord injury.

Deep vein thrombosis (DVT) is a frequent event in patients with spinal cord injury, even with prophylactic anticoagulant therapy. Lower limb paralysis is a known major risk factor for venous thrombosis, supposedly due to the venostasis in relation with total immobility. The main goal of this study was to evaluate the endothelial response to anoxia to determine whether recovery of fibrinolytic potential occurs in patients subjected to forced bedrest because of a spinal cord injury and whether this recovery is related to the incidence and/or evolution of DVT. We evaluated vascular endothelium reactivity in the lower limbs no longer submitted to the hydrostatic pressure of the erected position in 15 patients with paraplegia or tetraplegia and in 10 normal volunteers after venous occlusion produced by the application of 10 cm Hg pressure to the lower limb for 15 min comparatively to the upper limb used as reference. Among the 15 patients, 10 whose spinal cord injury had occurred 1 to 6 months earlier were still receiving prophylactic anticoagulant therapy, whereas the five other patients were not receiving prophylactic anticoagulants because the injury dated back 6 months or more. After venostasis, tissue plasminogen activator (tPA) increased significantly in both patients and controls in the upper limb (tPA levels twofold and threefold respectively in controls and patients) but showed no significant changes in the lower limb; prolonged immobility did not allow recovery in the lower limbs of a level of fibrinolytic responsiveness identical to that in the upper limbs. The plasminogen activator inhibitor (PAI1) remained unchanged after anoxia, although wide interindividual variations were seen. Natural coagulation inhibitors and circulating blood stigmates of hypercoagulability were measured. None of the patients had abnormally low levels of coagulation inhibitors (ie, antithrombin III, protein C and protein S levels were normal). Seventy-five per cent of patients (prophylactically anticoagulated or not) had very high levels of fibrin degradation products (D. Dimer levels sevenfold to eightfold those of the controls), but all patients had normal levels of thrombin-antithrombin complexes and prothrombin fragments 1 + 2. The permanence of the thrombotic process characterized by an increase in D. Dimer levels without recovery of fibrinolytic potential suggests a proposal for the patients an indefinite antithrombotic treatment at curative doses.

Adolescent↗
PubMed1996

Anticipatory responses to a self-applied load in normal subjects and hemiparetic patients.

A bimanual loading task was studied in eight right-handed normal subjects and nine hemiparetic patients in order to detect anticipatory adjustments and to analyse the reflex and voluntary, responses induced by the perturbation. The left forearm (or the impaired side in patients) was flexed at approximately 90 degrees and free to rotate in a vertical sagittal plane. It was held to resist a load (2-3 kg) dropped either by an experimenter (control situation), or by the subject himself with no visual control (self-applied situation). The load was dropped from the right hand by normal subjects and from the unimpaired hand by hemiparetic patients. The initial distance the load fell was 0.05-0.35 m. The elbow movements of the limb receiving the load were recorded with a linear accelerometer at the wrist, a potentiometer at the elbow and via the EMG signals from flexor muscles. Normal subjects always made an anticipatory flexion movement prior to the impact in the self-applied situation, but not in the control situation. The anticipatory flexion of hemiparetic patients was slower and longer. The amplitude of the anticipatory flexion at the time of impact and its duration were correlated with the mass of the load and the initial distance between the two hands in both groups. The anticipatory flexion reduced the distance through which the load fell and thus its kinetic energy at impact. The impact induced a brisk extension which was always smaller in the self-applied situation for a given kinetic energy. In normal subjects, the amplitude of the monosynaptic reflex (MSR) following the impact in flexor muscles was usually greater in the self-applied situation, but its gain was either reduced or unchanged. The gain of the functional stretch reflex (FSR) was consistently reduced in the self-applied situation. Depression of the FSR gain occurred in only two hemiparetic patients who had the best recovered motor function. Anticipation always ended up minimizing the perturbation following different motor strategies. The normal subjects fell into two groups. One group adjusted the anticipatory forearm flexion to correct the extension disturbance as fast as possible; the second group relied on an accurate adjustment of the final position. Hemiparetic patients showed idiosyncratic intermediate behavior.

Adult↗
PubMed1996

Intrathecal baclofen administration for control of severe spinal spasticity: functional improvement and long-term follow-up.

OBJECTIVES: To assess long-term efficacy and functional benefits of intrathecal baclofen for severe spinal spasticity. DESIGN: A prospective before-after trial. SETTING: A neurological rehabilitation department of a university hospital. Pump implantation was realized in neurosurgery; follow-up was carried out mostly on an outpatient basis. PATIENTS: Eighteen patients with severe and disabling spinal spasticity received intrathecal baclofen by an implantable pump; average follow-up was 37.4 months (range, 9 to 72). MAIN OUTCOME MEASURES: Spasticity (Ashworth and spasms frequency scores); disability (Functional Independence Measure [FIM]). RESULTS: A significant decrease in tone and spasms was observed in all patients. Tolerance appeared during the first 6 to 9 months. Later on, efficacy remained stable, except in cases of mechanical problems of the pump or catheter. Functional assessment found a highly significant (p < .001) increase of FIM score (particularly for bathing, dressing lower body, transfers, and in some cases, locomotion). This was particularly marked in patients with thoracic spinal cord lesion. In cases of severe upper limb dysfunction, FIM was only improved for wheelchair displacements, due to a better sitting position, but nursing became easier and life comfort was enhanced. Severe side effects (overdose) were observed in two cases. CONCLUSION: Efficacy remained stable after 6 to 9 months. Marked improvement of functional independence was observed in paraplegic patients. Improvement was less spectacular in patients with severe upper limb dysfunction, but nevertheless appreciable in terms of life comfort and use of attendants.

Activities of Daily Living↗
PubMed1996

Changes in the execution of a complex manual task after ipsilateral ischemic cerebral hemispheric stroke.

OBJECTIVE: To analyze behavioral adaptation of hemiplegic patients performing a complex manual task without time constraint. It was postulated that ipsilateral motor disturbance could not be observed after a hemispheric stroke. DESIGN: Two manual tasks were used: (1) a new one, "Pig-Tail," required the patients to run a 3-cm-diameter copper ring in a wooden handle along a wavy copper wire without any time constraint; (2) the second task was the Nine-Hole Peg Test (NHPT). SETTING: A hospital department of rehabilitation. PATIENTS: A consecutive sample of 36 patients, who had all suffered an ischemic stroke in the middle cerebral artery territory, 18 with left hemisphere damage (LHD) and 18 with right (RHD), and who had similar ages (mean 54 +/- 13), stroke severity, time since stroke (mean 60 days), and functional independence according to the FIM. MAIN OUTCOME MEASURE: Main data were number of faults, time in seconds, and difference of time for two trials. Analysis compared the results with the same hand for patients and 86 healthy subjects. RESULTS: Patients scores for NHPT were worse than controls, whatever the side of the lesion (p < .05). For Pig-Tail, the number of faults by patients was greater than by controls (p < .05); time was higher for LHD, but not significantly, and was similar to controls for RHD. All patients and controls speeded up between the two trials. Although the RHD were clumsy, they were always faster than LHD patients. CONCLUSION: There are ipsilateral motor disturbances in a complex manual task after hemispheric stoke, even without a speed constraint, and regardless of the hemisphere damaged. Further studies are needed to examine speed control that seemed impaired by right hemisphere damage and could explain clumsiness in these patients.

Adaptation, Physiological↗
PubMed1996

Working memory and supervisory control after severe closed-head injury. A study of dual task performance and random generation.

Survivors of severe closed-head injury (CHI) frequently suffer from slowed information processing. Whether supervisory strategies are additionally impaired remains a point of debate. The first part of this study employed a self-paced dual task; the second part, a random generation task, performed at a paced rate, under single and dual task conditions. A measure of information processing speed was used as a covariate in statistical analysis. In the first experiment, in addition to slow processing, patients performed slightly poorer than controls on each task. In the second experiment, patients' performance (one randomness index in single task condition, and processing of dual task) was impaired even after statistical control of slow processing. These results suggest that there is at least some degree of impairment in supervisory strategies in addition to, but independent of, slowed processing. The clinical significance of this finding is discussed.

Adolescent↗
PubMed1996

Late cognitive and behavioural improvement following treatment of disabling orthopaedic complications of a severe closed head injury.

Interactions of physical, emotional, cognitive and behavioural impairments after severe closed head injury (CHI) remain poorly understood. A 47-year-old man was referred to our department 13 months after a severe CHI. He demonstrated severe left hemiplegia and disabling orthopaedic complications (left hip infectious arthritis, after surgical treatment for heterotopic ossification). His hip was blocked and extremely painful. He was totally dependent for daily-life activities (Functional Independence Measure (FIM) score = 18). Moreover he exhibited severe cognitive and behavioural troubles, which had been stable for many months beforehand, e.g. complete disorientation for time and place, major memory disorders, agitation, anxiety, depression, irritability, disinhibition, aggressiveness and lack of initiative. Pain disappeared within a few weeks after treatment. Progressively, functional improvement occurred (sitting position, transfers, walking between parallel bars). The FIM score increased to 63. Aggressiveness, irritability and agitation disappeared. Surprisingly, neuropsychological assessment demonstrated parallel improvement of cognitive functions, especially in regard to orientation, and to a lesser degree attention and memory. Such an observation should encourage use of active treatment of physical disabilities, even in patients presenting with an apparently poor cognitive prognosis at a late stage of severe CHI.

Cognition Disorders↗
PubMed1996

Evidence for a spinal stepping generator in man. Electrophysiological study.

We present some evidence favouring the presence of a spinal stepping generator in humans. Electrophysiological studies have shown that the spinal cord even deprived of supraspinal influence can generate rhythmic activity, and that some elements of the spinal circuitry on which the generation of stepping rhythmic relies in lower vertebrates exist in man. Moreover, comparison of the variations of the polysynaptic spinal flexor reflex in normal subjects and paraplegic patients brought about some evidence that normal subjects use a spinal locomotor center. Nevertheless, these studies do not absolutely prove the existence of a central pattern generator in man.

Electrophysiology↗