Biomedical subjects

Ofer Keren

Publications and source records attributed to Ofer Keren.

6 recordsLinked to original sources

PubMed2006

Hemispheric visual atentional imbalance in patients with traumatic brain injury.

We find a spatially asymmetric allocation of attention in patients with traumatic brain injury (TBI) despite the lack of obvious asymmetry in neurological indicators. Identification performance was measured for simple spatial patterns presented briefly to a locus 5 degrees into the left or right hemifield, after precuing attention to the same (ipsilateral) or opposite (cross-hemifield) side. Though the cue was non-predictive of target location overall, performance was significantly slower for cross than for ipsilateral trials in both patients and controls. We tested 21 TBI patients without overt focal brain damage and nine control subjects. Only patients demonstrated significantly worse performance for left side presentation in the ipsilateral condition. Furthermore, in the cross-hemifield condition, the left-right difference seen in TBI patients was significantly larger-reflecting a failure in producing a leftward attention shift. Again no significant difference was found in controls. These hemifield effects suggest an asymmetry in the ability of TBI patients in shifting attention to the left hemifield, whether from central fixation or from a cue in the contra-lateral hemifield. The results support basic hypotheses regarding visual attention: Attentional control may be asymmetric and attention may be a distributed, rather than localized cortical function.

Adolescent↗

PubMed2006

Orthostatic hypotension and cerebral blood flow velocity in the rehabilitation of stroke patients.

The objective of this study was to investigate the results of transcranial Doppler monitoring during tilt table tests in stroke patients with and without orthostatic hypotension. In stroke patients without orthostatic hypotension, the mean flow velocity was almost similar in both middle cerebral arteries and was stable during the test. In patients with orthostatic hypotension symptoms, a significant difference was found between the two hemispheres. Mean flow velocity in the damaged middle cerebral artery was lower in the supine position and stayed almost the same at 80 degrees standing. In the non-damaged middle cerebral artery, however, the mean flow velocity was much higher when supine and dropped in the standing position. These findings suggest that the appearance of orthostatic hypotension symptoms may be associated in post-stroke patients with decreased blood velocity in the damaged middle cerebral artery. Those patients are at a high risk of developing syncopal reactions and should be treated on the tilt table with caution, especially at the beginning of the rehabilitation.

Acute Disease↗

PubMed2006

The influence of early cycling training on balance in stroke patients at the subacute stage. Results of a preliminary trial.

OBJECTIVE: To investigate the effect of early cycling training on balance and motor abilities of stroke patients in their subacute stage. DESIGN: Randomized clinical trial. SETTING: Inpatient rehabilitation. SUBJECTS: Twenty-four patients who had had a first stroke were randomly assigned to a cycling training group (N=10) or to a control (N=14) group. INTERVENTION: All subjects received their usual rehabilitation programme; the cycling training group received in addition a daily session of leg cycle ergometer, lasting three weeks. Both groups were followed for six weeks. MAIN OUTCOME MEASUREMENTS: Balance was assessed using the Postural Assessment Scale for Stroke Patients (PASS) and the standing balance test. The motor function of the lower extremity was also assessed by the Fugl-Meyer Assessment (FMA). RESULTS: In the within-group comparison, both the exercise group and the control group had improved significantly (P < 0.01) with time with respect to PASS total (exercise group 18.7 +/- 2.8 to 31.1 +/- 2.2, control group 18.1 +/- 3.2 to 26.4 +/- 3.8) and PASS subscores, as well as the FMA score (exercise group 17.2 +/- 7.5 to 29.1 +/- 5.9, control group 16.6 +/- 6.4 to 22.1 +/- 6.8). In addition there was a significant group-time interaction effect, with exercise group patients demonstrating better performance in both the total PASS score and PASS subscores and FMA score relative to the control patients (P < 0.01). CONCLUSIONS: These preliminary findings suggest that stroke patients in the subacute stage can improve their motor and balance abilities after an early short duration of cycling training.

Aged↗

PubMed2004

Differential time and related appearance of signs, indicating improvement in the state of consciousness in vegetative state traumatic brain injury (VS-TBI) patients after initiation of dopamine treatment.

OBJECTIVE: The goal of the study was to look for the response of treatment with increasing doses of dopaminergic medication on the recovery of vegetative state patients post-TBI. DESIGN: A prospective study of eight patients aged 25-50 years in vegetative state (VS) of mean duration of 104 days following traumatic brain injury (TBI) was performed by investigating changes of their state of consciousness while they were treated with levodopa/carbidopa. RESULTS: Initial improvement was observed in all patients within a mean of 13 days after onset of treatment. Seven patients recovered consciousness after a mean time of 31 days of treatment. The remaining patient showed only slight improvement to minimally conscious state. The sequence of symptoms leading to recovery was the same in all patients; the first to appear was moving a limb on a request, which appeared at a mean time of 13 days. Gradual increase of dose leads to the appearance of better-organized responses like reacting to more than one command, than opening the mouth and appearance of a reciprocal contact. The only side effect was visual hallucinations in one patient, which disappeared after decreasing the dosage. CONCLUSIONS: Clinical awareness to the structured order of responses and to the effect of dosage can help clinicians in early assessment of response to dopaminergic treatment in VS patients.

Adult↗

PubMed2004

[Restorgenesis: a new concept].

This article suggests a new concept, named "restorgenesis". It addresses issues related to the essence of rehabilitation, such as defining the patient's potential for recovery, the milestones of the recovery process, its facilitating and impinging factors. This concept is a "hybrid" of two already existing notions: "pathogenesis", i.e. the definition of the factors in the individual and his/her environment that are causative of illness, and "salutogenesis", i.e. the definition of factors in the individual as well as in the environment that promote health. We suggest the notion of "restorgenesis" to embrace the processes of re-building and re-equilibrating that are at the core of the recovery process. Finally, we study the relevance of the recently introduced concept of allostasis, which includes the psychological and physiological factors related to the human system optimal functioning, to the process of rehabilitation.

Attitude to Health↗

PubMed2004

Relationship between rehabilitation therapies and outcome of stroke patients in Israel: a preliminary study.

BACKGROUND: The relationship between the amount of rehabilitation therapy and functional outcome in stroke patients has not been established. OBJECTIVES: To evaluate the effectiveness of inpatient rehabilitation for post-acute stroke, and examine the relationship between intensity of therapies and functional status at discharge. METHODS: We evaluated 50 first-stroke patients, average age 63 years, in a prospective descriptive study. The impairment and Functional Independence Measurement were assessed both at admission to rehabilitation and at discharge. Patients were monitored weekly during their stay by means of discipline-specific measures of activity level. Predictor variables included intensity of physical, occupational and speech therapies; demographic characteristics; length of stay; and time since the stroke. RESULTS: A significant reduction in impairment was observed at discharge. The predictors of gains and activity level at discharge as well as motor vs. cognitive components of the FIM were neither consistent nor did they occur in the same trend of functional improvement. Greater FIM motor level at discharge was associated with younger age, higher admission motor and cognitive level, and receipt of any speech therapy, while greater FIM cognitive level was associated with higher cognitive level at admission, shorter interval from onset to admission, and more intense occupational therapy. More intense OT was associated with greater and more cognitive improvement during the hospitalization. CONCLUSION: Since the sample was relatively small and heterogenous in terms of the patients' functional abilities, the findings cannot be generalized to the whole population of stroke patients. Further efforts to identify the best timing, modalities, intensity and frequency of the various treatments are needed to improve the cost-benefit equation of rehabilitation in stroke patients.

Activities of Daily Living↗