[The effect of thalamic stimulation on levodopa induced dyskinesias--evaluation of a new target: the center parafascicular median]. / Effet de la stimulation thalamique sur les dyskinésies induites par la L-Dopa--évaluation d'une cible nouvelle: le centre médian parafasciculaire.

After 10 years of clinical practice (1987-1997), chronic thalamic deep brain stimulation (DBS) is considered to be effective in the treatment of drug-resistant parkinsonian tremor. DBS has produced few side-effects, which are usually reversible. More recently, DBS has been applied to other movement disorders (akinesia and rigidity, dyskinesias, dystonia), using new targets: internal pallidum, subthalamic nucleus. These targets have been selected on the basis of neurophysiological or anatomo-clinical data suggesting they could be effective. Control of L-Dopa peak-dose dyskinesias by thalamic ventralis intermedius nucleus (V.im.) stimulation has been reported by the Lille team, but not by the Grenoble team. We therefore re-examined all teleradioanatomical data of both teams, and compared them with the therapeutic effects. Location of 99 monopolar electrodes of thalamic stimulation, applied to treat parkinsonian tremor, has been retrospectively measured. The Lille team included 21 patients (22 electrodes); the Grenoble team included 52 patients (74 electrodes). L-Dopa dyskinesias were suppressed in all 9 patients in Lille, and improved clearly in only 8 out of 32 patients in Grenoble. The mean center of electrodes was significantly different between both teams, being deeper, more posterior and medial in Lille. This did not correspond to the coordinates of the V.im., but seems to be closer to those of the centromedian and parafascicular complex (CM-Pf), according to stereotactic atlases. Considering only the dyskinetic patients, the therapeutic effects on L-Dopa dyskinesias were related to the differences observed in the electrode position, but not to the team membership. Improvement of L-Dopa dyskinesias was significantly associated with deeper and more medial placement of electrodes. Retrospective analysis of ventriculographic data confirmed that the electrode position and therapeutic effects of DBS are strongly related. Our study suggested that CM-Pf stimulation could control both tremor and L-Dopa dyskinesias. This hypothesis is consistent with neuro-anatomical data showing that CM-Pf is connected to internal pallidum, the stimulation of which controls specifically L-Dopa dyskinesias.

Improvement of levodopa induced dyskinesias by thalamic deep brain stimulation is related to slight variation in electrode placement: possible involvement of the centre median and parafascicularis complex.

OBJECTIVE: To define the reason why two teams using the same procedure and the same target for deep brain stimulation (DBS) obtained different results on levodopa induced dyskinesias, whereas in both, parkinsonian tremor was improved or totally suppressed. METHODS: Deep brain stimulation can replace lesions in the surgical treatment of abnormal movements. After 10 years of experience with DBS in Parkinson's disease, a comparison of results between the teams of Lille (A) and Grenoble (B) was carried out, for as long as they used intraoperative ventriculography. Both teams aimed at the same target, the ventralis intermedius nucleus of the thalamus (VIM), but team A found a clear improvement of choreic peak dose dyskinesias, whereas team B did not consistently. Therefore all teleradioanatomical data of both teams were re-examined and compared with the therapeutic effects. Location of 99 monopolar electrodes of thalamic stimulation applied to treat parkinsonian tremor has been retrospectively measured (team A included 21 patients, 22 electrodes; team B included 52 patients, 74 electrodes). Peak dose levodopa dyskinesias were suppressed by DBS in all nine patients of team A, four of which were severely disabling. Only eight out of 32 patients from team B experienced a moderate (four) or clear (four) improvement of dyskinesias, whereas in the remaining 24 patients, dyskinesias were unchanged with stimulation. RESULTS: The mean centre of team A's electrodes was on average 2.9 mm deeper, more posterior and medial than team B's (t=8.05; p<0.0001). This does not correspond to the coordinates of the VIM, but seems to be closer to those of the centre median and parafascicularis complex (CM-Pf), according to stereotaxic atlases. Considering only the dyskinetic patients, significant differences were found in the electrode position according to the therapeutic effects on levodopa dyskinesias, but they were not related to the team membership. Improvement in levodopa dyskinesias was significantly associated with deeper and more medial placement of electrodes. CONCLUSION: The retrospective analysis of patients treated with DBS using comparable methodologies provides important information concerning electrode position and therapeutic outcome. The position of the electrode is related to the therapeutic effects of DBS. The results support the hypothesis that patients experiencing an improvement of dyskinesias under DBS are actually stimulated in a structure which is more posterior, more internal, and deeper than the VIM, very close to the CM-Pf. These results are consistent with neuroanatomical and neurophysiological data showing that the CM-Pf is included in the motor circuits of the basal ganglia system and receives an important input from the internal pallidum. This suggests that the CM-Pf could be involved specifically in the pathophysiology of levodopa peak dose dyskinesias.

Predictors of medical care utilization by independently living adults with spinal cord injuries.

A prospective study of 87 independently living adults with spinal cord injury (SCI) as a major disabling condition showed the following average annual health care utilization rates: 1.3 hospital admissions, 16.8 days hospitalized, 1.7 emergency room (ER) visits, and 22.4 outpatient contacts (in person or by telephone). Those hospitalized (n = 66) experienced a mean of 22.2 days hospitalized per person per year. Mean length of stay (LOS) was 11.1 days per admission. Stepwise regression analysis indicated no statistically significant (p less than or equal to .05) predictors of hospital admissions. There were three independent predictors of days hospitalized (greater age, fewer years of education, and more days hospitalized during the previous year), three predictors of days hospitalized for those hospitalized only (greater age, fewer years of education, and longer hospital LOS during the previous year), one predictor of LOS (self-assessment of health), three of emergency room (ER) visits (more unmet instrumental activities of daily living needs, lack of organizational memberships, and more ER visits during the previous year), and five predictors of outpatient contacts (greater age, less satisfaction with health care providers' expressions of concern for their health, lower frequency of leaving apartments, lower levels of life satisfaction, and nonparticipation in a managed medical care demonstration project). Many predictors of health services utilization are immutable. However, changes which facilitate social interaction and changes in the organization of health services may reduce certain types of medical care utilization by people with SCI.

The epidemiology of medical care utilization by severely-disabled independently-living adults.

A prospective study of the medical care utilization experience of 205 severely-disabled independently-living adults in Eastern Massachusetts shows that there was a mean of 0.83 +/- 1.26 hospital admissions, 9.9 +/- 22.7 hospital days, 1.5 +/- 2.31 emergency room (ER) visits, and 26.88 +/- 44.4 outpatient contacts per person per year. Among those hospitalized, the mean experience was 16.2 +/- 27.1 days per person per year; mean length-of-stay was 9.3 +/- 14.7 days per admission. Regression analysis indicates that those with spinal cord injuries as major disabling conditions were significantly more likely to be hospitalized. So were those with lower self-assessments of health, higher levels of depressions, and more baseline ER visits. Self-assessment of health is a significant predictor of hospital days for the total cohort (including those with no admissions); so are age at onset of disability (greater age; higher risk), and bed disability days in the month before the baseline survey (more disability days; higher risk). Among those hospitalized, the total number of days hospitalized is significantly related to both age at onset of disability (later onset; more days) and baseline days hospitalized (greater number; more days). Lengths-of-stay are significantly related to two factors; age and age at onset of disability (in both cases, greater age associated with longer stays). Prior ER visits are a significant predictor of subsequent ER visits (more baseline; more subsequent); so are respondents' reported satisfaction with their participation in their medical care (lower reported satisfaction; more ER visits), organizational affiliations, and frequencies of contacts with friends or relatives. Higher levels of social interaction (i.e. organizational affiliation and more frequent social contacts) were associated with more ER visits. Prior contacts with physicians, nurse-practitioners, or physician-assistants was the most powerful predictor of subsequent outpatient contacts (more baseline; more subsequent). There were also significant relationships between subsequent contacts and respondents' assessments of their health relative to others with similar disabilities (relatively worse health; more contacts), age (greater age; more contacts), and baseline ER visits (more visits; more contacts).

A prospective evaluation of the effect of managed care on medical care utilization among severely disabled independently living adults.

We conducted an 18-month longitudinal evaluation of a model-managed medical care program for severely disabled, independently living adults. Regression analyses using an additive model (no interaction effects) suggest that persons in the study group did not have statistically significantly different utilization experiences than members of the comparison group. Regression analyses that include interaction effects suggest that, for certain segments of the cohort, the study group's utilization experience was significantly lower than that of members of the comparison group. Persons in the study group with higher baseline emergency room (ER) utilization had significantly fewer hospital admissions (P = 0.0055). The participants with better self-assessments of health experienced significantly fewer hospital days per person (P = 0.0075) and days per person hospitalized (P = 0.0056), and persons with organizational affiliations reported significantly fewer ER visits (P = 0.0264).

Rehospitalization and spinal cord injury: cross-sectional survey of adults living independently.

A cross-sectional survey of 96 people living independently with spinal cord injuries (SCI) in Eastern Massachusetts shows that 57% had been hospitalized at least once in the year before the survey. Sample means were 1.0 admissions and 16.0 days/person/year. Eight percent of the sample (eight persons) accounted for 22% of admissions and 59% of total hospital days. For those hospitalized, the mean was 1.7 admissions and 45.1 days/person/year. Mean length-of-stay was 34.7 days/admission. Multiple regression analysis shows that three variables appear to be independently related to increased numbers of admissions: self-assessment of health; place of residence; and age (younger respondents at higher risk). One variable is independently associated with total days of hospitalization: leaving home at least once daily (as opposed to less frequently) is associated with lower risk. There were no statistically significant relationships between either numbers of hospitalizations or total days hospitalized and ADL or IADL status, education, employment, medical insurance, household composition, gender, age at onset of disability, time since onset of disability, substance use (alcohol, cannabis, or tobacco), level of SCI lesion, or social supports.

Evaluation of comprehensive rehabilitation services for elderly homebound patients with arthritis and orthopedic disability.

Fifty-seven elderly homebound patients with arthritis and orthopedic disabilities were randomized to a goal-oriented outreach rehabilitation program or to usual treatment. Although 64% of patient goals were met, there were no overall significant differences in functional scores, institutionalization, or contentment between treatment and control periods. Twenty-three patients had maintained clinical improvement at the end of the study and some patients were dramatically improved with simple measures. The program's marginal costs were modest and consisted primarily of expenses associated with therapist's visits. The total costs of assistive devices and home modifications amounted to $1,902. Twenty-five percent of the homebound population could benefit from such services but the actual number who would partake is small.

A continuum of care for the inner city: assessment of its benefits for Boston's elderly and high-risk populations.

We describe an approach to health care in the inner city: a multidisciplinary system of physicians and mid-level practitioners that provides individualized care to chronically ill, elderly, homebound, and nursing-home residents of urban Boston who would otherwise be forced into an inappropriate reliance on teaching hospitals. Linked to four neighborhood health centers, three home-care programs, and a teaching hospital, and financially self-supporting except for the home-care component, the system cared for 3000 ambulatory, 280 homebound, and 358 nursing-home patients in the representative year described. In-hospital use, particularly hospital days, was reduced when judged by existing data for comparable (though not identical) populations. Based on stable physician practices, the system offers a workable approach to the related problems of care, manpower, and cost in the urban core.