activa-results

ACTIVA Therapy:

Results

Tremor Control Therapy significantly reduces tremor in more than 80% of patients who have had the system implanted. The amount of tremor reduction varies. Most people experience almost complete relief from tremor on the side stimulated. Reduction in tremor is associated with improvement in performance of activities of daily living. Some people experience partial tremor relief, allowing them to be more functional. Some people may not benefit.
The effectiveness of the therapy for a particular person is tested during the surgery before a stimulation system is implanted . This testing helps ensure benefit prior to implantation.
Tremor Control Therapy has the additional advantage of "adaptability", because the stimulation can be adjusted as needed to optimize tremor relief and minimize side effects. Side effects, such as problems with balance, speech, and numbness, are usually reversible, mild, and accepted. The system also can be turned off or removed. Patients use a hand-held magnet to switch the stimulator between high, low, and off settings. For example, they can turn their stimulation level to high when their tremor increases because of stress, or they can turn their stimulation off when they go to sleep (tremor ceases with sleep).
Because brain tissue is not destroyed after the lead is implanted, patients treated with the therapy have preserved their future options as new therapies develop.
Ask your doctor…
As with any therapy, this procedure involves some risks. Persons considering this therapy should discuss both the potential risks and the benefits with their physician.
- Tremor Suppression is Immediate
High frequency thalamic stimulation may suppress tremor as soon as the system is turned on.
Thalamic stimulation allows most patients to resume activities inhibited by tremor, such as handwriting and self-feeding.
According to Benabid et al., thalamic stimulation may reduce or eliminate the need for medication. One study showed that one-third of Parkinson's Disease patients reduced their L-Dopa dosage by 30%.
The stimulation system is designed to deliver high frequency electrical stimulation using a multi-electrode lead placed in the ventral intermediate nucleus (Vim) of the thalamus. The implantable pulse generator (IPG) is placed subcutaneously in the pectoral area. The IPG is attached to an extension, which is tunneled and attached to the implanted lead.

Side effects, such as problems with balance, speech, and numbness, are reversible, mild, and accepted by most patients. Thalamic stimulation has the advantage of being adaptable. Stimulation can be turned up or down to minimize side effects and optimize symptom relief.

The New England Journal of Medicine -- February 17, 2000 -- Vol. 342, No. 7

A Comparison of Continuous Thalamic Stimulation and Thalamotomy for Suppression of Severe Tremor
P. Richard Schuurman, D. Andries Bosch, Patrick M.M. Bossuyt, Gouke J. Bonsel, Eus J.W. van Someren, Rob M.A. de Bie, Maruschka P. Merkus, Johannes D. Speelman

Abstract
Background. Deep-brain stimulation through an electrode implanted in the thalamus was developed as an alternative to thalamotomy for the treatment of drug-resistant tremor. Stimulation is thought to be as effective as thalamotomy but to have fewer complications. We examined the effects of these two procedures on the functional abilities of patients with drug-resistant tremor due to Parkinson's disease, essential tremor, or multiple sclerosis.

Methods. Sixty-eight patients (45 with Parkinson's disease, 13 with essential tremor, and 10 with multiple sclerosis) were randomly assigned to undergo thalamotomy or thalamic stimulation. The primary outcome measure was the change in functional abilities six months after surgery, as measured by the Frenchay Activities Index. Scores for this index can range from 0 to 60, with higher scores indicating better function. Secondary outcome measures were the severity of tremor, the number of adverse effects, and patients' assessment of the outcome.

Results. Functional status improved more in the thalamic-stimulation group than in the thalamotomy group, as indicated by increases in the score for the Frenchay Activities Index (from 31.4 to 36.3 and from 32.0 to 32.5, respectively; difference between groups, 4.4 points; 95 percent confidence interval, 2.0 to 6.9). After adjustment for base-line characteristics, multivariate analysis also showed that the thalamic-stimulation group had greater improvement (difference between groups, 5.1 points; 95 percent confidence interval, 2.3 to 7.9). Tremor was suppressed completely or almost completely in 27 of 34 patients in the thalamotomy group and in 30 of 33 patients in the thalamic-stimulation group. One patient in the thalamic-stimulation group died perioperatively after an intracerebral hemorrhage. With the exception of this incident, thalamic stimulation was associated with significantly fewer adverse effects than thalamotomy. Functional status was reported as improved by 8 patients in the thalamotomy group, as compared with 18 patients in the thalamic-stimulation group (P=0.01).

Conclusions. Thalamic stimulation and thalamotomy are equally effective for the suppression of drug-resistant tremor, but thalamic stimulation has fewer adverse effects and results in a greater improvement in function. (N Engl J Med 2000;342:461-8.)

Ann Neurol 1997 Sep;42(3):292-9

High-frequency unilateral thalamic stimulation in the treatment of essential and parkinsonian tremor.

Koller W, Pahwa R, Busenbark K, Hubble J, Wilkinson S, Lang A, Tuite P, Sime E, Lazano A, Hauser R, Malapira T, Smith D, Tarsy D, Miyawaki E, Norregaard T, Kormos T, Olanow CW
Department of Neurology, University of Kansas Medical Center, Kansas City 66160-7314, USA.

Pharmacologic treatment for essential tremor and the tremor of Parkinson's disease is often inadequate. Stereotaxic surgery, such as thalamotomy, can effectively reduce tremors. We performed a multicenter trial of unilateral high-frequency stimulation of the ventral intermedius nucleus of the thalamus in 29 patients with essential tremor and 24 patients with Parkinson's disease, using a blinded assessment at 3 months after surgery to compare clinical rating of tremor with stimulation ON with stimulation OFF and baseline and a 1-year follow-up. Six patients were not implanted because of lack of intraoperative tremor suppression (2 patients), hemorrhage (2 patients), withdrawal of consent (1 patient), and persistent microthalamotomy effect (1 patient). A significant reduction in both essential and parkinsonian tremor occurred contralaterally with stimulation. Patients reported a significant reduction in disability. Measures of function were significantly improved in patients with essential tremor. Complications related to surgery in implanted patients were few. Stimulation was commonly associated with transient paresthesias. Other adverse effects were mild and well tolerated. Efficacy was not reduced at 1 year. Chronic high-frequency stimulation is safe and highly effective in ameliorating essential and parkinsonian tremor.

Neurology 1996 Apr;46(4):1150-3

Deep brain stimulation for essential tremor.

Hubble JP, Busenbark KL, Wilkinson S, Penn RD, Lyons K, Koller WC
Department of Neurology, University of Kansas Medical Center, Kansas City, USA.

We examined the effects and safety of deep brain stimulation (DBS) as a treatment for essential tremor (ET). Ten ET patients with disabling medication-refractory tremor underwent stereotactic implantation of a DBS lead in the left Vim thalamic nucleus and completed a 6-month follow-up. The Clinical Tremor Rating Scale and disability assessments were performed at baseline, 1-, 3-, and 6-month follow-up. There were significant improvements in dressing, drinking, eating, bathing, and handwriting as reported by the subjects. Tremor severity, writing, pouring, and spiral and line drawing were significantly improved as rated by the examiner. Improvements persisted through the 6-month follow-up period. Although global disability significantly lessened in the group as a whole, one subject with hand-finger tremor accentuated by writing had no change in disability status. In this 6-month open-label study, DBS was effective and safe in reducing tremor and functional disability in ET.

Neurology 1998 Oct;51(4):1063-9

Unilateral thalamic deep brain stimulation for refractory essential tremor and Parkinson's disease tremor.

Ondo W, Jankovic J, Schwartz K, Almaguer M, Simpson RK
Department of Neurology, Baylor College of Medicine, Houston, TX, USA.

OBJECTIVE: To determine the efficacy and tolerability of unilateral thalamic deep brain stimulation (DBS) for patients with medically refractory essential tremor (ET) and the tremor associated with Parkinson's disease (PD). BACKGROUND: The tremor of ET and PD may produce functional disability despite optimal medical therapy. Several reports have demonstrated efficacy of thalamic DBS in this scenario. METHODS: Preoperative and 3-month postoperative tremor ratings were compared in 33 patients (14 ET and 19 PD) with severe tremor. Evaluations included Unified Parkinson's Disease Rating Scale (UPDRS) scores for PD patients and a modified Unified Tremor Rating Scale in ET patients. Open-label and blinded data (unknown activation status) were obtained. RESULTS: ET patients demonstrated an 83% reduction (p < 0.0001) in observed contralateral arm tremor. All measures of tremor including writing samples, pouring tests, subjective functional surveys, and disability scores improved significantly. PD patients demonstrated an 82% reduction (p < 0.0001) in contralateral tremor and significant improvement in disability and global impressions. There was, however, no meaningful improvement in other motor aspects of the disease, and the total UPDRS part II (activities of daily living) score did not change. Adverse events, more common in ET patients, were generally mild and were usually eliminated by adjustment of the device parameters. CONCLUSIONS: Thalamic DBS is a safe and effective treatment of ET and the tremor of PD. In PD, its use should be limited to patients in whom high-amplitude tremor results directly in significant functional disability.

J Neurol Neurosurg Psychiatry 1999 Mar;66(3):289-96

Multicentre European study of thalamic stimulation in parkinsonian and essential tremor.

Limousin P, Speelman JD, Gielen F, Janssens M
Department of Clinical and Biological Neurosciences, Joseph Fourier University, Grenoble, France.

OBJECTIVES: Thalamic stimulation has been proposed to treat disabling tremor. The aims of this multicentre study were to evaluate the efficacy and the morbidity of thalamic stimulation in a large number of patients with parkinsonian or essential tremor. METHODS: One hundred and eleven patients were included in the study and 110 were implanted either unilaterally or bilaterally. Patients were evaluated with clinical scales, before and up to 12 months after surgery. RESULTS: Upper and lower limb tremor scores were reduced in both groups. Eighty five per cent of the electrodes satisfied the arbitrary criteria of two point reduction in rest tremor reduction in the parkinsonian tremor group and 89% for postural tremor reduction in the essential tremor group. In the parkinsonian tremor group, limb akinesia and limb rigidity scores were moderately but significantly reduced. Axial scores were unchanged. In the essential tremor group, head tremor was significantly reduced only at 3 months and voice tremor was non-significantly reduced. Activities of daily living were improved in both groups. Changes in medication were moderate. Adverse effects related to the surgery were mild and reversible. CONCLUSIONS: Thalamic stimulation was shown to be an effective and relatively safe treatment for disabling tremor. This procedure initially applied in a very limited number of centres has been successfully used in 13 participating centres.