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ANS / St Jude Libra stimulator


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#1 Guest__*

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Posted 13 February 2010 - 09:24 PM

The web is being inundated by marketing releases on St Jude trying to grab market share in the DBS business from Medtronic. And a number of neuro-surgical teams, including yours at UFL, have been advertising being involved in clinical studies.

Now that the studies have apparently been concluded on 136 patients, could tell us prospective candidates for bilateral implant what advantage the LibraXP model offers relative to the Medtronic Kinetra or Activa PC... beyond cost.

More specifically:
- what would a constant current source at the IPG offer an advanced patient sensitive to small changes in stimulation; any knowledge of the Kinetra's constant voltage causing field fluctuations toward the end of battery life?
- how about stored programming options, to be compared with those advertised for the Activa PC
- product reliability
- availability of good technical support from the St Jude rep (do they program?) or from a hospital other than the implanting one

Have you found out anything from the European teams in Europe? Like being able to adapt a new Libra IPG to an already implanted Medtronic lead + extension cord
Thank you

#2 Dr. Okun

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Posted 15 February 2010 - 09:20 AM

We did indeed participate in this clinical trial. We must wait for the last patient to exit followup and then look at the data.

The devices are similar to what is available now. Constant current is a little different as the actual electrical field should not change much over time (its shape) compared to a voltage device. Whether this will make a difference is unknown till we have data. If a device can stay completely active until the day its battery gives out would be useful, as current DBS systems seem to wane as the battery runs lower....this is an unknown till we have data.

So far what we know is both devices work, but specifics and actual efficacy and comparisons need data. I would think 6-12 months we will have some answers.

Same deal with stored programs.....will they be useful....probably. If a patient can choose and switch between several settings that offer different benefits and side effect profiles this could get interesting.
Michael S. Okun, M.D.
Author of the Amazon Bestseller Parkinson's Treatment: 10 Secrets to a Happier Life
National Medical Director | NPF
UF Center for Movement Disorders & Neurorestoration
Read More about Dr. Okun at: http://movementdisor...hael-s-okun-md/
or Visit Parkinson's Disease treatment and research blogs at:
NPF's What's Hot in Parkinson's disease
or his parkinsonsecrets.com blog for treatment tips

#3 netgypsy

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Posted 16 July 2010 - 05:39 PM

Update on this study??

#4 Dr. Okun

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Posted 18 July 2010 - 11:48 AM

For the ANS St. Jude PD study we expect results toward the end of 2010.
Michael S. Okun, M.D.
Author of the Amazon Bestseller Parkinson's Treatment: 10 Secrets to a Happier Life
National Medical Director | NPF
UF Center for Movement Disorders & Neurorestoration
Read More about Dr. Okun at: http://movementdisor...hael-s-okun-md/
or Visit Parkinson's Disease treatment and research blogs at:
NPF's What's Hot in Parkinson's disease
or his parkinsonsecrets.com blog for treatment tips

#5 am0665

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Posted 10 August 2010 - 11:27 PM

Constant current stimulation is allegedly an option, advertised as an enhancement by both St. Jude and by Medtronic (for the Activa models).
Has your team tried it to date on any patient?

#6 Dr. Okun

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Posted 11 August 2010 - 06:12 AM

Yes, our team and many others have used constant current and we like it although it has not been tested head to head against regular current (voltage). The advantage is that throughout the life of the battery the current to the brain stays the same (constant) and this has a lot of advantages especially if you are one of the people needing frequent battery changes (more common in dystonia and OCD patients).

We will continue to watch this development.
Michael S. Okun, M.D.
Author of the Amazon Bestseller Parkinson's Treatment: 10 Secrets to a Happier Life
National Medical Director | NPF
UF Center for Movement Disorders & Neurorestoration
Read More about Dr. Okun at: http://movementdisor...hael-s-okun-md/
or Visit Parkinson's Disease treatment and research blogs at:
NPF's What's Hot in Parkinson's disease
or his parkinsonsecrets.com blog for treatment tips

#7 am0665

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Posted 15 August 2010 - 04:33 PM

Dr. Okun, thanks for your reply.

I was interested in the Constant Current option of the Medtronic or St.Jude IPGs less for battery longevity, more for keeping the field intensity as invariant as possible for advanced PD DBS patients sensitive to small changes in stimulation, and hence loosing their therapeutic window after leaving a recalibration session (delayed response for symptoms like speech or walking).

- would you know of a rough estimate of % changes in a constant voltage setup, due to any possible changes along the current loop: battery strength, tissue impedance, fluid penetration into the connectors, initial transients due to IPG capacitance, etc. Note that a 10% change on a 3 volt setting means 0.3 v, which could be significant
- would going from a beginner-programmer's monopolar setting to more advanced multi-polar tailoring of the field make any difference for the above question?
- have you tried more than monopolar in constant current mode? The Medtronic Activa PC manual has a vague statement "only two active contacts allowed ... anode or cathode"

Thank you in advance.

#8 Dr. Okun

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Posted 16 August 2010 - 08:41 AM

I am going to post this as we don't have a lot of experience in this realm.

There is no data so it is all empirical trials.

I would say that be careful as if you have a stim setting that lasts only days or weeks usually that is a symptom of a suboptimally placed lead. If that is the case, imaging as well as getting thresholds for benefits and side effects can be helpful in deciding about a replacement.'

The theoretical benefit of constant current is an excellent idea and now we need data.

Constant current may be ideal for the patient using extremely high stimulation setting where the battery drains fast....in that setting you get a constant current until the battery dies or is replaced.

If you are having suboptimal benefit you may want to have your doc check out this recent article:

Parkinsonism Relat Disord. 2008 Nov;14(7):532-8. Epub 2008 Mar 5.
A case-based review of troubleshooting deep brain stimulator issues in movement and neuropsychiatric disorders.
Okun MS, Rodriguez RL, Foote KD, Sudhyadhom A, Bova F, Jacobson C, Bello B, Zeilman P, Fernandez HH.

Department of Neurology and Neurosurgery, Movement Disorders Center, McKnight Brain Institute, Gainesville, FL 32610, USA. okun@neurology.ufl.edu
Abstract
OBJECTIVE: To review the spectrum of problems that can occur in the DBS patient and to suggest potential troubleshooting tips for identification and management of DBS related issues. BACKGROUND: Deep brain stimulation (DBS) has become commonplace for the treatment of medication-refractory neurological disorders. There remains no consensus on the best practices for screening, surgical techniques, and post-operative care. There are few experienced DBS programmers and scarce resources available describing approaches for troubleshooting DBS problems. METHODS: We present a case-based review that offers practical tips for the management and troubleshooting of difficult to manage DBS cases. We present 10 cases to demonstrate common issues encountered in DBS management. RESULTS: There are many important difficulties that may be encountered with DBS devices, and practitioners should be aware of these potential problems, as well as rational management solutions. The following areas should be emphasized as potential causes of difficulties: a non-ideal initial DBS candidate, inadequate multidisciplinary team care, failure of perceived expectations, DBS procedural complication, hardware complication, suboptimal lead placement, programming, access to care, disease progression, and tolerance/habituation. CONCLUSION: Neurologists seeing DBS patients should become familiar with issues involved in difficult to manage DBS cases. Many "DBS failures" are currently treatable by appropriate medicine, programming, and surgical approaches.

PMID: 18325819 [PubMed - indexed for MEDLINE]

Publication Types, MeSH Terms
LinkOut - more resources
Michael S. Okun, M.D.
Author of the Amazon Bestseller Parkinson's Treatment: 10 Secrets to a Happier Life
National Medical Director | NPF
UF Center for Movement Disorders & Neurorestoration
Read More about Dr. Okun at: http://movementdisor...hael-s-okun-md/
or Visit Parkinson's Disease treatment and research blogs at:
NPF's What's Hot in Parkinson's disease
or his parkinsonsecrets.com blog for treatment tips

#9 am0665

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Posted 29 August 2010 - 11:36 AM

I'd like to rephrase the above question on the Constant Current option in a hopefully easier way to reply. The main issue of concern is suspected fluctuations in the electrical field of a PD patient with a biDBS STN implant. Based on MRI and CT, the leads are allegedly in the right general position, no shorts, no fraying, no fluid penetration at the contacts. Initial implant Medtronic model Itrel2 over 10 years ago, current Kinetra IPG just replaced with Activa PC.

1. would you know of any clinical test results on the field varying in the brain in a Constant Voltage setup, due to changes in impedance and / or capacitance of the brain tissue ... over a time scale from days to years. Such situations are alluded to in Neurologist Erwin Montgomery's new book... and the IPG manufacturers also admit such a possibility.
2. given that the Medtronic Activa is FDA approved (ANS / St Jude Libra is certified in Europe), is there any regulatory restriction on a patient + clinician in the US or in Europe trying it out Constant Current "in production mode"?
3. any limitations on the Medtronic Activa PC operating in Constant Current mode relative to Voltage mode? for example on the choice of stimulation parameters, on the use of BIPOLAR sources?

Thank you

#10 Dr. Okun

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Posted 29 August 2010 - 03:58 PM

1. would you know of any clinical test results on the field varying in the brain in a Constant Voltage setup, due to changes in impedance and / or capacitance of the brain tissue ... over a time scale from days to years. Such situations are alluded to in Neurologist Erwin Montgomery's new book... and the IPG manufacturers also admit such a possibility.
-There are no clinical tests I know of. It is all empirical bedside trials.

2. given that the Medtronic Activa is FDA approved (ANS / St Jude Libra is certified in Europe), is there any regulatory restriction on a patient + clinician in the US or in Europe trying it out Constant Current "in production mode"?
-I am not aware of any restrictions

3. any limitations on the Medtronic Activa PC operating in Constant Current mode relative to Voltage mode? for example on the choice of stimulation parameters, on the use of BIPOLAR sources?
-So far the parameters when people switch are close but the required charge densities may be less in constant current (it depends on the voltage of the tissue). The parameters would in general be similar but there may be a chance for saving battery.
Michael S. Okun, M.D.
Author of the Amazon Bestseller Parkinson's Treatment: 10 Secrets to a Happier Life
National Medical Director | NPF
UF Center for Movement Disorders & Neurorestoration
Read More about Dr. Okun at: http://movementdisor...hael-s-okun-md/
or Visit Parkinson's Disease treatment and research blogs at:
NPF's What's Hot in Parkinson's disease
or his parkinsonsecrets.com blog for treatment tips

#11 am0665

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Posted 13 July 2011 - 12:48 PM

Hi Dr. Okun,
Since you said that your team is part of the clinical study of the SJM device for PD (single channel Libra only?), maybe you could update us as to whether anything has been released, or intends to be released.
It has been very "quiet on the Western Front" since the marketing releases last year.
There was also a question addressed to you on the advantage of Constant Current mode over Constant Voltage mode for SJM or Medtronic PD DBS stimulators. I just hit the following announcement:
http://clinicaltrial.../2010&lup_d=360
Thank you.

#12 Dr. Okun

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Posted 14 July 2011 - 12:12 PM

The trial was presented at the Movement Disorders Congress in Toronto.

It was positive and very effective. Primary outcome was reduction in dyskinesia and also improvement in off time-- it hit its goal.

The question as to whether constant current is better is still theoretical---trials have not been done comparing to straight voltage devices.

It may become moot as technology advances most companies will likely use constant current for their battery sources (this will include those with existing DBS leads on battery changes).
Michael S. Okun, M.D.
Author of the Amazon Bestseller Parkinson's Treatment: 10 Secrets to a Happier Life
National Medical Director | NPF
UF Center for Movement Disorders & Neurorestoration
Read More about Dr. Okun at: http://movementdisor...hael-s-okun-md/
or Visit Parkinson's Disease treatment and research blogs at:
NPF's What's Hot in Parkinson's disease
or his parkinsonsecrets.com blog for treatment tips

#13 am0665

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Posted 04 December 2011 - 01:32 PM

Hi Dr. Okun,

Assuming that you attended this closed session at the Toronto Conference, and that you hospital is still active with St. Jude patients ...
would you care to provide an update on the status of implant and post-op support of the St. Jude Libra and Brio stimulators, in the US and in Europe.
More specifically, what advantage would these stimulators and leads offer over the Medtronic Activa PC, SC, RC? I've seen no published medical literature, only heavy marketing promotion to investors.

Some specific issues I hear of from patients in Europe:

- very scant technical support, low funding of the effort by St. Jude
- rechargeable: the Brio is longer lasting than the Activa RC between recharges
- the St. Jude models are very limited in setting differences between the 2 brain sides; for example no mono-polar one side, bi-polar other side
- independent frequency control for each side not possible on any dual channel stimulator
- have you tried any independent programs and groups for the St. Jude ... maybe to address two separate PD symptoms? or is the current evaluation protocol restricted to just basic single mono-polar options?

Maybe some of your forum readers involved in the ST. Jude evaluation in the US can also comment on the status:

- what happens to the support level and insurance coverage after the funding runs out
- if a patient were to travel or move, or the hospital team were to stop offering the service, how easy is it to find recalibration support elsewhere?

Thank you.

#14 Dr. Okun

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Posted 06 December 2011 - 06:51 PM

I will try to address these questions.

More specifically, what advantage would these stimulators and leads offer over the Medtronic Activa PC, SC, RC? I've seen no published medical literature, only heavy marketing promotion to investors.

**They were not studied head to head against Medtronic devices.

- very scant technical support, low funding of the effort by St. Jude

**I cannot comment as I have no data, however you have to consider this is a brand new device and it will take time to ramp up support as the product gets out on the market. It is still not out in the US as it must clear the FDA.

- rechargeable: the Brio is longer lasting than the Activa RC between recharges

**Not sure this is true as I haven't seen the data.

- the St. Jude models are very limited in setting differences between the 2 brain sides; for example no mono-polar one side, bi-polar other side

**I am unaware that is true. Both brain sides can be programmed in mono- and bipolar.

- independent frequency control for each side not possible on any dual channel stimulator

**True for Medtronic and St. Jude both.

- have you tried any independent programs and groups for the St. Jude ... maybe to address two separate PD symptoms? or is the current evaluation protocol restricted to just basic single mono-polar options?

**The study did not have independent programs tested.

- what happens to the support level and insurance coverage after the funding runs out

**The company is required to support the device until FDA approval, and give some support to the patients if not approved.

- if a patient were to travel or move, or the hospital team were to stop offering the service, how easy is it to find recalibration support elsewhere?

**It probably depends on the area they move. One point about DBS is that settings usually don;t change much after 6 months of therapy and initial optimization during the first 6 months. Your scenario is of course always worth considering.
Michael S. Okun, M.D.
Author of the Amazon Bestseller Parkinson's Treatment: 10 Secrets to a Happier Life
National Medical Director | NPF
UF Center for Movement Disorders & Neurorestoration
Read More about Dr. Okun at: http://movementdisor...hael-s-okun-md/
or Visit Parkinson's Disease treatment and research blogs at:
NPF's What's Hot in Parkinson's disease
or his parkinsonsecrets.com blog for treatment tips

#15 am0665

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Posted 15 January 2012 - 07:59 PM

Dear Dr. Okun,

I see you posted first results of this clinical trial in the latest Lancet Neurology issue, and on this forum

In trying to understand what is significant in the findings, and since you appear as the main author and person to direct correspondence to, may I propose some non-controversial discussion on aspects of interest to a long term PD DBS recipient. Hopefully some of the 136 alleged PD DBS participants in the clinical trial also see it, and can comment. For a start:

1. given how selective the DBS candidacy is known to be, how should one interpret that your 15 teams found “136 eligible candidates among 168 applicants”?

2. now that the study is finished (and maybe the funding is exhausted); say I were a St. Jude Libra / LibraXP / Brio DBS recipient (from some approved location in the world); and I happened to be traveling in the US, and needed some recalibration: would your or any other US team provide the medical service?

3a. clarifying my previous question on this thread: have any of the study patients progressed from mono-polar stimulation fields to more fine-tuned settings: say mono-polar on one brain side AND bi-polar / multi-polar on the other side?

3b. has your team ever used Medtronic Activa implants in mono-polar / bi-polar combinations AND Constant Current Mode ...and know of any limitations on the number of active contacts?

4. given that some patients were implanted with the St. Jude Libra as long as 6-1/2 years ago, what can you tell us about hardware problems experienced: battery longevity, stability of the stimulation field close to battery end-of-life, manufr recalls on IPG / wiring / connectors / lead, need for resurgery?

5. I also notice in Lancet a follow-up peer-review of your article by Neurologist Jens Volkmann, who has been quite involved with PD DBS cases in Northern Germany. Assuming that you have interfaced your study with European groups (where the Libra, Libra XP and Brio models apparently are approved), I expected that your article reference their publications, specifically on St. Jude models. Short of such being available, and after I ignore the uninformative marketing releases on the web: which teams would you know of as being involved? ... in case one such study patient needed emergency help while on travel

Thank you


#16 Dr. Okun

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Posted 16 January 2012 - 07:38 AM

Thank you for the questions.

1. given how selective the DBS candidacy is known to be, how should one interpret that your 15 teams found “136 eligible candidates among 168 applicants”?

I would not over-interpret these findings as the centers were specialized and took referrals for DBS. In the general population DBS seems to be appropriate for 10-20% of individuals with PD.

2. now that the study is finished (and maybe the funding is exhausted); say I were a St. Jude Libra / LibraXP / Brio DBS recipient (from some approved location in the world); and I happened to be traveling in the US, and needed some recalibration: would your or any other US team provide the medical service?

I believe the answer is yes. All your center needs is a device that will communicate with and program the St. Jude hardware.

3a. clarifying my previous question on this thread: have any of the study patients progressed from mono-polar stimulation fields to more fine-tuned settings: say mono-polar on one brain side AND bi-polar / multi-polar on the other side?

Many patients in the study have different settings in the "other" brain side. This is common in DBS, no matter what the hardware.

3b. has your team ever used Medtronic Activa implants in mono-polar / bi-polar combinations AND Constant Current Mode ...and know of any limitations on the number of active contacts?

We are just getting into the new Medtronic batteries and I will report once we have more experience.

4. given that some patients were implanted with the St. Jude Libra as long as 6-1/2 years ago, what can you tell us about hardware problems experienced: battery longevity, stability of the stimulation field close to battery end-of-life, manufr recalls on IPG / wiring / connectors / lead, need for resurgery?

The data need to be processed and there is a long-term study already begun on the cohort, and also those consenting and interested will donate brains for post-mortem study which will also enhance our understanding of the effects on the brain.

5. I also notice in Lancet a follow-up peer-review of your article by Neurologist Jens Volkmann, who has been quite involved with PD DBS cases in Northern Germany. Assuming that you have interfaced your study with European groups (where the Libra, Libra XP and Brio models apparently are approved), I expected that your article reference their publications, specifically on St. Jude models. Short of such being available, and after I ignore the uninformative marketing releases on the web: which teams would you know of as being involved? ... in case one such study patient needed emergency help while on travel

I know the hardware for St. Jude is already in use in Europe and I think you can simply call St. Jude and they can tell you where the study sites are located.

Hope that helps shed some light on the above questions. I will also post for others to discuss.
Michael S. Okun, M.D.
Author of the Amazon Bestseller Parkinson's Treatment: 10 Secrets to a Happier Life
National Medical Director | NPF
UF Center for Movement Disorders & Neurorestoration
Read More about Dr. Okun at: http://movementdisor...hael-s-okun-md/
or Visit Parkinson's Disease treatment and research blogs at:
NPF's What's Hot in Parkinson's disease
or his parkinsonsecrets.com blog for treatment tips




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