Medtronic deep brain stimulation and spinal cord stimulation devices - multiple models
Consumers and health professionals are advised that Medtronic Australasia, in consultation with the TGA, has issued a hazard alert regarding two potential issues involving multiple models of its deep brain stimulation and spinal cord stimulation devices. Medtronic Australasia is undertaking a recall for product correction to address these problems.
Deep brain stimulation devices are implantable, programmable medical devices that deliver electrical stimulation to the patient's brain. Deep brain stimulation devices are used to treat the symptoms associated with movement disorders, epilepsy and Parkinson's disease, as well as other conditions.
Spinal cord stimulation devices are implantable, programmable medical devices that deliver electrical stimulation to the patient's spinal cord. Spinal cord stimulation devices are used to help treat certain types of chronic pain in the torso and/or limbs, and pain associated with certain vascular and heart conditions.
The following two issues have been identified with these devices:
- Potential for loss of stimulation - patients implanted with certain models of Medtronic Australasia's deep brain stimulation and spinal cord stimulation devices (see below for list of affected models) may experience unexpected loss of stimulation under certain conditions.
- Potential for over-stimulation or stimulation in the wrong area - patients implanted with certain models of Medtronic Australasia's deep brain stimulation and spinal cord stimulation devices (see below for list of affected models) may experience unexpected over-stimulation or stimulation in the wrong area under certain conditions.
The affected models are:
- deep brain stimulation - Activa PC, Activa RC and Activa SC models 37601, 37602, 37603, 37612 (Activa SC models 37602 and 37603 are not affected by the over-stimulation or stimulation in the wrong area issue)
- spinal cord stimulation - RestoreUltra and RestoreSensor models 37712, 37714
Medtronic Australasia will address the loss of stimulation issue by updating the software of the programmer device, which will correct the problems at the patient's next scheduled visit. This programmer device is used by the managing health professional and Medtronic representatives, and should not be confused with any patient programmers that some patients may have.
With regards to the over-stimulation or stimulation in the wrong area issue, Medtronic Australasia has made a recommendation that will significantly reduce the likelihood of this issue occurring (see Information for consumers and Information for surgeons and neurologists below).
As of 23 January 2014, there have been no reports of deaths or life-threatening injuries associated with these issues worldwide.
Information for consumers
Medtronic Australasia has written to health professionals who have implanted affected deep brain stimulation or spinal cord stimulation models, or are managing patients who have these devices, providing further information regarding the above issues and advice on how to treat patients.
If you have a deep brain stimulation or spinal cord stimulation device implanted and experience loss of stimulation, over-stimulation or stimulation in the wrong area, or if you have any questions or concerns regarding these issues, contact your managing health professional.
If you have an affected device, once the programmer device software is updated, the issue relating to potential loss of stimulation will be corrected at your next scheduled visit.
Medtronic Australasia recommends that you avoid over-discharge of your device. This will significantly reduce the likelihood of the over-stimulation or stimulation in the wrong area issue occurring. If your device becomes over-discharged phone 1800 668 670.
Information for all health professionals
If you are treating a patient who has a deep brain stimulation or spinal cord stimulation device implanted, and they have any questions or concerns about the above issues, refer them to their managing surgeon or neurologist.
Reassure them that, once the programmer device software is updated, the issue relating to potential loss of stimulation will be corrected at their next scheduled visit with their managing surgeon or neurologist. Also, if they avoid over-discharge of their device, the likelihood of the over-stimulation or stimulation in the wrong area issue occurring will be significantly reduced.
Advise them to contact their managing surgeon or neurologist, if they experience any loss of stimulation, over-stimulation or stimulation in the wrong area, and to phone 1800 668 670 if their device becomes over-discharged.
Information for surgeons and neurologists
Medtronic Australasia has written to surgeons and neurologists who have implanted affected deep brain stimulation or spinal cord stimulation models, or are managing patients who have these devices, providing further information regarding the above issues and advice on how to treat patients.
At their next scheduled visit, advise patients of these issues and to contact you if they experience any loss of stimulation, over-stimulation or stimulation in the wrong area, and to phone 1800 668 670 if their device becomes over-discharged.
Prophylactic removal of these devices is not recommended, as the loss of stimulation issue will be addressed non-invasively with the update to the 8870 software application card (to version BBR01A) used by the 8840 N'Vision clinician programmer device, or an implantable neurostimulator recharger (INSR) using the physician recharge mode (PRM). Also, if patients avoid over-discharge of their device, the likelihood of the over-stimulation or stimulation in the wrong area issue occurring will be significantly reduced.
Loss of stimulation may occur after the following specific conditions:
- the patient switches from a group with two programs to a group with three or four programs while a periodic battery measurement is being made within the device and a non-negative contact is shared within the programmed groups
- the surgeon or neurologist creates program groups when a second program is created for the first time during the periodic battery measurement within the device (Activa SC models only).
Over-stimulation or stimulation directed to a lead electrode other than what was intended may occur under the following specific conditions (typically related to device recovery from an over-discharge):
- the device reaches a power on reset (POR) state, which may be detected during interrogation with the patient or clinician programmer - the patient will experience a loss of therapy if a POR occurs
- a 'Therapy OFF' command is sent (by patient programmer, INSR, or 'THERAPY-STOP' button on the clinician programmer) to the device while it is making an automatic periodic battery measurement.
Please note that Activa SC models 37602 and 37603 are not affected by the over-stimulation or stimulation directed to a lead electrode other than what was intended issue.
In the case of loss of stimulation, if error code 509 is displayed on the patient programmer, programming is still possible with the 8840 N'Vision clinician programmer device. Depending on the model of the implanted device, programming with the patient programmer may still also be possible. Please note, neither the patient programmer nor clinician programmer will indicate a loss of therapy, even though stimulation output will not be delivered to the electrodes. If a patient experiences loss of stimulation, their managing health professional can restore stimulation with a patient recharger (model 37754 or 37751).
After the 8870 software application card is updated, any previous version of the application card should no longer be used.
If you have any questions or concerns regarding these issues, contact your Medtronic Australasia field representative.
Reporting problems
Consumers and health professionals are encouraged to report problems with medical devices. Your report will contribute to the TGA's monitoring of these products. For more information see the TGA Incident Reporting and Investigation Scheme (IRIS).
The TGA cannot give advice about an individual's medical condition. You are strongly encouraged to talk with a health professional if you are concerned about a possible adverse event associated with a medical device.