MAUDE Adverse Event Report: MEDTRONIC NEUROMODULATION ACTIVA; STIMULATOR, ELECTRICAL, IMPLANTED, FOR PARKINSONIAN TREMOR

Model Number 37601

Device Problems Energy Output Problem (1431); Low impedance (2285); Impedance Problem (2950); Patient Device Interaction Problem (4001)

Patient Problems Visual Impairment (2138); Visual Disturbances (2140)

Event Date 11/23/2020

Event Type  malfunction  

Manufacturer Narrative

Kern ds, fasano a, thompson ja, abosch a, ojemann s, munhoz rp.Constant current versus constant voltage: clinical evidence supporting a fundamental difference in the modalities.Stereotact funct neurosurg.2020:1-5.10.1159/000510803.Please note that this date is based off of the date of publication of the article as the event dates were not provided in the published literature.It was not possible to ascertain specific device information from the article or to match the events reported with previously reported events.Correspondence has been sent to the author of the article inquiring about individual patient information and additional information regarding the reported events.Other relevant device(s) are: product id: 3387, serial/lot #: unknown, udi#: (b)(4) ; product id: 37601, serial/lot #: unknown, ubd: , udi#: asku ; product id: 3387, serial/lot #: unknown, (b)(4) ; product id: 37603, serial/lot #: unknown, (b)(4) ; product id: 3389, serial/lot #: unknown, udi#: ask.If information is provided in the future, a supplemental report will be issued.

Event Description

Summary: deep brain stimulation (dbs) is an effective surgical treatment for movement disorders.Early versions of implantable systems delivered stimulation with constant voltage (cv); however, advances in available and newer platforms have permitted programming in constant current (cc).From a treatment management perspective, there are theoretical advantages of cc stimulation.In this case series, the authors present clinical evidence supporting the maintenance of current regardless of changes to impedance.This case series included 3 patients with parkinson¿s disease status post-bilateral subthalamic nucleus dbs.Patients in this series self-reported intermittent diplopia pressure applied to the scalp.Patients were subsequently examined and converted from cv to cc and re-examined.Impedances were checked prior to and after conversion from cv to cc as well as while applying pressure to the scalp that induced the adverse effects.Across patients, the authors observed that compression of the scalp overlying the connector, while patients were maintained in cv, consistently and objectively induced unilateral adduction of an eye.In addition, during scalp compression, while in cv, impedance was reduced, which would increase current delivery.Converting the patients to cc stimulation without changing other stimulation parameters eliminated diplopia and objective findings of eye deviation with compression of the scalp overlying the hardware despite changes in impedance.In this case series, the authors provide clinical support for the principal differences between cv and cc stimulation.Reported events: a (b)(6) male patient implanted with bilateral subthalamic nucleus (stn) deep brain stimulation (dbs) for parkinson's disease (pd) experienced blurry vision with stimulation from two most ventral contacts of the right lead.The left lead induced diplopia at thresholds of stimulation of 1.5v, 60 usec and 130 hz in the most ventral contact.At one year post-op, the patient reported that palpating the scalp overlying the connector of the lead wires to the extension wire resulted in right eye transient adduction.With stimulation-on, but without palpation of the affected region, the right eye was marginally injected and had a slight decreased palpebral fissure, and both eyes had normal extraocular movements.While maintaining pressure on the scalp overlying the connection, the right eye adducted and was sustained in fixed medial position, resolving immediately upon release, while there was minimal adduction of the left eye.No change in pupil size was observed in either eye.Reducing stimulation on the right lead resolved the findings while increasing stimulation exacerbated the symptoms.Turning off the ins resolved the issue.X-ray demonstrated normal connection between lead and extension.The stimulation was switched from constant voltage (cv) to constant current (cc), with other parameters held consistent.The oculomotor findings via compression of the connector could not be reproduced in ccmode, and the patient's symptoms were well controlled.The physicians theorized a short circuit was created when the connector was palpated, delivering stimulation to the most ventral contacts that were more medially positioned.A (b)(6) male patient implanted with bilateral stn dbs for pd experienced diplopia with stimulation of the left lead, primarily most severe with the ventral most contact.Thirteen months post-op, the patient reported palpating the scalp caused diplopia.Eye exam was normal with stimulation on and without palpating scalp, but left eye adducted with stimulation on and palpation overlying the connector.Eye adduction was sustained until pressure was released.Through testing it was determined that the left lead was primarily contributing to the oculomotor findings.Stimulation was changed from cv to cc without adjusting other parameters, which eliminated the ability to induce unilateral eye deviation with compression of the connector.The physicians theorized a short circuit was created when the connector was palpated, delivering stimulation to the most ventral contacts that were more medially positioned.A (b)(6) male patient implanted with bilateral stn dbs for pd experienced diplopia during initial programing with the most ventral contact of the right lead.Two years later, the patient reported diplopia with compression of the skin overlying the right lead connector.Eye exam was normal with stimulation on and without palpation of the scalp.Palpating scalp overlying connector resulted in adduction of the right eye without pupillary changes that was sustained until pressure was released.Turning off the ins resolved the findings as well as stimulating in more dorsal contacts.Cv was changed to cc without adjustment of other parameters, which eliminated the ability to induce unilateral eye adduction.Impedances were checked in various conditions.In cv, therapeutic impedance was 1104 ohms and 2.5 ma, but reduced to 884 ohms, and current increased to 3.1 ma while palpating the connector.Impedance reduction with compression compared to without compression was greatest for ventral contacts: 227 and 190 ohms for contacts 0 and 1, r espectively and the least for dorsal contacts: 82 and 74 ohms for contacts 2 and 3, respectively.Anatomical and dbs lead constructions were created and segmentations derived.The lead was positioned medial with the most ventral contacts within the substantia nigra pars reticulata.The physicians theorized a short circuit was created when the connector was palpated, delivering stimulation to the most ventral contacts that were more medially positioned.The following device information was identified in the article: ins models 37601 and 37603; lead models 3387 and 3389 see attached literature article.

• Brand Name: ACTIVA
• Type of Device: STIMULATOR, ELECTRICAL, IMPLANTED, FOR PARKINSONIAN TREMOR
• Manufacturer (Section D): MEDTRONIC NEUROMODULATION; 7000 central ave ne; minneapolis MN 55432
• Manufacturer (Section G): MEDTRONIC NEUROMODULATION; 7000 central ave ne; minneapolis MN 55432
• Manufacturer Contact: david gustafson ; 7000 central avenue ne rcw215; minneapolis, MN 55432 ; 7635149628
• MDR Report Key: 11318628
• MDR Text Key: 245938133
• Report Number: 2182207-2021-00241
• Device Sequence Number: 1
• Product Code: MHY
• Combination Product (y/n): N
• Reporter Country Code: US
• PMA/PMN Number: P960009
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: health professional,literatur
• Reporter Occupation: Physician
• Type of Report: Initial
• Report Date: 02/11/2021

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 02/11/2021
• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: Yes
• Device Operator: Health Professional
• Device Model Number: 37601
• Device Catalogue Number: 37601
• Was Device Available for Evaluation?: No
• Is the Reporter a Health Professional?: Yes
• Date Manufacturer Received: 01/12/2021
• Is the Device Single Use?: Yes
• Is This a Reprocessed and Reused Single-Use Device?: No
• Type of Device Usage: Initial
• Patient Sequence Number: 1