BEUDAMED
    FDA Adverse Event Malfunction Summary report: N

    UNKNOWN DEEP BRAIN STIMULATOR

    MDR report key: 2860888 · Received December 6, 2012

    Report

    Report Number
    3007566237-2012-02921
    Event Type
    Malfunction
    Date Received
    December 6, 2012
    Date of Event
    August 7, 2012
    Report Date
    November 9, 2012
    Manufacturer
    MEDTRONIC NEUROMODULATION
    Product Code
    MHY
    PMA / PMN Number
    P960009
    Adverse Event
    Yes
    Product Problem
    Yes
    Report Source
    Manufacturer report
    Reporter Location
    JA
    Reporter Occupation
    PHYSICIAN

    Narratives

    Additional Manufacturer Narrative · 1

    PRODUCT ID: NEU_UNKNOWN_LEAD, SERIAL#: UNKNOWN, PRODUCT TYPE: LEAD; PRODUCT ID: NEU_UNKNOWN_LEAD, SERIAL#: UNKNOWN, PRODUCT TYPE: LEAD. THE ACTUAL EVENT DATES WERE NOT PROVIDED. THIS DATE IS BASED ON THE DATE OF PUBLICATION OF THE ARTICLE. PATIENTS WERE IMPLANTED WITH IMPLANTABLE NEUROSTIMULATOR: MODEL 7424 OR 7426 AND LEAD MODEL: 3387 OR 3389. IT WAS UNKNOWN WHICH MODELS THIS PARTICULAR PATIENT WAS IMPLANTED WITH. (B)(4).

    Additional Manufacturer Narrative · 1

    (B)(4).

    Description of Event or Problem · 1

    LITERATURE: SAMURA, K., MIYAGI, Y., OKAMOTO, T., HAYAMI, T., KISHIMOTO, J., KATANO, M., KAMIKASEDA, K. SHORT CIRCUIT IN DEEP BRAIN STIMULATION. J. NEUROSURG. 2012;117(5):955-961. DOI: 10.3171/2012.8.JNS112073. SUMMARY: THE AUTHORS UNDERTOOK THIS STUDY TO INVESTIGATE THE INCIDENCE, CAUSE, AND CLINICAL INFLUENCE OF SHORT CIRCUITS IN PATIENTS TREATED WITH DEEP BRAIN STIMULATION (DBS). AFTER THE INCIDENTAL IDENTIFICATION OF A SHORT CIRCUIT DURING ROUTINE FOLLOW-UP, THE AUTHORS INITIATED A POLICY AT THEIR INSTITUTION OF ROUTINELY EVALUATING BOTH THERAPEUTIC IMPEDANCE AND SYSTEM IMPENDENCE AT EVERY OUTPATIENT DBS FOLLOW-UP VISIT, IRRESPECTIVE OF THE PRESENCE OF SYMPTOMS SUGGESTING POSSIBLE SYSTEM MALFUNCTION. THIS STUDY REPRESENTS A REPORT OF THEIR FINDINGS AFTER 1 YEAR OF THIS POLICY. IMPLANTED DBS LEADS EXHIBITING SHORT CIRCUITS WERE IDENTIFIED IN 7 PATIENTS (8.9% OF THE PATIENTS SEEN FOR OUTPATIENT FOLLOW-UP EXAMINATIONS DURING THE 12-MONTH STUDY PERIOD). THE MEAN DURATION FROM DBS LEAD IMPLANTATION TO THE DISCOVERY OF THE SHORT CIRCUIT WAS 64.7 MONTHS. THE SYMPTOMS REVEALING SHORT CIRCUITS INCLUDED THE WEARING OFF OF THERAPEUTIC EFFECT, APRAXIA OF EYELID OPENING, OR DYSARTHRIA IN 6 PATIENTS WITH PARKINSON DISEASE (PD), AND DYSTONIA DETERIORATION IN 1 PATIENT WITH GENERALIZED DYSTONIA. ALL DBS LEADS WITH SHORT CIRCUITS HAD BEEN ANCHORED TO THE CRANIUM USING TITANIUM MINIPLATE S. ALTERING ELECTRODE SETTINGS RESULTED IN CLINICAL IMPROVEMENT IN THE 2 PD CASES IN WHICH PATIENTS HAD SPECIFIC SYMPTOMS OF SHORT CIRCUITS (2.5%) BUT NOT IN THE OTHER 4 CASES. THE PATIENT WITH DYSTONIA UNDERWENT REPOSITIONING AND REPLACEMENT OF A LEAD BECAUSE THE PREVIOUS LEAD WAS LOCATED TOO ANTERIORLY, BUT DID NOT EXPERIENCE SYMPTOM IMPROVEMENT. IN CONTRAST TO THE SUDDEN LOSS OF CLINICAL EFFICACY OF DBS CAUSED BY AN OPEN CIRCUIT, SHORT CIRCUITS MAY ARISE DUE TO A GRADUAL DECREASE IN IMPEDANCE, CAUSING THE INSIDIOUS DEVELOPMENT OF NEUROLOGICAL SYMPTOMS VIA LIMITED OR EXTENDED POTENTIAL FIELDS AS WELL AS SHORTENED BATTERY LONGEVITY. THE INCIDENCE OF SHORT CIRCUITS IN DBS MAY BE HIGHER THAN PREVIOUSLY THOUGHT, ESPECIALLY IN CASES IN WHICH DBS LEADS ARE ANCHORED WITH MINIPLATES. THE CIRCUIT IMPEDANCE OF DBS SHOULD BE ROUTINELY CHECKED, EVEN AFTER A LONG HISTORY OF DBS THERAPY, ESPECIALLY IN CASES OF MINIPLATE ANCHORING. REPORTED EVENT: CASE 2. THE PATIENT HAD BILATERAL STIMULATION OF THE SUBTHALAMIC NUCLEUS (STN). THE LEFT LEAD HAD A SHORT CIRCUIT WITH ELECTRODES 0-3. IMPEDANCE MEASUREMENTS WERE LESS THAN 50 OHMS. DURING THE 5 YEARS BEFORE THE SHORT CIRCUIT WAS IDENTIFIED, THE PATIENT EXPERIENCED WEARING OFF OF THERAPEUTIC EFFECT AND FREEZING AND PROPULSIVE GAIT DURING THE OFF PHASE OF MEDICATION, CAUSING HIM TO VISIT THE HOSPITAL. GAIT FREEZING MAY HAVE RESULTED FROM A LIMITED POTENTIAL FIELD DUE TO THE 2 ANODES BEING INVOLVED IN THE SHORT CIRCUIT. THE PATIENT ALSO EXHIBITED MARKED DYSARTHRIA AND DROOLING. THE PATIENT'S LEFT IMPLANT DELIVERED BIPOLAR STIMULATION USING CONTACT 1 AS A CATHODE AND CONTACT 3 AS AN ANODE. THERAPY IMPEDANCE WAS 794 OHMS. EXAMINATION OF SYSTEM IMPEDANCE REVEALED A SHORT BETWEEN CONTACTS 3 AND 0. CONTACT 0 WAS 6.5MM UNDER THE MIDCOMMISSURAL PLANE, SUGGESTING A LOCATION IN THE VENTRAL AREA OF THE STN. ALTERING THE ELECTRODE SETTING TO A UNIPOLAR STIMULATION USING CONTACTS 1 AND 2 AS CATHODES LED TO THE SUBJECTIVE ALLEVIATION OF FREEZING AND PROPULSION, BUT THE SENSE OF WEARING OFF WAS NOT SUBJECTIVELY ALTERED. THESE FINDINGS SUGGESTED THAT A SHORT CIRCUIT BETWEEN CONTACTS 3 AND 0 UNEXPECTEDLY HAD LIMITED THE SPREAD OF THE THERAPEUTIC POTENTIAL FIELD AROUND CONTACT 1. SHORT CIRCUITS WERE NOT SUGGESTED IN RADIOGRAPHIC EXAMINATIONS AND WERE ASSOCIATED WITH NO OPEN CIRCUITS IN A UNIPOLAR CONFIGURATION. THE CAUSE OF THE SHORT CIRCUIT WAS NOT IDENTIFIED.

    Devices

    Seq Brand Generic Product Code Manufacturer Model Lot UDI-DI
    1 UNKNOWN DEEP BRAIN STIMULATOR STIMULATOR, ELECTRICAL, IMPLANTED, FOR PARKINSONIAN TREMOR MHY MEDTRONIC NEUROMODULATION NEU_INS_STIMULATOR

    Patients

    Seq Age Sex Outcome Treatment
    1 00065 YR