Medtronic Deep Brain Stimulation Linked to Wire Fractures, High Impedance
Medtronic Deep Brain Stimulation (DBS) Devices Associated with Wire Fractures, High Impedance
Parker Waichman is investigating potential lawsuits on behalf of individuals who suffered injuries related to Medtronic's Deep Brain Stimulation (DBS) devices, which are used to treat motor coordination problems in patients diagnosed with Parkinson's disease, tremor, and dystonia. In a June 2016 "Urgent Field Safety Notice," Medtronic indicated that it received 16 reports of high impedance measurements, a low current indicator. Further analysis showed that the high impedance measurements were caused by wire fractures. Medtronic issued a similar warning for another DBS device in April 2015.
If you or someone you know suffered injuries related to Medtronic DBS devices, including the Activa PC and Activa RC, contact Parker Waichman today.
Reports of Wire Fractures with Activa PC, Activa RC
In a June 2016 "Urgent Field Safety Notice," Medtronic indicated that it received 16 reports of high impedance with its DBS pocket adaptor Models 64001 and 64002, which may be used for implantable Neurostimulators Activa PC (Model 37601) and Activa RC (Model 37612). According to the notification, subsequent analysis found that the high impedance measurements were caused by wire fractures. In light of this, surgeons were cautioned against implanting DBS devices with sharply bent or kinked wires. The notification emphasized device labeling specific to handling the system as described in implant manuals and system integrity checks.
Out of the 16 reports of high impedance measurements, two were identified during surgery. The other 14 cases were not discovered until after the device was implanted, forcing patients to undergo revision surgery. Upon subsequent analysis, Medtronic found wire fractures located near where the adaptor wire exits the neurostimulation connector block. The company indicated that 0.08 percent of the 20,000 DBS pocket adaptors sold since 2009 exhibited this problem, to date. In the safety alert, Medtronic also wrote that it was still investigating the cause of wire fractures.
This is not the first time Medtronic has had issues with wire fractures associated with its DBS devices. The company issued a similar warning for its DBS Extensions, Models 37085 and 37086, in April 2015. The June 2016 alert notes that the pocket adaptor conductor body is similar in design to the DBS Extensions.
Medtronic DBS Overview
According to Medtronic's website, DBS devices are used to treat patients with movement disorders, including individuals diagnosed with Parkinson's disease, tremor, and dystonia. Electrical stimulation is applied to structures located deep within the brain in an attempt to treat motor coordination problems.
Regarding Parkinson's disease, DBS is used in those patients who have been symptomatic for at least four years in which medication has proven inadequate. DBS is also used for adjunctive therapy in patients who are responsive to Levodopa (also known as L-Dopa), a precursor molecule to several important neurotransmitters, such as dopamine. In these patients, DBS therapy stimulates the internal globus pallidus (GPi) or the subthalamic nucleus (STN) bilaterally (on both sides of the brain).
DBS therapy is also used in the treatment of tremors in upper body extremities, providing unilateral thalamic stimulation of the ventral intermediate nucleus (VIM). The product page notes that the safety of bilateral stimulation has not been established and is used in patients diagnosed with Essential Tremor or Parkinsonian tremor whose symptoms are not adequately controlled by medication, and in which the tremor causes significant dysfunction.
Patients who are diagnosed with dystonia, a neurological disorder characterized by muscle contractions that lead to slow repetitive movements or abnormal postures, are sometimes treated with DBS therapy. Medtronic DBS, for these patients, involves unilateral or bilateral stimulation of the internal globus pallidus (GPi) or the subthalamic nucleus (STN). DBS is given in patients seven years of age or older who exhibit "chronic, intractable (drug refractory), primary dystonia, including generalized and/or segmental dystonia, hemidystonia, and cervical dystonia (torticollis)."