Deep Brain Stimulation (DBS) is a surgical procedure for certain neurological conditions, involving the implantation of electrodes within specific brain areas. These electrodes are connected to a neurostimulator, a small device typically placed under the skin in the chest, which delivers controlled electrical impulses to regulate abnormal brain activity. While DBS can significantly improve symptoms, potential long-term side effects can develop or persist. This article explores these considerations.
Motor Changes Over Time
Motor side effects can emerge years after DBS. For example, dyskinesia, which are involuntary movements, might be exacerbated or newly appear. These movements are often related to the interaction between medication and stimulation settings.
Gait and balance issues can also worsen, leading to walking difficulties, freezing of gait, or a higher risk of falls. Speech changes are another motor side effect. Dysarthria, characterized by slurred or difficult speech, or hypophonia, which is soft speech, may develop or worsen.
Akinesia, the slowness of movement, or bradykinesia, difficulty initiating movement, can also occur. These issues are sometimes attributed to suboptimal stimulation settings or the natural progression of the underlying disease.
Cognitive and Behavioral Changes
Beyond motor effects, non-motor neurological and psychological side effects can also manifest. Mood disturbances are a concern, with patients experiencing persistent or new onset depression, anxiety, apathy, or irritability. Cognitive decline, including changes in memory, processing speed, or executive function, may become more noticeable.
Impulse control disorders can also emerge, such as compulsive gambling, hypersexuality, compulsive shopping, or binge eating. These behaviors are particularly relevant when linked to adjustments in medication after DBS implantation. Patients or their caregivers may also report alterations in demeanor or social interactions, indicating personality changes. These cognitive and behavioral changes can be complex, influenced by the underlying neurological condition, concurrent medications, and the specific stimulation settings.
Hardware and Other Concerns
Issues related to the implanted components of the DBS system can arise. Battery depletion is a common concern for non-rechargeable devices, necessitating battery replacement surgery. Lead fracture or migration, involving damage to the electrode wires or movement of the electrodes from their original position, can lead to a loss of therapeutic effect or the appearance of new side effects.
Although less common, there remains a small risk of infection at the implant sites, such as the scalp, neck, or chest. Skin erosion, where the skin thins over the implanted device, potentially exposing components, is another possible complication. Patients may also experience chronic discomfort or pain around the neurostimulator or along the lead pathways.
Addressing Long-Term Issues
Addressing long-term side effects of DBS involves a multi-faceted approach. Ongoing follow-up appointments with the DBS care team are important for monitoring symptoms and making adjustments. Device reprogramming, which involves adjusting the stimulation settings, is a primary method to mitigate side effects while maintaining therapeutic benefits.
Medication management is another important aspect, where concurrent medications are optimized to work synergistically with DBS and reduce unwanted side effects. Rehabilitation therapies, including physical therapy, occupational therapy, and speech therapy, can provide targeted support for persistent motor and speech issues. Psychological support, such as counseling or psychiatric intervention, is often beneficial for managing mood and behavioral changes. Open and consistent patient-doctor communication is important, as reporting any new or worsening symptoms allows for timely intervention and adjustment.