Deep Brain Stimulation Withdrawal Syndrome in Parkinson's Disease: Clinical Features and Outcomes of Two New Cases.

Introduction: Deep brain stimulation (DBS) withdrawal syndrome is a rare but potentially fatal complication in Parkinson's disease (PD), manifesting as akinetic crisis with severe rigidity, fever, autonomic instability, altered mental status, and elevated creatinine kinase (CK) levels. The syndrome is strongly associated with older age, long duration of the disease (>15 years), and the duration of DBS therapy (>5 years), with most reported cases having at least two of these risk factors. However, all available evidence comes from a limited number of case reports. Case Presentations: We report two cases of DBS withdrawal syndrome, including a patient without any of the currently acknowledged risk factors. This patient, in their late 50s with young-onset PD, was treated with bilateral subthalamic nucleus DBS with a good response, although requiring high stimulation amplitude (4.1 V bilaterally). The first patient developed an akinetic crisis after battery depletion at a PD duration of 11 years and a DBS duration of 4 years. Implantable pulse generator (IPG) replacement was performed 14 days later, resulting in permanent disability and, eventually, death. The second patient, in their mid-60s with long-standing PD and DBS therapy for 14 years, presented with a severe akinetic crisis and markedly elevated CK. IPG replacement within 2 days led to full recovery. Conclusion: DBS withdrawal syndrome can occur without the typical risk profile, and high stimulation amplitude may represent an additional risk factor. Early recognition and immediate DBS therapy restoration are critical to prevent severe, potentially fatal outcomes.