“Outflow” tremors, sometimes referred to in the literature by a variety of terms (outflow, rubral, midbrain, Holmes), are frequently associated with significant disability and are notoriously unresponsive or only partially responsive to medical treatment. Deep brain stimulation (DBS) has been successfully used in patients with outflow tremors; however, long-term outcomes are not well-documented because large case series are hard to assemble. This chapter describes a patient with disabling outflow tremors secondary to multiple sclerosis, treated with unilateral thalamic DBS, who achieved excellent tremor control with initial programming but shortly afterward developed rebound tremor. Intensive programming involved alternating the site of stimulation by using different combinations of contacts; this was a successful strategy for maintaining a clinically significant reduction in tremor. Disease progression, worsening of tremor, habituation, and loss of efficacy are known problems with some tremors, and their management can be challenging. The pathophysiology of worsening tremor after DBS is discussed in the chapter, as are potential programming strategies to manage this problem.
Could cough be an intraoperative indicator for venous air embolism in deep brain stimulation surgeries?: experiences from a large case series