Deep Brain Stimulation

Abstract

Tremor is one of the most elusive clinical signs being part of several ­different diagnosis and presenting variably (e.g., at rest, postural or action tremor) within the clinical spectrum of a single disease. Many neurological disorders are associated with tremor; the most common are Essential tremor (ET) and Parkinson disease (PD) (Deuschl et al. Mov Disord 13(Suppl 3):2–23, 1998). Although pharmacologic treatments for tremor are available, the result may be inconsistent or there may be no benefit (Lyons et al. Drug Saf 26:461–481, 2003; Olanow et al. 56(Suppl 5):S1–S88, 2001; Pahwa and Lyons Am J Med 115:134–142, 2003; Deuschl et al. Mov Disord 17(Suppl 3):S102–S111, 2002). DBS is currently the treatment of choice for medication-resistant tremor (Benabid et al. J Neurosurg 84:203–214, 1996; Tasker Surg Neurol 49:145–154, 1998; Schuurman et al. N Engl J Med 342:461–468, 2000; Pahwa et al. Mov Disord 16:140–143, 2001) and proved comparable benefit with fewer side effects than thalamotomy, especially with bilateral procedures (Hassler et al. Brain 83:337–350, 1960). The Food and Drug Administration (FDA)-approved indications for thalamic DBS are ET and PD, but only unilateral DBS has FDA approval. There is increasing evidence though that thalamic DBS is effective for tremor secondary to other causes, such as multiple sclerosis, or for complex tremor syndromes. In such cases, bilateral thalamic DBS or DBS for non-ET and non-PD would be considered “off-label” and eventually experimental or investigational.