Targeting the Subthalamic Nucleus for Deep Brain Stimulation in Parkinson Disease: The Impact of High Field Strength MRI

Functional neurosurgery is the only surgical alternative treatment for patients with Parkinson’s disease (PD) (Agid, 1999; Benzzouz & Hallett, 2000; Beric et al., 2001; DeLong & Wichmann, 2001; Dowsey-Limousin et al., 2001; Hariz & Fodstad, 2002; Kopper et al., 2003; Krause et al., 2001; Vesper et al., 2002). Dopamine deficiency in Parkinson’s disease leads to increased neuronal activity. Regulation of this overactivity using electrical stimulation of the basal ganglia (deep brain stimulation – DBS) has become an attractive neurosurgical option of alternative treatment strategy (Limousin et al., 1998; Kupsch & Earl, 1999). The subthalamic nucleus (STN) is the key structure for motor control through the basal ganglia and is mostly used as stimulation target since here, all cardinal symptoms of PD can be effectively ameliorated (Anderson et al., 2005; Benabid et al., 1998; Dujardin et al, 2001; Limousin et al., 1998; Martinez-Martin et al., 2002; Koller et al., 2001; Krack et al., 1998; Lopiano et al., 2001; Volkmann et al., 2001). Possible mechanisms of DBS include depolarization blockade, release of local inhibitory neurotransmitters, antidromic activation of inhibitory neurons, and jamming of abnormal neuronal firing patterns. The clinical experiences and practice confirm the beneficial effect of chronic bilateral STN-DBS.