Object: Deep brain stimulation (DBS) of the ventral [anterior internal] capsule/ventral striatum (VC/VS) is under investigation as an alternative to anterior capsulotomy for severe obsessive-compulsive disorder (OCD). In neuroimaging studies of patients with OCD, dysfunction in the orbitofrontal and anterior cingulate cortex, striatum, and thalamus has been identified; and modulation of activity in this circuit has been observed following successful nonsurgical treatment. The purpose of the current study was to test hypotheses regarding changes in regional cerebral blood flow (rCBF) during acute DBS at the VC/VS target in patients with OCD who were participating in a clinical DBS trial.
Methods: Six patients enrolled in a DBS trial for OCD underwent positron emission tomography to measure rCBF; the rCBF measured during acute DBS at high frequency was then compared with those measured during DBS at low frequency and off (control) conditions. On the basis of neuroanatomical knowledge about the VC/VS and neuroimaging data on OCD, the authors predicted that acute DBS at this target would result in modulation of activity within the implicated frontal-basal ganglia-thalamic circuit. Data were analyzed using statistical parametric mapping. In a comparison of acute high-frequency DBS with control conditions, the authors found significant activation of the orbitofrontal cortex, anterior cingulate cortex, striatum, globus pallidus, and thalamus.
Conclusions: Acute DBS at the VC/VS target is associated with activation of the circuitry implicated in OCD. Further studies will be necessary to replicate these findings and to determine the neural effects associated with chronic VC/VS DBS. Moreover, additional data are needed to investigate whether pretreatment imaging profiles can be used to predict a patient's subsequent clinical response to chronic DBS.