Sensory thalamus and periaqueductal grey area local field potential signals during bladder filling.

The periaqueductal grey area and sensory thalamus are thought to be important nuclei involved in the supraspinal bladder control network. Deep brain stimulation of the periqueductal grey area has been shown to increase bladder capacity in the human. In a single patient, we have recorded local field potential signals from implanted deep brain stimulation electrodes within the sensory thalamus during filling cystometry with periaqueductal grey area deep brain stimulation in the ON and OFF states. In the OFF stimulation state, we demonstrate correlations between bladder volume and oscillations in the high gamma frequency band in the sensory thalamus. Stimulation of the periaqueductal grey area abolishes this correlated activity in the gamma frequency band and also suppresses oscillations within the sensory thalamus in the alpha frequency band. These findings support the involvement of the sensory thalamus in the afferent limb of bladder-related brain networks. They also suggest that periaqueductal grey area deep brain stimulation may disrupt the normal processing of afferent signals within the sensory thalamus which may be related to the effect of stimulation on bladder capacity.