<prompt> Stimulation of which of the following areas of brain is experimentally used to control intractable pain:Periaqueductal grey matterMesencephalonSubthalamic nucleusMedial forebrain bundle  <response>: Ans. a. Periaqueductal grey matter Ref: Ganong 22e p260, 261 Stimulation of Periaqueductal grey matter PAG is an established experimental therapy reserved for intractable somatogenic andor noceceptive pain that remains poorly controlled despite all conservative measures. Deep Brain Stimulation for Intractable Pain Periaqueductal Grey Matter PAG Periventricular Grey Matter PVG Deep Brain Stimulation Sensory Thalamic Deep Brain Stimulation PAGPVG deep brain stimulation has shown to maximally benefit patients with intractable somatogenic and nociceptive painQ Sensory thalamic deep brain stimulation has shown to maximally benefit patients with intractable neuropathic painQ Scientific evidence demonstrating safety and efficacy is however, not robust to support widespread use of Deep brain Stimulation for the treatment of intractable pain. 