Intracranial neurostimulation for pain relief is most frequently delivered by stimulating
the motor cortex, the sensory thalamus, or the periaqueductal and periventricular gray
matter. The stimulation of these sites through MCS (motor cortex stimulation) and DBS
(deep brain stimulation) has proven effective for treating a number of neuropathic and
nociceptive pain states that are not responsive or amenable to other therapies or types
of neurostimulation. Prospective randomized clinical trials to confirm the efficacy of
these intracranial therapies have not been published. Intracranial neurostimulation is
somewhat different than other forms of neurostimulation in that its current primary
application is for the treatment of medically intractable movement disorders. However,
the increasing use of intracranial neurostimulation for the treatment of chronic pain,
especially for pain not responsive to other neuromodulation techniques, reflects the
efficacy and relative safety of these intracranial procedures. First employed in 1954,
intracranial neurostimulation represents one of the earliest uses of neurostimulation to
treat chronic pain that is refractory to medical therapy. Currently, 2 kinds of intracranial
neurostimulation are commonly used to control pain: motor cortex stimulation and deep
brain stimulation. MCS has shown particular promise in the treatment of trigeminal
neuropathic pain and central pain syndromes such as thalamic pain syndrome. DBS
may be employed for a number of nociceptive and neuropathic pain states, including
cluster headaches, chronic low back pain, failed back surgery syndrome, peripheral
neuropathic pain, facial deafferentation pain, and pain that is secondary to brachial
plexus avulsion.
The unique lack of stimulation-induced perceptual experience with MCS makes MCS
uniquely suited for blinded studies of its effectiveness.
This article will review the scientific rationale, indications, surgical techniques, and
outcomes of intracranial neuromodulation procedures for the treatment of chronic
pain.
Key words: Motor cortex stimulation, deep brain stimulation, pain,
neurostimulation
Reply to the Letter by L�v�que et al. Entitled �Simultaneous Deep Brain Stimulation/Motor Cortex Stimulation Trial for Neuropathic Pain: Fishing with Dynamite?'
