Pain and psycho-affective disorders

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Neurosurgery. 2008 Jun;62(6 Suppl 3):SHC901-19; discussion SHC919-20.

Pain and psycho-affective disorders.

Broggi G.

Department of Neurosurgery, Istituto Neurologico C. Besta, Milan,

Italy.

The subject of human pain can be subdivided into two broad

categories: physical pain and psychological pain. Since the dawn of

human consciousness, each of these two forms of pain-one clearly

physical, the other having more to deal with the mind-have played a

central role in human existence. Psychological pain and suffering add

dimensions that go far beyond the boundaries of its physical

counterpart. In the past 50 years, one of the more remarkable

accomplishments of medical science has been to increasingly enable

the clinician to impact, as never before, each of these critical

realms of human existence.

Our intention is, therefore, to initially describe a few of the many

exciting neuroscientific and neurosurgical advances that have been

made in the treatment of various types of pain and to speculate on

some of the emergent questions that we believe need to be addressed.

After this is accomplished, we will then use this information as a

kind of two-pronged philosophical entrance into questions of the

mind, brain, and soul that we feel are necessary to bring back into

the sphere of the modern physician's practice.

The goal of this article is two-fold: 1) to share some of our

exciting research and 2) to renew the interest in timeless questions,

such as that of the mind-brain and the brain-mind, in the

conversation of the modern neurosurgeon.

The International Association for the Study of Pain divides pain into

two broad functions and anatomical categories. In this

framework, " nociceptive " pain is defined as the kind of physical pain

that results when the tissue is damaged. Given this perspective, such

pain is usually considered a consequence of one's defense against

one's environment.

The other pain is the " neuropathic " one resulting from a lesion or a

dysfunction of the human nervous system. As such, we will take the

risk of crossing beyond the boundaries of neurosurgery and venture

into boundaries that, at another time, might seem more natural to the

discipline of psychiatry for two reasons. The first is that

psychiatry seems to be so focused on the brain-its biochemistry and

pharmacology--that questions of mind and soul have become rare and

almost negligible. The second is to follow the course of the results

of our own clinical investigations that have taken us into that very

human world where questions of physical pain, psychological pain, and

the experience of suffering abound.

Today, however, the strategy of neuromodulation offers the advantage

of being precisely tailored in neuroanatomical terms and, even more

importantly, of being altogether reversible. At both our own Istituto

Neurologico C. Besta and many other neurosurgical centers worldwide,

many procedures have been reported in which implant neuromodulation

devices successfully treat pain. For example, long-term stimulation

of the spinal cord has been fairly effective in the treatment of

neuropathic pain, multiple sclerosis, and various other forms of

pain.

Good results have been obtained in treating peripheral vascular

diseases and sympathetic reflex dystrophy syndrome. Good results have

also been achieved in trigeminal nerve stimulation and peripheral

nerve stimulation.

In the case of thalamic stimulation, there has also been an

improvement of symptoms, but a long-term degree of tolerance was

noticed. Hypothalamic stimulation has also been seen to be effective

in controlling trigeminal autonomic cephalalgic pain, as well as the

facial pain that is known to occur in multiple sclerosis.

Motor cortex stimulation was found to occasionally have good results

in treating neuropathic pain, whereas occipital nerve stimulation was

found to achieve good results in controlling chronic cluster headache

and other chronic headaches, although with only short-term follow-up

so far. Recent reports of functional magnetic resonance imaging have

prompted us to propose exciting new neurosurgical targets that may be

effective in treating psychoaffective disorders.

Our results appear to be more than promising so far. It appears that

neuropathic pain and psychoaffective disorders seem to be sharing an

anatomophysiological common background at the Brodmann Area 25 of the

anterior cingulated gyrus. On the basis of these exciting findings,

we believe that it is reasonable to suggest that neuropathic pain and

psychoaffective disorders may ultimately be managed with

complementary or, at least, similar, therapeutic strategies, each of

which lie within the domain of the neurosurgeon.