PALLIATIVE MEDICINE AND THE BRAIN
From an anatomical standpoint, the processes governing painful perceptions involve two different circuits: a lateral circuit, responsible of sensory and discriminatory aspects, and a medial circuit, involved in emotional aspects of perceiving discomfort and, more generally, suffering. At a cortical level, the first circuit reaches two parietal areas known as primary (S1) and secondary (S2) somatosensory cortex and the second one projects to more frontal regions, such as the anterior cingulate cortex [1].
This distinction clarifies the importance of psychological and emotional aspects involved in pain perception. The context in which therapy is administered is therefore fundamental and it is mainly represented by the relationship with the therapist. If medicines are the tool to cure the disease, language and relational context are the main resources to manage the patient.
In a recent study, published in Science Translational Medicine and conducted by Bingel [2] and collaborators, all participants have received an opioid-based analgesic treatment (remifentanil), along with some informations about the treatment itself.
1) Patients in the first group knew that they would receive the medicine and they were correctly informed about the administration of the painkiller, developing, in that way, expectations about pain reduction (open analgesic group).
2) Patients in the second group didn’t know that an analgesic was being administered to them; as a consequence, these subjects didn’t develop any expectation about the analgesic effect of treatment (“hidden” group without analgesic expectations).
3) the third group, instead, received opposite information about the administration of the drug, expecting therefore an increase in pain (open hyperalgesia group).
Results have demonstrated that patients who knew that they were receiving a strong analgesic, reported a double decrease of pain compared with those who did not receive that information. Such analgesic effect was associated to a reduction of the activity in S1 and in cingulate cortex. On the contrary, negative expectations completely cancelled pharmacologic effects and were associated to an increase of hippocampal activity.
One of the most important aspects that clinicians have to consider when treating terminal patients is pain management. Taking care of a terminal patient is an extremely difficult task: on the one hand, it entails paying attention to the adequate balancing of pharmacologic treatment and, on the other hand, it requires the management of fears and emotional states of patients. Bingel’s results, moreover, confirm the importance of positive expectations in regard to success of therapy. This means integrating a cure that is addressed to the person as a whole: that is the role of palliative medicine.
This distinction clarifies the importance of psychological and emotional aspects involved in pain perception. The context in which therapy is administered is therefore fundamental and it is mainly represented by the relationship with the therapist. If medicines are the tool to cure the disease, language and relational context are the main resources to manage the patient.
In a recent study, published in Science Translational Medicine and conducted by Bingel [2] and collaborators, all participants have received an opioid-based analgesic treatment (remifentanil), along with some informations about the treatment itself.
1) Patients in the first group knew that they would receive the medicine and they were correctly informed about the administration of the painkiller, developing, in that way, expectations about pain reduction (open analgesic group).
2) Patients in the second group didn’t know that an analgesic was being administered to them; as a consequence, these subjects didn’t develop any expectation about the analgesic effect of treatment (“hidden” group without analgesic expectations).
3) the third group, instead, received opposite information about the administration of the drug, expecting therefore an increase in pain (open hyperalgesia group).
Results have demonstrated that patients who knew that they were receiving a strong analgesic, reported a double decrease of pain compared with those who did not receive that information. Such analgesic effect was associated to a reduction of the activity in S1 and in cingulate cortex. On the contrary, negative expectations completely cancelled pharmacologic effects and were associated to an increase of hippocampal activity.
One of the most important aspects that clinicians have to consider when treating terminal patients is pain management. Taking care of a terminal patient is an extremely difficult task: on the one hand, it entails paying attention to the adequate balancing of pharmacologic treatment and, on the other hand, it requires the management of fears and emotional states of patients. Bingel’s results, moreover, confirm the importance of positive expectations in regard to success of therapy. This means integrating a cure that is addressed to the person as a whole: that is the role of palliative medicine.
[1] Willis WD, Westlund KN. Neuroanatomy of the pain system and the pathways that modulate pain. J Clin Neurophysiol 1997; 14: 2–31.
[2] Bingel U, et al. The effect of treatment expectation on drug efficacy: imaging the analgesic benefit of the opioid Remifentanil. Sci Transl Med 2011; 3: 70ra14.
