Disorders of Consciousness: Painless or Painful Conditions?-Evidence from Neuroimaging Studies.

The experience of pain in disorders of consciousness is still debated. Neuroimaging studies, using functional Magnetic Resonance Imaging (fMRI), Positron Emission Tomography (PET), multichannel electroencephalography (EEG) and laser-evoked potentials, suggest that the perception of pain increases with the level of consciousness. Brain activation in response to noxious stimuli has been observed in patients with unresponsive wakefulness syndrome (UWS), which is also referred to as a vegetative state (VS), as well as those in a minimally conscious state (MCS). However, all of these techniques suggest that pain-related brain activation patterns of patients in MCS more closely resemble those of healthy subjects. This is further supported by fMRI findings showing a much greater functional connectivity within the structures of the so-called pain matrix in MCS as compared to UWS/VS patients. Nonetheless, when interpreting the results, a distinction is necessary between autonomic responses to potentially harmful stimuli and conscious experience of the unpleasantness of pain. Even more so if we consider that the degree of residual functioning and cortical connectivity necessary for the somatosensory, affective and cognitive-evaluative components of pain processing are not yet clear. Although procedurally challenging, the particular value of the aforementioned techniques in the assessment of pain in disorders of consciousness has been clearly demonstrated. The study of pain-related brain activation and functioning can contribute to a better understanding of the networks underlying pain perception while addressing clinical and ethical questions concerning patient care. Further development of technology and methods should aim to increase the availability of neuroimaging, objective assessment of functional connectivity and analysis at the level of individual cases as well as group comparisons. This will enable neuroimaging to truly become a clinical tool to reliably investigate pain in severely brain-injured patients as well as an asset for research.

Migraine in menopausal women: a systematic review.

Evidence suggests that migraine activity is influenced by hormonal factors, and particularly by estrogen levels, but relatively few studies have investigated the prevalence and characteristics of migraine according to the menopausal status. Overall, population-based studies have shown an improvement of migraine after menopause, with a possible increase in perimenopause. On the contrary, the studies performed on patients referring to headache centers have shown no improvement or even worsening of migraine. Menopause etiology may play a role in migraine evolution during the menopausal period, with migraine improvement more likely occurring after spontaneous rather than after surgical menopause. Postmenopausal hormone replacement therapy has been found to be associated with migraine worsening in observational population-based studies. The effects of several therapeutic regimens on migraine has also been investigated, leading to nonconclusive results. To date, no specific preventive measures are recommended for menopausal women with migraine. There is a need for further research in order to clarify the relationship between migraine and hormonal changes in women, and to quantify the real burden of migraine after the menopause. Hormonal manipulation for the treatment of refractory postmenopausal migraine is still a matter of debate.

Contribution of Interoceptive Information to Emotional Processing: Evidence from Individuals with Spinal Cord Injury.

There is much evidence to suggest that recognizing and sharing emotions with others require a first-hand experience of those emotions in our own body which, in turn, depends on the adequate perception of our own internal state (interoception) through preserved sensory pathways. Here we explored the contribution of interoception to first-hand emotional experiences and to the recognition of others' emotions. For this aim, 10 individuals with sensory deafferentation as a consequence of high spinal cord injury (SCI; five males and five females; mean age, 48 ± 14.8 years) and 20 healthy subjects matched for age, sex, and education were included in the study. Recognition of facial expressions and judgment of emotionally evocative scenes were investigated in both groups using the Ekman and Friesen set of Pictures of Facial Affect and the International Affective Picture System. A two-way mixed analysis of variance and post hoc comparisons were used to test differences among emotions and groups. Compared with healthy subjects, individuals with SCI, when asked to judge emotionally evocative scenes, had difficulties in judging their own emotional response to complex scenes eliciting fear and anger, while they were able to recognize the same emotions when conveyed by facial expressions. Our findings endorse a simulative view of emotional processing according to which the proper perception of our own internal state (interoception), through preserved sensory pathways, is crucial for first-hand experiences of the more primordial emotions, such as fear and anger.