Sneddon's syndrome presenting with severe disabling bilateral headache.

Sneddon's syndrome is a rare vascular disease affecting mainly skin and brain arterioles leading to their occlusion due to excessive endothelial proliferation. The two main features of this syndrome are livedo reticularis and lacunar subcortical infarcts. Here, we describe the case of a 64-year-old woman presenting with a 4-year history of a throbbing, bilateral, parieto-occipital headache associated with facial pain, but without any other accompanying symptom. The pain, initially misdiagnosed as atypical trigeminal neuralgia, worsened up to chronic daily and such severely disabling headache that she was constrained to bed. She presented with reduced cognitive functions, diffuse and severe livedo reticularis, severe myalgias and mild stiffness. All diagnostic test for different diseases were performed and other diseases excluded except for Sneddon's syndrome. Her symptoms were reduced firstly using acetylsalicylic acid, then ticlopidine 250 mg bid was begun and then Pentoxyphillin, resulting in a significant improvement of symptoms with the disappearance of headache. Her worsening in the first year was characterized by obsessive-compulsive behaviours, body-image misperceptions and panic attacks, improved for a period using olanzapine. Considering this case, we remark the importance of using headache classification to avoid diagnostic errors, secondly, we describe an atypical manifestation of Sneddon's syndrome and therapeutic efficacy of using ticlopidine and pentoxyphillin.

The biochemical and neuroendocrine bases of the hyperalgesic nocebo effect.

Despite the increasing research on placebos in recent times, little is known about the nocebo effect, a phenomenon that is opposite to the placebo effect and whereby expectations of symptom worsening play a crucial role. By studying experimental ischemic arm pain in healthy volunteers and by using a neuropharmacological approach, we found that verbally induced nocebo hyperalgesia was associated to hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis, as assessed by means of adrenocorticotropic hormone and cortisol plasma concentrations. Both nocebo hyperalgesia and HPA hyperactivity were antagonized by the benzodiazepine diazepam, suggesting that anxiety played a major role in these effects. The administration of the mixed cholecystokinin (CCK) type-A/B receptor antagonist proglumide blocked nocebo hyperalgesia completely but had no effect on HPA hyperactivity, which suggests a specific involvement of CCK in the hyperalgesic but not in the anxiety component of the nocebo effect. Importantly, both diazepam and proglumide did not show analgesic properties on basal pain, because they acted only on the nocebo-induced pain increase. These data indicate a close relationship between anxiety and nocebo hyperalgesia, in which the CCKergic systems play a key role in anxiety-induced hyperalgesia. These results, together with previous findings showing that placebo analgesia is mediated by endogenous opioids, suggest that the analgesic placebo/hyperalgesic nocebo phenomenon may involve the opposite activation of endogenous opioidergic and CCKergic systems.

Loss of expectation-related mechanisms in Alzheimer's disease makes analgesic therapies less effective.

Expectation/placebo-related mechanisms and specific effects of therapies show additive effects, such that a therapy is less effective if the placebo component is absent. So far, the placebo component has been disrupted experimentally by using covert administrations of treatments. Here, we show for the first time that disruption of expectation/placebo-related analgesic mechanisms may occur in a clinical condition, Alzheimer's disease (AD). In order to assess the placebo component of a therapy, we used the recently developed open-hidden paradigm. A local anesthetic was applied, either overtly or covertly, to the skin of AD patients to reduce burning pain after venipuncture. The placebo (psychological) component is represented by the difference between the analgesic effect after open (expected) and after hidden (unexpected) application. We correlated the placebo component with both cognitive status and functional connectivity among different brain regions. We found that AD patients with reduced Frontal Assessment Battery scores showed reduced placebo component of the analgesic treatment. We also found that the disruption of the placebo component occurred when reduced connectivity of the prefrontal lobes with the rest of the brain was present. Remarkably, the loss of these placebo-related mechanisms reduced treatment efficacy, such that a dose increase was necessary to produce adequate analgesia. These findings highlight the active role of cognition and prefrontal lobes in the therapeutic outcome and underscore the need of considering a possible revision of the therapeutic approach in Alzheimer patients in order to compensate for the loss of the endogenous expectation and placebo mechanisms.

Pain reactivity in Alzheimer patients with different degrees of cognitive impairment and brain electrical activity deterioration.

Pain perception and autonomic responses to pain are known to be altered in dementia, although the mechanisms are poorly understood. We studied patients with Alzheimer's disease (AD) whose cognitive status was assessed through the Mini Mental State Examination test and whose brain electrical activity was measured by means of quantitative electroencephalography. After assessment of both cognitive impairment and brain electrical activity deterioration, these patients underwent sensory measurements in which the minimum stimulus intensity for both stimulus detection and pain sensation was determined. In addition, heart rate responses to pain threshold x 1.5 were recorded. We found that neither stimulus detection nor pain threshold was correlated to cognitive status and brain electrical activity decline. By contrast, we found a correlation between heart rate responses and deterioration of both cognitive functions and brain electrical activity. In particular, the heart rate increase after pain stimulation was correlated to the presence of slow brain electrical activity (delta and theta frequencies). This correlation was also found for the anticipatory heart rate increase just before pain stimulation. These results indicate that pain anticipation and reactivity depend on both the cognitive status and the frequency bands of the electroencephalogram, whereas both stimulus detection and pain threshold are not affected by the progression of AD. These findings indicate that, whereas the sensory-discriminative components of pain are preserved even in advanced stages of AD, the cognitive and affective functions, which are related to both anticipation and autonomic reactivity, are severely affected. This sensory-affective dissociation is well correlated with the neuropathological findings in AD.

Nonlinear analysis of electroencephalogram in frontotemporal lobar degeneration.

Frontotemporal lobar degeneration (FTLD) is a form of dementia characterized by a profound alteration in personality and social behavior and is associated with atrophy in the frontal and temporal brain regions. Despite recent advances, diagnosis of FTLD remains challenging. In the last decade, different studies have combined EEG analysis with mathematical models and theories that consider EEG signals as the result of nonlinear chaotic activity. The aim of the present study was to determine whether new nonlinear dynamic analysis can provide useful information on brain activity in FTLD patients. 19-lead EEG was recorded in patients with clinical diagnosis of FTLD and in healthy controls under two different conditions: closed eyes and open eyes. A nonlinear measure of complexity, correlation dimension (D2), was calculated. Our results show an increase in D2 in healthy individuals when the eyes are open, in keeping with an increase in information processing. Conversely, in FTLD patients, no increase in D2 occurred in the open eyes condition, and D2 was significantly lower than that observed in controls. Our results suggest that the dynamic processes underlying the EEG are less chaotic and complex in FTLD patients compared with normal individuals, thus providing important information on both brain functioning and possible clinical diagnostic applications.

Pain perception and tolerance in patients with frontotemporal dementia.

Pain management in elderly people with cognitive impairment poses special challenges, due to difficulties in pain assessment and specific neurodegenerative changes along pain pathways. Most studies have concentrated on Alzheimer's disease (AD) patients, in whom some contrasting findings have been found. For example, while psychophysical data suggest a selective blunting of the affective dimension of pain, pain-related fMRI signal increases have also been described. Few data have been reported in patients with frontotemporal dementia (FTD). By electrical stimulation, we have measured pain threshold and pain tolerance in clinically diagnosed FTD patients with SPECT cerebral hypoperfusion. We performed our analysis on two separate and overlapping subgroups selected on the basis of (1) neuropsychological scores below cut-off values (2) a strictly localized frontal and/or temporal hypoperfusion. We observed increased pain threshold in the first group and increased pain threshold and pain tolerance in the second group. Our results suggest differences in pain processing changes in distinct types of dementia, while at the same time caution that pain perception assessment may depend on the criteria adopted for diagnosis.

Insulin metabolism is altered in migraineurs: a new pathogenic mechanism for migraine?

BACKGROUND: Migraine is a complex biochemical dysfunction attributed to a disorder of the trigeminal and hypothalamic pathways. Impairment of glucose metabolism has been reported in migraine, but data are scanty and inconsistent. OBJECTIVE: The main aim was to verify whether migraineurs have abnormalities of the glucose and insulin metabolism. We also studied correlations between blood glucose and insulin and between insulin levels and migraine severity. PATIENTS AND METHODS: Patients with migraine or headache other than migraine, and healthy volunteers were included. All had general blood tests and a standard oral glucose tolerance test after a 12-hour fast, and glucose and insulin were measured. RESULTS: Over a 6-month period, we recruited 84 migraineurs (73 women, 11 men), 25 patients with nonmigraine headache (20 women, 5 men), and 26 healthy controls (24 women, 2 men). Multivariate analysis confirmed a significant difference between groups for glucose levels (P < .0001), but no significant time interaction. The differences were mostly between migraine and healthy controls (P < .0001) and to a lesser extent between other headaches and healthy controls (P < .05). A significant difference between groups was also found for insulin (P < .0001), with a significant time interaction. The difference was confirmed for migraine compared to other headaches (P < .0001) and healthy controls (P < .0001). CONCLUSIONS: Blood glucose levels may be high in headache patients, but do not seem to be specific to migraineurs. Insulin levels were higher in migraineurs, and seemed specific to this group. These findings are in keeping with recent reports on the effects of insulin on brain functions and lend support to the possibility that insulin is involved in the pathogenesis of migraine.