Biomedical subjects

B Colombo

Publications and source records attributed to B Colombo.

At least 19 recordsLinked to original sources

PubMed2006

Medications for neuropathic pain: current trends.

Neuropathic pain is by definition a chronic pain condition that occurs and persists in a heterogeneous group of aetiologically different diseases characterised by a primary lesion or dysfunction of the peripheral or central nervous system. Neuropathic pain has an important prevalence in the general population, and a severe impact on quality of life and mood of affected patients. Therapy is based on tricyclic antidepressants and antiepileptic drugs, the most frequently studied drug classes. Opioids and analgesics are a second-line choice. Topical medications could be useful in several pain situations.

Administration, Topical↗

PubMed2006

Diffusion tensor magnetic resonance imaging at 3.0 tesla shows subtle cerebral grey matter abnormalities in patients with migraine.

BACKGROUND AND OBJECTIVE: Diffusion tensor (DT) magnetic resonance imaging (MRI) has the potential to disclose subtle abnormalities in the brain of migraine patients. This ability may be increased by the use of high field magnets. A DT MRI on a 3.0 tesla scanner was used to measure the extent of tissue damage of the brain normal appearing white (NAWM) and grey matter in migraine patients with T2 visible abnormalities. METHODS: Dual echo, T1 weighted and DT MRI with diffusion gradients applied in 32 non-collinear directions were acquired from 16 patients with migraine and 15 sex and age matched controls. Lesion load on T2 weighted images was measured using a local thresholding segmentation technique, and brain atrophy assessed on T1 weighted images using SIENAx. Mean diffusivity and fractional anisotropy histograms of the NAWM and mean diffusivity histograms of the grey matter were also derived. RESULTS: Brain atrophy did not differ between controls and patients. Compared with healthy subjects, migraine patients had significantly reduced mean diffusivity histogram peak height of the grey matter (p=0.04). No diffusion changes were detected in patients' NAWM. In migraine patients, no correlation was found between T2 weighted lesion load and brain DT histogram derived metrics, whereas age was significantly correlated with grey matter mean diffusivity histogram peak height (p=0.05, r=-0.52). CONCLUSIONS: DT MRI at high field strength discloses subtle grey matter damage in migraine patients, which might be associated with cognitive changes in these patients.

Adult↗

PubMed2005

Movement preparation is affected by tissue damage in multiple sclerosis: evidence from EEG event-related desynchronization.

OBJECTIVE: To investigate the impact of brain tissue damage in Multiple Sclerosis (MS) on the efficiency of programming of voluntary movement, assessed using event-related desynchronization of the EEG. METHODS: The onset latency of mu ERD (percent desyncronization of the mu rhythm preceding movement onset) to hand movement was studied in 34 MS patients. ERD onset was compared with normative data and correlated with T1 and T2 total lesion volume (TLV) at magnetic resonance imaging (MRI). RESULTS: ERD onset latency was significantly correlated with T1-TLV (r = 0.53, P = 0.001) and T2 lesion load (r = 0.5, P = 0.003), even after correcting for disability. Patients with higher T1-TLV had significantly delayed ERD onset compared with normal subjects and with patients with lower T1-TLV; patients with higher T2-TLV had significantly delayed ERD compared with normal subjects only. ERD onset latency was not correlated to clinical disability. CONCLUSIONS: Our finding of delayed ERD onset in patients with more severe measures of brain damage, independently from clinical disability, suggests that functional cortico-cortical and cortico-subcortical connections underlying the expression of ERD during programming of voluntary movement are disrupted by the MS related pathological process. Further, studies are needed to evaluate the role of specific anatomical cortico-subcortical circuits in determining this abnormality. SIGNIFICANCE: The extent of brain lesion load in multiple sclerosis affects cortical changes related to motor preparation, detected by analysis of onset latency of event-related desynchronization (ERD) of the mu rhythm to self-paced movement.

Adult↗

PubMed2005

Age effect: results from a detailed prospective study on daily fecundability.

BACKGROUND: Demographers, epidemiologists and clinicians have long been interested in the estimation of age-specific fecundability. With the progressive postponement of age at family formation in Western countries, this topic has recently become the focus of renewed attention. METHODS: In order to correctly estimate the effect of biological ageing on fecundability it is crucial to collect detailed information through a rigorous study design and to apply suitable models for analysing time to pregnancy data. In this article we discuss some methodological problems concerning the study of fecundability and its dependence on biological ageing. We also present the Multinational Study in Daily Fecundability which has produced a very rich database with detailed behavioural and physiological information prospectively collected on every cycle. Finally, we review some results on age effects obtained from these data. RESULTS: Our findings show that the decline in fecundability from age 28 to age 33 is not statistically significant and very modest. CONCLUSION: The results presented here do not appear to be particularly alarming with regard to the postponement of conception of the first child from age 28 to 33. This postponement could however lead to attempts to conceive a second child after age 35, when fecundability starts to decrease rapidly and when the risk of genetic disorders increases.

Adolescent↗

PubMed2004

The prevalence of pain in multiple sclerosis: a multicenter cross-sectional study.

In a multicenter cross-sectional study, the authors assessed pain in patients with multiple sclerosis (MS) using a symptom-oriented approach. Out of 2,077 questionnaires, we used 1,672 for data analysis. Pain and frequencies included trigeminal neuralgia 2%, Lhermitte's sign 9%, dysesthetic pain 18.1%, back pain 16.4%, and painful tonic spasms 11%. Comparison between different groups showed significant differences for age, Expanded Disability Status Scale, disease duration, and disease course, but not for sex. This study underlines the relevance of pain in the clinical history of MS.

Adolescent↗

PubMed2004

Therapy of primary headaches: the role of antidepressants.

Antidepressants are included in evidence-based guidelines for the prophylactic therapy of migraine. Although they can cause several side effects depending on the neurochemical activity, and are to be used with caution in older patients, some of them have a well-documented efficacy. Amitriptyline is classified as a Group 1 drug, whereas Fluoxetine is included in Group 2. There is fair support for the effectiveness of other serotonine reuptake inhibitors in migraine prevention. Amitriptyline has demonstrated a consistent efficacy in Chronic Tension Type Headache, and Mirtazapine has a promising profile for the treatment of the same disease.

Antidepressive Agents↗

PubMed2004

Cortical function abnormalities in migraine: neurophysiological and neuropsychological evidence from reaction times and event-related potentials to the Stroop test.

Cortical hyperexcitability was studied in migraine patients using reaction times (RT's) and Event-Related Potentials (ERP) to the Stroop test. We found a slower RTs in patients if compared to controls, supporting the hypothesis of a mild cortical functions impairment even in interictal periods in this group of patients.

Adult↗

PubMed2004

Does headache represent a clinical marker in early diagnosis of cerebral venous thrombosis? A prospective multicentric study.

The main aim of this study is to look for early clinical markers of cerebral venous thrombosis (CVT). As headache represents the major clinical manifestation at presentation we focused our attention on this symptom. We present the preliminary results of a prospective multicentric study that includes cases diagnosed as CVT in the participating centres. We have so far studied 35 patients (5 males and 30 females) from the ages of 18 to 78. The most frequent manifestation was headache (77.1%). It was more frequently localised (66.7%) and continuous (77.8%). The onset of pain was mostly acute-subacute (38.5%-50.0%) and the intensity moderate-severe (37.0%-51.9%). On univariate analysis, we found a positive correlation between CVT, acute headache onset (p=0.001) and severe headache (p=0.004). These preliminary results seem in accordance with our previous findings in the retrospective study, suggesting that CVT is more often associated with acute-onset headache of severe intensity.

Acute Disease↗

PubMed2003

Neuropathic cranial pain.

Neuropathic cranial pain, i.e. pain due to central or peripheral nervous system damage localized in cranial area, is a clinical challenge for the neurologist. Despite major advances in knowledge of physiology and biochemistry of pain, relief for many patients suffering from neuropathic pain remains incomplete. Adjuvant analgesics play a key role in the management of neuropathic pain. The introduction in the therapeutical armamentarium of antiepileptic drugs and the results derived from clinical studies indicate that some of these compounds show promise in the treatment of neuropathic pain.

Acetates↗

PubMed2003

A diffusion tensor magnetic resonance imaging study of brain tissue from patients with migraine.

OBJECTIVE: To measure in vivo, using diffusion tensor magnetic resonance imaging (DT-MRI) the extent of pathological damage of normal appearing brain tissue (NABT) from patients with migraine. METHODS: Dual echo and DT-MRI scans of the brain were acquired from 34 patients with migraine and 17 sex and age matched healthy volunteers. Mean diffusivity (MD) and fractional anisotropy (FA) histograms of the NABT were obtained from all subjects and the histograms' peak heights and average NABT MD and FA measured. When present, average MD and FA values of T2 visible lesions were also measured. RESULTS: In comparison with healthy volunteers, patients with migraine had lower MD histogram peak height (p=0.02) of the NABT. No differences were found in FA histogram derived metrics between migraine patients and healthy subjects. No difference was found for any MD and FA histogram derived metrics between migraine patients with and without brain MRI lesions, and between patients with and without aura. CONCLUSIONS: This study shows that, although brain damage may extend beyond T2 weighted abnormalities in patients with migraine, the severity of these "occult" changes is mild compared with that found in other diseases associated with white matter abnormality.

Adolescent↗

PubMed2002

Cerebral grey matter pathology and fatigue in patients with multiple sclerosis: a preliminary study.

In patients with multiple sclerosis (MS), we investigated whether the extent of cerebral grey matter (GM) pathology is associated with the presence and severity of fatigue. We quantified cerebral GM pathology in 28 MS patients (14 with fatigue and 14 without fatigue) using magnetization transfer (MT) and diffusion tensor (DT) magnetic resonance imaging (MRI). The average MT ratio and mean diffusivity from cerebral GM did not differ between fatigued and non-fatigued patients. Fatigued and non-fatigued patients also did not differ in terms of GM pathology of the cerebral cortex of the frontal lobe and basal ganglia. No correlations were found between the fatigue severity scale scores and any of the MT- and DT-MRI quantities. These preliminary results suggest that structural GM pathology is not a major contributing factor to the development of fatigue in patients with MS.

Adult↗

PubMed2002

Functional magnetic resonance imaging correlates of fatigue in multiple sclerosis.

Although fatigue is a common and troublesome symptom of multiple sclerosis (MS), its pathogenesis is poorly understood. In this study, we used functional magnetic resonance imaging (fMRI) to test whether a different pattern of movement-associated cortical and subcortical activations might contribute to the development of fatigue in patients with MS. We obtained fMRI during the execution of a simple motor task with completely normally functioning hands from 15 MS patients with fatigue (F), 14 MS patients without fatigue (NF), and 15 sex- and age-matched healthy volunteers. F and NF MS patients were also matched for major clinical and MRI variables. FMRI data were analyzed using statistical parametric mapping. In all patients, severity of fatigue was rated using the Fatigue Severity Scale (FSS). Compared to healthy subjects, MS patients showed more significant activations of the contralateral primary somatomotor cortex, the contralateral ascending limb of the Sylvian fissure, the contralateral intraparietal sulcus (IPS), the contralateral supplementary motor area, and the ipsilateral and contralateral cingulate motor area (CMA). Compared to F MS patients, NF patients showed more significant activations of the ipsilateral cerebellar hemisphere, the ipsilateral rolandic operculum, the ipsilateral precuneus, the contralateral thalamus, and the contralateral middle frontal gyrus. In contrast, F MS patients had a more significant activation of the contralateral CMA. Significant inverse correlations were found between FSS scores and relative activations of the contralateral IPS (r = -0.63), ipsilateral rolandic operculum (r = -0.61), and thalamus (r = -0.62). This study provides additional evidence that fatigue in MS is related to impaired interactions between functionally related cortical and subcortical areas. It also suggests that fMRI might be a valuable tool to monitor the efficacy of treatment aimed at reducing MS-related fatigue.

Adult↗

PubMed2002

Correlations between structural CNS damage and functional MRI changes in primary progressive MS.

In patients with primary progressive multiple sclerosis (PPMS), we investigated whether brain and cervical cord structural changes in lesions and normal-appearing brain tissue (NABT), measured using conventional, magnetization transfer (MT), and diffusion tensor (DT) MRI, are correlated with movement-associated cortical activations measured using functional magnetic resonance imaging (fMRI). From 26 right-handed PPMS patients and 15 right-handed, sex- and age-matched healthy controls, we obtained: (a) brain and cervical cord dual-echo scans and MT ratio (MTR) maps; (b) brain mean diffusivity (D(-)) maps, and (c) f-MRI (flexion-extension of the last four fingers of the right hand). All PPMS patients had no previous symptoms affecting their right upper limbs, which were functionally normal. Healthy volunteers showed more significant activation in the ipsilateral cerebellar hemisphere than PPMS patients. PPMS patients showed greater activation bilaterally in the superior temporal gyrus, ipsilaterally in the middle frontal gyrus, and, contralaterally in the insula/claustrum. In PPMS patients, moderate to strong correlations (r values ranging from 0.59 to 0.68) were found between relative activations of cortical areas located in a widespread network for sensory-motor and multimodal integration and the severity of structural changes of the NABT (as measured using MT and DT MRI) and the severity of cervical cord damage (as measured using MT MRI). This study shows that the pattern of cortical activation of PPMS patients is different from that of normal controls even when performing a motor task with clinically unaffected limbs. It also suggests that cortical reorganization might be able to limit the consequences of MS injury in the brain and cervical cord.

Adult↗

PubMed2002

Chromogranin A in heart failure; a novel neurohumoral factor and a predictor for mortality.

BACKGROUND: In chronic heart failure, several hormonal systems are activated with diagnostic and prognostic implications. We tested the hypotheses that serum Chromogranin-A (CgA) -- a 49 kDa acid protein present in the secretor granules of neuroendocrine cells -- is increased in chronic heart failure and that CgA levels are a predictive factor for mortality. METHOD AND RESULTS: In 160 patients with chronic heart failure, we measured serum CgA and other neuroendocrine hormones. The results showed that CgA is increased in chronic heart failure and the increase is related to the clinical severity of the syndrome: CgA levels in New York Heart Failure (NYHA) class II (median 146.9 ng x ml(-1), inter-quartiles 108.3-265.5) were significantly higher (P<0.05) than in class I (median 109.7 ng x ml(-1), inter-quartiles 96.7-137.6), and significantly lower (P<0.05) than in class III (median 279.0 ng x ml(-1), inter-quartiles 203.6-516.1). Class IV patients showed the highest serum levels of CgA (median 545.0 ng. ml(-1), inter-quartiles 231.8-1068.3), being statistically significantly different from class III patients (P<0.001). The association between survival and some recognized variables of prognostic significance, including CgA was also studied. The results showed that ejection fraction, noradrenaline, atrial natriuretic peptide, NYHA class and CgA were significant univariate prognosticators; however, in the multivariate analysis by the Cox proportional-hazard model, CgA and NYHA class were the only independent predictive factors for mortality (P<0.005, RR=1.22, 95% CI=1.06-1.41 and P=0.04, RR=1.58, 95% CI=1.02-2.46, respectively). CONCLUSIONS: CgA is a pro-hormone, precursor of several active fragments likely to exert biological effects in chronic heart failure. CgA serum levels are increased in patients with chronic heart failure and are a predictive factor for mortality.

Adult↗

PubMed2002

Vasostatins exert negative inotropism in the working heart of the frog.

An in vitro isolated working frog heart (Rana esculenta) was used to study the effects of exogenous CGA(1-76) (vasostatin 1), CGA(1-113) (vasostatin 2), and the synthetic CGA(7-57) on cardiac performance. Under basal cardiac conditions, the dose-response curves of the three peptides from 10(-8) to 10(-7) M showed a significant calcium-dependent negative inotropism that involved neither the endocardial endothelium nor the adrenergic and muscarinic receptors. In addition, the CgA fragments clearly counteracted the typical positive inotropism of isoprenaline (10(-<9) M). Taken together, these results provide the first evidence for a cardio-suppressive role for the vasostatins.

Animals↗

PubMed2001

An MR study of tissue damage in the cervical cord of patients with migraine.

Hyperintense abnormalities on T2-weighted magnetic resonance (MR) scans of the brain from patients with migraine are a relatively frequent finding and may represent a diagnostic challenge. We studied the cervical cord of patients with migraine using T2-weighted and magnetization transfer (MT) scans to assess whether the study of macro- and microscopic tissue damage in the cervical cord of these patients may have some diagnostic utility. T2-weighted and MT scans of the cervical cord and dual-echo scans of the brain were acquired from 16 patients with migraine and 17 sex- and age-matched healthy volunteers. Cervical cord MT ratio (MTR) histograms were obtained from all subjects and the relative peak height, the peak position, and the average MTR measured. Five migraine patients (31%) had hyperintense lesions in the brain. Neither healthy controls nor patients with migraine had any abnormalities on cervical cord MR scans. There was no difference for any of the cord MTR histogram-derived metrics between patients with migraine and healthy controls. No MTR histogram-derived measures from migraine patients were 2 standard deviations below the mean values from controls. Patients with migraine do not have MR or MT abnormalities in the cervical cord. MR scanning of the cervical cord in patients with migraine and hyperintense brain lesions of unknown etiology may be a useful investigation to facilitate the diagnostic workout.

Adolescent↗

PubMed2001

Fatigue in multiple sclerosis is associated with abnormal cortical activation to voluntary movement--EEG evidence.

Converging evidence is consistent with the view that fatigue in Multiple Sclerosis is independent from pyramidal tract involvement, suggesting a possible involvement of frontal areas. During voluntary movement, changes of the EEG rhythms can be observed over sensorimotor areas. Event-related desynchronization (ERD) of the 10 and 20 Hz frequency bands occurs during motor planning and execution and is followed after movement termination by event-related synchronization (ERS), expressing cortical idling or inhibition. We evaluated the pattern of cortical activation to voluntary movement in MS patients complaining of fatigue assessed using the Fatigue Severity Scale. Fifteen MS patients complaining of fatigue, 18 MS patients without fatigue, and 14 normal controls were studied. The two patients groups were similar for age, sex, disease duration, and were not disabled (score <1.5 at the Expanded Disability Status Scale). Twenty-nine channel EEG was recorded during about 60 self-paced extensions of the right thumb. The onset latency and amount of the contralateral sensorimotor (C3 electrode) 10 and 18--22 Hz ERD were similar in the three groups. ERD was more widespread anteriorly in the fatigue group compared with normal controls (P < 0.01 over Fz electrode). Postmovement contralateral sensorimotor 18--22 Hz ERS was significantly lower in fatigue MS patients compared with normal subjects (P < 0.005) and with nonfatigue MS patients (P = 0.02). These findings are consistent with a central origin of fatigue in MS and indicate cortical dysfunction even during a simple motor task, resulting in hyperactivity during movement execution and failure of the inhibitory mechanisms intervening after movement termination.

Adult↗

PubMed2001

Physiopathology and treatment of fatigue in multiple sclerosis.

Fatigue is a common symptom of patients with multiple sclerosis (MS). It is reported by about one-third of patients, and for many fatigue is the most disabling symptom. Fatigue may be associated with motor disturbances and/or mood disorders, which makes it very difficult to determine whether the fatigue is an aspect of these features or a result per se of the disease. Although peripheral mechanisms have some role in the pathogenesis of fatigue, in MS there are clear indications that the more important role is played by "central" abnormalities. Neurophysiological studies have shown that fatigue does not depend on involvement of the pyramidal tracts and implicate impairment of volitional drive of the descending motor pathways as a physiopathological mechanism. Metabolic abnormalities of the frontal cortex and basal ganglia revealed by positron-emission tomography and correlations between fatigue and magnetic resonance imaging lesion burden support this hypothesis. Some recent studies also suggest that pro-inflammatory cytokines contribute to the sense of tiredness. No specific treatments are available. Management strategies include medications, exercise, and behavioural therapy; in most cases a combined approach is appropriate.

Antidepressive Agents↗