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Biomedical subjects

G Comi

Publications and source records attributed to G Comi.

At least 55 records · Page 3Linked to original sources

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↗

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↗

Late onset multiple sclerosis: clinical characteristics, prognostic factors and differential diagnosis.

Late onset multiple sclerosis (LOMS), defined as the first presentation of clinical symptoms in patients over 50, is not a rare phenomenon as previously thought, since the prevalence ranges between 4% and 9.6% in different studies. The course of the disease is often primary progressive and pyramidal or cerebellar involvement is observed in 60%-70% of the patients at presentation. LOMS is usually associated with a faster progression to disability compared to young adult multiple sclerosis (MS) patients. Moreover in patients over 50, MS variants and atypical forms which present a difficult diagnostic problem, may be frequently encountered. The differential diagnosis may be sometimes difficult and includes cerebro-spinal vascular syndromes, hypertension-related disorders, compressive myelopathies, primary or secondary vasculitis, metabolic diseases, degenerative and nutritional syndromes. Clinical characteristics, magnetic resonance imaging (MRI) pattern of abnormalities, evoked potential studies and cerebrospinal fluid (CSF) oligoclonal band analysis are of high diagnostic yield in LOMS patients, but expertise in interpreting their results is strongly required.

Age of Onset↗

Multiple sclerosis: pseudotumoral forms.

The pseudotumoral forms of multiple sclerosis often represent a diagnostic problem. In this paper, the main clinical, radiological and pathological characteristics of these forms are described. A short overview on the main treatments used in these cases is also provided.

Brain Diseases↗

A functional MRI study of movement-associated cortical changes in patients with Devic's neuromyelitis optica.

Movement-associated cortical changes have been shown in several neurological conditions and were found to be associated to the extent of brain and cord damage. Devic's neuromyelitis optica (DNO) is characterized by a severe involvement of the cord and optic nerve, with sparing of the brain. To assess the actual role of cord pathology on the pattern of movement-associated cortical recruitment, we obtained functional magnetic resonance imaging (fMRI) from patients with DNO and investigated whether the extent of brain activation is correlated with the extent of cervical cord damage. We studied 10 right-handed DNO patients and 15 sex- and age-matched healthy controls. The MRI assessment consisted of the following: (a) fMRI during repetitive flexion extension of the last four fingers of the right and left hand, (b) brain and cervical cord conventional MRI, and (c) cervical cord magnetization transfer (MT) MRI. Compared to controls and for both tasks, DNO patients had an increased recruitment of several regions of the sensorimotor network (primary sensorimotor cortex, postcentral gyrus, middle frontal gyrus, rolandic operculum, secondary sensorimotor cortex, precuneus, and cerebellum) and of several other regions mainly in the temporal and occipital lobes, such as MT/V5, the fusiform gyrus, the cuneus, and the parahippocampal gyrus. For both tasks, strong correlations (r values ranging from -0.76 to -0.85) were found between relative activations of cortical sensorimotor areas and the severity of cervical cord damage. This study shows an abnormal pattern of movement-associated cortical activations in patients with DNO, which extends beyond the 'classical' sensorimotor network and also involves visual areas devoted to motion processing. The correlation found between fMRI changes and the extent of cord damage suggests that such functional cortical changes might have an adaptive role in limiting the clinical outcome of DNO structural pathology.

Adult↗

Brain tissue loss occurs after suppression of enhancement in patients with multiple sclerosis treated with autologous haematopoietic stem cell transplantation.

To assess whether brain tissue loss occurs after profound and sustained suppression of magnetic resonance imaging (MRI) enhancement, we measured brain volume changes from 10 patients with rapidly evolving secondary progressive multiple sclerosis (MS) treated with autologous haematopoietic stem cell transplantation and followed up for 24 months. An average yearly decrease of brain volume of about 1.9% was observed despite only five enhancing lesions seen on triple dose follow up scans of two patients. This indicates that, in MS, progressive loss of tissue can occur independently of concomitant MRI-visible inflammation.

Artifacts↗

Cord damage elicits brain functional reorganization after a single episode of myelitis.

OBJECTIVE: To assess, using fMRI, the brain pattern of movement-associated cortical activations in patients with a previous remitting episode of acute cervical myelitis of possible demyelinating origin and to investigate whether the extent of cortical reorganization is associated with the extent of cervical cord pathology measured using magnetization transfer (MT) MRI. METHODS: From 14 right-handed patients in a chronic and stable phase after an isolated myelitis (male/female = 7/7, mean age = 35.3 years, median disease duration = 21.2 months) involving the cervical cord and 15 sex- and age-matched healthy control subjects, we obtained 1) fMRI during repetitive flexion-extension of the last four fingers of the right hand, 2) brain diffusion tensor MRI, and 3) brain and cervical cord conventional and MT MRI. FMRI data were analyzed using Statistical Parametric Mapping software. Brain mean diffusivity, fractional anisotropy, and MT ratio (MTR) histograms of the normal-appearing white and gray matter and cervical cord MTR histograms were produced. RESULTS: Patients with myelitis had lower average cord MTR (p < 0.0001) and cord MTR histogram peak position (p = 0.002) than control subjects. Compared with healthy volunteers, patients with myelitis showed increased recruitment of the ipsilateral hemisphere in the primary sensorimotor cortex (p < 0.0001), supplementary motor area (p = 0.002), and middle frontal gyrus (MFG) (p < 0.0001). Average cervical cord MTR was inversely correlated with relative activations of the ipsilateral MFG (r = -0.80) and of the ipsilateral postcentral gyrus (r = -0.80). The relative activation of the ipsilateral MFG was also correlated with cervical cord MTR peak position (r = -0.92). CONCLUSIONS: An abnormal pattern of movement-associated cortical activations was found in patients with a previous episode of cervical myelitis. These functional cortical changes might have an adaptive role in limiting the clinical outcome of structural cord damage.

Acute Disease↗

The effect of interferon beta-1b on quantities derived from MT MRI in secondary progressive MS.

BACKGROUND: Magnetization transfer (MT) MRI can provide in vivo markers reflecting the severity of irreversible, MS-related brain damage occurring within and outside T2-visible lesions. OBJECTIVE: To assess the effect of interferon (IFN) beta-1b treatment on the accumulation of brain damage in patients with secondary progressive (SP) MS, measured using MT MRI. METHODS: Eighty-two patients with SPMS from five centers participating in a European, multicenter, double-blind, placebo-controlled trial of IFNbeta-1b in SPMS underwent brain T2-weighted and MT MRI at baseline. Evaluable follow-up data were available for 75 patients at 12 months, 54 at 24 months, and 47 at 36 months. MT MRI scans were postprocessed and analyzed to obtain histograms of MT ratio (MTR) values from the whole brain. A region of interest-based analysis of MTR values from the normal-appearing white matter (NAWM) was also performed. RESULTS: In both the treatment arms, there was a decrease of average brain MTR values from baseline to month 24 (mean change -4.9%) and month 36 (mean change -4.3%). These changes were significant for the placebo group at both timepoints and for the IFNbeta-1b group at month 24 only, with no significant treatment effect. A decrease of NAWM MTR was also observed, with no significant difference between the two treatment arms. CONCLUSION: In this cohort of patients with secondary progressive MS, interferon beta-1b did not show an overall effect on the worsening of magnetization transfer MRI measures, when compared with placebo. The data show that change in magnetization transfer ratio is a promising tool for monitoring disease evolution in secondary progressive MS and that the information obtained from magnetization transfer MRI complements that obtained from MRI measures of lesion load and inflammation.

Adult↗

Immunoglobulins in chronic inflammatory demyelinating polyneuropathy.

This article reviews the efficacy and tolerability of intravenous immunoglobulins (IVIg) in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), including those forms associated with monoclonal gammopathy (paraproteinemic demyelinating neuropathy, PDN). Class I trials demonstrated that IVIg are effective in CIDP. About two-thirds of patients respond to initial treatment; however, most of them require repeated drug doses to maintain improvement. For PDN there are some evidences that IVIg are efficacious; however, it seems that less than 50% of the patients respond to this treatment and the persistence of the response over time has not been thoroughly investigated. The safety profile of immunoglobulins is generally good; however, the possibility of the occurrence of serious adverse effects should always be considered before starting treatment.

Chronic Disease↗

From inflammation to degeneration: the lessons of clinical trials.

About two-third of patients with multiple sclerosis (MS) accumulate severe disabilities before the age of 50. Disability depends mostly on axonal loss even if persistent conduction block also may be a contributing factor. Axonal loss is predominant in the early phase of the disease and is strictly related to the inflammatory activity. In this phase the axonal damage is mostly, if not exclusively, determined by axonal transection inside the lesions, so that reduction of the lesion rate results in a proportional effect of the irreversible tissue damage. With disease evolution, the redundancy of the central nervous system (CNS) starts to be insufficient to compensate the axonal loss resulting from reactivation (or persistence at a low degree) of inflammatory activity inside the lesions, secondary axonal degeneration of axons damaged by previous attacks and (possibly) by a primitive axonal degeneration. In this phase of the disease, most of the irreversible damage does not depend on new lesions; as a consequence, the reduction of disease activity produces only marginal efforts on nervous tissue degeneration. Clinical trials demonstrate that the positive effect of immunomodulatory and anti-inflammatory therapies is maximal in patients with clinically isolated syndromes and it starts to decrease in relapsing-remitting phases and is almost lost in secondary-progressive phases. From the practical point of view, early treatment is mandatory.

Animals↗

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↗

A molecular method to detect Bacillus cereus from a coffee concentrate sample used in industrial preparations.

AIMS: The aim of this work was to develop specific primers which are able to detect Bacillus cereus in a coffee concentrate sample. METHODS AND RESULTS: A pre-PCR step to clean the DNA, used for PCR, was developed to avoid PCR inhibition by Maillard products. The combination of centrifugation and washing the pellet, employing EDTA and water, before DNA extraction improved the detection of low numbers of B. cereus cells (10 cells ml-1). The development of specific primers enabled to detect low numbers of B. cereus without the need of a pre-enrichment step. CONCLUSIONS: The data obtained demonstrated the specificity and the sensitivity of the primers that could be used to check the presence of B. cereus in different food products, avoiding the need for labourious and time-consuming culture-based techniques. SIGNIFICANCE AND IMPACT OF THE STUDY: The method could help food microbiologists to check food samples quickly for the presence of B. cereus.

Bacillus cereus↗

Evidence for widespread axonal damage at the earliest clinical stage of multiple sclerosis.

Although axonal pathology is recognized as one of the major pathological features of multiple sclerosis, it is less clear how early in its course it occurs and how it correlates with MRI-visible lesion loads. To assess this early axonal pathology, we quantified the concentration of whole-brain N-acetylaspartate (WBNAA) in a group of patients at the earliest clinical stage of the disease and compared the results with those from healthy controls. Conventional brain MRI and WBNAA using unlocalized proton magnetic resonance spectroscopy were obtained from 31 patients at presentation with clinically isolated syndromes suggestive of multiple sclerosis and paraclinical evidence of dissemination in space, and from 16 matched controls. An additional conventional MRI scan was obtained in all patients 4-6 months later to detect dissemination of lesions in time. The mean WBNAA concentration was significantly lower in patients compared with the controls (P < 0.0001). It was not significantly different between patients with and without enhancing lesions at the baseline MRI or between patients with and without lesion dissemination in time. No correlation was found between WBNAA concentrations and lesion volumes. Widespread axonal pathology, largely independent of MRI-visible inflammation and too extensive to be completely reversible, occurs in patients even at the earliest clinical stage of multiple sclerosis. This finding lessens the validity of the current concept that the axonal pathology of multiple sclerosis is the end-stage result of repeated inflammatory events, and argues strongly in favour of early neuroprotective intervention.

Adult↗

Beta endorphin concentrations in PBMC of patients with different clinical phenotypes of multiple sclerosis.

The possible link between the opioid peptide beta endorphin and the heterogeneity of the clinical course of multiple sclerosis (MS) was investigated. Peripheral blood mononuclear cells (PBMC) concentrations of beta endorphin were measured in 50 patients in different phases of MS. Thirty nine patients also underwent post-contrast magnetic resonance imaging of the brain. Among MS forms, the highest beta endorphin concentrations were found in PBMC from patients with relapsing remitting MS and the lowest in patients with the progressive forms. Average beta endorphin concentrations were lower, although not significantly, in patients with than in those without magnetic resonance imaging enhanced lesions. These data suggest that beta endorphin may have a role in the downregulation of the inflammatory process.

Adult↗

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↗

An MRI study of Chlamydia pneumoniae infection in Italian multiple sclerosis patients.

We amplified sequences of the Chlamydia pneumoniae (CP) major-outer membrane protein in the cerebrospinal fluid (CSF) from 23 of 107 (21.5%) relapsing-remitting or secondary progressive multiple sclerosis (MS) patients and two of 77 (2.6%) patients with other neurological diseases (OND) (P = 0.00022). CP+ patients showed magnetic resonance imaging (MRI) evidence of more active disease (P = 0.02) compared to CP- MS patients and tended to have an anticipation of age at disease onset (32.3 +/- 12 versus 28.5 +/- 10 years; P = ns) causing a longer disease duration (7.5 +/- 5 versus 4.4 +/- 4 years; P = 0.016) at the time of clinical evaluation. These findings, although indirectly, suggest that CP infection of the central nervous system (CNS) might affect disease course in a subgroup of MS patients.

Adolescent↗

Towards a european network for multiple sclerosis trials (ENMST).

Quality standards for clinical studies in the field of multiple sclerosis (MS) have improved significantly, to the great benefit of patients. This development has been accompanied by soaring costs and ever increasing complexity, with industry-independent trials having become virtually impossible. We propose establishing a European network that would include expertise in all the relevant aspects of MS treatment trials. In a stepwise approach, all interested active centres across Europe should be recruited into the network, based on agreement upon common scientific standards and quality requirements. Three main goals are discussed: to facilitate identification of potentially useful agents for MS treatment; to establish protocols for the interaction between investigators and industry; and to identify common standards and a core set of data to allow for comparisons of MS trials. Collaboration with existing international organizations and institutions, especially the Sylvia Lawry Centre for MS Research, as well as with similar initiatives in North America and other parts of the world is envisaged.

Clinical Trials as Topic↗