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Biomedical subjects

R Nemni

Publications and source records attributed to R Nemni.

At least 19 recordsLinked to original sources
PubMed2006

Evaluating two group programmes of cognitive training in mild-to-moderate AD: is there any difference between a 'global' stimulation and a 'cognitive-specific' one?

This study evaluated the efficacy of two different group procedures of non-pharmacological treatment in mild-to-moderate Alzheimer's disease (AD). Thirty-two patients entered the study and were divided in groups of four subjects. We compared recreational activities ('global' stimulation) with a combination of procedural memory training on activities of daily living and neuropsychological rehabilitation of 'residual' functions ('cognitive-specific'). All patients and caregivers were ensured psychological support. Both group treatments were delivered for six weeks. Multidimensional efficacy assessment of functional, behavioural and neuropsychological aspects was performed. Patients receiving 'global' stimulation showed a substantial reduction in behavioural disturbances (Neuropsychiatric Inventory [NPI]: frequency p = 0.034; severity p = 0.012); Revised Memory Behaviour Problems Checklist (frequency p = 0.008; reaction p = 0.027), and better performance in the Functional Living Skills Assessment (FLSA), a standardized direct measure of performance in everyday life (p = 0.021) and Verbal Fluency for Letters (p = 0.000). Patients receiving 'cognitive-specific' treatment improved only on the scale evaluating functional competence in daily living (Nurses' Observation Scale for Geriatric Patients [NOSGER] p = 0.018). At follow-up (six months later), compared with baseline, patients following the 'global' stimulation treatment showed an improvement at caregiver distress on NPI (p = 0.04). No other significant difference was detected. Our results support the contention that a 'global' treatment can lead to a significant improvement in AD patients, both for behavioural and functional aspects. The 'cognitive-specific' treatment we used in this research did not show better efficacy.

Activities of Daily Living↗
PubMed2005

Brain tissue damage in dementia with Lewy bodies: an in vivo diffusion tensor MRI study.

The aim of the present study was to apply diffusion tensor MRI (DT-MRI), a quantitative MRI measure which reflects tissue organization, to dementia with Lewy bodies (DLB). DT-MRI scans were obtained from 15 patients with probable DLB and 10 sex- and age-matched healthy controls. Abnormalities were found in the corpus callosum, pericallosal areas and the frontal, parietal, occipital and, less prominently, temporal white matter of patients compared with controls. Abnormalities were also found in the caudate nucleus and the putamen. The average grey matter volume was lower in patients than in controls. These findings of concomitant grey matter atrophy and white matter abnormalities (as detected by DT-MRI) in regions with a high prevalence of long connecting fibre tracts might suggest the presence of neurodegeneration involving associative cortices. The modest involvement of the temporal lobe fits with the relative preservation of global neuropsychological measures and memory tasks in the early stage of DLB. The selective involvement of parietal, frontal and occipital lobes might explain some of the clinical and neuropsychological features of DLB, providing a possible distinctive marker for this disease. The abnormalities found in the subcortical grey matter may indicate that DLB and Parkinson's disease share a similar nigrostriatal involvement caused by common pathophysiological mechanisms.

Aged↗
PubMed2005

Procedure for the quantitative evaluation of motor disturbances in cerebellar ataxic patients.

Cerebellar ataxia is a complex motor disturbance that involves the planning and execution of movements and reduces movement accuracy and co-ordination. The quantification of ataxic signs is commonly realised through visual examination of motor tasks performed by the patient and assignment of scores to specific items composing the international co-operative ataxia rating scale (ICARS). The present work studied an experimental procedure to characterise specific aspects of motor disturbances in ataxia objectively. Four tests belonging to the ICARS were considered: walking, knee-tibia test, finger-to-nose and finger-to-finger test. Through a kinematic analysis performed during the above tests, specific indices were defined to quantify velocity, linearity, asymmetry, tremor, instability and smoothness of movement or posture. The procedure was applied to five patients with cerebellar ataxia and to ten healthy adult subjects. Results demonstrated that the patients moved significantly more slowly than the healthy subjects (0.67 against 0.97m s(-1) and 0.81 against 1.02 m s(-1), respectively, for straight walk and finger-to-nose tests) and showed poorer linearity and smoothness behaviour. Velocity, linearity, tremor, smoothness and instability indices showed moderate to good correlation with the corresponding ICARS score. Some of these indices can separately evaluate aspects that are combined in single ICARS subscores. It is concluded that the combination of clinical assessments and instrumental evaluations allows a better insight into ataxic patients' motor disturbances and is a useful tool for the definition and follow-up of rehabilitation programmes.

Adult↗
PubMed2004

Late-onset cerebellar ataxia with hypogonadism and muscle coenzyme Q10 deficiency.

Two brothers had late-onset progressive ataxia, cerebellar atrophy, and hypergonadotropic hypogonadism associated with coenzyme Q10 (CoQ10) deficiency in skeletal muscle. Both patients improved on high-dose CoQ10 supplementation, stressing the importance of CoQ10 deficiency in the differential diagnosis of cerebellar ataxia, even when onset is late.

Adult↗
PubMed2003

Autoantibodies to glutamic acid decarboxylase in downbeat nystagmus.

The cause of downbeat nystagmus (DBN) remains undiagnosed in about 40% of patients. This paper reports the presence of antiglutamic acid decarboxylase antibodies (GAD-Ab) in a patient with DBN. Antibodies against GABAergic neurons located in the vestibular complex may induce chemical denervation of the floccular neurons, which normally suppress the peripheral imbalance between vertical semicircular canal systems, thereby causing DBN. Testing for GAD-Ab may be indicated in DBN patients without an identifiable anatomical brain lesion.

Aged↗
PubMed2003

Peripheral neuropathy in hepatitis C virus infection with and without cryoglobulinaemia.

OBJECTIVES: Hepatitis C virus (HCV) infection is often associated with cryoglobulinaemia (CG). Peripheral neuropathy (PN) is a comparatively common complication of CG associated with HCV infection and it is thought to be attributable to nerve ischaemia. Only few HCV CG patients with PN have been reported. The recent finding of HCV RNA in nerve biopsy specimens has suggested a possible direct role of HCV in the pathogenesis of PN. The authors studied 51 HCV patients to determine the prevalence of CG and to clarify the possible mechanism by which HCV determines the PN. METHODS: All the patients were studied clinically, by laboratory tests and electrophysiologically. Twenty eight patients underwent sural nerve biopsy where both morphological and morphometric evaluation of the biopsy specimen was performed, as well as statistical analysis. RESULTS: CG was found in 40 of 51 cases (78%). Polyneuropathy was significantly prevalent in CG+ patients compared with CG- (18 of 40 compared with 1 of 11 patients; p=0.01). HCV CG- patients more frequently developed well defined mononeuropathy or multiple neuropathy when compared with HCV CG+ (10 of 11 compared with 22 of 40; p<0.03). HCV CG+ patients showed significantly higher proportion of rheumatoid factor positivity (p<0.001) and low C4 levels (p=0.001). Nerve biopsy was performed in 25 of 40 HCV CG+ patients and in 3 of 11 HCV CG- patients: epineurial vasculitis was present in 8 of 25 HCV CG+ (32%) and in 2 of 3 HCV CG-. Differential fascicular loss of axons was found in 10 of 25 CG+ (40%) and 1 of 3 CG-, signs of both demyelination and axonal degeneration were present in 7 of 25 CG+ (28%). No significant difference was found in neuropathological features, while histometrical analysis disclosed more severe involvement in CG+ patients. CONCLUSIONS: These findings suggest that the presence of CG is a negative predictive factor for the associated PN. Morphological findings in the sural nerve from HCV CG- and CG+ are consistent with an ischaemic mechanism of nerve damage and are against a direct role of the virus in causing the associated PN.

Aged↗
PubMed2002

Autoantibodies to amphiphysin I and amphiphysin II in a patient with sensory-motor neuropathy.

A proportion of patients with peripheral neuropathies has circulating autoantibodies directed against neural antigens. In some cases, autoantibodies may play a pathogenic role. We studied a patient with a progressive sensory-motor axonal neuropathy of unknown etiology, looking for circulating autoantibodies against neural antigens and we showed that the patient's serum contained anti-amphiphysin I (AMP I) and amphiphysin II (AMP II) autoantibodies. A sural nerve biopsy revealed an axonal neuropathy. Indirect immunofluorescence experiments with the patient's serum showed a staining of rat axons due to alpha-AMP I autoantibodies and a specific labelling of cytoplasm and Schmidt-Lanterman incisures of Schwann cells due to alpha-AMP II autoantibodies. In conclusion we identified a patient affected by a sensory-motor neuropathy with autoantibodies against both AMP I and AMP II.

Aged↗
PubMed2001

Human IgM anti-GM1 autoantibodies modulate intracellular calcium homeostasis in neuroblastoma cells.

Increased titers of IgM anti-GM1 antibodies are present in some patients with Lower Motor Neuron Disease (LMND) or Motor Neuropathy (MN), but their pathogenic role and the mechanism of action are unclear. Previous studies have shown that the B subunit of Cholera Toxin (CT), which binds and crosslinks ganglioside GM1, modulate intracellular calcium in murine neuroblastoma cells via the activation of L-type voltage-dependent calcium channels (VGCC). Therefore, using a fluorimetric approach, we have examined the hypothesis that the pentameric IgM anti-GM1 antibodies, could similarly alter calcium concentration in N18 neuroblastoma cells. Sera with human IgM anti-GM1 antibodies were obtained from 5 patients with LMND and 2 patients with MN. Human IgG anti-GM1, IgM anti-Myelin Associated Glycoprotein (MAG), IgM anti-sulfatide antibodies and lectin peanut agglutinin (PNA), that recognizes specifically the Gal(betal-3)GalNAc epitope, were used as control sera. Direct application of either human IgM anti-GM1 antibodies or the B subunit of CT to N18 neuroblastoma cells induced a sustained influx of manganese ions, as indicated by a quench of the intracellular fura-2 fluorescence. Furthermore, the dihydropyridine L-type channel antagonists completely inhibited the manganese influx, suggesting that it is due to activation of an L-type VGCC. The magnitude of the influx was correlated with antibody titers. None of human IgG anti-GM1, IgM anti-MAG, IgM anti-sulfatide antibodies or PNA induce an ion influx, pointing to the selective participation of the pentameric IgM isotype of anti-GM1 in the modulation of L-type calcium channels opening. Given that L-type calcium channels are present on motor neurons, the modulation of L-type calcium channels by IgM GM1 antisera may have important implications in diseases such as LMND and MN.

Adult↗
PubMed1999

Docetaxel neuropathy: a distal axonopathy.

Docetaxel has been implicated as a causative agent in peripheral neuropathy, but pathological changes in peripheral nerve have not been described. During docetaxel treatment a 54-year-old man developed a sensorimotor polyneuropathy when the overall docetaxel dosage was 540 mg/m(2). Neurophysiological investigation revealed a sensorimotor axonal neuropathy. Fascicular sural nerve biopsy showed an axonal neuropathy with a preferentially loss of large myelinated fibers. There was evidence of considerable fiber regeneration. Sensory and motor symptoms progressively improved after docetaxel withdrawal.

Antineoplastic Agents, Phytogenic↗
PubMed1999

Laminin receptor alpha6beta4 integrin is highly expressed in ENU-induced glioma in rat.

Laminins and their receptors influence neoplastic growth and invasiveness. We recently reported the abnormal expression of a laminin receptor, alpha6beta4 integrin, in human astrocytomas. To further investigate the role of alpha6beta4 in gliomas, we produced an experimental model of glioma in rat by transplacental ethylnitrosourea (ENU) administration. This animal model allowed us to study the timing of alpha6beta4 expression during tumor development and the topography of expression in the tumor and the surrounding tissue. Immunohistochemistry, in situ hybridization, and immunoprecipitation studies demonstrated that alpha6beta4 heterodimer forms in experimental gliomas, and confirmed that alpha6beta4 is expressed diffusely in neoplastic cells and reactive astrocytes, but not in normal glia surrounding the tumors. Interestingly, alpha6beta4 was expressed from the early phases of tumor development, and more highly expressed by cells in the proliferative centers of the tumors. Both neoplastic cells and reactive astrocytes also expressed the glial growth factor (neuregulin) receptors, Erb-B2 and Erb-B3. Finally, alpha6beta4 expression was reduced in a subset of tumor blood vessels. Thus, this study suggests a potential role for alpha6beta4 in the pathogenesis of gliomas. Furthermore, this is the first description of altered integrin expression in experimental gliomas; transplacental ENU-induced gliomas in rat will provide a useful model to study the role of altered adhesion in the pathogenesis of human gliomas.

Animals↗
PubMed1998

Malignancy and sensory neuropathy of unexplained cause: a prospective study of 51 patients.

OBJECTIVE: To investigate the frequency of cancer developing in patients with peripheral sensory neuropathy of unexplained cause. DESIGN: Prospective study. SETTING: A neurologic unit in a general hospital. METHODS: Following the diagnosis of neuropathy, we searched for occult malignancy. This search was repeated together with neurologic evaluations every 6 months thereafter. Patient recruitment began January 1, 1988, and ended December 31, 1995. The end point of the study was December 31, 1996. RESULTS: In the study period, we observed 363 patients with peripheral sensory neuropathy. Of these, 53 patients without any identified cause of neuropathy were invited to participate in the study. Of the 53, 2 patients refused. Thus, we examined and followed up 51 patients, 42 men and 9 women, with a mean age of 64.5 years (range, 19-80 years). The range between the onset of neurologic symptoms and the diagnosis of neuropathy was 2 to 72 months (mean, 13.9 months). The follow-up period ranged from 14 to 94 months (mean, 51.4 months). In 18 patients (35.3%) (16 men and 2 women) whose mean age at diagnosis of neuropathy was 66.5 years. malignant growths were found 3 to 72 months (mean, 27.4 months) after the onset of the neuropathy. The cancer was in the liver in 4 patients (all had a primary hepatoma), the bladder in 3, the lymph nodes in 3 (all with non-Hodgkin lymphoma), the prostate gland in 2, the lungs in 2 (small cell lung cancer in both), the breast in 1, the pancreas in 1, the sublingual gland in 1, and the bone in 1 (a metastatic sarcoma). CONCLUSIONS: More than one third of the patients with peripheral sensory neuropathy of unexplained cause developed cancer without any predominating type of malignancy.

Adult↗
PubMed1998

Light chain deposition disease neuropathy resembling amyloid neuropathy in a multiple myeloma patient.

A 65-year-old man with IgG lambda multiple myeloma developed severe polyneuropathy with prominent thermal-pain sensory impairment and autonomic failure. Although the clinical presentation suggested amyloid neuropathy, nerve biopsy showed the immunohistochemical and ultrastructural features typical of light chain deposition disease (LCDD). A precise morphologic and clinical description of LCDD neuropathy is given for the first time in the present report.

Aged↗
PubMed1998

Amyloid neuropathy simulating lower motor neuron disease.

We report a 57-year-old man with progressive symmetric weakness and fasciculation affecting the legs. Electromyography revealed fibrillations and neurogenic motor unit potentials in the leg muscles. Biopsy of a motor branch of the obturator nerve revealed axonal degeneration, loss of myelinated nerve fibers, and amyloidosis with deposits of lambda light chains. At 6-month follow-up, the patient manifested sensory and autonomic symptoms, and lambda light chains were first detected in the serum. In this case, diagnosis of amyloidosis remained elusive until motor nerve biopsy.

Amyloid Neuropathies↗