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Biomedical subjects

N Rizzuto

Publications and source records attributed to N Rizzuto.

At least 109 records · Page 6Linked to original sources
PubMed1993

Clinical spectrum of the tomaculous neuropathies. Report of 60 cases and review of the literature.

Tomaculous neuropathy has a distinctive pathological pattern of myelin thickenings in a high proportion of internodes but no specific pattern of nerve degeneration. We have analyzed the variable clinical expression of this disorder in a large series of patients. Different phenotypes have been recognized: the majority of our patients (52 cases) had hereditary neuropathy with liability to pressure palsy (HNPP) showing wide variability of clinical progression and of severity of the single episodes. 3 patients suffered from familial recurrent brachial plexus neuropathy (FBPN); 5 patients had a symmetrical progressive sensorimotor involvement of the limbs (SSMN), predominantly in the distal portions and leading to permanent disability. The explanation for this clinical variability does not emerge from our data or from the literature. Segmental demyelination is the major change correlating with the episodes of nerve palsy; axonal degeneration might be rarely associated. The myelin sausages are the markers of a selective vulnerability of the nerve fibers either to mechanical injury or to some other unknown event.

Adolescent↗
PubMed1993

Human peripheral nerve macrophages in normal and pathological conditions.

We investigated, by immunocytochemistry and immune electron microscopy, the immunophenotype, morphology and functional properties of human peripheral nervous system (PNS) macrophages (M phi) under normal and pathological conditions. Endoneurial M phi disclosed an elongated, ramified morphology, with the main processes oriented along the major axis of nerve fibers; they shared several lineage-related and functional markers with monocyte/macrophages and central nervous system (CNS) microglia, including CD4, CR3, CR4 and FcRIII. In addition, basal expression of HLA-DR antigens was exclusively confined to M phi in normal PNS. In the course of unrelated pathological conditions, resident M phi underwent activation with transformation to hypertrophic cells or foamy phagocytes and up-regulation of the markers expressed in normal conditions; new expression of a macrophagic antigen was detected on activated M phi. In different neuropathies, HLA-DR expression was also detected on non-myelin forming Schwann cells with ultrastructural features indicative of denervation. The present results demonstrate that the human PNS is provided with an intrinsic population of immunocompetent and potentially phagocytic M phi, which represent the peripheral counterpart of CNS microglia.

Adolescent↗
PubMed1993

Clinical features of Kleine-Levin syndrome with localized encephalitis.

We report the clinico-pathological findings regarding a 9 year-old girl with some clinical features of Kleine-Levin syndrome who died suddently as a result of pulmonary embolism in the course of femoro-iliac thrombophlebitis. Neuropathological examination provided evidence of perivascular inflammatory infiltrates and microglial proliferation of nodular type located in the diencephalon and midbrain. These findings suggest that a localized encephalitis may be the underlying condition in Kleine-Levin syndrome.

Brain Mapping↗
PubMed1993

IDPN impairs post-traumatic regeneration of rat sciatic nerve.

The role played by cytoskeletal proteins in nerve regeneration was investigated in a model in which the axonal transport of neurofilaments (NF) is almost selectively impaired. The administration of beta, beta'-iminodipropionitrile (IDPN), a synthetic lathyrogenic compound, induces an axonopathy characterized by proximal axonal enlargements, due to NF accumulation, and by diffuse atrophic changes associated with spatial segregation of NF from microtubules (MT). We investigated post-axotomy regeneration of rat sciatic nerve following IDPN administration. Changes induced by IDPN, as examined in the proximal and distal nerve stump at 15 and 30 days after lesion, consisted of a statistically significant reduction of the mean axonal diameter (P < 0.0001) as compared to control rats. In addition, the number of regenerating myelinated fibres was smaller in dosed rats (P < 0.001) 15 days after crush, whereas at the later stage the number of axons approached that of control animals. Electrophysiological investigation revealed a delay in target reinnervation in dosed rats. Regenerating IDPN axons, both 15 and 30 days after crush contained fewer NF (P < 0.001), while the number of MT was slightly increased as compared to controls. Taken together, our results suggest that severe alteration of NF transport, coupled with mild alteration of other components of cytoskeletal proteins, impairs the longitudinal and radial growth of regenerating myelinated axons and confirm that the number of NF is the major determinant of the cross-sectional area of each segment of the axon.

Animals↗
PubMed1992

Complement neoantigen and vitronectin are components of plaques in amyloid AL neuropathy.

We studied three patients with late onset, chronic sensorimotor and autonomic neuropathy in course of plasma cell dyscrasia with Bence Jones proteinuria. Histopathological findings of nerve biopsies consisted in diffuse loss of myelinated and unmyelinated fibers associated with perivascular deposits of amorphous material with physico-chemical and ultrastructural features of amyloid. By immunohistochemistry, light chains of the same type as Bence Jones protein, components of the classic and lytic pathways of the complement and vitronectin were detected at the level of amyloid nodules. The colocalization of complement neoantigen and vitronectin suggests that this complex derives from the circulation. The elucidation of the chemical composition of amyloid might shed some light in the pathogenesis of these disorders.

Amyloidosis↗
PubMed1992

Polyglucosan body myopathy: a new case.

We report a 51-yr-old woman with late-onset progressive weakness affecting proximal limb muscles. Muscle biopsy revealed a vacuolar myopathy with accumulation of amylopectin-like polysaccharide resembling the polyglucosan found in type IV glycogenosis and adult-onset polyglucosan body disease. A biochemical study ruled out specific enzymatic defects known to cause storage of this abnormal material. Our case confirms the existence of a 'polyglucosan body myopathy' as a distinct clinicopathological entity in which the biochemical defect is unknown.

Electromyography↗
PubMed1992

Inherited neuroaxonal dystrophy in C6 deficient rabbits.

We report the occurrence of a progressive neurological syndrome clinically characterized by subacute motor neuropathy in offspring of C6 deficient rabbits. On the basis of the pedigree analysis, the disease appears to be genetically transmitted, most probably with an autosomal recessive mode of inheritance. Pathological studies of affected animals revealed: transmitted, most probably with an autosomal recessive mode of inheritance. Pathological studies of affected animals revealed: 1) severe axonal degeneration in the sciatic nerve system involving mainly motor fibers; 2) occasional peripheral axonal enlargement closely associated with axonal degeneration; 3) presence of structured abnormal material in normal-size myelinated fibers of central nervous system (CNS) and peripheral nervous system (PNS); and 4) widespread occurrence of dystrophic axons and axonal spheroids in the gray matter of CNS. By ultrastructural examination, dystrophic axons are filled with tubulovesicular material, stalks of parallel membranes and dense bodies similar to what is described in human neuroaxonal dystrophies (NAD). The disease manifested by C6 deficient rabbits may represent an animal model of primary human NAD.

Animals↗
PubMed1991

Cytoskeletal changes induced by 2,5-hexanedione on developing human neurons in vitro.

Dissociated dorsal root ganglion cells from human fetuses were exposed to 2,5-hexanedione (2,5-HD) for 2 weeks. Morphological changes induced by 2,5-HD consisted in focal neurofilament (NF)-containing enlargements preferentially located in distal, preterminal regions of unmyelinated fibers. Tangles of NF were also observed in the perikarya of nerve cells. Morphometric analysis disclosed that the cross-sectional areas of the 2,5-HD treated axons were 30% smaller than those of control axons. This alteration was associated with reduction of number of NF per unit area. These findings demonstrate that 2,5-HD treatment induces a generalized disorganization of neuronal and axonal NF responsible for focal enlargements as well as atrophic changes of unmyelinated fibers.

Axons↗
PubMed1991

The epidemiology of inflammatory polyradiculoneuropathy. A critical review of the distribution, characteristics and outcome of the disease. Plasmapheresis Study Group.

An outline of the principal reports dealing with the definition, distribution, course and treatment of the inflammatory polyradiculoneuropathies, including the Guillain-Barré syndrome (GBS) and chronic inflammatory demyelinating polyneuropathy (CIDP), is given. Current diagnostic criteria for GBS are reaffirmed while the diagnosis of CIDP lacks proper standardization. Then, the boundaries between the two disorders are ill-defined. While GBS is rare and homogeneously distributed across developed and developing countries, the prevalence rate of CIDP is unknown. Several antecedent events have been implicated in the pathogenesis of GBS; yet, except for the swine-flu vaccine, the relation between infectious or toxic agents and the occurrence of the disease is purely anecdotal. The only factors known to influence the outcome of GBS are age, severity of opening symptoms, abnormal electrophysiologic characteristics of peripheral nerve function, and plasmapheresis. However, responders and non-responders to current treatment are far from defined. Although similarities have been found between experimental allergic neuritis and experimental allergic encephalomyelitis, the degree of CNS impairment in patients with inflammatory polyradiculoneuropathies needs further refinement. To provide a tentative answer to some of the unsolved questions on inflammatory polyradiculoneuropathies, a multicenter cohort study on newly diagnosed patients submitted to standard clinical and laboratory evaluation, and given common therapeutic regimes, is awaited.

Central Nervous System↗
PubMed1990

Familial spastic paraplegia with peroneal amyotrophy. A family with hypersensitivity to pyrexia.

We describe 4 siblings with spastic paraparesis and peroneal amyotrophy who were prone to severe pain and painful dysesthesias, tetraparesis and pyramidal signs during pyrexial episodes of variable etiology. These symptoms cleared almost completely in 10-20 days. Nerve conduction velocity was reduced more markedly during the spells of fever. Muscle biopsy specimen was normal. Some transient functional disturbance of membrane equilibrium of the nervous pathways of both central and peripheral nervous systems was probably responsible for the attacks during pyrexial episodes.

Adolescent↗
PubMed1989

Neurophysiological study in chronic GM2 gangliosidosis (hexosaminidase A and B deficiency), with motor neuron disease phenotype.

We report the electrophysiological investigation of two adult cases with GM 2 gangliosidosis with hexosaminidase A and B deficiency. Superficial peroneal biopsy was obtained from one patient. The electrophysiological alterations of the peripheral nervous system were fasciculations, signs of collateral reinnervation and loss of motor units, decrease in sensory potential amplitude and increase in distal motor latency. Increase in N9-N13 interpeak latency of the somatosensory evoked potentials and an increase I-V interpeak latency of the brain-stem auditory potentials were evident in both cases. Visual evoked potentials were normal. Nerve biopsy showed a severe loss of myelinated fibers, especially of those with the largest diameter, with no signs of segmental demyelination, or remyelination. A tentative interpretation of our findings is given.

Action Potentials↗
PubMed1989

Recurrent familial brachial plexus palsies as the only clinical expression of 'tomaculous' neuropathy.

Two familial cases of recurrent brachial plexus are described and similar episodes were noticed in other members of the family. Electrophysiological investigations found impaired motor and sensory nerve conduction velocity in affected and nonaffected members. Tomaculous neuropathy was found at biopsy of peripheral nerve in more than 40% of dissected fibers. In addition, two affected members showed a reduced interpupillary distance, i.e. the most common dysmorphic feature found in the hereditary neuralgic amyotrophy (HNA). A literature review showed only two other instances of recurrent familial brachial plexus palsies as the only manifestation of tomaculous neuropathy (hereditary neuropathy with liability to pressure palsy, HNPP). The dysmorphic feature found in our cases in addition to the clinical, electrophysiological and anatomical data support the hypothesis that these cases of HNPP and the HNA may represent the same disease.

Adult↗
PubMed1988

Blood lymphocytes in neuronal ceroid lipofuscinosis.

Ultrastructural examination of white blood cells of 8 patients with neuronal ceroid lipofuscinosis showed the characteristic cytosomes, i.e. curvilinear bodies, fingerprint profiles, osmiophilic bodies, as seen in nerve cells. The reliability of this simple technique in the diagnostic work-up of this progressive neurodegenerative disorder is emphasized.

Child↗
PubMed1988

Peripheral neuropathy associated with allergic granulomatous angiitis (Churg-Strauss syndrome): clinical features and histological findings.

We describe the case of a patient with a history of resistant asthma who presented with subacute neuropathy, hypereosiniphilia and central nervous system involvement; these findings were consistent with allergic granulomatous angiitis (Churg-Strauss syndrome). Although cutaneous biopsy prompted the diagnosis, the cases reported suggests that clinical, biological and histological data are all essential for the diagnosis. We emphasize that an early recognition of this syndrome may be important, since appropriate therapy may lead to recovery or influence favorably at least long term survival.

Aged↗
PubMed1988

Anatomical and clinical study of a case of subacute encephalomyelitis with hyperekplexia syndrome.

This case of subacute encephalomyelitis with a hyperekplexia type syndrome was characterized histologically by marked lymphomonocytic infiltrates, nodules of microglia, evidence of neuronophagia. These findings suggested a viral infection. The clinical peculiarities of this encephalomyelitis are explained by the elective site of the lesions in the grey substance of the spinal cord, of the tegmentum of the medulla oblongata and pons and of some nuclei of the extrapyramidal system.

Acoustic Stimulation↗
PubMed1988

Cerebro-ocular dysplasia and muscular dystrophy: report of two cases.

The authors report two cases with severe cerebro-ocular malformations and muscular dystrophy who died at 14 and 8 months of age. In both, muscular dystrophy was confirmed by EMG and high muscle enzyme values. In one case, autopsy showed severe cerebral malformation consisting of lissencephaly, hydrocephalus, agenesis of corpus callosum, chiasma and olfactory bulb and lobe, absence of pyramides and cerebellar vermis. In sections of cerebral cortex a clear absence of structural cellular organization and spongiosis of the white matter were evident. Similar disorganization was found in the cerebellum where numerous calcifications were present. The muscle showed signs of primitive muscular dystrophy. The clinical autonomy of the cerebro-ocular-dysplasia-muscular-dystrophy syndrome is discussed. The clinical and pathological data are compared with the two other similar syndromes (i.e. Fukuyama's and Warburg's diseases).

Abnormalities, Multiple↗