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Ivo N van Schaik

Publications and source records attributed to Ivo N van Schaik.

10 recordsLinked to original sources
PubMed2006

Comparison of CMT1A and CMT2: similarities and differences.

To evaluate the clinical and electrophysiological similarities and differences between two large groups of patients with Charcot-Marie-Tooth disease, i.e. CMT1A and CMT2, we performed a post hoc comparison of clinical and electrophysiological data. Most CMT1A and CMT2 patients had the classical CMT phenotype. Age of onset was significantly later in CMT2. Total areflexia was present in approximately half of the CMT1A patients whereas it was rare in CMT2. Foot deformities and weakness of knee extensor and foot dorsal flexor muscles were more frequent in CMT1A. Median nerve motor nerve conduction velocities (MNCV) were always less than 38 m/s in CMT1A patients, whereas this was also the case in 16% of the CMT2 patients. Sensory nerve conduction velocities showed less overlap. In both CMT1A and CMT2 CMAP and SNAP amplitudes were often reduced or not obtainable in the legs. In CMT1A, SNAP amplitude was more reduced and SNAP duration more prolonged than in CMT2. We conclude that there are no robust clinical signs or symptoms that differentiate between CMT1A and CMT2 patients. Electrodiagnostical studies show a length-dependent motor and sensory axonal dysfunction in both CMT-types. Additional SNAP and SNCV evaluation may be helpful in focusing molecular genetic analysis in the occasional case of CMT2 showing slow motor nerve conduction velocities overlapping with CMT1A values. The reduction of CMAP and SNAP amplitudes in CMT1A is probably a combined effect of demyelination and axonal dysfunction.

Action Potentials↗
PubMed2005

Early onset neuropathy in a compound form of Charcot-Marie-Tooth disease.

A 2-year-old boy presented with early-onset Charcot-Marie-Tooth disease (CMT). His parents had not been diagnosed previously with CMT, but on careful examination they showed clinical signs of CMT and reduced nerve conduction velocities. Genetic analysis identified the boy as a heterozygote for both a peripheral myelin protein 22 (PMP22) duplication and a mutation in the lipopolysaccharide-induced-tumour-necrosis-factor-alpha-factor (LITAF) gene, whereas each parent only had one mutated CMT gene. This suggests that LITAF mutations can severely affect the CMT phenotype caused by a PMP22 duplication.

Blotting, Southern↗
PubMed2005

Familial cortical myoclonic tremor with epilepsy: a single syndromic classification for a group of pedigrees bearing common features.

Fifty Japanese and European families with cortical myoclonic tremor and epilepsy have been reported under various names. Unfamiliarity with the syndrome often leads to an initial misdiagnosis of essential tremor or progressive myoclonus epilepsy. A detailed overview of the literature is lacking and is the scope of this study. Disease characteristics are adult onset, distal action tremor and myoclonus, epileptic seizures, autosomal dominant inheritance, benign course, effectiveness of antiepileptic drugs, and possibly cognitive decline. A channelopathy is hypothesized to be the basis of the disease. Despite phenotypic and genetic differences between the Japanese and European pedigrees, the clinical and electrophysiological data point toward one syndrome. To avoid confusion in literature and possible misdiagnosis of patients, we propose to use one description and suggest "familial cortical myoclonic tremor with epilepsy" (FCMTE). In addition, we put forward diagnostic criteria to give a starting point from which to conduct genetic studies.

Adolescent↗
PubMed2005

Severity of Guillain-Barré syndrome is associated with Fc gamma Receptor III polymorphisms.

Macrophages and ganglioside-specific IgG are involved in the pathogenesis of Guillain-Barre syndrome (GBS). Leukocyte IgG receptors (Fc gammaR) confer potent cellular effector functions to the specificity of IgG. The efficacy of IgG-mediated cellular inflammatory responses is determined by functional polymorphisms of three Fc gammaR subclasses (Fc gammaRIIa: H131/R131; Fc gammaRIIIa: V158/F158; Fc gammaRIIIb: NA1/NA2). Fc gammaR genotype distributions were determined in a Dutch, and British cohort of GBS patients and controls. In addition, a meta-analysis incorporating all previously published data, encompassing a total of 345 GBS patients and 714 healthy controls, was performed. Results suggest that Fc gammaRIII genotypes may represent mild disease-modifying factors in GBS.

Adult↗
PubMed2004

Clinical disease severity and axonal dysfunction in hereditary motor and sensory neuropathy Ia.

BACKGROUND: Hereditary motor and sensory neuropathy type Ia (HMSN Ia) is known as a primarily demyelinating peripheral nerve disease. Evidence is accumulating that axonal involvement determines the course of the disease process. METHODS: Fifty-one patients were investigated. Physical disability and impairments were scored. Nerve conduction velocities (NCVs) were used as indirect measures for myelination status and compound muscle/sensory nerve action potential (CMAP/SNAP) amplitudes served as indirect measures for axonal function. RESULTS: Median age was 39 years (range 6-69). Muscle weakness and sensory dysfunction was more severe in the legs than in the arms and distally more than proximally. However, more than 40% of the patients had proximal muscle weakness in the legs. Three point grip was used as representative of combined distal arm muscle groups. CMAP amplitude was the most important independent variable in a multiple linear regression model (forward selection) to explain the relation between three point grip strength and four different features, i. e., CMAP amplitude of the abductor pollicis brevis, median nerve MNCV, gender, and duration of signs and symptoms. The severity of axonal dysfunction was nerve length-dependent and was related to the myelination status. The mild physical disability due to both muscle weakness and sensory dysfunction was also related to axonal dysfunction. CONCLUSIONS: In HMSN Ia, clinical disease severity at the impairment and disability levels is related to the severity of axonal dysfunction. Our data support the hypothesis that the myelination status is one of the factors that determine the extent of axonal dysfunction later in life. Proximal weakness of the legs is encountered in a considerable proportion of our patients.

Action Potentials↗
PubMed2003

Expression of complement components in the peripheral nervous system.

We have generated a SAGE (serial analysis of gene expression) library of normal sciatic nerve and found tags encoding for mRNAs of the complement system highly represented. RNA (RT-PCR and northern blot hybridization) and protein (western blot analysis and immunohistochemistry) studies confirmed these findings. High expression of classical pathway components, alternative pathway components and inhibitory components was observed in specific regions of the sciatic nerve. The first components of complement were found in axons, whereas the inhibitory components were detected in the perineurium, thereby protecting the nerve from a complement attack. Immunoreactivity towards activated complement factors was noted in post traumatic neuromas and after acute crush injury, which exemplify nerve regeneration and degeneration. We propose that local production of complement in the peripheral nervous system participates in the protection of healthy nerve and is needed for efficient clearance of myelin after injury: a prerequisite for normal regeneration and remyelination of the peripheral nerve.

Animals↗
PubMed2003

Transcriptional profile of the human peripheral nervous system by serial analysis of gene expression.

The peripheral nerve contains both nonmyelinating and myelinating Schwann cells. The interactions between axons, surrounding myelin, and Schwann cells are thought to be important for the correct functioning of the nervous system. To get insight into the genes involved in human myelination and maintenance of the myelin sheath and nerve, we performed a serial analysis of gene expression of human sciatic nerve and cultured Schwann cells. In the sciatic nerve library, we found high expression of genes encoding proteins related to lipid metabolism, the complement system, and the cell cycle, while cultured Schwann cells showed mainly high expression of genes encoding extracellular matrix proteins. The results of our study will assist in the identification of genes involved in maintenance of myelin and peripheral nerve and of genes involved in inherited peripheral neuropathies.

Blotting, Northern↗
PubMed2003

Autoimmunoreactivity to Schwann cells in patients with inflammatory neuropathies.

Inflammatory demyelinating neuropathies are characterized by a loss of peripheral nerve myelin. Myelin breakdown is thought to result from an autoimmune reaction towards nerve components. Schwann cells play a crucial role in the synthesis and maintenance of peripheral nerve myelin. An immune attack targeting Schwann cells could therefore affect myelin integrity, leading to disease. We studied the reactivity of sera from patients with Guillain-Barré syndrome (GBS) and chronic inflammatory demyelinating polyneuropathy (CIDP) towards Schwann cells using immunofluorescence microscopy. We found 24% of the GBS (56 out of 233) and 26% of the CIDP (12 out of 46) patients to have circulating immunoglobulin G autoantibodies against proliferating, non-myelinating human Schwann cells. In contrast, healthy donors showed positive staining in only two out of 34 sera. No reaction was found with sera from patients with non-inflammatory neurological disorders. Immunofluorescence was localized at the distal tips (leading lamella) of the Schwann cell processes. Distal tips of neurites (nerve-growth-cones) of in vitro differentiated non-myelinated hNT2 neurons also stained strongly. GBS and CIDP serum immunoreactivity was also observed in teased nerve fibre preparations. These data suggest that, at least part of the immunoreactivity is not directed against myelin, but towards non-myelin proteins and epitopes possibly involved in Schwann cell-axon interaction.

Adolescent↗
PubMed2002

Intravenous immunoglobulin for chronic inflammatory demyelinating polyradiculoneuropathy: a systematic review.

This review discusses the efficacy and safety in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) of intravenous immunoglobulin and compares this treatment with plasma exchange and prednisolone. We searched publications from 1985 onwards for randomised controlled studies examining the effects of intravenous immunoglobulin in patients with this immune-mediated neuromuscular disorder. Six trials, with 170 patients in total, were judged eligible. A significantly higher proportion of patients improved in disability within a month after the start of treatment with intravenous immunoglobulin than with placebo (relative risk 3.17 [95% CI 1.74 to 5.75]). During this period, intravenous immunoglobulin has similar efficacy to plasma exchange and oral prednisolone; therefore which of these treatments should be the first choice is currently uncertain. An algorithm on treatment approaches for CIDP is proposed.

Algorithms↗