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Biomedical subjects

P P De Deyn

Publications and source records attributed to P P De Deyn.

At least 19 recordsLinked to original sources
PubMed2007

P300 and treatment effect of modafinil on fatigue in multiple sclerosis.

To evaluate the value of visual and auditory P300 for predicting the response of multiple sclerosis-related fatigue to modafinil treatment, 33 patients were treated with 100 mg modafinil once daily for 4 weeks, following a 4-week baseline phase and an optional 8-week extension phase. The main clinical outcome parameter was a decrease in the fatigue visual analogue score (VAS) before and after 4 weeks of treatment. Patients with shorter auditory P300 latency at baseline were more likely to benefit from modafinil treatment. Auditory P300 latency predicted treatment response with a specificity of 76% and a sensitivity of 75% at a cut-off latency of 350 ms. Visual P300 latency could not be used to predict treatment response. Baseline auditory P300 latency predicted treatment response, whereas visual P300 latency did not. Clinical improvement did not correlate with changes in either visual or auditory P300.

Acoustic Stimulation↗
PubMed2007

Volumetric evaluation of upper extremities in 250 healthy persons.

BACKGROUND AND PURPOSE: Upper extremity oedema frequently occurs as a complication of several diseases. The aim of this study was to establish normative data for upper extremity volumes with a modified water displacement method. These data were used to develop predictive formulas helpful in detecting abnormal swelling. SUBJECTS AND METHODS: Upper extremities of 250 healthy subjects (138 men and 112 women) were measured by water displacement. RESULTS: A mean difference of 3.0% (3.2%) between right and left arm (forearm) was found. Intra-class correlation coefficients were 0.99 for intra-rater and inter-rater reliabilities. Coefficient of variation was 0.23%. To predict the premorbid volume of an oedematous arm, prediction formulas were constructed. DISCUSSION AND CONCLUSION: Water displacement as used in this study is a highly reliable technique for volume measurement of upper extremities. This technique was applied to gather normative data for upper extremity volumes. We suggest that this technique can be used in daily clinical practice for the evaluation of upper extremity oedema or atrophy caused by various diseases as well as for volume monitoring. Prediction formulas can be used to define abnormal swelling.

Adolescent↗
PubMed2006

Differentiation between mild cognitive impairment, Alzheimer's disease and depression by means of cued recall.

BACKGROUND: Discriminating Alzheimer's disease (AD) and mild cognitive impairment (MCI) from depression is a challenge in psychogeriatric medicine. A study was set up to ascertain whether cued recall could be useful in differentiating early AD and MCI from depression among elderly individuals. METHOD: The Visual Association Test (VAT) and the Memory Impairment Screen-plus (MIS-plus) were administered together with the Mini-Mental State Examination (MMSE) and the Geriatric Depression Scale (GDS) to 40 MCI patients, 35 mild AD patients, 46 depressed patients and 52 healthy control subjects. RESULTS: A one-way analysis of variance (ANOVA) followed by post-hoc Scheffé tests showed that AD patients had significantly lower cued recall scores (i.e. combined VAT and MIS-plus scores) than MCI patients, who in turn had lower scores than depressed patients. The scores of depressed patients and controls were not significantly different. Discriminant analysis revealed that 94% of the AD patients and 96% of the depressed patients could be classified correctly by means of the GDS and the cued recall sores. Receiver operating characteristic (ROC) curves identified an optimal cut-off score of 8 (maximum score 12) for differentiating AD and MCI patients from depressed elderly patients and controls. Applying this cut-off, a sensitivity of 83% (58%) and a specificity of 85% (85%) was obtained when differentiating AD (MCI) from depression. CONCLUSIONS: Cued recall, operationalized by the combined scores of VAT and MIS-plus, is a useful method for differentiating AD patients from depressed individuals and healthy controls. Probably because of the great heterogeneity among MCI patients, the diagnostic power of cued recall decreases when applied to differentiate MCI from depression.

Aged↗
PubMed2006

Partial cure of established disease in an animal model of metachromatic leukodystrophy after intracerebral adeno-associated virus-mediated gene transfer.

Metachromatic leukodystrophy (MLD) is a lysosomal storage disease caused by genetic deficiency of arylsulfatase A (ARSA) enzyme. Failure in catalyzing the degradation of its major substrate, sulfatide (Sulf), in oligodendrocytes and Schwann cells leads to severe demyelination in the peripheral (PNS) and central nervous system (CNS), and early death of MLD patients. The ARSA knockout mice develop a disease that resembles MLD but is milder, without significant demyelination in the PNS and CNS. We showed that adeno-associated virus serotype 5-mediated gene transfer in the brain of ARSA knockout mice reverses Sulf storage and prevents neuropathological abnormalities and neuromotor disabilities when vector injections are performed at a pre-symptomatic stage of disease. Direct injection of viral particles into the brain of ARSA knockout mice at a symptomatic stage results in sustained expression of ARSA, prevention of Sulf storage and neuropathological abnormalities. Despite these significant corrections, the treated mice continue to develop neuromotor disability. We show that more subtle biochemical abnormalities involving gangliosides and galactocerebroside are in fact not corrected.

Animals↗
PubMed2006

FVB.129P2-Pde6b(+) Tyr(c-ch)/Ant, a sighted variant of the FVB/N mouse strain suitable for behavioral analysis.

Mice of the FVB/N strain are severely visual impaired as a result of tyrosinase gene defects, leading to a deficiency of the key enzyme for melanin synthesis in skin and eye and of cyclic guanosine monophosphate phosphodiesterase gene defects, which results in albinism (Tyr(c/c)) and retinal degeneration (Pde6b(rd1/rd1)), respectively. Nevertheless, FVB/N mice are commonly used for the generation of transgenic animals because of their large, strong pronuclei and high breeding performance. However, due to visual impairment of the FVB/N animals, the resulting transgenic animals cannot be used in tests that depend on vision, including tests of cognitive behavior. Therefore, we have bred a sighted version of the FVB/N strain by an outcross between FVB/N and 129P2/OlaHsd, followed by repeated backcrosses to FVB/N mice while selecting against albinism and homozygosity of the retinal degeneration mutation. After 11 generations of backcrossing, sighted animals were intercrossed to generate the congenic FVB.129P2-Pde6b(+) Tyr(c-ch)/Ant strain, which is pigmented (Tyr(c-ch)/(c-ch)) and devoid of the genetic predisposition to retinal degeneration. The accurate visual abilities of the FVB.129P2-Pde6b(+) Tyr(c-ch)/Ant mice, for which we propose the name FVBS/Ant, demonstrated a clear visual evoked potential in the presence of normal eye histology and improved performance in the Morris water maze test.

Albinism↗
PubMed2006

Mild cognitive impairment: what's in a name?

BACKGROUND: Nowadays the term mild cognitive impairment (MCI) is used to fill the gap between cognitive changes associated with normal ageing and those associated with dementia. Despite some agreement in general definitions, MCI is still a heterogeneous clinical syndrome for which no DSM-IV criteria have yet been established. Criteria by Petersen et al. are presently the most applied in clinical practice. Moreover, little attention has been paid to the specific relation between MCI and depression. OBJECTIVE: This review highlights some concerns about the concept of MCI and provides guidelines within the field of neuropsychology to solve them. In a second part, the paper focuses on the specific relationship between depression in the elderly and MCI. RESULTS: We hypothesize that certain test instruments can be used to operationalize the criteria proposed by Petersen et al. Moreover, we suggest that cued recall might be of help to differentiate between progressive and non-progressive MCI. Concerning the specific relation between depression and MCI, we assume that elderly depression with concomitant cognitive problems can be seen as an MCI. CONCLUSION: The proposed adjustments and additions (neuropsychological instruments and the incorporation of depressive symptoms) in the diagnostic flowchart of Petersen may serve as useful tools for clinicians when making a diagnosis of MCI.

Activities of Daily Living↗
PubMed2006

Modest phenotypic improvements in ASA-deficient mice with only one UDP-galactose:ceramide-galactosyltransferase gene.

BACKGROUND: Arylsulfatase A (ASA)-deficient mice are a model for the lysosomal storage disorder metachromatic leukodystrophy. This lipidosis is characterised by the lysosomal accumulation of the sphingolipid sulfatide. Storage of this lipid is associated with progressive demyelination. We have mated ASA-deficient mice with mice heterozygous for a non-functional allele of UDP-galactose:ceramide-galactosyltransferase (CGT). This deficiency is known to lead to a decreased synthesis of galactosylceramide and sulfatide, which should reduce sulfatide storage and improve pathology in ASA-deficient mice. RESULTS: ASA-/- CGT+/- mice, however, showed no detectable decrease in sulfatide storage. Neuronal degeneration of cells in the spiral ganglion of the inner ear, however, was decreased. Behavioural tests showed small but clear improvements of the phenotype in ASA-/- CGT+/- mice. CONCLUSION: Thus the reduction of galactosylceramide and sulfatide biosynthesis by genetic means overall causes modest improvements of pathology.

Analysis of Variance↗
PubMed2006

Neuropsychiatric symptoms in patients with Parkinson's disease and dementia: frequency, profile and associated care giver stress.

OBJECTIVE: To explore the profile of neuropsychiatric symptoms in patients with dementia associated with Parkinson's disease (PDD). METHODS: 537 patients with PDD drawn from an international multicentre clinical trial of rivastigmine were assessed using the 10-item Neuropsychiatric Inventory (NPI). A cluster analysis was used to investigate the inter-relationship of NPI items. Associations between the clusters and demographic and clinical variables were analysed. RESULTS: 89% of the patients presented at least one symptom on the NPI, 77% had two or more symptoms and 64% had at least one symptom with a score > or = 4. The most common symptoms were depression (58%), apathy (54%), anxiety (49%) and hallucinations (44%). Patients with more severe dementia and advanced Parkinson's disease had more neuropsychiatric symptoms. Nearly 60% of the care givers reported at least one NPI symptom to be of at least moderate severe distress. Five NPI clusters were identified: one group with few and mild symptoms (52%); a mood cluster (11%, high scores on depression, anxiety and apathy); apathy (24%; high apathy and low scores on other items); agitation (5%, high score on agitation and high total NPI score); and a psychosis cluster (8%; high scores on delusions and hallucinations). The psychosis and agitation clusters had the lowest Mini-Mental State Examination score and the highest Unified Parkinson's Disease Rating Scale and care giver distress scores. CONCLUSION: Neuropsychiatric symptoms are common in patients with PDD. The profile of these symptoms differs from that in other types of dementia. Subgroups with different neuropsychiatric profiles were identified. These subgroups may be associated with distinct neurobiological changes, which should be explored in future studies.

Aged↗
PubMed2006

Attentional deficits affect activities of daily living in dementia-associated with Parkinson's disease.

OBJECTIVE: To investigate the effects of attentional deficits on activities of daily living (ADL) in patients with dementia associated with Parkinson's disease (PDD). METHOD: 461 patients were assessed neuropsychologically. Factor analyses were used to differentiate attention from other cognitive functions and to differentiate different aspects of ADL functions. The effects of the attentional measure on ADL were examined using sequential multiple regression, controlling for age, sex, education, severity of motor symptoms and other cognitive functions. RESULTS: Three cognitive factors were identified, with one factor emerging as a measure of vigilance and focused attention. This factor predicted different aspects of ADL status even after controlling for motor functions and other cognitive factors. The attention factor was the single strongest cognitive predictor of ADL status, matching the strength of the effects of motor functions on ADL status. CONCLUSION: Impaired attention is an important determinant of ADL functions in patients with PDD.

Activities of Daily Living↗
PubMed2006

Paroxysmal neuralgic upper cervical pain attacks: the lower syndrome of cluster headache.

We present a group of seven patients with a lower syndrome (LS) of cluster headache (CH). Seventy-three newly diagnosed patients with CH were subjected to a 9 years follow-up study; 66 patients were classified as upper syndrome (US) and only seven patients (9.5%) as LS. We focus on the characteristics of this group of seven patients with LS and compare them with existing literature. The seven cases with LS illustrate the wider spectrum of clinical manifestations that can occur in CH, namely infraortibal symptoms or these outside the territory of the trigeminal branches such as the upper cervical region or the craniocervical margin. The duration of the attacks can last more than 180 min. The attacks show a circadian/circannual regularity and a stereotypic pattern of symptoms in most of the patients. The severity and duration of the attacks may increase over the years. The neck pain can overshadow all the other symptoms of CH. Because of the regularity of the attacks at particular times of day or night in some patients, even abortive therapy can be used as prevention when taken some hours before the suspected attack. We hypothesize that some patients with LS may represent an anatomical-functional variant of a primary chronic neurovascular pain disorder originating from the central nervous system, with possible involvement of the hypothalamus and the trigeminovascular (TV) system, with inputs from the cervical roots C(0)-C(2). Clinicians should consider CH when pain attacks are located outside the orbitotemporal regions, but fulfil the other diagnostic criteria for CH and should try ergotamine, oxygen, sumatriptan, verapamil, steroids or even combinations in these patients.

Adult↗
PubMed2006

Probably anti-Tr associated paraneoplastic cerebellar degeneration as initial presentation of a squamous cell carcinoma of the lung.

Paraneoplastic cerebellar degeneration (PCD) is the most frequent paraneoplastic syndrome affecting the brain. Until now, anti-Tr associated PCD was only seen in patients with Hodgkin's disease. We report a male patient who presented with a progressive ataxia, affecting predominantly the lower limbs and a cerebellar dysarthria. Extensive diagnostic approach initially showed no evidence of tumor. The patient was found to have anti-Tr antibodies in his serum. Fourteen months after onset of symptoms a whole body PET-scan showed a pathological focus at the right hilus of the lungs. A mediastinoscopy was performed and peribronchial node sampling was done. The anatomopathological analysis revealed a non-well differentiated squamous cell carcinoma. This is the first report about the association between an anti-Tr associated PCD and squamous cell carcinoma.

Aged↗
PubMed2006

Biochemical validation of a rat model for polycystic kidney disease: comparison of guanidino compound profile with the human condition.

Polycystic kidney disease (PKD) accounts for 7-10% of all dialyzed renal insufficient patients. Accumulation of specific guanidino compounds (GCs) has been related to neurological, cardiovascular, hematological, and immunological complications of renal failure. In this study, we investigate whether the PKD/Mhm rat model can be used as a biochemical model for human PKD. For the validation of the rat model, we performed the first detailed evaluation of the concentrations of GCs in serum and urine of patients with PKD in addition to the GC patterns in the plasma, urine, and tissues of the PKD/Mhm rat model. The GCs were determined after separation on a cation exchange resin and fluorescence detection. The GC levels and changes observed in blood and urine of patients with PKD are comparable with those found in patients with renal insufficiency due to different etiologies. The PKD/Mhm rat model can be used as a biochemical model for human PKD as the obvious increases of urea, guanidinosuccinic acid, creatinine, guanidine, methylguanidine, and N(G)N(G)-dimethylarginine (symmetrical dimethylarginine) seen in blood of oldest heterozygous and younger homozygous PKD rats were largely within the same range as those found in the studied human PKD population, especially in patients with a glomerular filtration rate below 60 ml/min/1.73 m(2). The decreased levels of plasma guanidinoacetic acid seen at end-stage renal disease in homozygous and oldest heterozygous rats were also observed in serum of patients with a glomerular filtration rate below 20 ml/min/1.73 m(2). The PKD/Mhm rat model has, besides similar disease characteristics with human PKD, comparable GC alterations.

Animals↗
PubMed2006

The normal phenotype of Pmm1-deficient mice suggests that Pmm1 is not essential for normal mouse development.

Phosphomannomutases (PMMs) are crucial for the glycosylation of glycoproteins. In humans, two highly conserved PMMs exist: PMM1 and PMM2. In vitro both enzymes are able to convert mannose-6-phosphate (mannose-6-P) into mannose-1-P, the key starting compound for glycan biosynthesis. However, only mutations causing a deficiency in PMM2 cause hypoglycosylation, leading to the most frequent type of the congenital disorders of glycosylation (CDG): CDG-Ia. PMM1 is as yet not associated with any disease, and its physiological role has remained unclear. We generated a mouse deficient in Pmm1 activity and documented the expression pattern of murine Pmm1 to unravel its biological role. The expression pattern suggested an involvement of Pmm1 in (neural) development and endocrine regulation. Surprisingly, Pmm1 knockout mice were viable, developed normally, and did not reveal any obvious phenotypic alteration up to adulthood. The macroscopic and microscopic anatomy of all major organs, as well as animal behavior, appeared to be normal. Likewise, lectin histochemistry did not demonstrate an altered glycosylation pattern in tissues. It is especially striking that Pmm1, despite an almost complete overlap of its expression with Pmm2, e.g., in the developing brain, is apparently unable to compensate for deficient Pmm2 activity in CDG-Ia patients. Together, these data point to a (developmental) function independent of mannose-1-P synthesis, whereby the normal knockout phenotype, despite the stringent conservation in phylogeny, could be explained by a critical function under as-yet-unidentified challenge conditions.

Animals↗
PubMed2006

Central nervous system metastases of pulmonary adenocarcinoma mimicking neurofibromatosis type 2.

We report a case of a 51-year-old man presenting with rapidly progressive unilateral tinnitus, hearing loss and imbalance. Neuroimaging revealed bilateral VIIIth cranial nerve masses and multiple cerebral and spinal cord lesions that were interpreted as being acoustic schwannomas and multiple meningeomas. An initial tentative diagnosis of neurofibromatosis type 2 (NF2) was made. Both clinical and radiological evolution were atypical for NF2 and the initial diagnosis of NF2 was questioned. Additional technical investigations demonstrated a pulmonary adenocarcinoma. Postmortem examination confirmed that this patient had multiple central nervous system metastases of a primary pulmonary adenocarcinoma, presenting clinically and neuroradiologically as a probable neurofibromatosis type 2. Clinicians should be aware of the rare possibility of central nervous system metastases mimicking NF2.

Adenocarcinoma↗
PubMed2005

Significant variation in mortality and functional outcome after acute ischaemic stroke between Western countries: data from the tinzaparin in acute ischaemic stroke trial (TAIST).

BACKGROUND: The medical care of patients with acute stroke varies considerably between countries. This could lead to measurable differences in mortality and functional outcome. OBJECTIVE: To compare case mix, clinical management, and functional outcome in stroke between 11 countries. METHODS: All 1484 patients from 11 countries who were enrolled into the tinzaparin in acute ischaemic stroke trial (TAIST) were included in this substudy. Information collected prospectively on demographics, risk factors, clinical features, measures of service quality (for example, admission to a stroke unit), and outcome were assessed. Outcomes were adjusted for treatment assignment, case mix, and service relative to the British Isles. RESULTS: Differences in case mix (mostly minor) and clinical service (many of prognostic relevance) were present between the countries. Significant differences in outcome were present between the countries. When assessed by geographical region, death or dependency were lower in North America (odds ratio (OR) adjusted for treatment group only = 0.52 (95% confidence interval, 0.39 to 0.71) and north west Europe (OR = 0.54 (0.37 to 0.78)) relative to the British Isles; similar reductions were found when adjustments were made for 11 case mix variables and five service quality measures. Similarly, case fatality rates were lower in North America (OR = 0.44 (0.30 to 0.66)) and Scandinavia (OR = 0.50 (0.33 to 0.74)) relative to the British Isles, whether crude or adjusted for case mix and service quality. CONCLUSIONS: Both functional outcome and case fatality vary considerably between countries, even when adjusted for prognostic case mix variables and measures of good stroke care. Differing health care systems and the management of patients with acute stroke may contribute to these findings.

Activities of Daily Living↗
PubMed2005

Regional distribution of biogenic amines, amino acids and cholinergic markers in the CNS of the C57BL/6 strain.

A reliable extrapolation of neurochemical alterations from a mouse model to human metabolic brain disease requires knowledge of neurotransmitter levels and related compounds in control mouse brain. C57BL/6 is a widely used background strain for knockout and transgenic mouse models. A prerequisite for reliable extrapolation from mouse brain to the human condition is the existence of analogous distribution patterns of neurotransmitters and related compounds in control mouse and human brain. We analysed regional distribution patterns of biogenic amines, neurotransmitter and non-neurotransmitter amino acids, and cholinergic markers. Distribution patterns were compared with known neurotransmitter pathways in human brain. The present study provides a reference work for future analyses of neurotransmitters and related compounds in mouse models bred in a C57BL/6 background strain.

Amino Acids↗