The apolipoprotein E epsilon4-allele and antihypertensive treatment are associated with increased risk of cerebral MRI white matter hyperintensities

OBJECTIVE

Apolipoprotein E-epsilon4 (APOE-epsilon4) is a potential risk factor for cerebral vascular disease. The aim of the present study was to examine the relative importance of APOE-epsilon4 and other relevant risk factors for the extent of cerebral white matter hyperintensity (WMH) in a community-based sample of elderly subjects.

MATERIALS AND METHODS

From a cohort of 976 subjects born in 1914, APOE genotype was determined and MRI examinations were carried out in 75 subjects. WMH were rated using a standard semi-quantitative method. ANOVA and regression analyses were conducted to explore the relative importance of the potential risk factors.

RESULTS

APOE genotype and antihypertensive treatment were significantly associated with severity of total WMH load (P < 0.05).

CONCLUSIONS

The study confirmed the association between APOE-epsilon4 and WMH. Pharmaceutical treatment for arterial hypertension was also associated with the total burden of WMH in this study.

Structural brain abnormalities in early onset first-episode psychosis

BACKGROUND

Brain morphometry in children and adolescents with first-episode psychosis offer a unique opportunity for pathogenetic investigations.

METHODS

We compared high-resolution 3D T1-weighted magnetic resonance images of the brain in 29 patients (schizophrenia, schizotypal disorder, delusional disorder or other non-organic psychosis), aged 10-18 to those of 29 matched controls, using optimized voxel-based morphometry.

RESULTS

Psychotic patients had frontal white matter abnormalities, but expected (regional) gray matter reductions were not observed. Post hoc analyses revealed that schizophrenia patients (n = 15) had significantly larger lateral ventricles as compared to controls. Duration and dose of antipsychotics correlated negatively with global gray matter volume in minimally medicated patients (n = 18).

CONCLUSION

Findings of white matter changes and enlarged lateral ventricles already at illness onset in young schizophrenia spectrum patients, suggests aberrant neurodevelopmental processes in the pathogenesis of these disorders. Gray matter volume changes, however, appear not to be a key feature in early onset first-episode psychosis.

Hereditary spastic paraplegia with cerebellar ataxia: a complex phenotype associated with a new SPG4 gene mutation

Complex forms of hereditary spastic paraplegia (HSP) are rare and usually transmitted in an autosomal recessive pattern. A family of four generations with autosomal dominant hereditary spastic paraplegia (AD-HSP) and a complex phenotype with variably expressed co-existing ataxia, dysarthria, unipolar depression, epilepsy, migraine, and cognitive impairment was investigated. Genetic linkage analysis and sequencing of the SPG4 gene was performed and electrophysiologic investigations were carried out in six individuals and positron emission tomography (PET) in one patient. The disease was linked to the SPG4 locus on chromosome 2p as previously reported for pure HSP. Sequence analysis of the SPG4 (spastin) gene identified a novel 1593 C > T (GLN490Stop) mutation leading to premature termination of exon 12 with ensuing truncation of the encoded protein. However, the mutation was only identified in those individuals who were clinically affected by a complex phenotype consisting of HSP and cerebellar ataxia. Other features noted in this kindred including epilepsy, cognitive impairment, depression, and migraine did not segregate with the HSP phenotype or mutation, and therefore the significance of these features to SPG4 is unclear. Electrophysiologic investigation showed increased central conduction time at somatosensory evoked potentials measured from the lower limbs as the only abnormal finding in two affected individuals with the SPG4 mutation. Moreover, PET of one patient showed significantly relatively decreased regional cerebral blood flow in most of the cerebellum. We conclude that this kindred demonstrates a considerable overlap between cerebellar ataxia and spastic paraplegia, emphasizing the marked clinical heterogeneity of HSP associated with spastin mutations.

Imaging of dopamine transporters and D2 receptors in patients with Parkinson's disease and multiple system atrophy

PURPOSE

The aim of this study was to ascertain whether combined presynaptic and postsynaptic dopaminergic single-photon emission computed tomography (SPECT) scanning is useful for differentiation between patients with idiopathic Parkinson's disease (IPD), patients with multiple system atrophy of the striatonigral type (MSA) and healthy subjects.

METHODS

SPECT measurements of the dopamine transporter (DAT) were done with 123I-beta-CIT, while for determination of the dopamine D2-like receptors (D2), 123I-epidepride was used. Clinical evaluation and SPECT scans were carried out in 14 patients with IPD, eight patients with MSA and 11 healthy age-matched control subjects.

RESULTS

Putaminal DAT binding was reduced to 32% of control values in IPD and to 19% of control values in MSA . Significantly higher striatal asymmetry in DAT binding was found in MSA than in controls, but IPD patients had significantly higher asymmetry than MSA patients. Striatal D2 binding did not differ significantly between patients and healthy controls but the ratio between caudate DAT and D2 binding was significantly higher in patients with IPD than in those with MSA, even when disease severity was taken into account.

CONCLUSION

Patients with reduced striatal 123I-beta-CIT binding and a side-to-side difference greater than 15% are likely to suffer from IPD. Patients with reduced striatal 123I-beta-CIT binding and a side-to-side difference of between 5% and 15% are more likely to have MSA. 123I-epidepride SPECT measurements may add further diagnostic information, since the ratio between DAT and D2 receptor binding is significantly higher in IPD than in MSA.

Relation between age-related decline in intelligence and cerebral white-matter hyperintensities in healthy octogenarians: a longitudinal study

BACKGROUND

White-matter hyperintensities are commonly found on magnetic resonance imaging (MRI) of elderly people with or without dementia. Studies of the relation between severity of white-matter hyperintensities and cognitive impairment have had conflicting results. We undertook a longitudinal study of age-related decline in intellectual function and MRI at age 80 years.

METHODS

From a cohort of 698 people born in 1914 and living in seven municipalities in Denmark, 68 healthy non-demented individuals had been tested with the Wechsler adult intelligence scale (WAIS) at ages 50, 60, and 70, and they agreed to further WAIS testing at age 80, and cerebral MRI at age 80-82 (mean age 82.3 years). We scored separately the numbers of periventricular and deep white-matter hyperintensities.

FINDINGS

Scores for periventricular hyperintensities in this sample included all possible degrees of severity, but no participant scored more than 75% of maximum for deep white-matter hyperintensities. Neither type was related to the WAIS IQs of the 80-year assessment, but both were significantly associated with decline in performance IQ from age 50 to age 80 years (bivariate correlation coefficients 0.32, p=0.0087, and 0.28, p=0.0227, respectively). An analysis based on two WAIS subtests showed that the association between white-matter hyperintensities and cognitive impairment was significant only for cognitive decline in the decade 70-80 years.

INTERPRETATION

Both periventricular and deep white-matter hyperintensities are related to decline in intelligence but, in healthy octogenarians, the cumulative effect of these features alone explains only a small part of the large differences among individuals in age-related decline in intelligence. Interpretation of the presence and severity of white-matter hyperintensities in a diagnostic context must be done cautiously.

Cytokines in aging and exercise

Aging is associated with increased inflammatory activity. Increased plasma levels of tumour necrosis factor (TNF)-alpha were found in centenarians aged 100 years and in individuals aged 80-81 years when compared to a young control group. Plasma levels of TNF-alpha were linearly correlated to plasma levels of interleukin (IL)-6, TNF-receptors and C-reactive protein. High levels of TNF-alpha were directly related to dementia and to a low blood pressure ankle-arm index, indicating generalized atherosclerosis. In hospitalized patients with Streptococcus pneumonia infection, aging was associated with prolonged inflammatory activity. Similar results were found using an in vivo endotoxin challenge model in old versus young humans. Strenuous exercise induces increased levels in a number of proinflammatory and anti-inflammatory cytokines, naturally occurring cytokine inhibitors and chemokines. Thus, increased plasma levels of TNF-alpha, IL-1, IL-6, IL-1 receptor antagonist (IL-Ira), TNF-receptors (TNF-R), IL-10, IL-8 and macrophage inflammatory protein (MIP)-1 are found after strenuous exercise. The cytokine response to strenuous exercise has similarities to the cytokine response to trauma and sepsis. Therefore, in future studies, exercise is suggested as an ethically applicable model to use in studies on mechanisms underlying the age-associated altered cytokine response.

Changes in renal function during weight loss induced by high vs low-protein low-fat diets in overweight subjects

BACKGROUND

Due to the high satiating effect of protein, a high-protein diet may be desirable in the treatment of obesity. However the long-term effect of different levels of protein intake on renal function is unclear.

OBJECTIVE

To assess the renal effects of high vs low protein contents in fat-reduced diets.

DESIGN

Randomized 6 months dietary intervention study comparing two controlled ad libitum diets with 30 energy (E%) fat content: high-protein (HP; 25 E%) or low-protein, (LP, 12 E% protein). All food was provided by self-selection in a shop at the department, and high compliance to the diet composition was confirmed by measurements of urinary nitrogen excretion.

SUBJECTS

65 healthy, overweight and obese (25<body mass index (BMI)<34 kg/m2).

RESULTS

Dietary protein intake changed from 91.1 g/d to a 6 months intervention average of 70.4 g/d (P<0.05) in the LP group and from 91.4 g/d to 107.8 g/d (P<0.05) in the HP group, producing changes in glomerular filtration rate (GFR) of -7.1 ml/min in the LP group and +5. 2 ml/min in the HP group (group effect: P<0.05). Kidney volume decreased by -6.2 cm3 in the LP group and increased by +9.1 cm3 in the HP group (P<0.05), whereas albuminuria remained unchanged in all groups.

CONCLUSION

Moderate changes in dietary protein intake cause adaptive alterations in renal size and function without indications of adverse effects.

Autosomal dominant pure spastic paraplegia: a clinical, paraclinical, and genetic study

OBJECTIVES

At least three clinically indistinguishable but genetically different types of autosomal dominant pure spastic paraplegia (ADPSP) have been described. In this study the clinical, genetic, neurophysiological, and MRI characteristics of ADPSP were investigated.

METHODS

Sixty three at risk members from five families were clinically evaluated. A diagnostic index was constructed for the study. Microsatellite genotypes were determined for chromosomes 2p, 14q, and 15q markers and multipoint linkage analyses were performed. Central motor conduction time studies (CMCT), somatosensory evoked potential (SSEP) measurement, and MRI of the brain and the total spinal cord were carried out in 16 patients from four families.

RESULTS

The clinical core features of ADPSP were homogeneously expressed in all patients but some features were only found in some families and not in all the patients within the family. In two families non-progressive "congenital" ADPSP was seen in some affected members whereas adult onset progressive ADPSP was present in other affected family members. As a late symptom not previously described low backache was reported by 47%. Age at onset varied widely and there was a tendency for it to decline in successive generations in the families, suggesting anticipation. Genetic linkage analysis confined the ADPSP locus to chromosome 2p21-p24 in the five families. The lod scores obtained by multipoint linkage analysis were positive with a combined maximum lod score of Z=8.60. The neurophysiological studies only showed minor and insignificant prolongation of the central motor conduction time and further that peripheral conduction and integrity of the dorsal columns were mostly normal. Brain and the total spinal cord MRI did not disclose any significant abnormalities compared with controls.

CONCLUSIONS

ADPSP linked to chromosome 2p21-p24 is a phenotypic heterogeneous disorder characterised by both interfamilial and intrafamilial variation. In some families the disease may be "pure" but the existence of "pure plus" families is suggested in others. The neurophysiological and neuroimaging investigations did not show any major abnormalities.

MRI of autosomal dominant pure spastic paraplegia

We examined 16 patients with autosomal dominant pure spastic paraplegia (HSP) and 15 normal controls matched for age and sex using MRI of the brain and spinal cord. Images were assessed qualitatively by two independent radiologists, blinded to the clinical diagnosis. Areas of the brain and corpus callosum on one midsagittal slice and the area of the brain on one axial slice were measured and a "corpus-callosum index" expressing the size of the corpus callosum relative to that of the brain was calculated. Cross-sectional areas and anteroposterior and transverse diameters of the spinal cord at the levels of C 2, C 5, T 3, T 6, T 9 and T 11 were measured. No significant differences between patients and controls were found on qualitative evaluation of the images. The patients had a significantly smaller corpus callosum and "corpus-callosum index" than controls. This finding, not reported previously, might indicate that the disease process in pure HSP is not confined to the spinal cord. The anteroposterior diameters of the spinal cord at T 3 and T 9 were significantly smaller in patients than in controls. This might correspond to the degeneration of the pyramidal tracts and the dorsal columns described at neuropathological examination.

MR diffusion imaging of human intracranial tumours

We used MRI for in vivo measurement of brain water self-diffusion in patients with intracranial tumours. The study included 28 patients (12 with high-grade and 3 with low-grade gliomas, 7 with metastases, 5 with meningiomas and 1 with a cerebral abscess). Apparent diffusion coefficients (ADC) were calculated in a single axial slice through the tumours, the sequence was sensitive to diffusion along the cephalocaudal axis. Our main finding was that ADC in contrast-enhancing areas within cerebral metastases was statistically significantly higher than ADC in contrast-enhancing areas in high-grade gliomas (P < or = 0.05). Furthermore, the ADC in oedema surrounding metastases were statistically significantly higher the ADC in oedema around high-grade gliomas (P < or = 0.02). The ADC in patients with meningiomas did not differ significantly from those seen with high-grade gliomas or cerebral metastases. The highest ADC were found within cystic or necrotic tumour areas. In one patient with a cerebral abscess, suspected of having a high-grade glioma, the ADC was similar to that in high-grade gliomas. The finding of higher ADC in cerebral metastases than in high-grade gliomas may be helpful in trying to distinguish between these tumours preoperatively; it suggests increased free extracellular and/or intracellular water fraction in cerebral metastases. The method seems to hold potential for further noninvasive characterisation of intracranial tumours.

Hereditary haemochromatosis: a case of iron accumulation in the basal ganglia associated with a parkinsonian syndrome

Hereditary haemochromatosis is characterised by excessive parenchymal iron deposition, particularly in the liver. Usually hereditary haemochromatosis is not associated with neurological symptoms and iron deposition in the brain has not previously been described as a pathological phenomenon. A patient is reported with hereditary haemochromatosis and a syndrome of dementia, dysarthria, a slowly progressive gait disturbance, imbalance, muscle weakness, rigidity, bradykinesia, tremor, ataxia, and dyssynergia. The findings on MRI of a large signal decrease in the basal ganglia, consistent with excessive iron accumulation, indicate a causal relation to the symptoms. Although the neurological symptoms did not improve in our patient, hereditary haemochromatosis should be considered in the differential diagnosis of parkinsonian syndromes, because complications of iron induced organ injury may be prevented by phlebotomy.