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Biomedical subjects

G W Bruyn

Publications and source records attributed to G W Bruyn.

At least 19 recordsLinked to original sources
PubMed1992

Hereditary spastic dystonia with Leber's hereditary optic neuropathy: neuropathological findings.

Neuropathological findings in a 59-year-old male case of hereditary spastic dystonia with Leber's hereditary optic atrophy included: marked depletion of myelinated nerve fibres in the posterior funiculi, corticopontine tracts and striatum; practically complete neuronal depletion in the putamen and lateral part of the caudate, and mild cell loss in the substantia nigra. The putamina had changed into a spongy fibrillary scar, the pallidal fibres and laminae were practically all degenerated. Moreover, there was generalised mild fibre degeneration of the white matter. The optic nerve showed marked, predominantly central, loss of nerve fibres with demyelination.

Brain↗
PubMed1992

Altered postural reflexes in Parkinson's disease: a reverse hypothesis.

In subjects standing on a movable platform, sudden dorsiflexion of the ankle joint elicits a set of reflexes in leg muscles. These responses include a short latency (SL) and medium latency (ML) stretch reflex in the gastrocnemius muscle and a distal to proximal innervation sequence of long latency (LL) reflexes in the shortened tibialis anterior and vastus lateralis muscles. Because of their role in maintaining upright stance these responses have been termed postural reflexes. In patients with Parkinson's disease (PD), the following abnormalities have been described: 1) enhanced ML-amplitudes; 2) a reversed LL innervation sequence; and 3) delayed onset latencies. These abnormalities are thought to be due to defective motor programming and disturbed control of spinal and supraspinal reflex centers by basal ganglia circuits. The altered reflexes have been held responsible for some of the clinical features of PD, including balance impairment and rigidity. In this paper, we argue the reverse hypothesis that postural reflexes are essentially normal in PD, and that the observed alterations are at least in part consequence rather than cause of balance impairment, the stooped parkinsonian posture and rigidity of PD patients.

Humans↗
PubMed1991

The hypothalamic lateral tuberal nucleus and the characteristics of neuronal loss in Huntington's disease.

Neurons in the hypothalamic lateral tuberal nucleus (NTL) were counted in 16 Huntington's disease (HD) patients and 12 controls. The control range was 47,500-71,700. In the HD cases the number ranged from 2,800 to 40,600. The log-transformed counts of the HD patients correlated closely with age-at-death (r = 0.66, P less than 0.01) and age-at-onset (r = 0.78, P less than 0.001), but not with duration of disease, nor with the severity of the neostriatal changes. Because of its vulnerability to the effects of the HD gene and its simplicity, the NTL seems fit to study the characteristics of neuronal death in HD.

Age Factors↗
PubMed1991

Intrathecal immunoglobulin synthesis. Comparison of various formulae with the 'gold standard' of isoelectric focusing.

The recent introduction of a further new formula for calculating intrathecal Ig synthesis led us to compare the results of calculations obtained when using it and certain other older formulae with those of isoelectric focusing (IEF), since only the latter proves the intrathecal synthesis of oligoclonal proteins. On comparison, it was found that the results produced by the usual formulae were, without exception, inferior to those of isoelectric focusing. By using Receiver Operating Characteristic (ROC) curves, it is shown that calculations with the Reiber formula agree best with IEF. Virtually the same results are obtained with the "ln IgG index + 1" and "IgG index".

Algorithms↗
PubMed1991

Hereditary spastic dystonia: a new mitochondrial encephalopathy? Putaminal necrosis as a diagnostic sign.

A large kindred, in which either Leber's hereditary optic atrophy, or a hereditary spastic dystonia, or a combination of both manifested over many generations was restudied after the first report on it in 1964. NMR scans revealed bilateral, and, in two patients with hemidystonia, unilateral necrosis with shrinkage of the putamen, in one case associated with total disappearance of the head of the caudate nucleus. Except for age-appropriate cortical atrophy in one instance, no other changes were observed in the brain, brainstem, and cerebellum. The putaminal necrosis appears as typical "striatal slits" on the NMR scans. It is argued that this rare disease, since the princeps description in 1964 only reported in England (1986) and the U.S.A (1986), is most likely a singular type of mitochondrial encephalopathy: it is associated with Leber's optic atrophy, and the NMR changes observed have been signalled in other mitochondrial encephalomyelopathies, such as Leigh's disease and MELAS.

Adult↗
PubMed1991

Age at onset in Huntington's disease: effect of line of inheritance and patient's sex.

The Leiden Roster for Huntington's disease (HD) contained data on 2617 cases up to July 1988. The age at onset (AO) was known in 1084 cases and in 1020 of these both their AO and the sex of the affected parent was known. The mean AO was higher for females than for males and higher for maternal than for paternal cases. However, in the group born before 1925 only females with maternal inheritance had a higher mean AO. Data on influence of sex and line of inheritance were present for the grandparents as well as for the great grandparents. Influence of the line of inheritance from the grandparents was particularly present for the grandmother-father (MP) lineage; regarding the great grandparents a significant difference was found between the MPM and PMP lineage. The results obtained for juvenile HD cases were comparable to those previously published. In late onset cases (over 50 years) no maternal preponderance in inheritance was found.

Adult↗
PubMed1990

Autosomal dominant adult amyotrophic lateral sclerosis. A six generation Dutch family.

A pedigree is reported in which adult autosomal dominant ALS with complete penetrance manifested in 18 individuals through 6 generations. The clinical and neuropathological details are analysed of 13 and 5 persons, respectively, from the 2nd generation onward. Onset was between the ages 19 and 46; duration of disease averaged 1.7 years. The clinical symptoms were predominantly those of initial shoulder girdle and ultimate partial bulbar muscle involvement. Neuropathological findings included, next to classical features, degeneration of various spinal tracts (as revealed most clearly with the Häggqvist procedure) and Purkinje cells loss. As accurate clinicopathological screening and the use of more than just routine staining methods indicate, presently available MND/ALS classifications accommodate actual data insufficiently.

Adult↗
PubMed1990

The HAF enigma: origin and clinical consequences of the appearance of high alkaline fractions on isoelectric focusing patterns of cerebrospinal fluid.

High alkaline fractions (HAF) are irregularly present on isoelectric focusing (IEF) patterns of cerebrospinal fluid (CSF). Therefore, this phenomenon was studied retrospectively in more detail. First, the appearance of HAF in time was recorded and attempts were made to discover a relationship to the biochemical parameters of CSF. No such relationship could be established, nor could any effect of age or sex of the patients or any correlation with ambient temperature or clinical diagnosis be shown. Finally, we have shown conclusively that the cause of this random appearance of HAF can be found in the collodion bags used to concentrate the CSF. This irregular feature of the collodion bags also produces a rise in the frequency of appearance of oligoclonal bands on IEF, probably by blocking the passage of proteins. We conclude that the CSF contains protein material, and that the passage of this through the collodion filters during CSF concentration depends on the regularity of composition of the filters used, occasioning the presence (or absence) of a HAF. Of even greater consequence is the observation that when HAFs do not pass a certain collodion filter, other protein-like material can also be retained, leading to the appearance of oligoclonal bands in IEF, and causing more frequent occurrence of IEF patterns containing oligoclonal bands in CSF. Also, a slight change in the spectrum of oligoclonal bands of CSF has been found when HAFs occur. This indicates that the collodion bags do not retain all protein material in the same way.

Alkalies↗
PubMed1990

Senile plaques in Huntington's disease: a preliminary report.

The brains of 10 patients with Huntington's disease (HD) were studied for the presence of senile plaques (SP), neurofibrillary tangles, and granulovacuolar degeneration in the frontobasal, the parietal and occipital cortices and the anterior and posterior hippocampus. Five had died at a mean age of 42 years and 5 at one of 74 years. Senile plaques were found in 3 of 5 elderly HD patients and no were found in the young group. This finding supports the hypothesis that dementia in HD is not related to the presence of senile changes of the Alzheimer type.

Adult↗
PubMed1990

Methionine-enkephalin in migraine and tension headache. Differences between classic migraine, common migraine and tension headache, and changes during attacks.

We measured methionine-enkephalin (MET) in platelets and platelet-poor-plasma of drug-free patients with classic migraine, common migraine or tension headache (TH). Migraineurs were studied both between and during attacks. TH patients were characterized by low platelet-MET and high plasma-MET levels, whereas migraine patients showed high platelet-MET and reduced plasma-MET levels. During migraine attacks both platelet and plasma-MET concentrations increased considerably. We suggest that determination of MET levels in platelets and plasma may be a useful marker to discriminate between TH and common migraine. The rise in MET during attacks may be directed against the ictal increase of serotonin.

Biomarkers↗
PubMed1990

Neuroexcitatory plasma amino acids are elevated in migraine.

To investigate the role of glutamic (Glu) and aspartic acid (Asp) in migraine, we measured the plasma amino acids in migraine patients with and without aura, between and during attacks, and compared the profiles with the plasma amino acid profiles of tension headache patients and healthy controls. Between attacks, migraineurs (notably with aura) had substantially higher plasma Glu and Asp levels than did controls and tension headache patients. In addition, patients with migraine without aura showed low plasma histidine levels. During migraine attacks, Glu (and to a lesser extent Asp) levels were even further increased. The results suggest a defective cellular reuptake mechanism for Glu and Asp in migraineurs, and we hypothesize a similar defect at the neuronal/glial cell level, predisposing the brain of migraineurs to develop spreading depression.

Adult↗
PubMed1989

Intrathecal Ig synthesis. Its detection by isoelectric focusing and IgG index.

In a retrospective study on 999 patients, the likelihood ratios of the IgG index, Tourtellotte formula and IgG concentration in CSF and in serum, the albumin concentration in CSF and in serum, and the total protein in CSF, were compared in predicting intrathecal Ig synthesis. This synthesis was detected with isoelectric focusing (IEF). No patient was included more than once in the data collection. All patients with high IgG and other abnormalities in serum, as well as all xanthochromic and blood-tinged CSF specimens, were excluded from the study. Construction of ROC curves established that the IgG index, Tourtellotte formula and CSF IgG yield the same information: these parameters indicate the presence of intrathecal IgG synthesis. The likelihood ratio for the IgG index at a cut-off point of 0.80 for a positive test is 20; at a cut-off point of 0.5 for a negative test it is 5. For the Tourtellotte formula, it was found that the likelihood ratio reached a maximal value of 7 at a cut-off value of synthesis of 10 mg/day for a positive test. For a negative result, the formula had a likelihood ratio of 6 at a cut-off value of -5. For CSF IgG, it was found that the likelihood ratio was 4 for a positive test with a cut-off value of 0.1 g/l. For a negative outcome, the determination of CSF IgG is only meaningful at a very low cut-off value (0.03 g/l). The other parameters studied (serum IgG concentration, albumin concentration in CSF and in serum, and total protein in CSF) showed a likelihood ratio equal to 1. It is concluded that only the IgG index, the Tourtellotte formula and the CSF IgG concentration have predictive value for intrathecal Ig synthesis as recorded with IEF.

Female↗
PubMed1989

Serotonin metabolism in migraine.

To investigate systemic serotonin (5-HT) metabolism in migraine, we determined platelet and platelet-free plasma concentrations of 5-HT, its precursors tryptophan and 5-hydroxytryptophan, and its main metabolite 5-hydroxyindoleacetic acid (5-HIAA), as well as the activities of the platelet enzymes monoamine oxidase and phenolsulfotransferase in classic and common migraineurs. Between attacks, migraineurs had lower plasma 5-HT and higher 5-HIAA levels than did healthy controls and patients with tension headache. During migraine attacks, plasma 5-HT levels were substantially higher than during attack-free periods, while 5-HIAA concentrations and platelet enzyme activities were lower. Platelet 5-HT was reduced only during common, but not classic, migraine attacks. We hypothesize that systemic 5-HT metabolism is enhanced in migraineurs during headache-free periods and transiently decreases during attacks, presumably due to a fall in enzymatic degradation. Furthermore, platelet behavior differs during migraine attacks with and without aura, and release of platelet 5-HT cannot (exclusively) be held accountable for the rise of plasma 5-HT during migraine attacks.

5-Hydroxytryptophan↗
PubMed1986

Juvenile Huntington disease.

Of 195 cases of juvenile Huntington disease gathered from case descriptions, the sex, age at onset, duration of disease, clinical type, sex of the affected parent, as well as sex, mean age at onset and at death of adult cases in the same pedigrees were noted when available, and the data were investigated for evidence of relationships between different features. Examination of a subset of 112 cases showed a preponderance of rigid cases, whose affected parent proved to be the father in a significantly high number of cases. Rigid paternal cases had a significantly lower age at onset, as well as a shorter duration of disease than choreatic paternal cases. No such relationship exists between rigid maternal and choreatic maternal cases. In rigid cases duration of disease proved to be shorter for those with a lower age at onset. Female juvenile cases tended to have a lower age at onset than male ones, regardless of clinical type or sex of the affected parent. The mean ages at onset and at death of adult members of the same pedigrees were not related to clinical type or age at onset of juvenile cases. It is argued that juvenile Huntington disease should not be regarded as a separate clinical entity, but as a manifestation of the rigid variant of the disease.

Adolescent↗
PubMed1978

Biparietal osteodystrophy.

Following an exhaustive literature review of 126 cases, a personal series of 8 instances is presented. The following inferences are drawn: 1) the condition is not an anatomical variant, but a pathological lesion. 2) the lesion occurs in all races, and at all latitudes; its prevalence can be estimated to range between 0.4 and 0.5%. 3) the lesion occurs predominantly in females (sex ratio male: female = 1 : 2.5) and after the age of 60. 4) histological evidence indicated erosion of the external table, compensated by remodeling of the diploe, with resultant loss of the diploe. 5) Neither senility nor senescence, nor chronic trauma, nor muscular traction, nor inflammation, can explain the lesion, its symmetry, its site or its age/sex predilection.

Adult↗
PubMed1976

Further observation on the possible relationship between migraine and serum ammonia levels.

Although patients diagnosed as having migraine, have been studied extensively, there is no definite proof of a primary biochemical abnormality which is of significance in the pathogenesis of migraine. Several authors have suggested that increased serum ammonia levels may play a decisive role in the pathogenesis of migraine. This possibility was first put forth by Russell, who studied a single family with ornithine carbamyl transferase deficiency and 8 juveniles with migraine, RUSSELL'S finding was supported by a preliminary study carried out by one of the authors in which hyperammo-naemia was found in 22 adults during migraine attacks. In order to etknd these earlier findings, serum ammonia levels were determined in 35 adults with either classic or complicated migraine and in 20 healthy adults. No significant difference was found between the patients (44 microgram/100 ml +/- 13.9) and the controls (74 microgram/100 ml +/- 9.5). Ammonia level was determined in 10 patients within two hours of the onset of an acute migraine and was unchanged (65 microgram/100 ml). This study suggests that alterations in serum ammonia level are not important in the pathogenesis of migraine in adults.

Adult↗