PubMed Health⌕ Search

Biomedical subjects

P Bruhn

Publications and source records attributed to P Bruhn.

At least 19 recordsLinked to original sources
PubMed1990

Focal cerebral dysfunction in developmental learning disabilities.

In 24 children with developmental learning disabilities and 15 age-matched controls regional cerebral activity was studied with xenon-133 single photon emission tomography. In the 9 children with pure attention deficit and hyperactivity disorder (ADHD), the distribution of regional cerebral activity was abnormal--low in striatal and posterior periventricular regions and high in occipital regions. Low activity in striatal and posterior periventricular areas was also seen in the 8 children with ADHD in combination with phonologic-syntactic dysphasia. 7 children with dysphasia, but without hyperactive behaviour, had low cerebral activity in left temporofrontal regions.

Adolescent↗
PubMed1990

Aniracetam tested in chronic psychosyndrome after long-term exposure to organic solvents. A randomized, double-blind, placebo-controlled cross-over study with neuropsychological tests.

In order to examine if the nootropic drug, aniracetam, was capable of improving cognitive performance, 44 subjects suffering from chronic psychosyndrome after long-term exposure to organic solvents were included in a randomized, double-blind, placebo-controlled, cross-over study. The treatment periods were 3 months with aniracetam 1 g daily and 3 months with placebo. Neuropsychological tests as well as a physical and neurological examination were performed at entry into the study and after each treatment period, together with an evaluation of the subjects' overall condition. Neither the doctors' nor the subjects' own assessment of the overall condition indicated that the trial medication had had any effect. No significant changes in neuropsychological symptoms were observed. A statistically significant difference in favour of antiracetam was found in only 1 of the 19 neuropsychological test measures, namely a test for constructional ability. However, in another test on visuo-spatial function, a statistically significant result was found in favour of placebo. Thus, aniracetam was found to be ineffective in the treatment of subjects suffering from chronic psychosyndrome after long-term exposure to organic solvents.

Adult↗
PubMed1989

Striatal dysfunction in attention deficit and hyperkinetic disorder.

We have previously reported that periventricular structures are hypoperfused in attention deficit and hyperactivity disorder (ADHD). This study has expanded the number of patients, who were divided into two groups: six patients with pure ADHD, and 13 patients with ADHD in combination with other neurologic symptoms. By using xenon 133 inhalation and emission tomography, the regional cerebral blood flow distribution was determined and compared with a control group. Striatal regions were found to be hypoperfused and, by inference, hypofunctional in both groups. This hypoperfusion was statistically significant in the right striatum in ADHD, and in both striatal regions in ADHD with other neuropsychologic and neurologic symptoms. The primary sensory and sensorimotor cortical regions were highly perfused. Methylphenidate increased flow to striatal and posterior periventricular regions, and tended to decrease flow to primary sensory regions. Low striatal activity, partially reversible with methylphenidate, appears to be a cardinal feature in ADHD.

Attention Deficit Disorder with Hyperactivity↗
PubMed1989

Cerebral ventricular enlargement relates to neuropsychological measures in unselected AIDS patients.

In a cross-sectional study of unselected Danish AIDS patients various linear measures of cerebral ventricular size obtained by computed tomography were compared with results of neuropsychological test performances. Third ventricular width as well as right and left septum-caudate distances were enlarged in the patients (P less than 0.01). Of 20 patients 15 had at least one abnormal ventricular measurement. Although only one patient was demented, ventricular size correlated inversely with neuropsychological function (r = -0.61, P less than 0.02). The correlation between ventricular size and variation of the reaction time was even closer (r = 0.74, P less than 0.01). It is concluded that neuroradiological signs of central atrophy often occur in AIDS patients.

Acquired Immunodeficiency Syndrome↗
PubMed1988

"Chronic painter's syndrome". A reanalysis of psychological test data in a group of diagnosed cases, based on comparisons with matched controls.

Twenty solvent-exposed workers, most of them painters, had been diagnosed as cases of toxic encephalopathy in 1978/79. Two years later they were re-examined with an extensive battery of neuropsychological tests. Their performance was unchanged on retesting. We have now compared their test results with those of non-exposed control subjects. Previous impressions of significant intellectual impairment in the solvent-exposed patients could not be confirmed when the influence of age, education, and intelligence was taken into consideration. The present group with presumed toxic encephalopathy is assumed to be representative of other patients who were similarly diagnosed in our department. The presently reanalyzed cases had been diagnosed as brain damaged and reported as such in the literature. Thus, they may have contributed to the formation of the concept of the "chronic painters' syndrome" with dementia.

Adult↗
PubMed1987

AIDS and dementia: a quantitative neuropsychological study of unselected Danish patients.

Retrospective studies of hospitalized patients with the acquired immune deficiency syndrome (AIDS) have indicated that dementia occur in the majority of cases. In order to study the occurrence of dementia among AIDS patients, we conducted a controlled study of 16 unselected cases with a battery of neuropsychological tests known to be sensitive to brain damage of various etiologies. Except for fatigue, mental complaints and neuropsychiatric signs of dementia were generally sparse. As a group, the AIDS patients' performance in the neuropsychological tests did not differ from that of matched, healthy controls. Based on analyses of individual test results only one patient performed significantly inferior to what should be expected. The diagnosis of dementia should not be ascribed to AIDS victims on account of non-specific psycho-behavioral deviations that may represent a normal psychologic reaction to the disease, extreme fatigue, or both. Further, frequency measures of dementia in AIDS, based on large, unselected groups and with sufficient control, are still lacking. However, our study indicates that dementia is a less frequent complication of AIDS than so far assumed.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Increased vigilance and dopamine synthesis by large doses of tyrosine or phenylalanine restriction in phenylketonuria.

In a group of 9 patients with classical phenylketonuria (PKU) aged 15-24 years we examined the effect of phenylalanine restricted diet on vigilance, as judged by the continuous visual reaction times, and neurotransmitter synthesis, as judged by cerebrospinal fluid (CSF) homovanillic acid (HVA) and 5-hydroxyindole acetic acid (5-HIAA) levels. HVA and 5-HIAA levels decreased significantly with increase in plasma phenylalanine concentration on free diet (p less than 0.01 and p less than 0.0005 respectively). Vigilance improved on phenylalanine restricted diet in 6 of the 7 patients with abnormally long reaction times on free diet. Addition of tyrosine (160 mg/kg/24 h) to the free diet resulted in an increased CSF in the six patients examined. In 14 patients on free diet supplemented with tyrosine, an improvement in vigilance (reaction times at the 90 percentile) was seen in all 12 patients with values longer than the normal mean (264 msec) (p less than 0.001). Tyrosine treatment may be a therapeutical alternative when phenylalanine restriction is impractical.

Adolescent↗
PubMed1986

Prognosis of dementia in normal-pressure hydrocephalus after a shunt operation.

Forty patients who had normal-pressure hydrocephalus were examined neuropsychologically before and 12 months after a ventriculoatrial shunt operation. Comparison of the preoperative and postoperative test results showed that cognitive functions improved in 16 patients, were unchanged in 19, and deteriorated in 5. Moreover, we found that the outcome of the operation depended on patient selection criteria. When three or more of the following preoperative signs were present (known cause, short history, low cerebrospinal fluid outflow, small sulci and/or periventricular hypodensity indicated by computed tomography), an improvement in cognitive function was seen in 80% of the patients after a shunt operation.

Adult↗
PubMed1986

Cortical hypoperfusion as a possible cause of 'subcortical aphasia'.

This study was designed to investigate whether aphasia in stroke patients with subcortical lesions ('subcortical aphasia') was due to the subcortical lesion itself or to dysfunction of cortical language zones. A consecutive series of 25 right-handed stroke patients with left hemisphere lesions verified by CT scanning were examined for aphasia in the acute stage, and two weeks, three months and six months after the insult. Cerebral angiography, CT scan and regional cerebral blood flow (rCBF) measurements with the 133Xe intracarotid method were performed in the acute stage. The CT scan was repeated six months later. Seven patients had lesions which involved cortical structures. All of these were severely aphasic in the acute stage and six months later. The rCBF studies showed severe reduction of flow in the infarcts; the perfusion was incompatible with tissue viability. Eighteen patients had subcortical lesions. Eight of these were midly to severely aphasic in the acute state. Recovery was always excellent. Five patients recovered completely, while 3 showed only discrete (clinically undetectable) aphasia after six months. The rCBF demonstrated low-flow areas in the cortex overlying the deep lesions, with a blood flow which was sufficient for tissue viability, but insufficient for normal tissue function (an 'ischaemic penumbra'). The blood flow was pressure dependent (showing impaired autoregulation) in these low flow areas. Ten patients with subcortical lesions were not aphasic. Their CBF was normal. The subcortical lesions were permanent on CT scan while aphasia was transient in these patients as recovery was seen within three months. It was therefore unlikely that the subcortical lesions as such were the cause of aphasia. The present findings indicate that aphasia in patients with subcortical lesions may be due to hypoperfusion and functional loss in cortical language zones. The cortical low-flow areas were invariably confined to occluded vascular territories. These territories were kept viable by collateral circulation characterized by penumbral flow and impaired autoregulation. The patients showed excellent recovery from aphasia. We suggest that the recovery of language is caused by spontaneous arterial recanalization or expansion of collaterals, giving rise to enhancement of flow in the hypoperfused cortical penumbra.

Adult↗
PubMed1985

Decreased vigilance and neurotransmitter synthesis after discontinuation of dietary treatment for phenylketonuria in adolescents.

Four adolescent or young adult patients with phenylketonuria were examined before and after discontinuation of dietary treatment. Plasma and CSF phenylalanine concentrations increased about two-fold in three patients. In these patients the CSF concentration of the dopamine and serotonin metabolites homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) decreased markedly; 5-HIAA to extremely low values. The reaction time variability increased in these patients. In the fourth case plasma phenylalanine levels, CSF HVA and 5-HIAA levels, and reaction time variability were essentially unchanged. The relationship between reaction time variability and the CSF 5-HIAA level for all four patients could be presented as a linear function. However, a causal relationship is still unproven. These preliminary findings demonstrate that there may be hazards in the discontinuation of dietary treatment, even in adolescents or young adults, for neurotransmitter metabolism and mental function.

Adolescent↗
PubMed1979

Controlled trial of EMG feedback in muscle contraction headache.

Twenty-eight patients suffering from severe, longstanding muscle contraction headache were randomly assigned to two groups, one receiving electromyographic (EMG) feedback therapy and the other, "most suitable alternative therapy." Headache intensity and severity as well as drug intake were reduced in the feedback group (p less than or equal to 0.01) as opposed to no improvement in the control group. The positive treatment effect in the feedback group persisted through a three-month follow-up period. EMG feedback therapy is effective in the treatment of muscle contraction headache even in its chronic, severe form, which is resistant to traditional treatment methods.

Adult↗
PubMed1979

Chronic painters' syndrome. Chronic toxic encephalopathy in house painters.

Seventy house painters were examined after being referred because organic solvent intoxication of dementia was suspected. In 50 cases no competitive etiological factors to the cerebral symptoms other than exposure to organic solvents could be disclosed. In these, neuropsychological examination showed signs of intellectual impairment in 39 patients and neuroradiological examination by PEG or CT demonstrated the presence of cerebral atrophy in 31 patients; 38 patients studied with CT were compaired to an age-matched control group regarding maximum sulcus width, and a highly significant difference was found. It is argued that long-term exposure to turpentine substitute-often through a period with acute intoxication symptoms--gradually may lead to the development of a chronic brain syndrome, which we have called the "chronic painters' syndrome".

Adult↗
PubMed1977

Reaction time variability in epileptic and brain-damaged patients.

Median reaction times and intra-individual variability were studied in epileptic (N = 63), brain-damaged (non-epileptic) (N = 25) and control patients (N = 25) using a six and one half minute visual, continuous reaction time task. Epileptic and brain-damaged groups were significantly slower than control patients on median reaction times at the 10th, 50th, and 90th percentiles and on the differences between the 10th and 90th percentiles. Thus both general slowing and greater intra-individual variability were found in the epileptic and brain-damaged patients. Reaction times were not related to presence, type and severity of EEG abnormality or to age of onset of epilepsy. Grand mal patients did have significantly greater variability than other types of seizure patients. Epileptic and brain-damaged patients did not differ significantly on any reaction time variables. Both groups were discriminated significantly from the controls on all reaction time measures, especially on the intra-individual variability measure.

Adolescent↗
PubMed1977

Aphasia and epilepsy in childhood.

The syndrome of progressive aphasia and epilepsy in childhood is delineated. Four cases are presented, three of which show the typical gradual onset, fluctuating course and EEG changes with bilateral foci of spike and spike-wave activity, and, finally, normalization after some years of the EEG. Also the aphasia tends to subside, but often with considerable delay in relation to the other features. Neuropsychological assessment showed varying residual defects mainly on language functions. The aetiology is unknown. No pathoanatomical data on this disorder has hitherto been published. In one of the present cases a cortical biopsy was performed on suspicion of a left temporal tumour. The biopsy showed changes indicative of a slow virus infection. It is therefore suggested that the newly established language function in children particularly is vulnerable to a subchronic viral encephalitis affecting both hemispheres.

Adolescent↗
PubMed1976

[The effect of caffeine on the resorption and various central effects of ethanol].

Caffeine given in a dose of 400 mg one hour before 1 g/kg ethanol did not influence the course of blood alcohol levels in male volunteers. Furthermore, caffeine did not improve psychomotoric skills impaired by ethanol. Two cups of coffee ingested 30 min. after ethanol (0.5 g/kg) caused a statistically significant increase of blood ethanol levels one hour afterwards (from 0.49 to 0.61%). This may be due to an accelerated absorption of ethanol caused by the ingestion of warm fluid.

Animals↗
PubMed1975

Intellectual and neuropsychological functions in young men with heavy and long-term patterns of drug abuse.

The authors attempted to determine the long-term effects of heavy drug abuse in 87 male prisoners. The sample was divided into the following groups: 1) nondrug users; 2) users of cannabis and hallucinogens; 3) users of cannabis, hallucinogens, and amphetamines; and 4) users of cannabis, hallucinogens, amphetamines, and opiates. Intellectual and neuropsychological tests sensitive to brain dysfunction revealed no intergroup differences. This finding casts some doubt on other reports suggesting that long-term drug abuse results in neuropsychological disorders. However, the authors caution that one should not conclude that no organic changes occurred in their sample.

Adolescent↗