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Biomedical subjects

G Schroth

Publications and source records attributed to G Schroth.

At least 145 records · Page 8Linked to original sources
PubMed1992

Cerebrospinal fluid flow. I. Physiology of cardiac-related pulsation.

Cardiac-related motion of the cerebrospinal fluid (CSF) was investigated by analysis of the velocity-dependent phase of CSF protons and flow-dependent signal enhancement in magnitude images using ECG-gated FLASH sequences. In the cerebral aqueduct, CSF flow from the third to the fourth ventricle begins 200 ms after the R-wave of the ECG and simulates an arterial pulse wave pattern. It lasts about 60% of the cardiac cycle and is followed by backflow from the fourth to the third ventricle, which is slower and shorter. In the spinal canal, oscillating caudad motion precedes flow from the third to the fourth ventricle by about 50-100 ms and is superimposed on a bulk flow, which moves simultaneously in opposite directions in separate subarachnoid channels; it is directed mainly caudally in the anterior cervical subarachnoid space.

Adolescent↗
PubMed1992

Cerebrospinal fluid flow. II. Physiology of respiration-related pulsations.

Cerebrospinal fluid (CSF) flow in the cerebral aqueduct and spinal canal was analysed using real-time magnetic resonance imaging measurement techniques. Respiration-induced rhythmic modulation of the cardiac-related oscillating CSF pulsation in the cerebral aqueduct and spinal canal was found. Deep inspiration was immediately followed by a marked increase in downward CSF flow in the cervical spinal canal, whereas a delay of about two heart beats was seen before downward flow from the third to the fourth ventricle increased. This pattern was also detected during yawning and was followed by a marked increase of blood flow in the internal jugular vein.

Cerebral Aqueduct↗
PubMed1992

Cerebrospinal fluid flow. III. Pathological cerebrospinal fluid pulsations.

Cardiac- and respiration-related movements of the cerebrospinal fluid (CSF) were investigated by MRI in 71 patients. In most patients with arteriosclerotic occlusive vascular disease CSF pulsations are normal. Decreased pulsatile flow is detectable in those with arteriovenous malformations, intracranial air and following lumbar puncture and withdrawal of CSF. Increased pulsatile flow in the cerebral aqueduct was found in 2 patients with large aneurysms, idiopathic communicating syringomyelia and in most cases of normal pressure hydrocephalus (NPH). CSF flow in the cervical spinal canal is, however, reduced or normal in NPH, indicating reduction of the unfolding ability of the surface of the brain and/or inhibition of rapid CSF movements in the subarachnoid space over its convexity.

Adult↗
PubMed1992

Do women develop alcoholic brain damage more readily than men?

Chronic alcoholism is related to brain damage (i.e., volume changes) in both men and women. There is an open question whether the brains of women are more vulnerable than those of men to alcohol toxicity. The present follow-up study focuses on a direct comparison of sex-related differences in alcoholic brain shrinkage and its reversibility. In a prospective design, a random sample of 65 alcoholics of both sexes (51 males and 14 females) was studied. Computerized tomography brain scans before and after a 6-week inpatient treatment program with controlled abstinence revealed a significant re-expansion of the brain as assessed by linear measurements. By controlling for moderating variables such as age, mean daily alcohol consumption, liver dysfunction, etc. the degree of brain shrinkage was found to be similar in men and women despite significantly shorter ethanol expositions in the women. These findings corroborate the hypotheses of other investigators about basic biological differences between the two sexes as to the effects of alcohol. The hypothesis of an enhanced vulnerability of women to acute and chronic complications of alcoholism is supported.

Adult↗
PubMed1991

[Thiamine deficiency and brain atrophy in alcoholic patients].

CT brain scans of 65 alcohol-dependent inpatients were compared before and after 6 weeks of confirmed abstinence. Linear measurements revealed a significant reduction of the enlargement of the ventricular system in accordance with the re-expansion of the brain after alcohol abstinence (ANOVA, significant time effects). 22 patients showed a moderate or severe thiamine deficiency. CT findings on thiamine-deficient patients did not differ from those on patients without thiamine deficiency (ANOVA, no significant group effects). Correlations between thiamine deficiency and subcortical atrophy before treatment were not significant. The results are discussed in relation to the pathogenesis of reversible brain shrinkage in chronic alcoholics.

Adult↗
PubMed1990

Impairment of vertical motion detection and downgaze palsy due to rostral midbrain infarction.

We present two cases with acute onset of vertical gaze palsy, mainly consisting of impaired downgaze and apraxia of downward head movements, together with neuropsychological deficits (hypersomnia, impaired attention and disorders of memory and affective control). CT and MRI revealed bilateral post-ischaemic lesions in the dorsomedial thalamus and the mesodiencephalic junction, dorsomedial to the red nucleus, thus being restricted to the territory of the posterior thalamosubthalamic paramedian artery, which includes the region of the rostral interstitial nucleus of the medial longitudinal fascicle as the main premotor nucleus for the generation of vertical saccades. In our patients, oculographic examination with electro-oculography and magnetic search coil recording showed severe impairment of downward more than upward saccades and only minor deficits of vertical pursuit and the vestibulo-ocular reflex. Visual functions were normal, with one exception: a psychophysical test of motion perception revealed a significant deficit in the detection of vertical movements. This could be due to a central adaptive mechanism which, in order to minimize oscillopsia, might elevate thresholds for vertical motion perception in cases of vertical gaze palsy. As an alternative explanation, lesions within the midbrain tegmentum could have damaged subcortical visual pathways involved in motion perception.

Cerebral Infarction↗
PubMed1990

Central spinal cord lesions in stenosis of the cervical canal.

34 patients suffering from cervical spondylotic myelopathy confirmed by myelography were examined by delayed CT 6-10 h after myelography. Twelve patients showed bilateral intramedullary collections of contrast medium, predominantly cranial to the stenosis. In these patients males predominated, the duration of clinical symptoms lasted longer although their age was lower. There was no correlation to the degree and the extension of the narrowing of the cervical spinal canal. Half of 20 patients undergoing consecutive decompressive surgery showed intramedullary contrast enhancement, and this was shown again by postoperative MRI in eight. The postoperative clinical and neurophysiological results revealed no change in the majority of patients, but three patients showing intramedullary contrast medium deteriorated in neurophysiological outcome, while only one of the patients in whom intramedullary contrast medium was not noticed got worse.

Adult↗
PubMed1990

MRI findings in medial temporal lobe structures in schizophrenia.

In an MRI volumetric study of 10 young male schizophrenics (DSM-III-R 295.9x) a temporal lobe segment, corresponding hippocampal formation and parahippocampal gyrus were found smaller as compared with healthy controls while temporal horn was enlarged. Temporal lobe segment and parahippocampal gyrus were larger on the right in patients and controls, reversed asymmetry was found for the hippocampus.

Adult↗
PubMed1990

Idiopathic cerebellar ataxia of late onset: natural history and MRI morphology.

Twenty eight patients with the clinical diagnosis of idiopathic late onset cerebellar ataxia were examined clinically and by magnetic resonance imaging (MRI) or computed tomography (CT). In addition, the clinical records of all patients were analysed retrospectively. On the basis of their clinical presentation they were subdivided into patients with a pure cerebellar syndrome (n = 9) and patients with a cerebellar syndrome and additional non-cerebellar symptoms (n = 13). No attempts were made to classify patients with a disease duration of less than four years (n = 6) because the retrospective analysis showed that the disease started almost invariably with a pure cerebellar syndrome and additional symptoms came later. Patients with a lasting pure cerebellar syndrome had a significantly better prognosis than patients with additional non-cerebellar involvement (annual progression rate rate: 0.40 versus 0.80). Calculated median lifetime from onset of symptoms was 20.7 years in patients with a pure cerebellar syndrome and 7.7 years in patients with additional non-cerebellar symptoms. Among the latter, disease progression was faster the earlier non-cerebellar symptoms occurred. All of them presented with Parkinsonian symptoms, whereas bulbar symptoms, vertical gaze paresis, pyramidal deficits, dementia and urinary incontinence were encountered less frequently. MRI or CT showed cerebellar atrophy without apparent involvement of brainstem structures in all patients with a pure cerebellar syndrome suggesting the diagnosis of cerebellar cortical atrophy (CA). The majority of the patients with additional non-cerebellar symptoms had evidence of an atrophy of the cerebellum and the brainstem suggesting the presence of olivo-ponto-cerebellar atrophy (OPCA). In two of them, however, MRI morphology was not compatible with the diagnosis of OPCA.

Adult↗
PubMed1989

Significance of MRI-confirmed atrophy of the cranial spinal cord in Friedreich's ataxia.

The severity of Friedreich's ataxia was graded in ten patients by clinical examination and in five by use of posturography. These data were compared with neuroradiology findings. CT-confirmed infratentorial atrophy occured only in advanced cases of Friedreich's ataxia; the correlation with the clinical score was poor. On mid-sagittal MRI planes the diameters of fourth ventricle, brain stem at the level of the inferior olive and spinal cord at the levels of the foramen magnum and C3 were measured. Patients with Friedreich's ataxia had significant MRI-confirmed atrophy of the cranial spinal cord as compared with a normal, age-matched control group. This was also observed in patients with Friedreich's ataxia in the early stages. A reliable correlation between atrophy of the cranial spinal cord and the clinical score, however, could again not be found. MRI exploration of the cranial spinal cord may be recommended as an additional diagnostic marker in Friedreich's ataxia.

Adult↗
PubMed1989

Intramedullary cavernous angiomas.

Two cases of histologically verified intramedullary cavernous angiomas at C3 and D5-6 are presented. Both patients suffered progressive myelopathy with intermittent improvement. In both cases preoperative diagnosis was possible by means of magnetic resonance imaging using spin echo techniques, fast imaging, and phase display, while spinal angiography was not helpful. Laminectomy and total removal of the tumors were performed with temporary increased neurological deficits. It is thought that magnetic resonance imaging provides a useful diagnostic tool in these tumors and is also essential for planning surgical strategy.

Adult↗
PubMed1989

The Rett syndrome: magnetic resonance imaging and clinical findings in four girls.

The clinical and laboratory findings in 4 girls with the Rett syndrome are presented. The MRI results at different disease stages with detailed descriptions of the techniques applied-including quantification of T1 and T2 relaxation times in the brain-are reported. There were no pathological signal intensities in T1- or T2-weighted images. Thus, MRI does not provide any significant additional help in the diagnosis of the Rett syndrome. However, it does indicate that disturbances of myelinization or the brain water content are not probable etiologies in this syndrome.

Adolescent↗
PubMed1989

[Comparison of angiography and continuous-wave Doppler sonography in the diagnosis of subclavian stenoses and of the subclavian steal syndrome].

Angiographic control of ultrasonographic findings (continuous-wave (CW) Doppler sonography) at the subclavian artery was performed in 149 patients, altogether 254 subclavian arteries, 89 with and 165 without stenosis or occlusion at Doppler examination. Additionally, in 70 of these persons the vertebral haemodynamic situation was investigated by means of angiography. CW Doppler sonography proved a highly reliable method for the diagnosis of subclavian lesions and subclavian steal syndrome. If properly performed, CW Doppler sonography does not fail to reveal stenoses amounting to more than 50%, occlusions, and retrograde vertebral blood flow. Regarding tight stenosis or occlusion of the subclavian artery and retrograde blood flow in the vertebral artery, Doppler sonography yielded no false positive findings, but false positive results may be possible in mild stenoses.

Adolescent↗