PubMed Health⌕ Search

Biomedical subjects

M Mull

Publications and source records attributed to M Mull.

50 records · Page 3Linked to original sources
PubMed1997

Cerebral hemispheric low-flow infarcts in arterial occlusive disease. Lesion patterns and angiomorphological conditions.

BACKGROUND AND PURPOSE: Among the pathogenetic causes of subcortical hemispheric infarcts are small-vessel disease, thromboembolic occlusions of small arteries, and hemodynamic compromise in low-flow conditions. A topographic classification of these infarcts based on CT and MRI can be misleading. METHODS: We evaluated 30 consecutive patients with presumed supratentorial low-flow infarcts. CT was available in all cases, with additional MRI in 14 patients. In all cases the occlusion pattern of the extracranial and intracranial arterial system was studied in detail with angiography. RESULTS: The dominant lesion patterns seen on CT and MRI were multilocal chainlike lesions in 19 and confluent striated lesions in 8 cases located in the supraventricular and paraventricular deep white matter. In 8 patients subcortical lesions extended into the adjacent cortex. Angiography revealed that extracranial occlusive disease (n = 24) or stenosis of the middle cerebral artery (n = 6) was always accompanied by impairment of the circle of Willis, in either the anterior part (n = 25) and/or the posterior part (n = 16). Moreover, leptomeningeal pathways indicative of vascular hemispheric compromise were identified in 26 cases. In total, 29 of 30 patients displayed a noncompetent circle of Willis. CONCLUSIONS: Low-flow infarcts show typical but not pathognomonic lesion patterns on CT and MRI. Definite diagnosis requires knowledge of the complex vascular compromise of the extracranial and/or intracranial arterial system. A noncompetent circle of Willis should be regarded as the additional predisposing condition in hemispheric low-flow infarcts.

Arterial Occlusive Diseases↗
PubMed1997

Prevalence and time course of microembolic signals in patients with acute stroke. A prospective study.

BACKGROUND AND PURPOSE: Cerebral emboli can be identified by the presence of typical microembolic signals (MES) in transcranial Doppler (TCD) spectral curves. The usefulness of this technique was studied by evaluating the prevalence and time course of MES in patients with acute stroke. In addition, we examined the influence of anticoagulation therapy on the occurrence of MES. Another study objective was to identify the value of MES in elucidation of the underlying pathology of cerebral ischemia in patients with acute stroke. METHODS: We used bilateral TCD monitoring of the middle cerebral artery to search for microemboli in 100 patients with acute nonhemorrhagic stroke in the anterior circulation. Monitoring time was for 30 minutes at admission (examination I), after 24 hours (examination II), and again after 48 hours (examination III). RESULTS: Twenty-two of the 100 patients had to be excluded from the study after examination 1 because retrospectively they did not fulfill the inclusion criterion or because they had an insufficient bone window. Forty of the patients (51%) showed MES during at least one of the three TCD examinations. In 9 of the 47 patients without MES during examination I (19%), MES could be recorded subsequently during examinations II and III. A statistically significant decrease in the prevalence of MES occurred between examinations I and III (P = .01). The frequency of MES in a single patient decreased between examinations I and II but increased again in examination III, although it did not reach the initial level. Prevalence of MES was the highest during the period up to 6 hours after the onset of symptoms. However, even at > 72 hours after the onset of symptoms, a substantial number of MES could be recorded. In 18 of the 21 patients with carotid artery stenosis or occlusion who showed MES (86%), these signals occurred ipsilateral to the affected carotid artery. In 5 of the 13 patients with MES and a potential cardiac source of embolism (38%), MES were observed bilaterally. Forty-one patients were without anticoagulation treatment at the time of examination: 19 of these patients (46%) presented with MES. In contrast, of the 37 patients receiving anticoagulation treatment at the time of the first examination, MES could be recorded in only 12 (32%). CONCLUSIONS: Microemboli are a frequent phenomenon in patients with acute stroke arising from a variety of causes, both in the very early stages and several days after the onset of symptoms. The prevalence of MES decreases significantly over time. MES occur more frequently in patients with carotid artery disease than in patients with a potential cardiac source of embolism. Ipsilateral MES are frequent in patients with carotid artery disease, whereas bilateral MES are suggestive of a cardioembolic origin. Anticoagulation treatment appears to decrease the prevalence of MES, but microemboli still occur in patients receiving intravenous therapy with heparin. Because MES occur intermittently, TCD examinations should be repeated several times, even in patients without MES in the first examination, and long-term monitoring equipment is necessary.

Acute Disease↗
PubMed1997

Fasting improves discrimination of grade 1 and atypical or malignant meningioma in FDG-PET.

UNLABELLED: We investigated the use of PET with 2[18F]fluoro-2-deoxy-D-glucose (FDG) to discriminate between atypical or malignant and grade 1 meningiomas. The influence of fasting state and high-dose corticosteroid medication was analyzed retrospectively. METHODS: Preoperative PET scans of 75 patients with suspected diagnosis of intracranial meningioma were evaluated using standardized uptake values (SUV) and tumor-to-contralateral gray matter ratios (TGR) of FDG uptake. Fifty-one of 75 patients fasted before the PET scan, and 27 of 75 patients were studied under high-dose corticosteroid medication. Eighteen tumors had recurred. PET results were compared to histopathological grading. RESULTS: PET correctly identified 8/9 atypical or malignant meningiomas and 58/66 grade 1 meningiomas using TGR and a threshold of 1.05 in primary meningioma and 0.85 in tumor recurrence. This corresponds to a specificity of 0.88 for the detection of higher tumor grading. Specificity was significantly higher in fasting compared to nonfasting subjects (0.96 versus 0.73; p < 0.025). SUV quantification lead to a reduced specificity of 0.77 at the same level of sensitivity. The only false-negative PET finding occurred in a recurrent meningioma, which had been operated on four times before. CONCLUSION: Overnight fasting before injection is needed to improve the diagnostic accuracy of FDG-PET for noninvasive metabolic grading of meningioma. Hyperglycemia in nonfasting patients and in diabetic patients may lead to overestimation of meningioma grading.

Adolescent↗
PubMed1996

[Sensory Jacksonian seizures as initial manifestation of sarcoidosis].

A 46-year old patient is reported presenting with somatosensory focal seizures of either arm as the only manifestation of an otherwise clinically inapparent sarcoidosis. MRI showed signs of a granulomatous leptomeningeal affection. Histological examination of a meningeal biopsy proved the diagnosis of sarcoidosis by demonstrating noncaseating granulomas. There was no other clinical manifestation of sarcoidosis. Chest X-ray was normal and the serum level of angiotensin-converting-enzyme was only slightly elevated. The CD4/CD8 ratio in the bronchoalveolar lavage cell population, however, was clearly abnormal, supporting the role of this diagnostic tool in the diagnosis of sarcoidosis.

Biopsy↗
PubMed1995

Subarachnoid and intraventricular hemorrhage caused by hypernephroma metastasis, accompanied by innocent bilateral posterior communicating artery aneurysms.

We present a case of subarachnoid and intraventricular hemorrhage due to an infratentorial metastasis of a renal cell carcinoma. The lesion was not apparent on initial magnetic resonance imaging (MRI) or in a follow-up examination (MRI and angiography) 6 weeks after the bleeding. The innocent bilateral posterior communicating artery aneurysms detected by cerebral angiography were treated surgically. The origin of the hemorrhage, however, remained unclear. Five months later, a surgically proven metastasis in the fourth ventricle subsequently gave the explanation for the bleeding.

Carcinoma, Renal Cell↗
PubMed1995

Volitional type of facial palsy associated with pontine ischaemia.

A dissociation between voluntary and emotional facial innervation is described in a patient with a pure motor stroke due to a unilateral ischaemic pontine infarction. Voluntary facial innervation of the contralateral orbicularis oris muscle was affected whereas emotionally induced innervation of the same muscle was spared. This report provides evidence that fibres conveying voluntary and emotional commands are still separated in the pons. Whereas corticobulbar tracts carry the information for voluntary facial innervation, efferents from the amygdala and the lateral hypothalamus are candidates for the somatomotor aspects of emotions.

Brain Ischemia↗
PubMed1995

Evidence for cardioembolic stroke in a case of Kearns-Sayre syndrome.

BACKGROUND: Cerebral infarction is a known complication in patients with mitochondrial encephalomyopathies (MELAS, MERRF, Kearns-Sayre syndrome), but the etiology in the different types remains uncertain. CASE DESCRIPTION: A 33-year-old woman who had suffered from ophthalmoplegia, bilateral ptosis, ataxia, retinitis pigmentosa, and epilepsy since childhood was diagnosed to have Kearns-Sayre syndrome. The diagnosis was confirmed by muscle biopsy when she was 17 years old. A pacemaker was implanted because of the occurrence of bradyarrhythmias when she was 24 years old. The patient was admitted to the hospital with left-sided hemiparesis of sudden onset due to right striatocapsular infarction. Results of Doppler sonography of the carotid arteries were normal; however, transesophageal echocardiography revealed a thrombus in the left atrial appendage. CONCLUSIONS: Stroke in Kearns-Sayre syndrome is likely to be due to cardiac embolism. Anticoagulant therapy should be considered even for mild forms of cardiomyopathies leading to left ventricular dysfunction.

Adolescent↗
PubMed1995

[Effect of morphological changes on perfusion and metabolism in cerebral microangiopathy. A comparison of PET, SPECT, and magnetic resonance imaging findings].

51 patients with cerebral microangiopathy were studied with MRI, 18FDG-PET, and 99mTc-HMPAO-SPECT. Exact morphological correlation of MRI-findings to functional data from PET and SPECT was obtained by a special head holder system applied to the patient's head. Patients with less than four lacunar infarctions (LI) and without or only slight deep white matter lesions (DWML) in MRI showed no significantly changed parameters (rMRGlu, rCBF) compared to patients with four or more LI and severe DWML. Patients with medium to severe outer and inner brain atrophy showed significantly lower rMRGlu and rCBF values in both cortex and white matter than patients with no to only slight atrophy. Thus, in patients with cerebral microangiopathy only atrophy and not the presence of LI and DWML is associated with a significant reduction of rCBF and rMRGlu.

Brain↗
PubMed1994

[18FDG-PET in intracranial meningiomas versus grading, proliferation index, cellular density and cytogenetic analysis].

62 intracranial meningiomas in 60 patients were studied with 18FDG-PET prior to neurosurgery in order to evaluate the relationship between 18FDG uptake and biological aggressiveness of the tumors. Histopathological grading, cellular density, Ki-67 proliferation index and evidence of chromosomal aberrations were used to assess tumor aggressiveness. Significantly elevated 18FDG uptake was found in grade 2- and 3- compared to grade 1-meningiomas, in tumors of high cellularity compared with those of low cellularity, and in meningiomas with an elevated Ki-67 proliferation index (above 2%). The two meningiomas with the most pronounced chromosomal aberrations revealed the highest 18FDG uptake of all cytogenetically studied meningiomas. We conclude that 18FDG-PET is useful for estimating the biological aggressiveness of intracranial meningiomas.

Adult↗
PubMed1990

Transcranial Doppler ultrasonography versus arteriography for assessment of the vertebrobasilar circulation.

The investigation of the vertebrobasilar arterial system by transcranial Doppler (TCD) ultrasonography is difficult due to the numerous anatomical variations in the posterior circulation. To test the validity of TCD, we compared topographic measurements from vertebrobasilar angiograms and corresponding TCD findings in 58 patients with cerebrovascular diseases (N = 37, 21 affecting the vertebrobasilar system), brain tumors (N = 8), and other neurological diseases (N = 13). Normal TCD recordings of the vertebrobasilar system were confirmed by the angiograms in 25 patients, although the noninvasive method failed to separate morphologic variants (N = 15). In patients with pathological conditions of the vertebrobasilar system revealed by either method (N = 17), the combined use of both hemodynamic and radiomorphologic methods improved the diagnostic validity in 24%. We conclude that TCD examination of the posterior fossa circulation provides unambiguous results only if used in combination with cerebral arteriography.

Adult↗
PubMed1989

Good recovery after sublethal ethylene glycol intoxication: serial EEG and CT findings.

The case of a young man with sublethal ethylene glycol poisoning is reported. Complete recovery occurred after 12 days of deep coma and a prolonged flaccid tetraplegia. The lesions of gross degree in the CNS, demonstrated by serial CT, resolved and electrophysiological testing as well as neuromuscular signs improved. The recovery, clinically and radiographically, over 35 days was dramatic. Ethylene glycol intoxication should always be considered in the differential diagnosis of acute severe encephalopathy because complete recovery is possible with correct therapy.

Adult↗
PubMed1989

Controlled, double-blind study of iosimide, a new, nonionic, monomeric contrast medium, and ioxaglate in cerebral angiography.

Iosimide is a new synthetic, nonionic, monomeric contrast medium in which a new substance, triiodine-trimesine acid, is used. It has definite advantages compared with the basic substances used in the past, diaminobenzoic acid and monoaminoisophthalic acid. Due to the high stability, the possibility of the formation of toxicologically questionable, free nuclei amino compounds disappears. Only the slightest probability of a cross-reaction with present antibodies exists, because of the low frequency in the environment. On the basis of the hydrophilic structure of the side chains, there is only a slight chemotoxicity. In a controlled, double-blind study on 100 randomized patients iosimide was tested in cerebral angiography against ioxaglate. Ioxaglate is an ionic contrast medium, popular because of its low osmolality. In this study iosimide exhibited no differences in comparison with ioxaglate with respect to the contrast, the neurological status or the liver or renal tolerance. In examining cardiovascular tolerance there is only a slight tendency toward liver changes with iosimide. Examination of the general tolerance, however, shows a statistically significant lower incidence of sensation of heat and pain with iosimide than with ioxaglate.

Adult↗
PubMedDate not supplied

Outcome of acute vertebrobasilar occlusions treated with intra-arterial fibrinolysis in 180 patients.

BACKGROUND AND PURPOSE: To evaluate predictors of recanalization and a favorable neurologic outcome in patients with acute vertebrobasilar occlusion (VBO) treated with local intra-arterial fibrinolysis (LIF). METHODS: The multicentric data of 180 patients with acute VBO treated with LIF were retrospectively evaluated. The modified Rankin scale (mRS) was used to evaluate the neurologic status before LIF and at the time of discharge. Patient's sex, age, etiology of VBO, recanalization, symptom duration before LIF, and pretreatment mRS were correlated with posttreatment mRS. Multiple logistic regression analysis was used to identify independent variables for recanalization and neurologic outcome. RESULTS: The overall mortality was 43%. Complete recanalization was achieved in 99 (55%) patients and a partial recanalization in 35 (19%) patients, respectively. Recanalization was significantly associated with a favorable outcome (P < .001). The success of recanalization was negatively correlated with the volume of the thrombus (P < .001). No correlation was found between site and etiology of VBO and recanalization. Neurologic outcome correlated strongly with the pretreatment mRS (P < .001) and also with age (P < .02). Coma lasting less than 4.5 hours led to a positive trend toward a better outcome after univariate testing (P < .001). CONCLUSIONS: Success of recanalization and neurologic status before treatment predict neurologic outcome in patients with VBO. Thrombus volume has an adverse effect on the recanalization success.

Acute Disease↗