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Biomedical subjects

S Cronqvist

Publications and source records attributed to S Cronqvist.

At least 19 recordsLinked to original sources

A randomized study of chemotherapy with procarbazine, vincristine, and lomustine with and without radiation therapy for astrocytoma grades 3 and/or 4.

The authors undertook a controlled, prospective, randomized study of 171 patients with supratentorial astrocytoma grades 3 and/or 4 (classified according to Kernohan). All patients were given chemotherapy consisting of procarbazine, vincristine, and lomustine (CCNU) (PVC). Half of the patients received whole-brain irradiation (RT) to a dose of 5800 cGy in the tumor-bearing hemisphere and 5000 cGy in the contralateral hemisphere. After diagnosis of progressive tumor growth, patients received individual treatment. The endpoint of the study was time to progression, but cases were followed until the patients died. Median time to progression (MTP) for the whole randomized population was 21 weeks. Median survival time (MST) was 53 weeks; 18% of patients survived for 2 years or longer. Survival analysis showed that patients less than 50 years of age treated with PVC plus RT had significantly longer MTP (81 weeks) and MST (124 weeks) than all other patients. For patients less than 50 years of age treated with PVC alone, MTP was 21 weeks and MST was 66 weeks. For patients more than 50 years of age treated with PVC plus RT, MTP was 23 weeks and MST was 51 weeks; in the PVC group, MTP was 17 weeks and MST was 39 weeks. Age, Karnofsky index, areas of Grade 2, and absence of extensive necrosis in the tumor were significant prognostic factors in the univariate analyses. Patients less than 50 years of age treated with PVC plus RT had significantly longer survival (P = 0.037) when correcting for these factors in a multi-variate analysis.

Adult

Lateral medullary infarction: prognosis in an unselected series.

We describe the acute and long-term prognosis in 43 patients with lateral medullary infarction (LMI) collected from a population-based stroke registry from 1982 to July 1988. Mean age was 63.9 years and median time of follow-up was 33 months. In the acute phase, 5 patients (11.6%) died from respiratory and cardiovascular complications and 2 new strokes occurred, both in the posterior circulation. During follow-up, recurrent vertebrobasilar territory strokes occurred in only 2 patients (a rate of 1.9% per year). The mechanisms of stroke were vertebral artery (VA) branch occlusion, causing a medial medullary syndrome, and basilar artery thrombosis propagating from a contralateral, distal VA stenosis. In the acute phase of LMI, respiratory and cardiovascular events, presumably caused by autonomic dysfunction related to the lateral medullary lesion, are the major hazards. Recurrent posterior circulation strokes were uncommon during follow-up.

Adult

Volumes of chronic traumatic frontal brain lesions measured by MR imaging and CBF tomography.

The volumes (ml) of chronic traumatic frontal brain lesions were compared measured "morphologically" with MR imaging (T1 and T2 weighted images) and "functionally" with a tomographic rCBF technique (SPECT with 133Xe i.v.). The T1 volumes varied between 11 and 220 ml. The correlation between T1 and T2 volumes was 0.95, the T2 volumes being 33% larger than T1 volumes (p less than 0.001). The functional SPECT volumes were considerably larger (range 16-324 ml) than the MR volumes. The mean volume difference was 81% between T1 and SPECT images (p less than 0.001), and 35% between T2 and SPECT images (p less than 0.001). Correlations between the MR and SPECT volumes were also higher for T2 than T1 volumes. The volume difference is most likely explained by a functional decrease in regions around the lesion in which no morphologic change visible on MR images had taken place. MR and SPECT volume measurements were positively related to persistent lack of energy and personality changes, but only moderately related to duration of impaired consciousness and neuropsychologic outcome.

Adult

A long-term prospective study of optic neuritis: evaluation of risk factors.

Eighty-six patients with monosymptomatic optic neuritis of unknown cause were followed prospectively for a median period of 12.9 years. At onset, cerebrospinal fluid (CSF) pleocytosis was present in 46 patients (53%) but oligoclonal immunoglobulin in only 40 (47%) of the patients. The human leukocyte antigen (HLA)-DR2 was present in 45 (52%). Clinically definite multiple sclerosis (MS) was established in 33 patients. Actuarial analysis showed that the cumulative probability of developing MS within 15 years was 45%. Three risk factors were identified: low age and abnormal CSF at onset, and early recurrence of optic neuritis. Female gender, onset in the winter season, and the presence of HLA-DR2 antigen increased the risk for MS, but not significantly. Magnetic resonance imaging detected bilateral discrete white matter lesions, similar to those in MS, in 11 of 25 patients, 7 to 18 years after the isolated attack of optic neuritis. Nine were among the 13 with abnormal CSF and only 2 belonged to the group of 12 with normal CSF (p = 0.01). Normal CSF at the onset of optic neuritis conferred better prognosis but did not preclude the development of MS.

Adolescent

Intraventricular choroid plexus "arachnoid" cyst. MRI findings.

A young women presented with chronic headaches associated with a cyst of the right lateral ventricle. The diagnosis of intraventricular so-called "arachnoid" cyst was supported by CT scan, MRI and stereotactic puncture. MRI was of great value for demonstrating that the cyst was located within the lateral ventricule, that it was delineated by a thin wall adherent to the choroid plexus and that the cyst content was CSF-like.

Adult

Isthmic lumbar spondylolisthesis with sciatica. MR imaging vs myelography.

Seventeen patients with sciatica and isthmic lumbar spondylolisthesis were studied with magnetic resonance (MR) imaging. In 13, myelography was also performed: 5 had dural sac deformation and root sleeve shortening, 2 had deformation with unilateral root sleeve shortening, one had bilateral root sleeve shortening only, and one had sac deformation only. In 4, myelography was normal. On sagittal MR examinations the neural foramen had an altered shape bilaterally with the long axis horizontal in all cases. In addition to altered shape the following was found in the 33 foramina evaluated. I: normal nerve (n = 8); II: compressed nerve (n = 16); III: disappearance of fat, nerve not possible to identify (n = 9). In patients with unilateral sciatica, the degree of foraminal stenosis correlated well with the side of symptoms. Coronal views showed the course of the nerve and pedicular kinking. Eight patients underwent decompressive surgery which revealed nerve compression by hypertrophic fibrous tissue and pedicular kinking, which correlated well with the findings on MR. Since the site of nerve compression often was peripheral to the root sleeves, myelography did not give complete information.

Adult

Clinical and radiologic features of lacunar versus nonlacunar minor stroke.

We determined the angiographic presence of extracerebral and intracerebral arterial disease in 122 patients with minor stroke within the carotid territory; we excluded patients with a recognized cardiac source of emboli. Based on clinical features and computed tomographic findings, patients were classified as having lacunar infarcts (n = 61), nonlacunar infarcts (n = 53), and infarcts of indeterminate type (n = 8). Severe carotid bifurcation disease (greater than or equal to 50% stenosis or occlusion) was significantly more common in nonlacunar than in lacunar infarcts, on both the ipsilateral (p less than 0.001) and the contralateral (p less than 0.01) sides; 79% of the patients with nonlacunar infarcts had severe carotid bifurcation and/or middle cerebral artery disease on the ipsilateral side compared with 3.3% of the patients with lacunar infarcts. Our data underscore the need for classification of patients by the underlying mechanisms in future studies of treatment of ischemic stroke.

Cerebral Angiography

Repeated cranial computed tomographic and magnetic resonance imaging scans in two cases of eclampsia.

In two cases of eclampsia with consumptive thrombocytopenia, the maximum increase in blood pressure and the lowest platelet count coincided with the maximum degree of neurologic and neuroradiologic abnormality. Computed tomograms showed decreased attenuation, and T2-weighted magnetic resonance images showed increased signal intensity focally in the cerebral cortex and the deep gray and white matter. Blood pressure, platelet count, clinical status, and roentgenograms normalized completely in both cases. Severe arterial hypertension and disseminated transitory microvascular occlusions presumably caused multiple small foci of brain edema that resolved without remaining detectable ischemic brain damage.

Adult

Arterial occlusion due to Listeria meningoencephalitis in an immunocompromised boy.

Sequential CAT scan studies of the brain were performed in a 7-year-old boy with Listeria monocytogenes serotype 1 meningoencephalitis. The infection occurred while he was receiving maintenance chemotherapy for T-cell non-Hodgkin lymphoma. A lesion in the right hemisphere during the infection resulted in an excessive enlargement of the right ventricle 10 months later, most probably caused by arterial occlusion.

Arterial Occlusive Diseases

Postoperative CT findings in acoustic neurinomas operated upon by a translabyrinthine approach.

The findings at CT examinations, performed on 46 patients with acoustic neurinomas about 6 months after translabyrinthine surgery, were analyzed and compared with preoperative findings. Direct as well as indirect signs of expansion had disappeared postoperatively. Bulging of cerebellar tissue towards the operative defect in the petrous bone, a finding not connected with local adhesions, was notable. Hypodensity in the vicinity of the removed tumor occurred either due to local widening of the subarachnoid space or due to changes within the cerebellar parenchyma. Local and general widening of the fourth ventricle as a sign of atrophy was a frequent finding.

Adolescent

Significance of tortuous filling defects at lumbar myelography.

At lumbar myelography, tortuous filling defects frequently occur in the presence of a marked local narrowing of the spinal canal. This may lead to a displacement and compression of nerve roots, which may partially or completely fill the subarachnoid space. However, truly elongated nerve roots have also been observed, both at myelography and at operation. Such elongation appears to be a congenital malformation. The recognition of the true nature of tortuous filling defects is important with regard to differentiation against arteriovenous malformations and congested veins.

Cauda Equina

Pulsatile tinnitus and therapeutic embolization.

Fifteen patients with disabling pulse-synchronous tinnitus were investigated with super-selective angiography demonstrating an arteriovenous malformation in 8 cases, chemodectoma of the jugular bulb in 3, and a local arterial stenosis in one case. In 12 of these cases the murmur could be registered objectively, while in the 3 cases with a negative angiographic finding no such murmur could be heard, an observation which may be of importance when selecting patients for further angiographic examination. The cases with a tumour and those with an arteriovenous malformation were all treated with gelatin sponge embolizatioected cases embolization is recommended alone or in combination with surgery.

Adult

Neurocirculatory analysis of potential EIAB patients.

Twelve patients with gross vascular occlusions and with infarcts demonstrated in CT were examined with regard to their hemodynamic situation. Angiography and rCBF with intra-arterial and inhalation techniques were performed. Response to increased arterial hypertension and to CO2 inhalation was tested. It is concluded that one technique alone does not provide enough information for the selection of patients suitable for EIAB operation.

Brain Ischemia

On cerebral infarction in childhood and adolescence.

This report is based on a retrospective analysis of clinical and angiographic findings in 14 children and adolescents suffering from cerebral infarction. They were all examined during the acute stage and selective angiography was performed within a day or two of the stroke. Pathogenesis is discussed and focuses particularly on the occurrence of segmental arteritis from unknown (infectious?) aetiology.

Adolescent

Therapeutic embolization in the external carotid artery region.

Therapeutic transcatheter embolization with spongostan in the region of the external carotid artery has been employed in 17 patients, in some of them on several occasions. The technique is presented and different means of avoiding complications are discussed in detail. Embolization has been used preoperatively and as the single mode of treatment of ENT tumours or meningeomas, and also as the only treatment in arteriovenous malformations. The technique has proven particularly useful in preoperative de-arterialization of ENT tumours when surgery follows in 1 to 2 days. In cases with arteriovenous shunts, a subjective improvement has been achieved.

Adolescent

Pattern of radioactivity in the CSF after intravenous injection of 99mTc.

It has been shown that intravenously injected pertechnetate enters to CSF space and also that a transport of pertechnetate ions to the blood occurs when injected into the ventricles. Activity curves obtained by repeated samplings of CSF after intravenous injection of pertechnetate appears to differ at different levels of the intraventricular pressure but also in patients with different types of intracranial pathology, i.e. in patients with ventricular dilatation due to hydrocephalus and due to cerebral atrophy.

Brain Diseases