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Biomedical subjects

P Nakstad

Publications and source records attributed to P Nakstad.

At least 37 records · Page 2Linked to original sources
PubMed1987

Secondary retinal detachment interpreted as a part of uveal melanoma by CT-scan.

Four patients with histologically verified uveal melanomas were examined with computed tomography (CT) scan. Ophthalmoscopy revealed a sharply deliminated tumour surrounded by a secondary retinal detachment. The clinically calculated size of the tumours corresponded well with the histological specimens. The CT-scan indicated a greater size of the tumours. The discrepancies were due to difficulties in differentiation between the tumour tissue and the subretinal fluid which have almost identical CT-numbers. By combining axial and coronal views it was possible to distinguish the tumour from the secondary retinal detachment.

Adult↗
PubMed1986

Traumatic aneurysms of the pericallosal arteries.

Of a total of 912 operated intracranial aneurysms only three were classified as traumatic (0.3%). They were found in children after severe head trauma and were all located on the pericallosal artery or its branches and not at bifurcations. Shearing forces between the falx, the arteries and the brain at the time of injury are held responsible for the development of these aneurysms. Unlike these traumatic aneurysms, 29 "spontaneous" pericallosal aneurysms (3.2%) in adults were located at the bifurcations of the artery. As significantly fewer reports of traumatic aneurysms have been published during the last decade than before 1976, it is suggested that some might have been overlooked as a consequence of CT replacing cerebral angiography in the neuroradiological evaluation of severe head injury. This possibility should be kept in mind, especially when dealing with children after head injury and when CT scans indicate brain damage around the falx. The possibility of overlooking traumatic pericallosal aneurysms is described by other authors and discussed further in this paper.

Adolescent↗
PubMed1986

Intra-arterial digital subtraction angiography of the carotid arteries. Special reference to contrast media.

A cross-over test in intra-arterial digital subtraction angiography (IADSA) of the carotid arteries was performed in 50 patients to evaluate image quality and side-effects with iohexol and metrizoate injected at concentrations of 100 mg I/ml by hand. The image quality was excellent or good in all cases. Although the severity and the frequency of side-effects were higher with metrizoate, both contrast media were suitable for IADSA at this low concentration. No complications were seen. It was assumed that the risk with IADSA was less than that of conventional precerebral angiography when performed semi-selectively and with small amounts of contrast media, as in this study.

Adult↗
PubMed1986

Herpes zoster ophthalmicus with cerebral angiitis and reduced cerebral blood flow.

Two patients with herpes zoster ophthalmicus (HZO) who experienced a delayed contralateral hemiparesis, the so-called crossed zoster syndrome, are described. Particular emphasis is paid to the cerebral blood flow (CBF) findings studied with the Xenon-133 inhalation technique using single photon emission computed tomography (SPECT). In a 40-year-old female with right-sided hemiparesis, angiography showed multiple segmental narrowings of the intracerebral arteries. Cerebral computer tomography (CT) scans were normal. The CBF studied 11 months after the HZO showed a generalized reduction of flow which, however, was more pronounced in the left hemisphere. On re-examination 8 months later both the mean hemispheric flow and regional CBF (rCBF) had increased to normal values. In a 66-year-old male with dysphasia and right-sided hemiparesis, cerebral CT scans demonstrated two small deep left-sided infarcts. CBF examination showed a generalized reduction of flow in the left hemisphere. The flow was slightly increased on re-examination 12 months later. These findings suggest that the Xenon-133 inhalation method represents a useful way to demonstrate the CBF pattern in this group of patients.

Adult↗
PubMed1986

Patency and flow velocity profiles in the internal carotid artery assessed by digital subtraction angiography and Doppler studies three months following endarterectomy.

Pulsed Doppler spectral analysis and intravenous digital subtraction angiography have been carried out in 55 patients, three months after a total of 60 carotid endarterectomies. Five patients were operated on both sides and there were no re-operations. There were no re-stenoses and only one of the 60 internal carotid arteries was occluded. Spectral spreading of of the Doppler signal at the site of the endarterectomy was found in 52% of the internal carotid arteries, whereas wall irregularities were demonstrated in 25% by intravenous digital subtraction angiography. A stenosis or occlusion was found in 11 (18%) of the 60 ipsilateral external carotid arteries.

Carotid Artery Diseases↗
PubMed1986

A non-invasive Doppler ultrasound method for the evaluation of patients with subarachnoid hemorrhage.

Measurements of flow velocity in the basal cerebral arteries can be obtained non-invasively through the intact skull using 2 MHz pulsed Doppler ultrasound. We investigated 47 patients with subarachnoid hemorrhage and compared flow velocity with angiography. Flow velocity in the middle and posterior cerebral arteries (MCA and PCA) was inversely related to the lumen diameter. Further clues to diagnose MCA spasm were obtained from the ratio of MCA flow velocity divided by the velocity in the distal extracranial internal carotid artery. In the individual patient, the two anterior cerebral arteries should be considered together, since this communicating system often has unique possibilities for collateral flow. Recordings from large MCA aneurysms were obtained before angiography in 4 patients.

Adult↗
PubMed1985

The correlation of myelographic root sleeve deformity, uncovertebral spondylosis and radiculopathy.

Myelographic root sleeve deformities, uncovertebral spondylosis and myelopathy were correlated in 56 patients. Good correlation between root sleeve deformities and uncovertebral spondylosis was found. However, in some cases with spinal canal stenosis root sleeve deformities were found without corresponding bone changes. The correlation of radiculopathy to root sleeve deformity and uncovertebral spondylosis was 61 and 67%, respectively. Radiologic changes at an adjacent root level were often seen in patients without clinically correlated radiculopathy. The myelographic changes were verified at operation in all the 46 patients operated upon.

Adult↗
PubMed1985

Digital subtraction angiography (DSA) in the evaluation of brain death. A comparison of conventional cerebral angiography with intravenous and intraarterial DSA.

Demonstration that intracranial circulation has ceased is the ultimate proof of brain death. This study was performed to evaluate digital subtraction angiography (DSA) compared with conventional cerebral angiography in the diagnosis of brain death. Intravenous as well as intraarterial DSA was found suitable in the diagnosis of arrested intracranial circulation.

Adolescent↗
PubMed1985

Functional cervical myelography with iohexol.

Thirty patients underwent functional cervical myelography, i.e. radiographs in the lateral view were obtained in extension as well as in flexion of the neck. Sagittal tomography was performed in both positions. Widening of the subarachnoid space and decreased sagittal diameter of the spinal cord due to shortening were demonstrated in the lateral view in flexion. In some cases with advanced narrowing or spinal block in extension, such widening in flexion resulted in better diagnostic images by providing passage of the contrast medium caudally. Although iohexol (Omnipaque, Nyegaard & Co., Oslo) was regularly forced into the posterior cranial fossa by the movements, the frequency of side effects was approximately the same as in our former trials with iohexol in conventional cervical myelography. EEG changes occurred in two patients (7%). A sitting position for 3-4 min after the examination followed by an elevated head end of the bed was probably important for preventing side effects from the contrast medium. Specific questioning revealed twice as many subjective side effects as reported after general questions alone.

Adult↗
PubMed1985

A comparison of pulsed Doppler spectral analysis and intravenous digital subtraction angiography in the detection of carotid occlusive disease.

The purpose of this study was to compare the accuracy of pulsed Doppler spectral analysis and intravenous digital subtraction angiography (IVDSA), in the detection of carotid occlusive disease. In 132 carotid arteries the results of these two examinations have been assessed independently and compared with findings by conventional arteriography. All 39 stenoses causing a diameter reduction of more than 25% were found by Doppler examination and 36 (92%) by IVDSA. Twelve occlusions of the internal carotid artery, shown by conventional arteriography, were also detected by Doppler examination and 11 (92%) by IVDSA. Both Doppler and IVDSA detected 56% of the lesions which reduced the diameter by less than 25%. All 54 arteriographically normal vessels were assessed correctly by Doppler examination and 53 (98%) of them by IVDSA. This study shows that Doppler and IVDSA are well suited for assessing patients with symptoms suggestive of carotid occlusive disease, both methods being accurate in the detection of lesions which reduce the diameter of the carotid artery by more than 25%.

Carotid Artery Thrombosis↗