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Biomedical subjects

M Collice

Publications and source records attributed to M Collice.

At least 37 records · Page 2Linked to original sources

Dermoid cyst mimicking hematoma in the posterior fossa.

Intracranial dermoid cysts are usually reported to be associated with long lasting or waxing-waning symptoms. Computer tomography (CT) scans usually depict such neoplasms as well-defined areas of low density. This report is about a case of a dermoid cyst, the acute clinical features and CT hyperdensity of which mimicked a hematoma in the posterior fossa. The association of acute onset with CT hyperdensity makes this case of dermoid cyst very unusual.

Adult↗

Long-term noninvasive single photon emission computed tomography monitoring of perfusional changes after EC-IC bypass surgery.

The rCBF was evaluated using I-123 HIPDM and single photon emission computed tomography (SPECT) on 14 patients undergoing extracranial-intracranial (EC-IC) bypass surgery because of internal carotid artery (ICA) occlusion. Before surgery, all patients showed cortical areas of hypoperfusion over the affected cerebral hemisphere. Shortly after EC-IC bypass a rCBF increase was observed in six patients. However, at the 6 and 12 month follow-ups, with angiographic control of bypass patency, rCBF studies did not show any significant rCBF change. Long-term noninvasive tomographic monitoring of perfusion changes occurring after EC-IC bypass surgery failed to show a long-lasting improvement in perfusion.

Adult↗

Continuous intraoperative electroencephalographic monitoring in carotid endarterectomy.

Continuous electroencephalographic (EEG) monitoring was done during 143 consecutive carotid endarterectomies in 130 patients to detect intolerance to cross-clamping. An intraluminal shunt was inserted when EEG changes appeared (in the first 100 procedures) or when EEG changes appeared and a long clamping time was supposed (in the last 43 cases). 121 patients had no EEG changes at clamping time and only 1 had a postoperative deficit due to embolization, which occurred before clamping and was revealed by a decrease of voltage on tracing. 15 patients showed early (within 4 min after clamping) changes and in 11 patients shunting led to the reversal of EEG anomalies in all cases but 2. The state of these 2 patients was worse after surgery, in one because of embolic problems, in the other (shunted 30 min after clamping) probably for hemodynamic reasons. 4 patients with early EEG changes, not shunted because of the short clamping time, had no neurological deficit. 7 patients, 2 of which were shunted, showed late (after 4 min) EEG changes. Only 1 nonshunted patient in this group awoke with a minor, transitory neurological complication. Moreover, EEG changes have been correlated with the preoperative clinical condition and with the presence, on angiography, of contralateral carotid lesions. Also, EEG findings have been correlated with the computed tomography data (in 71 cases) and with the values of interior carotid artery (ICA) back pressure (in 58 cases). No possibility to predict the tolerance to clamping appeared from these correlations. However, a relatively higher risk of intolerance to clamping in patients with contralateral ICA occlusion was noted.(ABSTRACT TRUNCATED AT 250 WORDS)

Arteriosclerosis↗

Complications after subclavian-cortical middle cerebral artery bypass.

Subclavian-cortical middle cerebral artery bypass by saphenous vein interposition is an uncommon recent revascularization technique used for immediate volume flow to the brain or when donor arteries are unavailable or inadequate. We used this technique in four cases of symptomatic common carotid artery occlusion. In the last two cases, severe, reversible neurological complications occurred. We think that these complications are due to this particular technique, and more cautious indications than for traditional extra-intracranial arterial bypass are recommended.

Aphasia↗

Superficial temporal artery to proximal middle cerebral artery anastomosis: clinical and angiographic long term results.

Anastomosis of the superficial temporal artery (STA) with a proximal segment of the middle cerebral artery (MCA) has been proposed as a new cerebral revascularization technique alternative to the conventional bypass on the cortical surface. We introduced this procedure in our surgical practice in 1982 for patients with internal carotid artery (ICA) aneurysms not suitable for direct repair in whom occlusion of the ICA is considered necessary. One patient died because a conventional STA-MCA bypass did not prevent a major stroke caused by a therapeutic ICA occlusion. We are reporting our surgical technique and the immediate and long term clinical and angiographic results in five cases operated on during the period June 19, 1982, through January 19, 1983. The early and late patency rates were good. No neurological complications were observed after the bypass procedure or during a 3-year follow-up period. In our opinion, the use of proximal segments of the MCA as recipient arteries for supratentorial revascularization is a good alternative to the use of cortical surface arteries and, in selected cases, could be the first choice technique.

Adult↗

Role of EEG monitoring and cross-clamping duration in carotid endarterectomy.

The usefulness of electroencephalographic (EEG) monitoring as well as the significance of the period of cross clamping in carotid endarterectomy have not been completely defined. In particular, the clinical importance of major EEG changes has not been fully investigated and some recent studies seem to indicate that the method has little value. As to the duration of cross clamping, there is strong evidence that occlusion times of about 15 minutes are tolerated under general anesthesia, but no information is available regarding longer periods of occlusion. The authors describe a consecutive series of 141 carotid endarterectomies in which the patients with EEG changes were shunted only when occlusion was anticipated to last longer than 30 minutes. Early major EEG changes (during the first 4 minutes) occurred in 14% of the cases. In the absence of EEG changes, long occlusion periods of 40 to 50 minutes were well tolerated. In contrast, the 20 patients with major persistent EEG changes did not tolerate protracted occlusion and three of them had immediate postoperative neurological complications. It seems that, in these circumstances, the incidence of neurological deficit is a function of the duration of cross clamping: these three patients had undergone occlusion for 15 to 30 minutes. Their deficits partially resolved. On the basis of these results it is concluded that: EEG recording is a reliable monitoring system in carotid artery cross clamping. No major strokes due to temporary carotid artery occurred in the series. The clinical significance of major persistent EEG changes is not negligible. Cross clamping for longer than 15 minutes in the presence of significant EEG alterations is potentially dangerous.

Aged↗

Tomographic assessment of regional cerebral perfusion using intravenous I-123 HIPDM and a rotating gamma camera.

The feasibility of assessing regional cerebral perfusion using the new brain imaging agent N,N,N'-trimethyl-N'-(2)-hydroxy-3-methyl-5-(123I) iodobenzyl)-1,3-propanediamine 2 HCl (I-123 HIPDM) and single photon emission computed tomography (SPECT) was evaluated in normal subjects and patients with cerebrovascular disorders. Following intravenous injection, I-123 HIPDM was rapidly extracted from the circulating blood by the brain (6.7%) and other organs. Its intracerebral distribution, as tomographically assessed by SPECT with a rotating gamma camera, reflected the distribution of blood flow within brain structures (gray and white matter, basal ganglia, etc.). Asymptomatic patients with history of transient ischemic attacks or minor stroke and angiographic evidence of internal carotid artery occlusion showed large cortical areas of reduced I-123 HIPDM distribution with normal or slightly positive CT. After extracranial-intracranial bypass surgery, reperfusion could be shown in previously ischemic areas. This study indicates the clinical usefulness of using I-123 HIPDM and gamma camera SPECT for the functional evaluation of brain disorders.

Adult↗

Tomographic assessment of cerebral perfusion using a single-photon emitter (krypton-81m) and a rotating gamma camera.

Continuous carotid infusion of short-lived krypton-81m (t1/2 13 sec) yields an assessment of regional cerebral perfusion. This assessment can be obtained in three dimensions if activity is recorded with a rotating gamma camera and a computer to reconstruct krypton-81m distribution in tomographic sections. These showed several advantages over conventional views: (a) visualization of blood-flow distribution within brain structures (gray and white matter, basal ganglia); (b) more accurate location and evaluation of areas of relatively reduced or increased perfusion; (c) better definition of patterns of collateral circulation; (d) greater sensitivity and specificity in detecting and defining blood-flow changes during physiological activation studies. A limitation of the krypton-81m technique is its invasiveness. However, this study shows that the combination of new advances in radiochemistry with single-photon emission computed tomography may result in accessible methods for assessing, noninvasively and in three dimensions, the behavior of cerebral function in man.

Brain Diseases↗

Fibrinolytic activity in blood and cerebrospinal fluid in subarachnoid hemorrhage from ruptured intracranial saccular aneurysm before and during EACA treatment.

10 patients suffering from intracranial aneurysm causing subarachnoid hemorrhage (SAH) have been treated during the acute pre-and postoperatory phase with omega-aminocaproic acid. The blood and the cerebrospinal fluid of the treated patients have been analyzed in order to study fibrin(ogen) degradation products (FDP) and fibrinolytic activity (FA). The results so obtained show only an alteration of local fibrinolytic processes either inside or around the aneurysmatic clot: there were no alterations of the systemic FA. Furthermore, monitoring of FDP and FA was a very useful tool in those patients who took advantage of the treatment with omega-aminocaproic acid which protected them from rebleeding.

Aminocaproates↗

Monoamine acid metabolites in ventricular CSF of patients with brain tumours.

Homovanillic acid (HVA) and 5-hydroxyindolacetic acid (5-HIAA) in ventricular CSF were determined in 19 patients (12 female 7 male) with brain tumours. No relationship was found between ventricular fluid pressure (VFP) and levels of HVA and 5-HIAA. A relationship was observed between ventricular CSF, HVA concentrations and tumour induced alterations in CSF dynamics. HVA concentrations were very high in patients whose tumours involved the third ventricle, the aqueduct, or the fourth ventricle, producing marked alterations in CSF flow. HVA concentrations significantly lower than in controls were observed in cases where tumours involved the lateral ventricles. Concentrations of acid metabolites in patients with little or no alteration in CSF dynamics corresponded with those in patients with other neurosurgical disorders.

Adolescent↗

[Monitoring of intracranial pressure].

An account of the significance of intracranial pressure is followed by a review of the various sites in which it can be recorded (spinal canal, lateral ventricles, subarachnoidal spaces, operation cavity, other sites). Monitoring of ventricular pressure is discussed in detail; this deals with the classic site and its technique has become part of clinical practice. The utilisation and interpretation of the data in the form of pressure levels and their changes in the course of time are also discussed. The clinical indications for monitoring are noted.

Brain Injuries↗

Homovanillic acid and 5-hydroxyindole-acetic acid in the csf of patients after a severe head injury. I. Lumbar csf concentration in chronic brain post-traumatic syndromes.

Lumbar CSF concentrations of homovanillic acid (HVA) and 5-hydroxyindole-acetic acid (5HIAA) have been determined in ten patients suffering from chronic brain post-traumatic syndromes, at various length of time after the brain trauma. Lower concentrations of HVA (mean 21 +/- 14 mug/ml) compared to controls (mean 46 +/- 10 mug/ml) was observed in 7 cases; 5HIAA levels were within normal values. The 5HIAA/HVA ratio (1.59 +/- 0.66) was significantly higher (p less than 0.001) than the one recorded in controls (0.66 +/- 0.10). Monitoring of lumbar HVA and 5HIAA over time, before, during and after L-dopa treatment, revealed interesting correlations between modification of clinical picture and the levels of monoamines acid metabolites. The data indicate a profound alteration of brain monoamines in chronic syndromes following a severe head injury and suggest that measurements of lumbar HVA and 5HIAA in these patients may be of euristic and diagnostic value.

Adolescent↗