The role of MRI in the surgical selection of cerebral metastases.

BACKGROUND: About one third of patients operated on for a "single" cerebral metastasis diagnosed by CT scan have probably more than one lesion. In fact, Gd-DTPA enhanced MRI has proved to be more sensitive than CT in detecting the number of cerebral metastases, reducing the number of patients candidate to surgery. METHODS: Thirty-five patients with a CT scan picture of a single cerebral neoplasm of presumable metastatic nature performed a Gd-DTPA enhanced cerebral MRI. In 25 cases MR images confirmed a single lesion, while in other 10 (28.6%) showed a number of metastases ranging from 2 to 6. In order to assess the utility of MRI in surgical selection of patients and then to reconsider the concept of operability limited to single brain metastases only, we compared the survival of the 25 cases who preoperatively performed MRI (MRI group) with that of other 25 consecutive patients operated on in pre-MR era (during a 24-month period), with a CT picture of single cerebral metastasis (non-MRI group). RESULTS: The median survival was 36 +/- 5 weeks for MRI group and 40 +/- 15 for non-MRI group. The Kaplan-Meier product-limit survival analysis and the log-rank test do not reveal any statistically significative difference of survival between the two groups. CONCLUSIONS: Even if the number of patients is limited for definitive considerations, our preliminary results seem to suggest that the further selection of surgical cases obtained with MRI could not impact significatively the survival. Therefore, in selected patients with multiple cerebral metastases a surgical treatment could be reasonable.

Rare combination of spinal lesions and subcutaneous meningioma in a 44 year old man.

A 44 year-old man with subcutaneous meningioma and rare combination of spinal lesions, consisting of dermal sinus and lipoma of the filum terminale. The literature concerning the subcutaneous meningioma is reviewed and the embryogenesis of these lesions is discussed.

[Acute effects of ventricular and bicameral stimulation on plasma levels of natriuretic hormone]. / Effetti acuti della stimolazione ventricolare e bicamerale sui livelli plasmatici dell'ormone natriuretico.

Atrial natriuretic factor (ANF) is a peptide produced by the atrium in response to increases in atrial pressure. It is a potent vasodilator and recent studies suggest that ANF may modulate vasomotor changes in patients (pts) with pacemaker (PM) syndrome. To evaluate the incidence of pacing mode on peptide secretion, plasma concentrations of ANF were determined in 32 pts (18 men and 14 women, mean age 71 +/- 4 years) with a DDD PM implant. Blood samples were collected one hour after a randomly assigned PM programming either in VVI or DDD mode at 70 ppm. Mean plasma ANF levels were 84.12 +/- 51 pg/ml in DDD mode and 156.0 +/- 15 pg/ml in VVI mode (p < 0.05). In 12 pts presenting ventriculoatrial retroconduction, the ANF levels were 77.16 +/- 50 pg/ml during DDD stimulation and 219.0 +/- 16 pg/ml during VVI stimulation (p < 0.05). ANF level was 88.50 +/- 46 pg/ml in DDD mode and 114.25 +/- 65 pg/ml in VVI mode in the 20 pts without AV retroconduction (p < 0.05). During DDD mode, 18 patients showed a DVI stimulation whereas 14 showed a VDD stimulation: the mean ANF level was 67.40 +/- 15 pg/ml during DVI and 100.40 +/- 28 pg/ml during VDD stimulation; the difference between these data was not significant. The increase in ANF levels during VVI pacing confirms the lower haemodynamic performance of this stimulation mode. The increase of ANF levels during VVI stimulation, which was in the subgroup without AV retroconduction, confirms the benefits of DDD stimulation also in this group of patients as well. Atrial pacing at physiological rates does not trigger the release of ANF.

Local capture by atrial pacing in spontaneous chronic atrial fibrillation.

BACKGROUND: Atrial fibrillation (AF) is considered to be maintained by multiple reentrant circuits without or with a very short excitable gap. However, the possibility of local atrial capture has been shown recently in experimental AF or induced AF in humans. METHODS AND RESULTS: This study was undertaken to evaluate the feasibility of atrial capture-suggestive of an excitable gap-in spontaneous chronic AF. Decremental pacing was performed in 47 right atrial sites in 14 patients with chronic AF, not taking antiarrhythmic drugs. A Franz catheter (for pacing and monophasic action potential recording) and a recording quadripolar catheter positioned about 10 mm apart were used. Local capture was achieved in 41 (87.2%) sites for a total of 100 captures. In 71 episodes the capture was lost within 15 seconds, while in the remaining 29, pacing was stopped after 15 seconds of stable capture. AF types immediately before capture were type 1 in 83 and type 2 in 17 episodes. Type 3 AF was never captured. Pacing cycle at capture was 175.7 +/- 20.9 ms. The baseline atrial interval (FF) was 185.4 +/- 24.5, significantly longer than the FF recorded during pacing immediately before capture (176.0 +/- 19.8 ms) (P < .02). CONCLUSIONS: During spontaneous chronic AF in humans, (1) local capture by atrial pacing is possible up to at least 15 mm from the pacing site, (2) regional entrainment is possible during type 1 and type 2 AF but not type 3 AF, and (3) pacing before capture accelerates AF, probably by transient or local capture. These findings suggest that an excitable gap is present in chronic AF, therefore supporting the hypothesis that leading circle reentry is not the unique electrophysiological mechanism maintaining the arrhythmia.

Intravenous administration of high doses of carboplatin in multimodal treatment of high grade gliomas: a phase II study.

The object of this study is to evaluate the efficacy of a high dose of carboplatin in 20 patients operated on for high grade glioma (Group A) compared with a matched control (Group B) treated with BCNU administered after radiotherapy. The toxicity profile has been evaluated during the therapy. The survival of patients entering this study was measured in terms of months: the mean survival time was 10.45 months and the median 11.0 months in the group treated with carboplatin (8 patients are still alive); the 18-month survival rate was 10%. The mean survival time of the control group was 9.85 months and the median 10.5 months; no patients are still alive and the 18-month survival rate was 0%. On the basis of our phase II clinical study, we could conclude that i.v. administration of high-doses of carboplatin in high grade gliomas is generally well tolerated and the results are better than those of a matched control treated with 1-2 courses of BCNU (low-dose). The adjuvant treatment and the role of carboplatin in the therapy of high grade gliomas is discussed.

Chronic spontaneous spinal epidural hematoma simulating a lumbar stenosis.

A case of a patient with a clinical picture of lumbar spine stenosis actually caused by a chronic, spontaneous, spinal epidural hematoma is reported. There was no history of major or minor trauma to the lumbar spine. The correct preoperative diagnosis was made by magnetic resonance imaging. The possible etiology and clinical and radiological findings and treatment of this rare entity are discussed.

Transthoracic DC shock may represent a serious hazard in pacemaker dependent patients.

External defibrillation is widely used for the termination of various atrial and ventricular tachyarrhythmias, including pacemaker patients. Our study was intended to evaluate the effects of DC shocks in 36 patients with unipolar pacemakers implanted in the right pectoral region (25 DDD, 10 VVI, 3 AAI). The shocks were delivered with paddles on the anterior surface of the thorax, as far as possible away from the pacemaker. The pacing output was programmed at 0.5 msec and 5 V (25 patients), 4 V (1 patient), and 2.5 V (10 patients). Transient loss of capture occurred in 18 patients (50%). These patients, compared with those without capture failure, received higher peak and cumulative shock energies, respectively, 216 +/- 99 versus 123 +/- 50 joules (P < 0.002) and 352 +/- 62 versus 147 +/- 98 joules (P < 0.004) and had a lower pacemaker pulse amplitude (4.0 +/- 1.2 vs 4.6 +/- 1.0 V, P = 0.11). Failure to capture lasted from 5 seconds to 30 minutes (mean 157 sec). In 15 patients the ventricular stimulation threshold was measured before and serially after cardioversion. A six-fold threshold increase was observed 3 minutes after the shock (P < 0.004) with gradual recovery to nearly baseline values at 24 hours. Transient sensing failure occurred in 7 of the 17 patients in whom it could be evaluated (41%). Furthermore, three cases of shock induced pacemaker malfunctions were observed requiring replacement of the stimulator in two patients. In conclusion, the incidence of loss of capture in pacemaker patients subjected to electrical cardioversion/defibrillation is high.(ABSTRACT TRUNCATED AT 250 WORDS)

Salivary gland tumors: revision of 391 cases according to the new WHO classification.

We reviewed 391 cases of salivary gland tumors collected in a 13 year period at the Institute of Pathological Anatomy of the University of Modena, according to the new WHO classification (1991). A diagnosis of pleomorphic adenoma was changed in adenoid cystic carcinoma. Within malignant tumors, 16 cases were reclassified, and new entities, such as polymorphous low-grade adenocarcinoma, papillary cystoadenocarcinoma and salivary duct carcinoma were introduced. Mucoepidermoid carcinomas were subdivised in low-grade and high-grade tumors, but at the follow-up histological grade did not correlate with clinical behaviour of the lesions.

Prognostic significance of nucleolar organizer regions in recurrent pleomorphic adenomas of salivary glands.

Pleomorphic adenoma (PA) is the commonest tumor of salivary glands. It is considered a benign tumor which may recur and rarely metastatize. There are no reliable histological criteria for predicting recurrences of PA. In this paper, Ag-NOR expression, evaluated by means a computer assisted image analysis system, has been tested on 11 cases of PA, their recurrences, 10 non recurrent PA and 5 cases of carcinoma ex PA. Mean AgNOR count, mean AgNOR area and mean AgNOR area/particle were determined in each group. AgNOR count and area did not show any significant differences between recurrent and non recurrent PA. On the contrary, AgNOR area/particle seems to be a useful tool in predicting the clinical behaviour of this lesion.

Pulpal neuropeptidergic fibers.

A study was carried out on Met- and Leu-enkephalin, Gastrin/CCK-, SP-, CGRP-, NPY-immunoreactive fibers using paraffin sections of dental pulp taken from 8 apparently normal teeth (wisdom teeth or teeth extracted for orthodontic reasons). Within the limitations of the samples studied, dental pulp is characterized by the presence of sensory (Enkephalin-, Gastrin/CCK-immunoreactive) and pain fibers (SP-immunoreactive) and of fibers with a potent vasodilatory action (CGRP-immunoreactive) and by the absence of fibers with a vasoconstrictor action (NPY-immunoreactive).

Transcutaneous cardiac pacing: evaluation of cardiac activation.

The effects of transcutaneous cardiac pacing (TCP) on cardiac activation were evaluated by endocavitary recording (HRA, RVA) in eight patients, in order to test the possibility to obtain a simultaneous atrial and ventricular stimulation. The transcutaneous pacemaker used was the Pace Aid 52 (pacing rate 50-160 ppm, current output 10-150 mA, pulse width 20 sec). The two skin electrodes (surface area 50 cm2) were placed on the chest in anteroposterior position. Ventricular capture was observed in all patients (threshold = 74 +/- 14 mA), simultaneous atrial capture was obtained in only four cases (threshold = 138 +/- 25 mA). In conclusion, our data show that four-chamber simultaneous stimulation by TCP is possible, but only with pacing energies much higher than those usually required to capture the ventricle. The ability of TCP to simultaneously pace the atria and ventricles, though not relevant in the emergency cardiac stimulation for symptomatic severe bradyarrhythmias, could be useful in the treatment of reentrant supraventricular tachycardias.

Transcutaneous cardiac pacing for termination of tachyarrhythmias.

Transcutaneous cardiac pacing (TCP) was used for interruption of tachyarrhythmias in 31 patients: 20 with ventricular tachycardia (VT); eight with atrioventricular reentrant tachycardia (AVRT) and three had atrioventricular nodal tachycardia (AVNT). The stimulators used (Pace Aid 50/52) allow pacing at programmable rates (50-160 ppm) and output (10-200 mA at 20-msec pulse duration), when possible overdrive pacing was used. Short bursts of stimuli were delivered with increasing current intensity until interruption of the arrhythmia or to the maximum energy tolerated by the patient. VTs were interrupted in eight of the 20 patients: four of the six (67%) treated by overdrive pacing and four of the 14 (29%) were treated by underdrive pacing. Supraventricular tachycardias (SVT) were terminated in eight of the 11 patients: seven out of eight (88%) AVT, and one out of three AVNT (33%). We observed two cases of arrhythmia worsening: a VT acceleration and induction of ventricular fibrillation in a patient with AVNT. TCP was well tolerated by the majority of the patients. We conclude that TCP is an effective method for interruption of ventricular and supraventricular reentrant tachycardias, but the risk of arrhythmia worsening must be considered.

Emergency cardiac pacing for severe bradycardia.

UNLABELLED: Our study included the treatment of transcutaneous cardiac pacing (TCP) in 32 patients: (A) 19 patients were treated in the emergency area for complete symptomatic AV block before endocavitary pacing; (B) five patients were in asystole following DC shock or out-of-hospital cardiac arrest; and (C) eight patients were affected by bifascicular block undergoing emergency surgery and were treated in order to prevent complete AV block. Two transcutaneous stimulators were used. PaceAid-CRC model 50/52 with 20-msec pulse width; the electrodes were positioned on the V3 ECG position and on the back. RESULTS: in all but two patients, it was possible to obtain stable cardiac capture; in one patient arrived in hospital in asystole after prolonged cardiac arrest and in the other one was affected by complete AV block, TCP was ineffective. In groups A and B, TCP was maintained for a mean time of 15 minutes; in group C, TCP was tested in all patients, but performed in only one patient during surgery. Mean threshold was 81 mA. Stimulation was well tolerated in all but five patients. TCP is a reliable, noninvasive method that offers the possibility to initiate pacing within seconds and can be used by medical staff. In our opinion, it should be considered as the first choice emergency treatment of severe symptomatic bradycardia. In asystole, beneficial effects can be obtained only if TCP is performed early enough after the onset of arrhythmia.

[Malignant ventricular hyperkinetic arrhythmia: role of permanent electric treatment]. / Aritmie ipercinetiche ventricolari maligne: ruolo del trattamento elettrico definitivo.

While the technics of cardiac pacing have shown to have a precise role in the diagnosis and treatment of ventricular arrhythmias on a temporary basis, the role of permanent antiarrhythmic devices (PAD) in the treatment of these arrhythmias is still ill defined mainly because of the technological limits concerning the pacemakers and the frequent complications observed during the attempts to interrupt such tachycardias. On the basis of the available data and of theoretical considerations, three groups of pts susceptible of treatment with PAD can be selected: a) pts with brady-dependent arrhythmias where PAD is used as a prophylactic mean; b) pts with recurrent sustained ventricular tachycardia refractory to medical treatment, in whom PAD can be used to interrupt tachycardia; c) pts affected by ventricular fibrillation or rapidly deteriorating ventricular tachycardia (sudden death pts), refractory to conventional treatment, in whom the implantable defibrillator represents the only therapeutic possibility. Even if scanty, the data available seem to confirm that PAD does have a role in the treatment of malignant arrhythmias, although in selected cases and almost always together with drug treatment.