P674 Epicardial fat volume is associated with the risk of atrial fibrillation recurrence following pulmonary vein isolation

Funding Acknowledgements

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Background

Atrial fibrillation (AF) is the most common supraventricular rhythm disturbance and pulmonary vein (PV) isolation has an important role in rhythm control treatment strategies of this disease. Various anatomical and clinical characteristics have been well established as predictors of the risk of recurrence following ablation procedures, but the role of epicardial fat tissue (EFT) in the recurrence of AF has not been elucidated so far.

Purpose

To investigate the influence of left atrial size and EFT volume in the recurrence of AF after pulmonary vein ablation, during a 6-month follow-up.

Methods

A total of 40 patients, 52.5% with paroxysmal and 47.5% with chronic AF underwent PV isolation using radiofrequency and cryoablation techniques. EFT was determined using cardiac computed tomography angiography (CCTA) associated with advanced image post-processing techniques.

Results

In patients who developed AF recurrence at 6 months after AF ablation, the volume of EFT and of left atrium were significantly larger than in the group who maintained sinus rhythm (202.5 ± 64.56 ml vs. 138 ± 55.74 ml, p = 0.01 for EFT, and 149.3 ± 4.66 ml vs. 90.63 ± 5.19 ml, p <0.0001 for left atrial volume, respectively). The left ventricular ejection fraction was significantly lower in patients with AF recurrence (50.25 ± 6.54% vs. 54.22 ± 3.95%, p = 0,04). The analysis of AF recurrence between the two different ablation techniques did not show any difference in recurrence rates between radiofrequency and cryoablation methods (29% vs. 23%, respectively p = 0.73). At the same time, recurrence rates after AF ablation were not influenced by the main cardiovascular risk factors (age, hypertension, dyslipidemia and smoking) and was not associated with different risk scores (CHA2DS2-VASc and HAS-BLED).

Conclusion

Patients with AF recurrence after pulmonary vein ablation present significantly higher EFT or left atrial volumes compared to patients who maintained sinus rhythm. This indicates the inflammatory mediated response, usually accompanied by an increased amount of EFT, could be associated with the risk of AF recurrence following catheter ablation of the pulmonary veins.

Type III interferon (IFN-lambda) antagonizes the antiviral activity of interferon-alpha in vitro

Type III interferons (IFN-lambda) are the most recently discovered members of IFN family. Synergism between different IFN types is well established, but for type I and type III IFNs no conclusive evidence has been reported so far. Possible synergism/antagonism between IFN-alpha and IFN-lambda in the inhibition of virus replication (EMCV, WNV lineage 1 and 2, CHIKV and HSV-1), and in the activation of intracellular pathways of IFN response (MxA and 2'-5' OAS) was evaluated in different cell lines (Vero E6, A549 and Wish cells). The antiviral potency of IFN-lambda1 and -l2 was lower than that of IFN-alpha. When IFN-alpha and -lambda were used together, the Combination Index (CI) for virus inhibition was greater than 1 virtually for all virus/host cell systems, indicating antagonistic effect. Antagonism between IFN-alpha and -l was also observed for the induction of mRNA for both MxA and 2'-5'OAS. Elucidating the interplay between IFN-alpha and -lambda may help to better understand innate defence mechanisms against viral infections, including the molecular mechanisms underlying the influence of IL-28B polymorphisms in the response to HCV and other viral infections.

A case of dengue type 3 virus infection imported from Africa to Italy, October 2009

In October 2009, a traveller returning from Africa to Italy was hospitalised with symptoms suggestive of a haemorrhagic fever of unknown origin. The patient was immediately placed in a special biocontainment unit until laboratory investigations confirmed the infection to be caused by a dengue serotype 3 virus. This case reasserts the importance of returning travellers as sentinels of unknown outbreaks occurring in other countries, and highlights how the initial symptoms of dengue fever resemble those of other haemorrhagic fevers, hence the importance of prompt isolation of patients until a final diagnosis is reached.

A case of dengue type 3 virus infection imported from Africa to Italy, October 2009

In October 2009, a traveller returning from Africa to Italy was hospitalised with symptoms suggestive of a haemorrhagic fever of unknown origin. The patient was immediately placed in a special biocontainment unit until laboratory investigations confirmed the infection to be caused by a dengue serotype 3 virus. This case reasserts the importance of returning travellers as sentinels of unknown outbreaks occurring in other countries, and highlights how the initial symptoms of dengue fever resemble those of other haemorrhagic fevers, hence the importance of prompt isolation of patients until a final diagnosis is reached.

Bcl-2 inhibits the caspase-dependent apoptosis induced by SARS-CoV without affecting virus replication kinetics

Vero cells transfected with either neo- or bcl-2-plasmid were infected with SARS-CoV at a high multiplicity of infection. Apoptosis appeared after the onset of CPE and completion of virus replication, and could be prevented by Bcl-2 expression. Apoptosis is likely mediated by the mitochondrial pathway, as demonstrated by its inhibition using Bcl-2, and by the activation of the caspase cascade, resulting in PARP cleavage. Prevention of apoptosis did not affect susceptibility to infection, kinetics and extent of viral replication and release, thus implying that apoptosis is not involved in facilitating release and/or dissemination of SARS-CoV in Vero cells.

Pregnancy and subarachnoid hemorrhage: a case report

Cerebrovascular diseases are rare in pregnancy and mostly caused by rupture of an arterial aneurysm. We present the case of a pregnant woman at 36 weeks of gestation who had a subarachnoid hemorrhage resulting from rupture of an unknown aneurysm, and who underwent a Cesarean section and an endovascular treatment to embolize the aneurysm.

Expression of Werner and Bloom syndrome genes is differentially regulated by in vitro HIV-1 infection of peripheral blood mononuclear cells

In HIV infection, continuous immune activation leads to accelerated ageing of the adaptive immune system, similar to that observed in elderly people. We investigated the expression of WRN and BLM (genes involved in disorders characterized by premature ageing, genomic instability and cancer predisposition) in peripheral blood mononuclear cells (PBMC) activated in vitro with phytohaemagglutinin (PHA) and infected with different HIV-1 strains. The steady state levels of mRNA were analysed by reverse transcription-polymerase chain reaction (RT-PCR), and protein expression was assayed using immunocytochemistry and Western blot techniques. In uninfected PBMC, PHA stimulation induced an increase in BLM mRNA and protein expression, while WRN expression remained virtually unchanged. When PBMC were infected in vitro with a lymphotropic HIV-1 strain, the level of BLM mRNA showed a peak at 24 h of infection, followed by a decline to uninfected culture levels. A similar result failed to be seen using an R5-tropic HIV-1 strain. In accordance with mRNA expression, in HIV-infected cultures PBMC were stained more frequently and more intensely by a BLM-specific antibody as compared to uninfected cultures, staining peaking at 24. Conversely, WRN expression was not modulated by HIV-1. The proportion of cells showing BLM up-regulation, established by immunocytochemical staining, was much greater than the proportion of productively infected PBMC, as established by proviral DNA measurement. This result indicates that BLM up-regulation is probably a result of an indirect bystander cell effect. Activation of the BLM gene in infected PBMC suggests that premature ageing could be a further immunopathogenetic mechanism involved in HIV-induced immunodeficiency, and points to a possible new candidate target for innovative therapeutic intervention.

In vivo binding and hierarchy of assembly of the yeast RNA polymerase I transcription factors

Transcription by RNA polymerase I in Saccharomyces cerevisiae requires a series of transcription factors that have been genetically and biochemically identified. In particular, the core factor (CF) and the upstream activation factor (UAF) have been shown in vitro to bind the core element and the upstream promoter element, respectively. We have analyzed in vivo the DNAse I footprinting of the 35S promoter in wild-type and mutant strains lacking one specific transcription factor at the time. In this way we were able to unambiguously attribute the protections by the CF and the UAF to their respective putative binding sites. In addition, we have found that in vivo a binding hierarchy exists, the UAF being necessary for CF binding. Because the CF footprinting is lost in mutants lacking a functional RNA polymerase I, we also conclude that the final step of preinitiation-complex assembly affects binding of the CF, stabilizing its contact with DNA. Thus, in vivo, the CF is recruited to the core element by the UAF and stabilized on DNA by the presence of a functional RNA polymerase I.

[The effect of cardiovascular rehabilitation on the variability of the RR cycle after a first uncomplicated acute myocardial infarct]

BACKGROUND

The aim of this study was to verify the changes in the autonomic balance by means of heart rate variability assessment in patients with myocardial infarction referred for cardiac rehabilitation.

METHODS

We studied 122 patients (79 males, 43 females, mean age 56 +/- 5 years), with a first uncomplicated myocardial infarction (anterior 48, thrombolysis 72), Killip class 1, preserved left ventricular function (ejection fraction 49 +/- 6%). All patients were free of inducible residual ischemia. Four weeks after myocardial infarction, patients were randomized into two groups; Group 1 (n = 58) referred for an 8 week cardiac rehabilitation program (scheduled: 24 sessions); Group 2 (n = 64): normal daily physical activity. During a 24-hour Holter ECG monitoring the following parameters were calculated in pharmacological wash-out at randomization (T0) and at the end of cardiac rehabilitation/control period (T1): mean value of RR intervals (RR), its standard deviation (SDNN), pNN50, rMSSD in the time domain; low frequency (LF) and high frequency (HF) value and the LF/HF ratio in the frequency domain. T1-T0 changes in percent values (delta %) were considered and compared between the two groups.

RESULTS

Thirty-one patients were excluded from the study either for insufficient adhesion to the cardiac rehabilitation program (< 13 sessions, 22 patients) or recurrent ischemia (3 Group 1 patients and 3 Group 2 patients) and non-assessable 24-hour Holter ECG monitoring (3 patients). Thirty-one Group 1 patients and 60 Group 2 patients completed the study with a first and a second 24-hour Holter ECG monitoring performed at 30 +/- 3 days and 60 +/- 4 days respectively. At the same time an ergospirometric test was performed to evaluate cardiopulmonary function by means of exercise time, maximum oxygen consumption, anaerobic threshold, exercise time at the anaerobic threshold, and maximum oxygen consumption at the anaerobic threshold. Twenty-eight Group 1 patients and 44 Group 2 patients completed the study with a first and a second ergospirometric test. Baseline heart rate variability parameters were comparable in the two groups. During the observation period only in Group 1 patients heart rate variability parameters changed significantly: RR (Group 1 = +18.3 +/- 21.3; Group 2 = +4.2 +/- 5.2, p = 0.000), pNN50 (Group 1 = 45.0 +/- 38.9; Group 2 = +24.2 +/- 34.7, p = 0.011), HF (Group 1 = +81.6 +/- 124; Group 2 = -28.7 +/- 75.4, p = 0.014) and LF/HF ratio (Group 1 = -26.0 +/- 16.1; Group 2 = -4.9 +/- 6.1, p = 0.062). There were no significant differences in SDNN, rMSSD and LF. A linear correlation between delta LF/HF ratio and baseline LF/HF ratio values was found in Group 1 (r = 0.489, p = 0.006), whereas no correlation was found between this parameter and age, ejection fraction, creatine phosphokinase, and infarct localization. Group 1 patients had a significant improvement in exercise tolerance compared to Group 2 patients.

CONCLUSIONS

A cardiac rehabilitation program positively modifies the sympatho-vagal balance in patients with uncomplicated myocardial infarction, increasing the parasympathetic tone and exercise tolerance.

Surgical treatment of intracranial aneurysms in patients aged over 70: 25 years of experience

Many references and communications regarding neurosurgical topics in elderly patients underline the interest of our Unit for this subject. We already presented in 1978 a series of 75 patients over 60 years of age operated on for intracranial aneurysms; we reported a 90% of success in all the cases operated with clinical grade 1 or 2 according to Botterel grading system on admission. In 1986, during the XXXV Congress of the Italian Neurosurgical Society, we presented other 15 cases operated for intracranial aneurysm over 70 years of age. We present an upgrading of our casistic.

Prognostic value of residual ischaemia assessed by exercise electrocardiography and dobutamine stress echocardiography in low-risk patients following acute myocardial infarction

BACKGROUND

Risk stratification after uncomplicated myocardial infarction is major clinical problem. In particular, the prognostic value of residual inducible ischaemia is still controversial. We compared the relative prognostic value of exercise ECG and dobutamine stress echocardiography performed in the early post-infarction period.

METHODS

Four hundred and six patients (53 female) aged 57 +/- 9 years, undergoing maximal exercise ECG and dobutamine stress echocardiography within 10 days of an uncomplicated myocardial infarction off therapy, were prospectively followed-up for 8.8 months. Age, sex, diabetes, smoking habit, hypertension, dyslipidaemia, infarct location, thrombolysis and resting wall motion score index were taken into account among clinical variables. Prognostic correlations were made vs spontaneous events (cardiac death, non-fatal reinfarction and unstable angina requiring hospitalization) whilst patients undergoing revascularization (by means of percutaneous transluminal coronary angioplasty or coronary artery bypass surgery) at the time of the procedure were censored.

RESULTS

One hundred and twenty-seven events occurred during the follow-up: 41 (10%) were spontaneous (five deaths, 12 reinfarctions and 24 unstable angina) and 86 procedural (27 angioplasty and 59 bypass surgery). Spontaneous events were not predicted by any clinical, exercise ECG or dobutamine stress echocardiography variable, but the negative predictive value of both tests was excellent (91% and 90% respectively). With a multivariate Cox analysis, male gender, positive low-workload (< 100 W) exercise ECG (P < 0.0001), positive low-dose dobutamine stress echocardiography (P < 0.0001) and rest-stress wall motion score index variation (P < 0.001) were found to predict cumulative cardiac events with an independent and additive value. Dobutamine stress echocardiography was significantly more sensitive (P < 0.05) and less specific (P < 0.01) in predicting the outcome of patients with anterior infarction, whilst exercise ECG was significantly more sensitive (P < 0.05) in patients with non-Q wave infarction.

CONCLUSIONS

(1) Spontaneous events are poorly predicted by provocative tests in low-risk patients after uncomplicated myocardial infarction. (2) However, both exercise ECG and dobutamine stress echocardiography can predict a favourable outcome with a very high negative predictive value. (3) Dobutamine stress echocardiography should be considered a secondary option in cases where the exercise ECG is equivocal or when the location of ischaemia is a relevant issue. (4) The possibility that the two tests have a differential utility depending on the infarct location and type (Q wave vs non-Q wave) may be clinically relevant and deserves further evaluation.

Two-step development of a pituitary adenoma: from hyperprolactinemic syndrome to Cushing's disease

In this report we describe the case of a young female patient with amenorrhea-galactorrhea syndrome apparently due to pituitary PRL-secreting adenoma who, after three years of dopaminergic therapy without any shrinkage of the tumor, developed true Cushing's disease. Progression from hyperprolactinemia to hypersecretion of ACTH has been rarely described and it may be due to different possibilities. However, histopathological and immunohistochemical studies of the adenoma showed a pattern of PRL negative and ACTH positive cells, excluding mixed pituitary tumor. In order to explain the progression from hyperprolactinemia with amenorrhea-galactorrhea to an ACTH hypersecretion syndrome, it must be hypothesized either pituitary stalk compression or the influence of paracrine regulation factor(s) (such as Galanine) due to an "initially silent" corticotropinoma. This case confirms that the presence of hyperprolactinemia in a patient with pituitary tumor and amenorrhea-galactorrhea syndrome is insufficient to confidently conclude for prolactinoma. Furthermore, it underlines the importance both of clinically monitoring the patient with prolactin pituitary adenoma if dopaminergic therapy does not reduce tumor volume, and of accurately and repeatedly measuring the other pituitary hormonal secretions.

[Prognostic value of echo-dobutamine test in patients with ischemic heart disease: comparison with exercise test]

BACKGROUNDS

The aim of the study was to assess the relative prognostic accuracy of dobutamine echocardiography (TED) vs maximal bicycle exercise electrocardiography (TE) in patients with proven coronary artery disease.

METHODS

One hundred and thirty consecutive patients (70 patients with uncomplicated recent myocardial infarction, 19 asymptomatic patients with previous myocardial infarction and 41 patients with stable angina pectoris and previous myocardial infarction or previous myocardial revascularization procedure) underwent TED (incremental dobutamine infusion: 5 to 40 ncg/kg/min, continued with atropine 0.25 to 1 mg iv if necessary) and TE on different days and in random order. Criteria for positivity were: new or worsening regional dyssynergy for TED; ST segment shift > or = 1 mm from baseline for TE. End points were defined as spontaneous events (cardiac death, myocardial infarction and unstable angina) and total events (spontaneous events plus myocardial revascularization procedures).

RESULTS

During 15.4 +/- 7.9 (range 1-33) months of follow-up, 33 events occurred: cardiac death (1), myocardial infarction (4) unstable angina (21) myocardial revascularization (7). Sensitivity, specificity, positive and negative predictive value, prognostic accuracy were similar for TED and TE (P = NS). Cumulative event-free survival curves as a function of TED and TE results were both statistically significant. A Cox stepwise regression analysis identified TED positivity obtained without atropine administration as the best predictor of spontaneous and total events (Odds ratio 5.33 and 4.38, respectively). Cumulative survival curves obtained by the combination of TED and TE results were statistically different (P < 0.05 and P < 0.001 for spontaneous and total events, respectively) and showed a poor clinical outcome in patients with both tests or only TED positive. TED correctly predicted clinical outcome in 24/39 patients in whom there was disagreement between the two tests.

CONCLUSIONS

In patients with proven coronary artery disease, TED and TE have a similar accuracy for predicting clinical outcome. Where a discrepancy is seen between the two tests, TED appears to have a slightly higher prognostic value.

Prognostic value of high dose dipyridamole echocardiography in patients with chronic coronary artery disease and preserved left ventricular function

OBJECTIVES

The prognostic value of dipyridamole echocardiography was assessed in patients with chronic coronary artery disease and preserved left ventricular function.

BACKGROUND

Few data are available on the prognostic value of dipyridamole echocardiography in patients with a low risk of cardiac events.

METHODS

Two hundred sixty-eight consecutive patients with stable, proven or suspected coronary artery disease and ejection fraction > or = 0.40 underwent high dose (up to 0.84 mg/kg body weight) dipyridamole echocardiography. In 204 patients definite exercise electrocardiographic (ECG) results were also available.

RESULTS

During a mean (+/- SD) follow-up period of 16 +/- 8 months (range 6 to 36), 33 spontaneous events occurred: 15 "hard" events (cardiac death [n = 6], myocardial infarction [n = 9]) and 18 "soft" events (unstable angina). Events occurred more frequently in patients with positive findings on dipyridamole echocardiography (59% vs. 3%, p < 0.001; hard events 24% vs. 2%, p < 0.01). A positive response at the low dose (up to 0.56 mg/kg) identified patients with a high incidence of hard events (7 of 16 patients, sensitivity 50%, specificity 96%). In patients with an exercise ECG, a comparable sensitivity for cardiac events was found (89% vs. 93%, p = NS), but dipyridamole echocardiography was more specific (91% vs. 61%, p < 0.01). A positive response on the low work load exercise ECG (< 8 min) and a positive response to low dose dipyridamole echocardiography had similar accuracy (82% vs. 90%, p = NS). Cox analysis identified dipyridamole echocardiography as the best predictor of cardiac events (odds ratio [OR] 20.9, 95% confidence interval [CI] 10.8 to 37.9); the highest risk of hard events was found in patients with a positive response to low dose dipyridamole echocardiography (OR 25.4, 95% CI 12.2 to 54.1).

CONCLUSIONS

In patients with chronic coronary artery disease and a low incidence of cardiac events, dipyridamole echocardiography was effective in prognostic stratification, and positive low work load exercise ECG results were a reliable predictor of subsequent events. Consequently, dipyridamole echocardiography should be considered a complementary tool in the presence of high work load positivity or ambiguous exercise ECG results.

Surgical management of haemangioblastoma of the posterior fossa

Fifty-one cases of posterior fossa haemangioblastoma have been seen in our department over a period of 23 years. Seven cases were associated with spinal cord lesions and one with a supratentorial lesion. There were 22 cases of Lindau's disease (43%). The onset was earlier and recurrences commoner than in isolated cases. In 10 cases the development of new tumours in different parts of the central nervous system (CNS) required re-operation, demonstrating the multicentric nature of this disease. The majority of the tumours occupying the fourth ventricle or medulla oblongata (8 cases) were macroscopically solid and had higher post-operative morbidity than the cystic tumours in the cerebellum. The recent development of magnetic resonance imaging (MRI) provides accurate anatomical information of the lesions (especially those of the brain stem and spinal cord) even while asymptomatic. The brilliant enhancement of these tumours on MRI with Gadolinium-diethyline-triamine-pentaacetic acid (Gd-DTPA) has proved to be particularly useful.

Neuromas of the facial nerve: a report of 12 cases

Twelve patients with facial nerve neurinoma have been treated at The National Hospital, Queen Square, London, during the last 20 years. Nine tumours lay in the middle fossa arising from the area of the geniculate ganglion, two lay in the posterior fossa arising from the segment of the facial nerve in the internal auditory canal, and one tumour arose from the vertical segment of the facial nerve with extracranial extension through the stylomastoid foramen. Two patients had neurofibromatosis. The clinical and radiographic features of those tumours, the operative approaches employed, and the postoperative outcome are described. Complete tumour excision was achieved in all patients; all 12 remain free of recurrence 3-80 months after surgery. Facial nerve function was restored at least in part in all cases by transposition with end-to-end anastomosis, placement of a cable graft from the sural nerve or hypoglosso-facial anastomosis. The major determinant of the outcome of facial nerve function was the duration of preoperative facial paralysis, the results being invariably poor when this was of long duration.

Classification of supratentorial arteriovenous malformations. A score system for evaluation of operability and surgical strategy based on an analysis of 66 cases

A classification of arteriovenous malformations (AVM) is proposed, which is based on a retrospective analysis of the records and results of radical operation in 57 patients between 1983 and 1990. It represents the new developments and more recent technical facilities which influence operability of supratentorial AVMs. Predictability of outcome has been settled upon three groups of factors: anatomical, haemodynamical, and clinical. Anatomical factors are localisation and sectorisation of AVM, determination, caliber and straightening of feeding arteries. Haemodynamical factors are volume of AVM and vascular autoregulation, circulatory velocity of red blood cells in the main arteries of the neck and brain tissue cellular steal. Clinical factors are age, previous rupture of AVM, associated diseases and malformations of vital organs. Each of these factor groups has been divided into parameters to which a code number from 0 to 5 according to the severity of the considered parameter has been attributed. When a contraindication for radical surgery was clearly obvious, as, for example, an AVM with extension to the upper brain stem, number 10 was given. This grading has been done by a team of four persons (3 neurosurgeons including the senior author, and one biophysicist). By adding up all code numbers an Operability Score for a given patient is defined by the number of points, with a minimum of 3 and a maximum of 69. In cases with a score higher than 30 surgery is not advisable. A score between 21 and 30 indicates that always several staged operations are required, whilst only some of the patients with a score between 11 and 20 may require two stage operative treatment. The AVM in patients with a score under 10 can always be radically excised in a single stage operation. We have been able to demonstrate that the Operability Score allows a reliable prediction of outcome, thus giving indications and contraindications for surgery, and also for the surgical strategy. Moreover, we have explained why surgery had been refused in 9 additional cases during the same period. The causes of 8 fatalities out of 57 surgical cases are analyzed. These 57 cases represent a systematically explored series of the senior author; his experience is based upon 295 personal AVM cases (1958-1990).

Cavernous angioma of the cerebello-pontine angle: a case report

A case of cavernous angioma involving the facial nerve is described. The patient presented with decreased hearing on one side and after investigation a small mass was discovered enlarging the internal auditory meatus. The final diagnosis was made at operation. The pathology of this type of malformation is discussed.

Haemostatic clips and clamps used in surgical neurology with special reference to non ferro magnetic Phynox spring clips by Aesculap

This paper concerns the historical developments and technical properties of haemostatic devices used in neurosurgery with the exception of coagulation. Therefore there are described haemostatic clips designed for the scalp, clips used on arteries and veins, a clamp for the reduction of the carotid diameter in the neck, and a clamp for closing the venous dural sinuses. Special reference will be made regarding non ferro magnetic Phynox clips by Aesculap.

Hypoglossal neuroma following excision of a huge recurrent acoustic neuroma and facio-hypoglossal anastomosis. A complex management problem

A case of neuroma of the intracranial part of the hypoglossal nerve, not associated with neurofibromatosis, is presented. The patient had previously undergone surgery for the removal of a contralateral acoustic neuroma, and subsequent facio-hypoglossal anastomosis. The importance of early diagnosis, pre-operative clinical assessment and post-operative care is stressed.

Lhermitte-Duclos disease (dysplastic gangliocytoma of the cerebellum). Report of a case and review of the literature

The authors report the third published case of a Lhermitte-Duclos disease diagnosed preoperatively with the help of MRI, stressing its possible extension beyond the limits of the posterior fossa. The pertinent literature is reviewed concerning the clinical and radiological picture of this disease, as well as the different pathogenic hypothesis.

Trigeminal neuroma. A report of eleven cases

The clinical features, diagnosis, and management of a series of 11 cases of trigeminal neuroma (four men, seven women; mean age 40 years) are summarized. Symptoms at presentation were generally those of cerebellopontine angle and petrous apex space occupying lesions. Computed tomography scanning and magnetic resonance imaging were found to provide the best preoperative localization of these lesions, allowing better planning of the surgical approach and thereby maximizing tumor exposure, an essential for any attempt at total excision, considering the large size (greater than 3 cm) of these tumors when diagnosed. A retromastoid incision and posterior fossa craniectomy or a combined suprainfratentorial approach was used. Total excision was possible in four cases. In seven cases, a macroscopic clearance was effected (operative mortality nil, excellent outcome occurred in ten of the 11 cases). There has been no clinical evidence of recurrence or ongoing tumor growth despite possibly subtotal excision.

Detection of a ruptured aneurysmal sac by MRI in a case of negative angiogram. Successful clipping of an anterior communicating artery aneurysm. Case report

A case of a ruptured aneurysm is presented in which the angiograms did not disclose the sac. Rupture of an aneurysm of the anterior communicating artery was suspected from the distribution of subarachnoid blood on computerized tomography (CT), and the presence of a sac was highly suggestive on magnetic resonance imaging (MRI), which led us to open surgery. A non-thrombosed aneurysm was discovered at the suspected site, and successfully clipped. The necessity is discussed of MRI investigation in patients with subarachnoid haemorrhage (SAH) of unknown aetiology.

Brain tissue concentrations of ATP, phosphocreatine, lactate, and tissue pH in relation to reduced cerebral blood flow following experimental acute middle cerebral artery occlusion

Local CBF (LCBF) was compared with the corresponding local tissue concentration of ATP, phosphocreatine (PCr), and lactate in anaesthetized baboons subjected to focal ischaemia produced by middle cerebral artery occlusion (MCAO). LCBF hydrogen electrodes were implanted in cortical regions where MCAO had been previously shown to produce severe and penumbral ischaemia and in posterior regions where blood flow is not altered. Metabolites were assayed in small tissue samples collected either by cryoprobe biopsy in the regions where LCBFs were measured (series 1) or by sampling appropriate regions of the rapidly frozen brain (series 2). Subsequent topographical study of brain tissue pH with umbelliferone was performed in this latter series. The results from these two series are compared and discussed in terms of the more appropriate way to perform simultaneous electrode measurements and analysis of tissue samples for studying focal ischaemia in the primate brain. They confirm that the concentrations of ATP and PCr decrease, and that lactate level increases, with decreasing blood flow. These metabolites tended to change more rapidly below a blood flow threshold, rather than showing a steady decrease as the blood flow was reduced, although the variability of the data precluded us from establishing this with confidence. Topographical study of tissue pH often showed sharp boundaries between zones of very low pH and regions with normal pH.

In situ freezing of the brain for metabolic studies: evaluation of the "box" method for large experimental animals

The box method of freezing the brain in situ was assessed in baboons. The cooling rate of the tissue was monitored in several regions located at various depths from the skull surface. These measurements allowed us to examine the time required for the tissue to reach 0 degree C, in relation to its depth measured from the top of the skull. To define brain regions with proven ischaemia, frozen tissue sections were surveyed for areas of decreased pH. In addition, concentrations of ATP, phosphocreatine, and lactate were determined in gray matter located at various depths from the top of the brain surface. Normal tissue pH and low lactate concentration, without any significant decrease in high-energy phosphate levels, were found in regions at a depth less than approximately 10 mm from the brain surface. Deep structures including the inferiomedial aspect of the temporal lobe, the lateral geniculate body, and the limbic system (hippocampus) consistently showed mild tissue acidosis, indicating that these regions were subjected to some degree of ischaemia before they were reached by the freezing front. In some cases, acidosis was also detectable in the thalamus, basal ganglia, and in the deeper part of some sulci. We conclude that, with baboons, in situ freezing using the box method is valid for metabolic studies of the cerebral cortex and structures located at a depth less than approximately 10 mm from the top of the brain surface.

[Effect of the acute administration of molsidomine in refractory congestive heart failure. A double-blind randomized non-invasive study]

The effect of vasodilator Molsidomine (M) vs placebo on left ventricular dimensions and function measured by echocardiography was evaluated in a randomized study on 23 patients (pts) with refractory congestive heart failure (R CF) (NYHA class III-IV). The pts were randomized in two groups: group A (12 pts) received M, group B received an identical appearing placebo. Adequate echocardiograms were obtained before and one hour after 2 tablets of M (4 mg) or P; left ventricular end-diastolic and end-systolic diameters (LVEDD and LVESD), mean rate of circumferential shortening and left ventricular fractional shortening were calculated on the echocardiograms obtained. At the same time mean arterial pressure (MAP) and heart rate were measured. In group A, the single-dose test induced a significant reduction in LVEDD (74.1 +/- 7.2 to 72.1 +/- 7.1 mm; p less than 0.01), in LVESD (64.4 +/- 8.4 to 61.6 +/- 7.4 mm; p less than 0.01) and in MAP (96.5 +/- 8.3 to 85.4 +/- 7.2 mmHg; p less than 0.05). No significant changes were noted in the other parameters. Moreover, changes of parameters evaluated in group A between pts with idiopathic cardiomyopathy and pts with ischemic heart disease showed no statistical differences. Thus, acute Molsidomine therapy is effective in reducing left ventricular diameters and MAP in pts with RCF without changes of echocardiographic contractility indexes.

Phenyl-T-butyl-nitrone is active against traumatic shock in rats

Oxygen free-radicals appear to be involved in the pathogenesis of shock; therefore trapping of these radicals would modify the evolution of experimental shock. Experiments were performed on rats submitted to 100% lethal whole body trauma (rotating drum) and their survival, pathology, acid-base status and hematocrit level observed. The spin trapping agent phenyl-t-butyl-nitrone (PBN) was administered before trauma (50, 100, 150 mg/kg i.p.) or at various intervals (30, 60 minutes) after establishment of a severe traumatic shock. It appeared that PBN administration was highly effective both in prevention and in reversion of traumatic shock in rats.