Cigarette Smoking and Intracranial Aneurysms: A Pilot Analysis of SNPs in the CYP2A6 Gene in the Italian Population

BACKGROUND

Cigarette smoking is a modifiable risk factor associated with formation and rupture of intracranial aneurysms (IAs). Cytochrome P450 2A6 (CYP2A6) is the main enzyme implied in catabolism of nicotine and xenobiotics, giving rise to oxidative stress products. Our study investigated the associations between specific single-nucleotide polymorphisms (SNPs) in the CYP2A6 gene and the presence of sporadic IAs in a cluster of Italian patients, as well as their rupture regarding cigarette smoking habit.

METHODS

Three hundred and thirty-one Italian patients with sporadic IAs were recruited in a single institution. We recorded data on clinical onset with subarachnoid hemorrhage (SAH) and smoking habit. Genetic analysis was performed with a standard procedure on peripheral blood samples: CYP2A6 ∗1B2, CYP2A6 ∗2, and CYP2A6 ∗14 SNPs were analyzed in the study group along with 150 healthy control subjects. Statistical analysis was conducted according to genetic association study guidelines.

RESULTS

In the patient cohort, the frequency of aSAH was significantly higher in current smokers (P < 0.001; OR=17.45), regardless of the pattern of CYP2A6 SNPs. There was a correlation between IA rupture and cigarette smoking in patients with the heterozygous CYP2A6 ∗1B2 allele (P < 0.001; OR=15.47). All patients carrying the heterozygous CYP2A6 ∗14 allele had an aSAH event (100%), regardless of smoking habit, although this correlation was not statistically significant (P = 1).

CONCLUSIONS

According to our findings, a cigarette smoker carrying a fully active CYP2A6 enzyme (heterozygous ∗1B2 allele) may have an increased risk of IA rupture compared to those with functionally less active variants: further investigation on a larger sample is needed to verify this result. The role of the heterozygous CYP2A6 ∗14 allele in aSAH is yet to be clarified.

Imaging markers of intracerebral hemorrhage expansion in patients with unclear symptom onset

Background:

Hematoma expansion (HE) is common and associated with poor outcome in intracerebral hemorrhage (ICH) with unclear symptom onset (USO).

Aims:

We tested the association between non-contrast computed tomography (NCCT) markers and HE in this population.

Methods:

Retrospective analysis of patients with primary spontaneous ICH admitted at five centers in the United States and Italy. Baseline NCCT was analyzed for presence of the following markers: intrahematoma hypodensities, heterogeneous density, blend sign, and irregular shape. Variables associated with HE (hematoma growth > 6 mL and/or > 33% from baseline to follow-up imaging) were explored with multivariable logistic regression.

Results:

Of 2074 patients screened, we included 646 subjects (median age = 75, 53.9% males), of whom 178 (27.6%) had HE. Hypodensities (odds ratio (OR) = 2.67, 95% confidence interval (CI) = 1.79–3.98), heterogeneous density (OR = 2.16, 95% CI = 1.46–3.21), blend sign (OR = 2.28, 95% CI = 1.38–3.75) and irregular shape (OR = 1.82, 95% CI = 1.21–2.75) were independently associated with a higher risk of HE, after adjustment for confounders (ICH volume, anticoagulation, and time from last seen well (LSW) to NCCT). Hypodensities had the highest sensitivity for HE (0.69), whereas blend sign was the most specific marker (0.90). All NCCT markers were more frequent in early presenters (time from LSW to NCCT ⩽ 6 h, n = 189, 29.3%), and more sensitive in this population as well (hypodensities had 0.77 sensitivity).

Conclusion:

NCCT markers are associated with HE in ICH with USO. These findings require prospective replication and suggest that NCCT features may help the stratification of HE in future studies on USO patients.

An international call for a new grading system for cerebral and cerebellar cavernomas

Surgical indications for cerebral cavernous malformations remain significantly center- and surgeon-dependent. Available grading systems are potentially limited, as they do not include epileptological and radiological data. A novel grading system is proposed for supratentorial and cerebellar cavernomas: it considers neuroradiological features (bleeding, increase in size), neurological status (focal deficits and seizures), location of the lesion and age of the patient. The score ranges from -1 to 10; furthermore, surgery should be considered when a score of 4 or higher is present. Based on neuroradiological characteristics, 0 points are assigned if the CCM is stable in size at different neuroradiological controls, 1 point if there is an increase in volume during follow-up, 2 points if intra- or extra-lesional bleeding <1 cm is present and 3 points if the CCM produced a hematoma >1 cm. Regarding focal neurological deficits, 0 points are assigned if absent and 2 points if present. For seizures, 0 points are assigned if absent, 1 point if present, but controlled by medications, and 2 points if drug resistant. We considered the site of the CCM, and in case of deep-seated lesions in a critical area (basal ganglia, thalamus) 1 point (-1) is subtracted, while for subcortical or deep cerebellar lesions 0 points are assigned, for CCMs in a cortical critical area 1 point is assigned and in case of lesions in cortical not in critical area or superficial cerebellar area, 2 points are assigned. As far as age is concerned, 0 points are assigned for patients older than 50 years and 1 point for patients younger than 50. In conclusion, a novel grading for surgical decision making in cerebral cavernomas, based on the experience of selected neurosurgeons, basic scientists, and patients, is suggested with the aim of further improving and standardizing the treatment of CCMs. The aim of this paper was also to call for both retrospective and prospective multicenter studies with the aim of testing the efficacy of the grading system in different centers.

Pituitary Adenomas and Invasiveness from Anatomo-Surgical, Radiological, and Histological Perspectives: A Systematic Literature Review

Invasiveness in pituitary adenomas has been defined and investigated from multiple perspectives, with varying results when its predictive value is considered. A systematic literature review, following PRISMA guidelines, was performed, searching PubMed and Scopus databases with terms that included molecular markers, histological, radiological, anatomical and surgical data on invasiveness of pituitary adenomas. The results showed that differing views are still present for anatomical aspects of the sellar region that are relevant to the concept of invasiveness; radiological and histological diagnoses are still limited, but might improve in the future, especially if they are related to surgical findings, which have become more accurate thanks to the introduction of the endoscope. The aim is to achieve a correct distinction between truly invasive pituitary adenomas from those that, in contrast, present with extension in the parasellar area through natural pathways. At present, diagnosis of invasiveness should be based on a comprehensive analysis of radiological, intra-operative and histological findings.

Alcohol intake and the risk of intracerebral hemorrhage in the elderly: The MUCH-Italy

OBJECTIVE

To investigate the role of alcohol as a causal factor for intracerebral hemorrhage (ICH) and whether its effects might vary according to the pathogenic mechanisms underlying cerebral bleeding.

METHODS

We performed a case-control analysis, comparing a cohort of consecutive white patients with ICH aged 55 years and older with a group of age- and sex-matched stroke-free controls, enrolled in the setting of the Multicenter Study on Cerebral Haemorrhage in Italy (MUCH-Italy) between 2002 and 2014. Participants were dichotomized into excessive drinkers (>45 g of alcohol) and light to moderate drinkers or nondrinkers. To isolate the unconfounded effect of alcohol on ICH, we used causal directed acyclic graphs and the back-door criterion to select a minimal sufficient adjustment set(s) of variables for multivariable analyses. Analyses were performed on the whole group as well as separately for lobar and deep ICH.

RESULTS

We analyzed 3,173 patients (1,471 lobar ICH and 1,702 deep ICH) and 3,155 controls. After adjusting for the preselected variables in the minimal sufficient adjustments, heavy alcohol intake was associated with deep ICH risk (odds ratio [OR], 1.68; 95% confidence interval [CI], 1.36-2.09) as well as with the overall risk of ICH (OR, 1.38; 95% CI, 1.17-1.63), whereas no effect was found for lobar ICH (OR, 1.01; 95% CI, 0.77-1.32).

CONCLUSIONS

In white people aged 55 years and older, high alcohol intake might exert a causal effect on ICH, with a prominent role in the vascular pathologies underlying deep ICH.

Cerebral small-resistance artery structure and cerebral blood flow in normotensive subjects and hypertensive patients

INTRODUCTION

The aim of this study was to prospectively investigate whether the structure of cerebral small-resistance arteries is related to cerebral perfusion parameters as measured with dynamic susceptibility-weighted contrast magnetic resonance imaging (DSC-MRI) in a selected cohort of hypertensive and normotensive patients.

METHODS

Ten hypertensive and 10 normotensive patients were included in the study. All patients underwent neurosurgical intervention for an intracranial tumor and were investigated with DSC-MRI at 1.5 T. Cerebral small-resistance arteries were dissected from a small portion of morphologically normal cerebral tissue and mounted on an isometric myograph for the measurement of the media-to-lumen (M/L) ratio. A quantitative assessment of cerebral blood flow (CBF) and volume (CBV) was performed with a region-of-interest approach. Correlation coefficients were calculated for normally distributed variables. The institutional review board approved the study, and informed consent was obtained from all patients.

RESULTS

Compared with normotensive subjects, hypertensive patients had significantly lower regional CBF (mL/100 g/min) in the cortical grey matter (55.63 ± 1.90 vs 58.37 ± 2.19, p < 0.05), basal ganglia (53.34 ± 4.39 vs 58.22. ± 4.33, p < 0.05), thalami (50.65 ± 3.23 vs 57.56 ± 4.45, p < 0.01), subcortical white matter (19.32 ± 2.54 vs 22.24 ± 1.9, p < 0.05), greater M/L ratio (0.099 ± 0.013 vs 0.085 ± 0.012, p < 0.05), and lower microvessel density (1.66 ± 0.67 vs 2.52 ± 1.28, p < 0.05). A statistically significant negative correlation was observed between M/L ratio of cerebral arteries and CBF in the cortical grey matter (r = -0.516, p < 0.05), basal ganglia (r = -0.521, p < 0.05), thalami (r = -0.527 p < 0.05), and subcortical white matter (r = -0.612, p < 0.01).

CONCLUSION

Our results indicate that microvascular structure might play a role in controlling CBF, with possible clinical consequences.

Ruptured aneurysm in sphenoid sinus: which is the best treatment?

Internal carotid artery (ICA) aneurysms involving the sphenoid sinus are uncommon, and their optimal treatment remains debated. We report the case of a patient presenting with recurrent epistaxis due to a bleeding cavernous ICA aneurysm. We suggest a combined endovascular and endoscopic approach when ICA occlusion may not be performed.

Ruptured aneurysm in sphenoid sinus: which is the best treatment?

Internal carotid artery (ICA) aneurysms involving the sphenoid sinus are uncommon, and their optimal treatment remains debated. We report the case of a patient presenting with recurrent epistaxis due to a bleeding cavernous ICA aneurysm. We suggest a combined endovascular and endoscopic approach when ICA occlusion may not be performed.

Limits of intermittent jugular bulb oxygen saturation monitoring in the management of severe head trauma patients

OBJECTIVE

To evaluate, in a prospective, observational study, whether bilateral monitoring of jugular bulb oxyhemoglobin saturation (SjO2), in addition to standard monitoring, results in modification of the management of severe head trauma.

METHODS

The patients underwent bilateral jugular bulb cannulation and observation at 8-hour intervals, during which SjO2 was measured and the neurological condition and physiological variables were assessed. The study group was responsible for evaluating whether the physician's decision-making process was influenced by the detection of SjO2 abnormalities. The SjO2 discrepancy in simultaneous bilateral samples was also evaluated to determine whether it interfered with the interpretation of data and with clinical decision-making. The SjO2-related complications were monitored.

RESULTS

Thirty patients underwent 319 observations. In 96% of patients, SjO2 was normal or high and had no influence on the diagnostic or therapeutic strategies. Treatment decisions were dictated by changes in clinical status and in intracranial and cerebral perfusion pressure. When these parameters were abnormal, treatment was administered, even if SjO2 was normal (101 observations). Conversely, when SjO2 was the only detected abnormality (34 observations), no treatment was administered. Abnormally low SjO2 values, caused by hypovolemia and hypocapnia, were detected in 3.4% of observations and actually modified the management. The discrepancies in simultaneous bilateral samples were substantial and gave rise to relevant interpretation problems. Fifteen percent of jugular catheters showed evidence of bacterial colonization.

CONCLUSION

Intermittent SjO2 monitoring did not substantially influence the management of severe head trauma. Therefore, recommendation for its routine use in all patients seems inadvisable, and indications for this invasive method should no longer be defined on the basis of experts' opinions, but rather on randomized, prospective studies.

Emergent decompressive craniectomy in patients with fixed dilated pupils due to cerebral venous and dural sinus thrombosis: report of three cases

OBJECTIVE AND IMPORTANCE

Cerebral venous and dural sinus thrombosis is a rare cause of stroke. Although morbidity and mortality have greatly decreased in recent years as a result of early diagnosis and timely medical treatment, when coma occurs the prognosis remains poor. We evaluated whether emergent decompressive craniectomy has a role in the treatment of patients with brain herniation from dural sinus thrombosis and hemorrhagic infarct.

CLINICAL PRESENTATION

Three patients developed large hemorrhagic infarct with coma and bilaterally fixed and dilated pupils resulting from aseptic dural sinus thrombosis.

INTERVENTION

Two patients underwent emergent surgical decompression as soon as brain herniation developed, and these patients had complete functional recovery. One underwent delayed surgical decompression and remained severely disabled.

CONCLUSION

Our results provide preliminary evidence that emergent decompressive craniectomy is effective in patients with brain herniation from dural sinus thrombosis, provided that the clinical onset is recent. We therefore recommend consideration of this aggressive surgical technique for such patients, who may survive with good outcomes.