Roger M. Krzyżewski

Configurations of the circle of Willis: a computed tomography angiography based study on a Polish population

The aim of the study was to investigate the distribution of the circle of Willis variants in Polish population by means of computed tomography angiography (CTA). The results were then analysed and compared with another study that used similar methods but that was carried out on an ethnically distinct population. Patients presenting with intracranial pathology were excluded from the initial study population. In total, 250 CTA belonging to 129 female and 121 male patients were reviewed. A modified classification system of the circle was proposed, which took into consideration the anterior and the posterior aspects of the circle individually. The typical variant of Williss circle occurred in 16.80% of cases. The anterior and the posterior portions of the circle were normal in 47.20% and 26.80% of the patients respectively. As for the anterior part, lack of the anterior communicating artery was the most frequent abnormality (22.80%). Bilateral absence of posterior communicating arteries was the most common anomaly in the posterior part of the circle (29.20%). This type of anomaly was also the most common, when taking into consideration the entire circle (12.00%). There were statistically significant differences between the age groups and genders when considering the occurrence of an incomplete circle. Overall, a substantial proportion of patients manifested clinically important variants that were incapable of providing collateral circulation. Comparison with other imaging-based and cadaveric studies revealed noticeable differences, that may have resulted from the variable technical features of other studies or other factors such as the ethnical origins of the studied populations.

Variations and morphometric analysis of the proximal segment of the superior cerebellar artery

INTRODUCTION The superior cerebral artery is a clinically significant vessel, but little is known about its radiological anatomy. The aim of this study was to describe the anatomical variations of the proximal segment of the superior cerebellar artery using Computed Tomography Angiography. MATERIALS AND METHODS The study group consisted of 200 subjects (54.5% female, mean age ± SD 56.2 ± 17.2 years) that had undergone head Computed Tomography Angiography. Subjects with any intracranial pathologies were excluded. Images in Maximum Intensity Projections were used to study the anatomical anomalies of the superior cerebellar artery. RESULTS In 200 subject 388 superior cerebellar arteries were found. Twelve (3.09%) SCAs were duplicated in 11 patients and all originated from the basilar artery. In 8 (4.00%) patients the superior cerebellar artery was absent. The origin of the SCA was most often bilateral, mainly from the basilar artery (76.29%). The superior cerebellar artery diameter, measured at the site of the origin, was statistically significantly different depending on the place of the origin: wider when originating from the basilar artery as a single vessel (1.48 ± 0.42 mm vs. 1.34 ± 0.52 mm; p=0.03) and narrower when originating as duplicated one (1.38 ± 0.48 mm vs. 1.46 ± 0.44 mm; p=0.55). CONCLUSION Superior cerebellar artery usually originates bilaterally from the basilar artery as a single trunk. Its diameter is significantly wider in that type in comparison to other anatomical variations.

Endoscopic biopsy of intra- and paraventricular brain tumors

Introduction Selection of the optimal treatment method of intra- and paraventricular tumors often requires histopathological verification that can be obtained by endoscopic biopsy. Aim To discuss the usefulness of the method in their own experience. Material and methods The results of 32 biopsies carried out during a 15-year period were reviewed retrospectively. All tumors were located supratentorially, 25 of them were intraventricular and 7 paraventricular. In 18 patients the tumor was accompanied by internal hydrocephalus. If the ventricular system was narrow, the biopsy was supported by a neuronavigation system. A rigid neuroendoscope was used. The obtained material was subjected to intraoperative and final histopathological examination. Results Viable diagnostic material was obtained from all patients. In 11 patients with tumor of the posterior portion of the third ventricle, cerebrospinal fluid was collected additionally for diagnostic tests. In 9 patients with obstructive hydrocephalus concomitant third ventriculostomy was performed. In 4 patients with tumor of the interventricular foramen, the tumor mass was reduced and in 2 cases septostomy was performed. In 3 (9.4%) cases the histopathological diagnosis was descriptive and did not explain the nature of the lesion. Four biopsies resulted in persistent bleeding, in 3 patients transient memory impairments were observed, and in 1 patient an epileptic seizure occurred. Five patients needed ventriculoperitoneal shunt placement. Conclusions Endoscopic biopsy is a safe method to verify the histopathological nature of intra- and paraventricular lesions. It enables sampling of cerebrospinal fluid, reduction of tumor size, and in cases of coexisting obstructive hydrocephalus also third ventriculostomy or septostomy.

Computer-aided analysis of middle cerebral artery tortuosity: association with aneurysm development

OBJECTIVEBlood vessel tortuosity may play an important role in the development of vessel abnormalities such as aneurysms. Currently, however, there are no studies analyzing the impact of brain blood vessel tortuosity on the risk of aneurysm formation. Therefore, the authors performed a computer-aided analysis of middle cerebral artery (MCA) tortuosity, especially among patients diagnosed with MCA aneurysms.METHODSAnatomy of the MCAs of 54 patients with unruptured MCA aneurysms was retrospectively analyzed, as was that of 54 sex-, age-, and vessel side-matched control patients without MCA aneurysms. From medical records, the authors obtained each patients medical history including previous and current diseases and medications. For each patient, they calculated the following tortuosity descriptors: relative length (RL), sum of angle metrics (SOAM), triangular index (TI), product of angle distance (PAD), and inflection count metric (ICM).RESULTSPatients with an MCA aneurysm had significantly lower RLs (0.75 ± 0.09 vs 0.83 ± 0.08, p < 0.01), SOAMs (0.45 ± 0.10 vs 0.60 ± 0.17, p < 0.01), and PADs (0.34 ± 0.09 vs 0.50 ± 0.17, p < 0.01). They also had significantly higher TIs (0.87 ± 0.04 vs 0.81 ± 0.07, p < 0.01) and ICMs (3.07 ± 1.58 vs 2.26 ± 1.12, p < 0.01). Female patients had significantly higher RLs (0.76 ± 0.11 vs 0.80 ± 0.09, p = 0.03) than male patients.CONCLUSIONSMiddle cerebral artery aneurysm formation is strongly associated with blood vessel tortuosity parameters, which can potentially be used to screen for patients at risk for MCA aneurysm formation.

The relation of pituitary adenomas invasiveness and the proliferative index measured by immunoexpression of topoisomerase IIα

INTRODUCTION Cavernous sinus invasion by pituitary adenoma affects surgical procedure radicality and consequently the postoperative course and prognosis in pituitary adenoma treatment. The search for pituitary adenoma aggressive behaviour markers is still a matter of debate. MATERIAL AND METHODS This study evaluates the relation of pituitary adenoma invasiveness to the expression of topoisomerase IIα in 72 patients who underwent transsphenoidal pituitary surgery. The assessment of tumour growth was conducted according to the Hardy scale as modified by Wilson and the Knosp scale. Topoisomerase IIα expression in tumour specimens was evaluated using immunohistochemical staining. RESULTS There was a correlation between the Knosp scale degree and the topoisomerase IIα expression (Spearman R = 0.3611, p < 0.005). The Kruskal-Wallis H test (p = 0.0034) showed that there was a statistically significant topoisomerase IIα expression increase in tumours classified as grade E on the Hardy scale. The topoisomerase IIα expression correlated also with tumour size (Spearman R = 0.4117, p < 0.001). Higher levels of expression were observed in macroadenomas, as compared to microadenomas (p < 0.05, Mann-Whitney test). Topoisomerase IIα expression correlated with cavernous sinus invasion. CONCLUSIONS The topoisomerase IIα expression correlated more with invasiveness than with extensiveness, which might make it an eminently useful marker in the assessment of aggressive pituitary adenoma behaviour.

Intracranial aneurysm distribution and characteristics according to gender

Abstract Objective: Female sex is associated with a greater prevalence of cerebral aneurysms. However, it also might be linked to the location and size of the aneurysm. The aim of this study was to find the link between female sex and aneurysm characteristics. Methods: Our study group consisted of 357 patients admitted to the hospital with both unruptured and ruptured aneurysms confirmed by Digital Subtraction Angiography or Computed Tomography Angiography and aneurysmal subarachnoid haemorrhage confirmed by head CT. Patients’ medical records were analyzed for necessary information including, but not limited to medical history, blood test results, and aneurysm prevalence, size and location. Results: Women constituted 232 (64.98%) of all patients. In this group, compared to males, we observed a more common occurrence of multiple aneurysms (1.35 ± 0.67 vs. 1.2 ± 0.57; p = .046) and left internal carotid artery aneurysms (25.88% vs. 13.93%; p < .01). Anterior communicating artery aneurysms were less common (17.11% vs. 31.15%; p < .01). Women also had lower dome-to-neck ratios (2.16 ± 0.82 vs. 2.82 ± 1.92; p < .01), were less likely to be smokers (53.6% vs. 33.19%; p < .01) and smoked fewer cigarettes per day (15.09 ± 6.62 vs. 21.09 ± 11.08; p < 0.01). Conclusions: Female patients have a greater risk of multiple aneurysms and left internal carotid artery aneurysms, but a lower risk of anterior communicating artery aneurysms.

The comparison of the 1972 Hodkinson’s Abbreviated Mental Test Score (AMTS) and its variants in screening for cognitive impairment

BackgroundSince its introduction by Hodkinson in 1972, Abbreviated Mental Test Score (AMTS) and its English and other language versions have been widely used in research and clinical practice alike. However, whether the various versions of AMTS yield equivalent information has never been tested.MethodsWe performed cross-sectional assessment of inpatients aged 65+ years with seven AMTS versions and the Mini-Mental State Examination (MMSE) after correction for age and education (MMSEc). We used the MMSEc cut-off score of < 24 as comparator and fitted linear regression models from which we obtained the receiver operating characteristics, and further compared the c-statistics obtained for each version of AMTS. We used Spearman’s correlation to check the relation between different AMTS versions.ResultsThe mean (SD) age of 72 (52.8% women) patients was 76.2 (7.6) years. The average time spent on education was 11.3 (3.5) years. The AMTS score across versions varied between 7.4 (2.0) and 8.2 (1.7). The MMSE averaged 24.1 (4.6) and the MMSEc averaged 25.2 (4.1). We found that the c-statistic across AMTS versions with dichotomised MMSEc as comparator ranged from 0.83 to 0.85 and did not significantly differ from the c-statistic of 0.87 for original AMTS (all p > 0.16). We found AMTS versions to be significantly correlated (all r between 0.83 and 0.99, all p < 0.0001).ConclusionsWe found AMTS to be a reliable and useful tool in the screening for possible cognitive impairment. This seems to be true irrespective of whether we use the original test or any of its studied modifications.

The Role of the Cerebellum in the Regulation of Language Functions

The present paper is a review of studies on the role of the cerebellum in the regulation of language functions. This brain structure until recently associated chiefly with motor skills, visual-motor coordination and balance, proves to be significant also for cognitive functioning. With regard to language functions, studies show that the cerebellum determines verbal fluency (both semantic and formal) expressive and receptive grammar processing, the ability to identify and correct language mistakes, and writing skills. Cerebellar damage is a possible cause of aphasia or the cerebellar mutism syndrome (CMS). Decreased cerebellocortical connectivity as well as anomalies in the structure of the cerebellum are emphasized in numerous developmental dyslexia theories. The cerebellum is characterized by linguistic lateralization. From the neuroanatomical perspective, its right hemisphere and dentate nucleus, having multiple cerebellocortical connections with the cerebral cortical language areas, are particularly important for language functions. Usually, language deficits developed as a result of a cerebellar damage have subclinical intensity and require applying sensitive neuropsychological diagnostic tools designed to assess higher verbal functions.