Critical closing pressure during experimental intracranial hypertension: comparison of three calculation methods.

Objectives: The critical closing pressure (CrCP) defines arterial blood pressure below which cerebral arteries collapse. It represents a clinically relevant parameter for the estimation of cerebrovascular tone. Although there are few methods to assess CrCP, there is no consensus which of them estimates this parameter most accurately. The aim of present retrospective, experimental study was to compare three methods of CrCP estimation: conventional Aaslid's formula and methods based on the cerebrovascular impedance: the established continuous flow forward (CFF) and a new pulsatile flow forward (PFF) model.Methods: The effects of the following physiological manoeuvres on the CrCP were studied in New Zealand white rabbits: lumbar infusion of Hartmann's solution to induce mild intracranial hypertension, sympathetic blockade to induce arterial hypotension, and modulation of respiratory tidal volume to induce hypocapnia or hypercapnia.Results: During intracranial hypertension, all CrCP estimates were significantly higher than at baseline, decreased with decreasing ABP and increased with gradual hypocapnia. During hypercapnia, all CrCP estimates were significantly decreased but only in the case of CrCPA the negative, non-physiological values were observed (16% of the cases). The Bland-Altman analysis revealed that a good agreement between each impedance method and Aaslid's method deteriorated significantly in the low range of the average numerical value of the estimates.Discussion: Our results confirm the limited usage of Aaslid's formula for the calculation of CrCP. Although both impedance methods seem to be equivalent, the fact that PFF model better describes cerebrovascular hemodynamic allows the recommendation of this model for the calculation of CrCP.

How does early decompressive craniectomy influence the intracranial volume relationship in traumatic brain injury (TBI) patients?

BACKGROUND: Decompressive craniectomy (DC) is a common neurosurgical procedure involving the removal of part of the skull vault combined with subsequent duroplasty. The goal of DC is to produce extra space for the swollen brain and/or to reduce intracranial pressure. In the present study, DC was performed in order to create space for the swollen brain. AIM OF THE STUDY: to compare the volume alteration of selected intracranial fluid spaces before and after DC, to evaluate the volume of post-decompressive brain displacement (PDBD) and the largest dimension of oval craniectomy (LDOC), and to assess the early clinical effects of DC. MATERIAL AND METHODS: The study group consisted of 45 patients with traumatic brain injury (four females and 41 males, mean age 54.5 years) who underwent DC (not later than five hours after admission to hospital) due to subdural haematomas and/or haemorrhagic brain contusions localised supratentorially and diagnosed by computed tomography (CT). The mortality rate in the study group was 40%. Study calculations were performed using Praezis Plus software by Med Tatra, Zeppelin and Pax Station by Compart Medical Systems. For statistical analysis, IBM SPSS Statistics software was used. RESULTS: The DC-related additional space was responsible for a statistically significant increase in the volume of preoperatively compressed intracranial fluid spaces. The mean volume of extra space filled by the swollen brain was 42.2 ml ± 40.7. The best early treatment results were achieved in patients under the age of 55. CONCLUSIONS: DC has limited effectiveness in patients aged over 70 years. In every patient with clamped basal cisterns, a skin incision enabling appropriate LDOC should be planned before surgery. DC should be as large as possible, and the limits of its dimensions should be the limits of anatomical safety.

Malignant middle cerebral artery (MCA) infarction in people over 85 years old - Diagnosis, management and risk factors.

INTRODUCTION: Malignant ischemic stroke of the middle cerebral artery (MCA) territory causes neurological deterioration due to the effects of space occupying cerebral edema. The prognosis is poor, and death usually occurs as a result of brainstem compression. There is no information on ischemic stroke, especially the malignant ones, in patients over 85 years old. AIM: The aim of this retrospective study was to evaluate the disease course, risk factors, survival rate and treatment of MCA malignant infarction in people over 85 years old. METHOD: The medical history of 66 patients with malignant MCA stroke was analyzed. The frequency of the occurrence of the risk factors like hypertension, hyperlipidemia, atrial fibrillation, heart failure, diabetes was evaluated. Disability was measured with the use of the National Institutes of Health Stroke Scale (NIHSS). Safety and effectiveness of the anticoagulants used in the group of patients with atrial fibrillation were analyzed. Chi-quadrat test and Mann-Whitney U test were used for statistical analysis of data. We also described 85 year-old patient with malignant brain stroke who was treated neurosurgically with a positive effect. RESULTS: Atrial fibrillation was diagnosed in 65% of patients of the investigated group. There were no statistically significant changes in the survival rate between the group of patients treated with the use of mannitol and patients without this treatment. CONCLUSION: The key risk factor in this group is the atrial fibrillation. The elderly patients require an intensive monitoring of the health condition by reference to brain stroke risk factors, especially atrial fibrillation.

Discriminant Analysis of Intracranial Volumetric Variables in Patients with Normal Pressure Hydrocephalus and Brain Atrophy.

A method was developed for the computerized volumetric assessment of the intracranial cerebrospinal fluid (CSF) distribution. The study involved 62 patients differentiated into two groups: with CSF resorption disorders (normal pressure hydrocephalus - 30 patients) and without CSF resorption disorders (various types of brain atrophy - 32 patients). The goal of the study was to ascertain whether the assessment, depending on the linear discriminant analysis of volumetric brain features, could be an effective tool differentiating the two groups. Volumetric measurements were performed using VisNow software. For each patient, five features were determined and subjected to discriminant analysis: CSF volume in the subarachnoid space and basal cisterns (SV), CSF volume in the intracranial ventricular system (VV), brain volume (BV), total intracranial CSF volume (FV), and total intracranial volume (TV). Discriminant analysis enables the achievement of a high percentage of correct classification of patients to the appropriate group determined on the result of a lumbar infusion test. The discriminator, based on three features: BV, SV, and VV, showed a complete separation of the groups; irrespective of age. The squared Mahalanobis distance was 70.8. The results confirmed the applicability of the volumetric method. Discriminant analysis seems a useful tool leading to the acquisition of a computer-aided method for the differential diagnosis of CSF resorption disorders.

Importance rating of risk factors of ischemic stroke in patients over 85 years old in the polish population.

INTRODUCTION: The European population is aging and the number of elderly patients suffering from ischemic brain stroke increases. A better knowledge of the correlation between the risk factors and the course of the disease in old people may be useful for planning medical care and prophylactic strategies. AIM: This prospective study aimed to perform a demographic and clinical analysis of the etiology of ischemic stroke, survival rate and severity of post-stroke disability in patients who developed ischemic stroke at the age of over 85 years in the Polish population. METHOD: The study group consisted of 159 patients over 85 years old with ischemic stroke. The prevalence of risk factors such as sex, hypertension, hyperlipidemia, atrial fibrillation, heart failure and diabetes was evaluated. The outcome was assessed using the Barthel scale and the National Institutes of Health Stroke Scale. RESULTS: The most common risk factors of ischemic stroke were hypertension and atrial fibrillation. Patients with atrial fibrillation had a more severe course of ischemic stroke. CONCLUSION: The course of brain stroke in the Polish population is more severe in patients over 85 years old than in younger ones. The key risk factor in this group is atrial fibrillation.

Polymerase chain reaction based detection of bacterial 16S rRNA gene in the cerebrospinal fluid in the diagnosis of bacterial central nervous system infection in the course of external cerebrospinal fluid drainage. Comparison with standard diagnostics currently used in clinical practice.

BACKGROUND AND PURPOSE: External drainage of cerebrospinal fluid (CSF) is a commonly used neurosurgical procedure. Complications of the procedure comprise central nervous system (CNS) bacterial infections, the frequency of which is estimated at around 6-10%. Detection of these infections is ineffective in many cases. The aim of the study was to evaluate the usefulness of a polymerase chain reaction (PCR)-based detection of bacterial 16S rRNA gene (16S rDNA) in the CSF. MATERIAL AND METHODS: The study group consisted of 50 patients. Clinical signs of CNS infection were monitored and routine laboratory and microbiological tests were performed. The results of standard methods were compared with the bacterial 16S rDNA detection. RESULTS: Using cultures, CNS infection was diagnosed in 8 patients, colonization of the drainage catheter in 6 patients, and sample contamination in 7 patients. In the group of the remaining 29 patients, no positive CSF culture was obtained and 13 of these patients also had all negative results for 16S rDNA detection. For the remaining 16 patients of this group, CNS infection, colonization of the catheter and sample contamination were diagnosed via PCR alone. Routine biochemical CSF tests and blood inflammatory parameters had a supporting value. CONCLUSIONS: Routine hospital tests do not provide rapid and efficient detection of the external drainage related bacterial CNS infection. It is justified to use several diagnostic methods simultaneously. The16S rDNA determination in CSF can increase the probability of detection of possible pathogens.

Robotic stereotactic body radiation therapy for liver-limited malignant tumors.

INTRODUCTION: Stereotactic body radiotherapy (SBRT) is rapidly gaining favor as a new treatment modality for malignant liver tumors. Most of the studies have recruited patients with disseminated disease originating from the liver. This study focuses on disease limited to the liver. AIM: To perform a retrospective analysis of all patients with liver tumors treated by robotic stereotactic body radiation therapy in a single center. MATERIAL AND METHODS: The study included 13 patients with 22 lesions. The inclusion criteria were: patients with 1-4 inoperable liver lesions and absence of any extrahepatic disease. All but 3 patients received 3 fractions delivered by the Cyberknife system of a total of 45 grey (Gy). The other 3 patients received 30 Gy. RESULTS: The median follow-up time was 10.8 months (range: 7-16). The median dose was 41.5 Gy (range: 30-45). One lesion regressed (8%). In 5 patients, the disease was locally stabilized (38%), and in 7 other patients progression occurred (54%). Twelve patients (92%) are still alive, and 1 patient (8%) died. In 1 patient a new cancer (leukemia) was diagnosed. CONCLUSIONS: The SBRT is well tolerated and effective for local control of most liver malignant tumors. It appears that SBRT is best suited for those patients in whom systemic recurrence can be controlled by chemotherapy. Further studies are mandatory to elucidate these effects on tumors of varying histology and to elaborate upon criteria used to select patients who can benefit most from this treatment.

Asymptomatic and symptomatic glial cysts of the pineal gland.

Glial cysts of the pineal gland are benign and mostly asymptomatic incidental lesions found in the brain MRI or at autopsy examinations. In rare cases pineal cysts become symptomatic and require surgical intervention. Symptomatic glial cysts may be clinically and radiologically indistinguishable from cystic neoplasms of the pineal region; therefore, histopathological diagnosis is critical for further prognosis and therapy in operated patients. In this paper we present detailed histopathological characteristics of symptomatic glial cysts in 2 surgical cases and of asymptomatic cysts of the pineal gland found at random in 3 autopsy cases. Both surgical patients, a 19-year-old girl and a 17-year-old boy, presented with severe headaches, associated with syncope in one case and insomnia in the second one. Preoperative MR imaging suggested tumour of the pineal gland in case no. 2. Histopathological and immunohistochemical examination of the specimens from both surgical and all autopsy cases revealed a characteristic pattern of cystic structures within the pineal gland, surrounded by layers of a dense fibrillar glial tissue and pineal parenchyma, consistent with non-neoplastic glial cysts. Although histopathological findings in asymptomatic and symptomatic cysts are essentially the same, the cyst in surgical case 1 was unilocular and partly lined with ependymal cells, whereas the cysts in other cases were multilocular, comprising cavities of various size, formed in the central part of gliotic tissue or directly within the pineal parenchyma, and lacked ependymal lining. Possible pathophysiological and clinicopathological significance of some morphological variants of pineal glial cysts is discussed.

Granular cell astrocytoma. A case report with immunohistochemical and ultrastructural characterization.

Granular cell astrocytoma (GCA) is an uncommon type of granular cell tumours (GCTs) in the central nervous system. Granular cells in these tumours are of enigmatic origin. We report a case of cerebral GCA in a 59-year-old man who suffered from diabetes and Addison-Biermer disease. The tumour was localized in the left parietal lobe. Microscopically, the tumour was almost entirely composed of large, polygonal cells with round to oval, granular eosinophilic, PAS-positive cytoplasm. The nuclei were located centrally or eccentrically and sometimes exhibited nucleolar vacuoles. The tumour cells were arranged in nests surrounded by blood vessels and connective tissue. Immunohistochemically, the granular tumour cells were reactive for GFAP and vimentin. They were intensively stained for ubiquitin and some of them were reactive for CD68. Moreover, a lot of stromal cells expressed CD68 reactivity. Ultrastructurally, most tumour cells were round or oval with only a few or without filaments. Their cytoplasm was filled with electron-dense granular material limited by a single membrane and autophagic vacuoles. Another type of tumour cells, present in a significantly lower number, revealed abundant cytoplasm with numerous intermediate filaments, swollen rough endoplasmic reticulum, mitochondria and a few clusters of granular material. Cells with numerous condensed electron-dense, bizarrely-shaped mitochondria and few filaments were occasionally observed. Among granular cells, macrophages with vacuoles and/or lamellar structures were visible. In our case, both immunohistochemical and ultrastructural analysis supported astroglial origin of the granular cell tumour.

[Deep brain stimulation and motor cortex and spinal cord stimulation in the treatment of movement disorders and pain syndromes -- the theoretical baseline and practical guidelines]. / Stymulacja mózgu i rdzenia kregowego w leczeniu zaburzen ruchowych oraz zespolów bólowych -- podstawy teoretyczne i zalecenia praktyczne.

The authors present the current views on the use of electrical stimulation in selected movement disorders (Parkinson's disease, dystonia) and pain syndromes (central and neuropathic pain) refractory to pharmacological therapy. Stimulation should be applied in cases with an established diagnosis (especially Parkinson's disease and dystonia) and with a lack of efficacy despite the best available medical therapy. Therefore it should be the last treatment option, except of generalized dystonia, where it seems to be nowadays the treatment of choice. Suggested selection criteria are based on experience of different centers and on current medical literature. They are published to make the procedure more rational and more available in Poland.

[Modeling of cerebrospinal fluid circulation with consideration of a pressure-volume curve in infusion tests of patients with suspected hydrocephalus. Preliminary report]. / Modelowanie krazenia plynu mózgowo-rdzeniowego z uwzglednieniem zjawiska zmiany nachylenia krzywej cisnieniowo-objetosciowej w testach infuzyjnych u pacjentów z podejrzeniem wodoglowia. Doniesienie wstepne.

AIM OF THE STUDY: To verify the model of CSF circulation for both the increasing and decreasing CSF pressure during and after the infusion test. MATERIAL: Computerized infusion tests of 27 patients diagnosed for communicating hydrocephalus in the Department of Neurosurgery, Medical University of Warsaw were analyzed. METHOD: Pressure-volume (P-V) curves were plotted separately for ascending and descending phases of the test for comparison purposes. RESULTS: The phenomenon of significant change of the P-V curve slope after the infusion was identified in 70% of tests. It was found that the elastance coefficient was significantly greater during the infusion than after the infusion. The pulsatile changes in cerebral blood volume were higher after the infusion in comparison to values during the infusion. The baseline pressure was higher than that before the infusion. There was a significant increase in mean arterial blood pressure after the infusion and it was not associated with any change in the heart rate. CONCLUSIONS: We hypothesized that vasogenic component of intracranial pressure is responsible for the change of P-V curve slope. We also presume that the higher value of the pressure after the infusion can be due to by the excessive accumulation of cerebrospinal fluid in the intracranial space, including extra cellular parenchymal space. Both hypotheses require further studies to be evaluated.

[Vagus nerve stimulation (VNS) in the treatment of drug-resistant epilepsy. A 4-year follow-up evaluation of VNS treatment efficacy]. / Stymulacja nerwu blednego (SNB) w leczeniu lekoopornej padaczki. Ocena skutecznosci po 4 latach leczenia.

OBJECTIVES: Vagus nerve stimulation (VNS) is an alternative non-destructive surgical treatment for patients with medically intractable epilepsy. Neither the rationale nor proper indications for this treatment modality have been fully established yet. AIM OF THE STUDY: To assess the long-term efficacy of chronic VNS. MATERIAL: A series of 6 patients with drug-resistant epilepsy, subjected to VNS therapy. (4 females, 2 males, mean age 35.5 years, 3 patients with focal epilepsy, 3 with non-focal epilepsy, mean history of seizures 10 years, seizures frequency 10-400/per month). METHOD: An open-label prospective study with a 4-year follow-up. RESULTS: At a 4-year follow-up one patient (with non-focal epilepsy) was seizure-free, with only rare episodes of aura (Engel Ia), while in another one (with bitemporal epilepsy) seizures frequency remained unchanged with VNS (Engel IVb). In the remaining 4 cases (one with bitemporal, one with parietal, and two with non-focal epilepsy) the mean overall reduction in seizures frequency as compared to the baseline was 60% (Engel IIIa). VNS resulted in a reduction of seizures by 90% in a patient with a history of an unsuccessful anterior callosotomy. CONCLUSIONS: 1. VNS was found to reduce both the frequency of seizures (an overall 60% reduction in seizures frequency) and the duration of post-seizure consciousness disturbances in focal and non-focal epilepsies, but seizures-free state could be obtained in only one out of six patients. 2. A previous unsuccessful callosotomy did not prevent a good anticonvulsant effect in one patient. 3. The anticonvulsant effect of VNS was cumulative over time during the first 3 years postoperatively, then it tended to reach a plateau. 4. The best clinical outcome was positively correlated with the currents 1.5-2.0 mA. No significant correlation was noted for the current adjustments at the level of 2.0-3.5 mA. 5. Since no difference between the two stimulation patterns tested (30 s stimulation + 5 min break vs. 14 s + 3 min) was found as regards the anticonvulsant action of VNS, the latter pattern was subsequently used as the one more sparing the battery.

Clinicopathological and ultrastructural study in two cases of chordoid glioma.

Chordoid glioma is a rare benign neoplasm of uncertain histogenesis occurring in the third ventricle/ /suprasellar region. Recently, data have emerged suggesting that chordoid glioma is a variant of ependymoma related to a specialised ependyma of the subcommisural organ or the lamina terminalis area. In this study, we report clinicopathological and ultrastructural findings in two chordoid glioma cases. In case 1, a tumour (1.5 cm in diameter) in a 62-year-old man invaded the anterior-basal part of the third ventricle in the lamina terminalis region. In case 2, a large tumour in a 51-year-old woman occupied the whole third ventricle. The tumour attached to the medio-basal hypothalamic region. Histologically, both cases revealed a distinct chordoma-like pattern and glial immunophenotype of tumour cells. Under the electron microscope the tumour cells exhibited microvilli, intercellular lumina, intermediate type junctions and focal basal lamina formations. These findings were similar to those previously reported in the chordoid glioma cases. Moreover, the intracytoplasmic cilia and subplasmalemmal pinocytic vesicles or caveoles were observed. The study supports the view of ependymal derivation of chordoid glioma. Its relation to lamina terminalis or infundibular/median eminence area presumably reflecting tumour origin from the modified ependyma of circumventricular organs of the third ventricle is discussed.

[The effect of chronic Vagus Nerve Stimulation (VNS) on the central conduction time assessed by multimodal evoked potentials in patients with drug resistant epilepsy: preliminary report]. / Wplyw przewleklej Stymulacji Nerwu Blednego (SNB) u chorych z padaczka lekooporna na centralny czas przewodzenia, oceniany badaniami multimodalnych potencjalów wywolanych. Doniesienie wstepne.

Changes over time in evoked potentials of various modality (VEP, SSEP and BAEP) were analyzed in 3 patients, submitted to chronic Vagus Nerve Stimulation (VNS) due to drug resistant epilepsy. The aim of a study was to establish which cerebral structures are most prone to change their baseline electrophysiological status in consequence of chronic VNS. Evoked potentials were examined before the Vagus Nerve Stimulator implantation and at arbitrarily defined follow-ups several months after the implantation. Preliminary results obtained in a small group of 3 patients suggest a possible prolongation of the central conduction time in the examined modalities of evoked potentials due to the VNS treatment. A hypothetical mechanism of antiepileptic VNS action might be related to the permanent stimulation of brainstem and cortical structures that limit seizures propagation through hyperpolarisation both at the cortical level and in subcortical structures.

[The DREZ lesion as an effective treatment for chronic hypothetically post-herpetic neuropathic pain. Case report and review of literature]. / Operacja DREZ lesion w skutecznym leczeniu przewleklego bólu neuropatycznego prawdopodobnie po przebytym pólpascu. Opis przypadku i przeglad pismiennictwa.

The authors present a case of a 54-year-old woman with a 3-year history of chronic pain syndrome, probably of postherapeutic origin, with diffuse segmentary dermatome characteristics, both somatic and autonomic. The former were exemplified by a constant "burning" skin pain in the representation of Th8-LI dermatomes unilaterally, while the latter by a unilateral visceral pain within the abdominal cavity. Electrophysiological examination indicated a neuropathic origin of the pain, despite the lack of clinically evident sensory deficits and/or hypersensitivity. The pain was so intense that normal walking was difficult for the patient and ineffectiveness of her treatment made her suicidal. Since both pharmacological treatment (non-steroid analgesics, opioids, antidepressants, and anticonvulsants including gabapentin) and minimally invasive methods of treatment (blockades, thermolesions) failed to control pain, she was subjected to surgery. A right-sided DREZ lesion within the Th8-LI dermatomes resulted in a complete pain relief, both within the somatic and autonomic innervation projections, and in the patient's functional recovery.

[Difficulties in stereotactic biopsies of brain tumors]. / Trudnosci w biopsjach stereotaktycznych guzów mózgu.

MATERIAL: 28 stereotactic biopsies of organic brain processes (brain tumours) were performed in the years 1997-2000 in the Department of Neurosurgery, Medical University of Warsaw. In this series the lesions were located in corpus callosum in 5 patients, in basal nuclei in 9, and deeply in the white matter of cerebral hemispheres in 14. METHOD: The Baklund biopsy kit and Leksell's stereotactic frame were used, target localisation was based on the CT scan. Histological verification was based on hematoxillin--eosin staining, completed with histochemical evaluation if necessary. In 9 patients intraoperative smear evaluation was performed. RESULTS: Sensitivity of stereotactic biopsies was 86% (24/28), although the rate of conclusive biopsies was lower, being 60% (17/28). False negative results were observed in 14% of the patients (4/28). Analysis of the results revealed, that the sensitivity was not dependent on the size, neither on the location of the tumour, but was related to its morphology. The false negative results were obtained in the tumours with significant necrosis (as seen on CT scans). There were no surgical complications in this series. CONCLUSIONS: 1. Difficulties in stereotactic biopsies of brain tumours are associated mainly with tumour morphology. In tumours with marked necrosis, other degenerative changes or cystic ones, higher risk of non-conclusive biopsy may be expected. 2. Size of the tumour and its location do not affect the diagnosis based on the stereotactic biopsies. 3. In the polymorphic tumours, the policy to take biopsy material from different tumour sites, should be a rule, as different parts of the lesion may represent different stages of malignancy and histological evaluation of separate parts of the tumour may lead to inadequate oncological treatment.

[Blister-like aneurysm of anterior wall of the internal carotid artery, non related to arterial branches. Case report and review of literature]. / "Plaski" tetniak przedniej sciany tetnicy szyjnej wewnetrznej, niezwiazany z odgalezieniami naczyniowymi. Opis przypadku i przeglad pismiennictwa.

The authors present (for the first time in polish medical literature) a case of a 41-year old woman, presenting with subarachnoid haemorrhage due to ruptured blister-like aneurysm of the anterior wall of internal carotid artery, unrelated to any arterial branches. The patient was successfully treated surgically (clipping below the aneurysm base within the margin of normal parent artery wall). The authors present diagnostic and therapeutic difficulties of the case, which are characteristic of this type of aneurysms: 1. difficulty to diagnose the aneurysm in angiography (small size and blister-like shape) 2. high risk of massive bleeding and high surgical risk (danger of whole arterial wall rupture). 3. specific surgical approach and technique: subpial dissection of the dome, use of clipgraft, or positioning the clip branches below the base of aneurysm within the margin of normal arterial wall (as the aneurysm dome is composed exclusively of adventitia and is not a part of artery wall. The authors discuss the peculiarities concerning the nature, localisation and possible mechanism of formation of this rare type of aneurysms. The analysis is based on the present case and on the review of literature.