Automatic Calibration of a Device for Blood Pressure Waveform Measurement.

This article presents a prototype of a new, non-invasive, cuffless, self-calibrating blood pressure measuring device equipped with a pneumatic pressure sensor. The developed sensor has a double function: it measures the waveform of blood pressure and calibrates the device. The device was used to conduct proof-of-concept measurements on 10 volunteers. The main novelty of the device is the pneumatic pressure sensor, which works on the principle of a pneumatic nozzle flapper amplifier with negative feedback. The developed device does not require a cuff and can be used on arteries where cuff placement would be impossible (e.g., on the carotid artery). The obtained results showed that the systolic and diastolic pressure measurement errors of the proposed device did not exceed ±6.6% and ±8.1%, respectively.

Endoscopic third ventriculostomy before surgery of third ventricle and posterior fossa tumours decreases the risk of secondary hydrocephalus and early postoperative complications.

Endoscopic third ventriculostomy (ETV) is an effective treatment for obstructive hydrocephalus (HCP) at the level of third or fourth ventricle. To date, there is no consensus regarding its role as intervention preceding the operation of tumour removal. The aim of this prospective open-label controlled study is to assess if ETV prevents secondary HCP after tumour removal and if ETV influences the early results of tumour surgery. The study was performed on 68 patients operated for tumours of the third ventricle and posterior fossa. In 30 patients, ETV was performed several days before tumour removal, while in 38 patients, the tumour was removed during a one-stage procedure without ETV. Patients who did not receive ETV before the tumour removal procedure had a higher probability of developing postoperative HCP (n = 12, p = 0.03). They also demonstrated a substantially higher rate of early postoperative complications (n = 20, p = 0.002) and a lower Karnofsky score (p = 0.004) than patients in whom ETV was performed before tumour removal. The performance of external ventricular drainage in the non-ETV group did not prevent secondary HCP (p = 0.68). Postoperative cerebellar swelling (p = 0.01), haematoma (p = 0.04), cerebrospinal fluid leak (p = 0.04) and neuroinfection (p = 0.04) were the main risk factors of persistent HCP. Performance of ETV before tumour removal is not only beneficial for control of acute HCP but also prevents the occurrence of secondary postoperative HCP and may also minimize early postoperative complications.

Awake craniotomy with dexmedetomidine during resection of brain tumours located in eloquent regions.

INTRODUCTION: An awake craniotomy (AC) is the gold standard for the resection of supra-tentorial brain tumours in eloquent areas. Intraoperative monitoring "on-demand" of essential eloquent brain functions and the increasing need to preserve higher intellectual functions during surgery requires a unique anaesthetic approach during AC. Dexmedetomidine is considered the first-choice pharmacological agent for sedation during AC. MATERIAL AND METHODS: Twenty-six patients with a single brain tumour located in areas of eloquent brain function were enrolled in this prospective study. The patients underwent AC under conscious sedation. Motor-evoked potentials and brainstem-evoked auditory potentials were measured using neurophysiological tests during surgery to assess brain potentials. Intraoperative brain relaxation was reached using a modified Bristow scale. Neuromonitoring and psychological tests were maintained until meningeal closure. RESULTS: All operations were carried out successfully, and no reoperations were needed. No significant impact on circulatory and respiratory parameters was observed during conscious sedation based on dexmedetomidine. Neither instrumental airway support nor conversion to general anaesthesia was necessary. Brain relaxation was good in 84% of cases. Intraoperative epileptic episodes were observed in 15% of the patients. Neuro-logical and psychological monitoring was satisfactory. Unaltered muscle force was observed postoperatively in 88% of the patients. CONCLUSIONS: AC performed under conscious sedation, and dexmedetomidine infusion without instrumental airway support, was safe and well-tolerated by patients with comfortable physiological sleep for most of the procedure. This approach to AC was associated with minimal risk of perioperative adverse events and may be particularly beneficial in patients with severe comorbidities.

Various neuromodulation methods including Deep Brain Stimulation of the medial forebrain bundle combined with psychopharmacotherapy of treatment-resistant depression-Case report.

Background: Treatment-resistant depression remains one of the main concerns of modern psychiatry. Novel methods such as Transcranial Magnetic Stimulation (including deep and theta burst protocols, iTBS) and Deep Brain Stimulation (DBS) can be considered as alternative treatment options. Case presentation: Twenty-nine-year-old Caucasian female, single, higher-educated was treated with major depressive disorder initially with standard pharmaco- and psychotherapy. Due to diagnosed treatment resistance additional therapeutic approaches were introduced sequentially: Electroconvulsive therapy (efficient only 4 months) and Transcranial Magnetic Stimulation (intermittent Theta Burst Stimulation, iTBS improved just insomnia). Finally the patient was enrolled to the Deep Brain Stimulation (DBS) study with the medial forebrain bundle target. After 20 months of active DBS a reduction of over 80% of depressive symptom severity was observed (Montgomery-Asberg and Hamilton Depression Rating Scales), together with an 87% reduction of anxiety symptoms intensity (Hamilton Anxiety Rating Scale) and a 90% increase in social and occupational functioning. Subjective assessment of the patient performed with questionnaires and visual analog scales showed less pronounced improvement in terms of depressive and anxiety symptoms, and high reduction of anhedonia. Some mild, transient side effects of neurostimulation were eliminated with an adjustment in stimulation parameters. Conclusions: The presented clinical case confirms the possibility of achieving remission after the use of MFB DBS in treatment-resistant depression, but postponed for many months. Nevertheless, personalization of every combined therapy with DBS is necessary with exploration of individual factors as past traumas and personality traits. More reports on long-term observations in DBS treatment in TRD trials (especially focused on MFB target) are needed.

Navigated neuroendoscopy combined with intraoperative magnetic resonance cysternography for treatment of arachnoid cysts.

Endoscopic cystocysternostomy or cystoventriculostomy is the treatment of choice in patients with symptomatic intracranial arachnoid cysts. There are no objective diagnostic tests for reliable intraoperative evaluation of the effectiveness of performed stomies. The aim of this prospective open-label study is to demonstrate for the first time the usefulness of intraoperative cysternography performed with the low-field 0.15-T magnetic resonance imager Polestar N20 during endoscopic cysternostomies. The study was performed in patients operated for middle fossa arachnoid cysts (n = 10), suprasellar cysts (n = 4), paraventricular or intraventricular cysts (n = 6), and a pineal cyst (n = 1). The operations were performed with use of a navigated neuroendoscope. Intraoperative magnetic resonance (iMR) cysternography was performed before and after the cystostomy. In each case, iMR cysternography was safe and could show clearly the cyst morphology and the effectiveness of performed endoscopic cystostomies. In six cases, iMR cysternography had a significant influence of the surgical decision (p = 0.027). The rate of inconsistency between the intraoperative observations and iMR imaging-based findings was 29%. A good contrast flow through the fenestrated cyst walls correlated with a good long-term clinical outcome (ρ = 0.54, p < 0.05) and good long-term radiological outcome (ρ = 0.72, p < 0.05). Intraoperative low-field MR cysternography is a safe and reliable method for assessment of the efficacy of performed endoscopic cystostomies and has significant influence on the surgical decision. It may be reliably used for prediction of the long-term clinical and radiological outcome.

Deep brain stimulation: new possibilities for the treatment of mental disorders. / Gleboka stymulacja mózgu (Deep Brain Stimulation) ­ nowe mozliwosci leczenia zaburzen psychicznych.

Deep brain stimulation (DBS) is a treatment method that is currently getting more and more attention from psychiatrists. It has proven to be efficacious and safe in the treatment of neurological disorders, mainly Parkinson's disease (PD), dystonia and essential tremor. DBS has very often contributed to successful treatment in cases that had proved resistant to all other methods of treatment. Nowadays treatment-resistant obsessive-compulsive disorder (OCD) is the main psychiatric indication for DBS. Many studies have focused on assessing the efficacy and safety of this method in different mental disorders, including depressive disorders, Alzheimer's disease, anorexia nervosa, Tourette syndrome, substance addiction or aggressive behaviors. Single cases of successful treatment in bipolar disorder, schizophrenia and post-traumatic stress disorder have also emerged in recent years. In this review the current state of knowledge on the applicability of DBS in psychiatry is presented, based on the available systematic reviews, clinical trials and case studies, as well as on neurophysiological and neuroimaging data.

Deep brain stimulation in obsessive-compulsive disorder - case report of two patients. / Gleboka stymulacja mózgu w zaburzeniu obsesyjno-kompulsyjnym ­ dwa przypadki kliniczne.

Obsessive-compulsive disorder (OCD) occurs in 2-3% of the general population. Due to its chronicity and high resistance to standard treatment, alternative clinical management based on neuroscientific findings has been sought. Deep brain stimulation (DBS) is a modern and dynamic approach in the treatment of OCD giving hope to patients who are resistant to current pharmacotherapy and psychotherapy based treatments. This paper presents two cases of patients diagnosed with refractory OCD who received DBS therapy with concurrent pharmacotherapy and cognitive behavioral psychotherapy (CBT). Both patients underwent a neurosurgical procedure to implant electrodes into the anterior limb of the internal capsule (ALIC) and nucleus accumbens (NAc). Before and after the start of neurostimulation, patients underwent a clinical evaluation which consisted of a psychiatric examination and psychometric measurements (Y-BOCS, HAMA, HDRS, GAF, SOFAS). During the follow-up period, a blind attempt to switch off the neurostimulation was made. During the 6-month follow-up period, a significant reduction in the obsessive-compulsive, depressive and anxiety symptoms was achieved as well as an improvement in global patient functioning. The tolerance of DBS was found to be very good and no significant side effects were observed. The obtained results provide the basis for the implementation of this method in patients with OCD who are resistant to current treatment.

Usefulness of intraoperative magnetic resonance ventriculography during endoscopic third ventriculostomy.

BACKGROUND: Endoscopic third ventriculostomy (ETV) is the preferred method for the treatment of noncommunicating hydrocephalus. The different success rates of ETV indicate the difficulties in predicting the success of this procedure. OBJECTIVE: To show the usefulness of intraoperative ventriculography performed by the low-field 0.15-T magnetic resonance imager Polestar N20 during ETV. METHODS: The study was conducted in 11 patients with noncommunicating hydrocephalus caused by tumors or cysts of the third ventricle (n = 5), nontumoral stenosis of the sylvian aqueduct (n = 3), and fourth ventricle outlet obstruction (n = 3). Intraoperative magnetic resonance (iMR) ventriculography was performed before and after the ETV. RESULTS: In each case, iMR-ventriculography was a safe procedure and determined the exact site of obstruction of cerebrospinal fluid flow. In all cases, iMR-ventriculography performed after ETV showed with the greatest accuracy the patency of the performed fenestrations, demonstrating in 9 patients good flow of the contrast from the third ventricle to the basal cisterns, restricted flow in 1 patient, and no flow in 1 patient. The results of ventriculography were consistent with the postoperative neurological status of operated-on patients. In 3 patients, the opinion of the surgeons about the patency of endoscopic fenestration, based on intraoperative observation of the third ventricle floor, was inconsistent with the results from iMR-ventriculography. CONCLUSION: Low-field iMR-ventriculography is a safe procedure that can be successfully applied during ETV to determine the site of obstruction in hydrocephalus and the patency of performed ventricle fenestration.

Assessment of cerebral blood flow during infusion test in the diagnosis of normal pressure hydrocephalus.

BACKGROUND: Many studies indicate that the increase in intracranial pressure (ICP) leads to cerebral blood flow velocity (CBFV) changes. This relationship was accurately determined in patients with traumatic brain injury, OBJECTIVES: The aim of this study was to determine how the changes in intracranial pressure induced during an infusion test influence cerebral blood flow. MATERIAL AND METHODS: 40 patients with enlarged ventricular systems (Evan's ratio > 30%) who underwent a diagnostic lumbar infusion test (LIT) were included. Tests were performed at the Department of Neurosurgery, Wroclaw Medical University. CBFV in the middle cerebral artery was measured using transcranial Doppler (TCD) simultaneously during the standard lumbar infusion test. TCD measurements were continued with simultaneous recording of CSF pressure with a frequency of 100Hz. A total number of 5800 measurements (10-second periods) performed during the three phases of the infusion test (stable, infusion and decrease) was obtained. RESULTS: In the stable phase of LIT, a weak positive correlation between ICP and mean CBFV (R = 0.193, p < 0.01) was observed. There was no statistically significant correlation between ICP and the pulsatility index (PI, Gosling Index). During the increased-ICP phase of LIT (infusion, decrease), we observed significant changes in CBFV expressed by a decrease of diastolic velocity and an increase of systolic velocity. A simultaneous increase of pulsation correlated with an increase in ICP (R = 0.371, p < 0.01). There were no significant changes in mean CBFV. CONCLUSIONS: In patients with ventriculomegaly, the mean cerebral blood flow is maintained despite a significant increase in ICP, within the limits of the infusion test. It is noted the relative increase of the pulsatility indices of CBF may indicate preserved cerebrovascular reactivity.

[Analysis of expression of estrogen (ER) and progesterone receptors (PR) in brain glial tumors and its correlation with expression of p53 protein and proliferating cell nuclear antigen (PCNA)]. / Analiza wystepowania receptorów progesteronowych (PR) i estrogenowych (ER) w glejakach mózgu i ich zaleznosc od ekspresji bialka p53 i jadrowego antygenu proliferacyjnego (PCNA).

BACKGROUND AND PURPOSE: All the types of the glial cells contain estrogen (ER) and progesterone receptors (PR) but their occurrence in glial tumors of the brain is still controversial. The aim of this research was the clinical analysis of ER and PR expression in correlation with histological malignancy and expression of p53 and PCNA. MATERIAL AND METHODS: The investigation was carried out on a group of 56 patients operated on at the Neurosurgical Department of Wroclaw Medical University. The percentage of tumors containing ER and PR was assessed and mean receptor expressions were compared. Classical histological tests, immunohistochemical tests for ER, PR, p53 and PCNA with monoclonal antibodies (DACO) were performed for every specimen of tumor tissue. RESULTS: ER occurred in 24 cases (42.9%), PR in 10 cases (17.9%). 49% of highly malignant gliomas (WHO III and IV) were ER positive, whereas 29% of tumors grade I and II were ER positive. Frequencies of PR positive tumors were similar in both groups. Mean PR expression in p53 positive group was 8% and in p53 negative group 1.5% (p=0.017). Mean ER expression in PCNA positive group was 7.4%, whereas in PCNA negative group 2.7% (p<0.01). CONCLUSIONS: Frequency of ER occurrence is higher in highly malignant tumors. ER expression is correlated with proliferative activity (PCNA). PR expression is positively correlated with intensity of mutant p53 protein.

[Analysis of PCNA, Ki67, AgNOR and p53 expression in brain glial tumors]. / Analiza ekspresji antygenów proliferacyjnych (PCNA, Ki67), regionów organizatorów jaderkowych (AgNOR) i bialka p53 w nowotworach glejowych mózgu.

BACKGROUND AND PURPOSE: The aim of this study was to evaluate clinical usefulness of proliferating cell nuclear antigen (PCNA), Ki67 antigen, p53 protein and silver-binding nucleolar organizer regions (AgNOR) in brain glial tumors. MATERIAL AND METHODS: The investigation of PCNA, Ki67 and p53 was carried out on a group of 120 patients with glial tumors operated on at the Neurosurgical Department of Wroclaw Medical University including 63 patients operated again because of recurrence. AgNOR was evaluated on a group of 64 patients including 38 patients operated again. Classical histological tests, immunohistochemical tests for PCNA, p53 and Ki67 activity with monoclonal antibodies (DACO) and histochemical tests for AgNOR were performed on every specimen of tumor tissue. The level of 40% for PCNA, 2.75 (equal to median) for AgNOR and 5% for Ki67 and p53 was adopted as significant. RESULTS: Mean expression of PCNA of glial tumors grade I and II was 32%, grade III and IV - 44% (p<0.05). Mean expression of AgNOR was 1.88 and 3.16 (p=0.00001), respectively. Average PCNA expression in recurrent tumors to 12 months was 52.7% and for later recurrences - 35.4% (p<0.05). Average expressions of AgNOR were 3.38 and 2.68 (p<0.05), respectively. Differences of Ki67 and p53 expressions were not significant. CONCLUSIONS: PCNA and AgNOR expressions correlate with proliferative activity, growth rate and histological malignancy, reaching high values in highly malignant and early recurrent tumors. Antigens Ki67 and p53 do not seem to be predictive markers of glial tumors.