External quality monitoring facilitates improvement in already well-performing stroke units: insights from RES-Q Poland.

INTRODUCTION: The Registry of Stroke Care Quality (RES-Q) is used in Poland for quality monitoring by numerous hospitals participating in the Angels Initiative. Our aim was to assess the degree of improvement in highly stroke-oriented centres that report cases to the RES-Q each year. MATERIAL AND METHODS: This retrospective analysis included Polish stroke units that from January 2017 to December 2020 contributed to the RES-Q at least 25 patients annually. RESULTS: Seventeen out of 180 Polish stroke units reported patients each year (2017, n = 1,691; 2018, n = 2,986; 2019, n = 3,750; 2020, n = 3,975). The percentage of ischaemic stroke patients treated with alteplase remained stable (26%, 29%, 30% and 28%, respectively). The door-to-needle time progressively decreased, from a median 49 minutes to 32 minutes. The percentage of patients treated ≤ 60 minutes and ≤ 45 minutes significantly increased (from 68% to 86% and from 43% to 70%, respectively), with no change observed between 2019 and 2020. Despite a general improvement in dysphagia screening (81%, 91%, 98% and 99%), screening performed within the first 24h from admission became less frequent (78%, 76%, 69% and 65%). In-hospital mortality significantly increased (11%, 11%, 13% and 15%), while the proportion of patients discharged home remained stable. CONCLUSIONS: Quality-oriented projects facilitate the improvement of stroke care, even in centres demonstrating good baseline performance. Polish stroke units that consistently reported cases to the RES-Q demonstrated improvement in terms of door-to- -needle time and dysphagia screening. However, there is still a need to shorten the time to dysphagia screening, and carefully monitor stroke unit mortality following the COVID-19 pandemic.

Temporal changes in regulatory T cell subsets defined by the transcription factor Helios in stroke and their potential role in stroke-associated infection: a prospective case-control study.

BACKGROUND: Regulatory T cells (Tregs) are involved in the systemic immune response after ischemic stroke. However, their role remains unclear, and the effect appears to be both neuroprotective and detrimental. Treg suppressor function may result in immunodepression and promote stroke-associated infection (SAI). Thus we assume that the bidirectional effects of Tregs may be in part attributed to the intracellular transcription factor Helios. Tregs with Helios expression (H+ Tregs) constitute 70-90% of all Treg cells and more frequently than Helios-negative Tregs (H- Tregs) express molecules recognized as markers of Tregs with suppressor abilities. METHODS AND RESULTS: We prospectively assessed the circulating Treg population with flow cytometry in 52 subjects on days 1, 3, 10 and 90 after ischemic stroke and we compared the results with those obtained in concurrent age-, sex- and vascular risk factor-matched controls. At all studied time points the percentage of H+ Tregs decreased in stroke subjects-D1: 69.1% p < 0.0001; D3: 62.5% (49.6-76.6), p < 0.0001; D10: 60.9% (56.5-72.9), p < 0.0001; D90: 79.2% (50.2-91.7), p = 0.014 vs. controls: 92.7% (81.9-97.0) and the percentage of H- Tregs increased accordingly. In patients with SAI the percentage of pro-suppressor H+ Tregs on post-stroke day 3 was higher than in those without infection (p = 0.03). After adjustment for confounders, the percentage of H+ Tregs on day 3 independently correlated with SAI [OR 1.29; CI 95%: 1.08-1.27); p = 0.02]. Although the percentage of H+ Tregs on day 3 correlated positively with NIHSS score on day 90 (rS = 0.62; p < 0.01) and the infarct volume at day 90 (rS = 0.58; p < 0.05), in regression analysis it was not an independent risk factor. CONCLUSIONS: On the first day after stroke the proportion of H+ vs. H- Tregs changes in favor of pro-inflammatory H- Tregs, and this shift continues toward normalization when assessed on day 90. A higher percentage of pro-suppressive H+ Tregs on day 3 independently correlates with SAI and is associated positively with NIHSS score, but it does not independently affect the outcome and stroke area in the convalescent phase of stroke.

Brain injury mobile diagnostic system: Applications in civilian medical service and on the battlefield-General concept and medical aspects.

To present the concept of a portable ultrasound tomography device for diagnosing traumatic and vascular brain lesions. The device consisting of multiple transcranial ultrasound probes placed on the surface of the head, specifically but not exclusively in natural acoustic windows. An integral part of the mobile diagnostic system (MDS) is a decision support system based on artificial intelligence algorithms utilizing information from: head images, laboratory data, and assessment of the patient's clinical condition. The MDS can significantly reduce the time from stroke onset to rtPA therapy in civilian medical services and support therapeutic and evacuation strategies in instances of brain and skull trauma on the battlefield.

Ambiguities in blood pressure management in acute ischaemic stroke.

INTRODUCTION: Blood pressure management in acute ischaemic stroke is crucial. Here we highlight uncertainties surrounding haemodynamic management in acute ischaemic stroke on the basis of current guidelines and the data available from recent studies. This review provides practical treatment options and suggestions for future research. STATE OF THE ART: The U-shaped relationship between baseline blood pressure value and patients' functional outcome or death is well established. Nonetheless, there is scant evidence for the benefits of early pharmacological intervention. Current guidelines differentiate blood pressure targets on the basis of implemented reperfusion treatment and allow blood pressure reduction in certain clinical situations. However, there is a substantial lack of evidence to guide management during acute stroke. CLINICAL IMPLICATIONS: Taking into account several aspects of blood pressure management can improve stroke care, although they are not included in current guidelines. To make an optimal decision as to whether to intervene regarding blood pressure, it is important to consider dehydration, recanalisation status, blood pressure variability, and autoregulation state as measured by novel imaging techniques. FUTURE DIRECTIONS: Further trials considering patient-specific factors with the use of continuous monitoring of blood pressure, as well as neurovascular imaging, are needed to resolve the current ambiguities.

Association between nocturnal oxygen desaturation and ischaemic stroke outcomes.

CLINICAL RATIONALE FOR THE STUDY: This study aimed to assess the association between nocturnal hypoxemia and early acute ischaemic stroke (AIS) outcomes in patients without oxygen supplementation. MATERIAL AND METHODS: One hundred and six AIS patients consecutively admitted to the stroke unit were included in this study. Baseline demographic and medical data and arterial blood saturation (SpO2) measurements during night-sleep (from 10pm to 6am) were examined for their association with stroke outcomes, including the National Institutes of Health Stroke Scale (NIHSS) score on the 7th day or differences between the NIHSS score on the 1st day and the 7th day after stroke onset. Measurements of SpO2 were made using a pulse oximeter of the Spacelabs Medical Inc. (USA) monitoring system, and the number of apnoea episodes and their duration were recorded by ECG Holter with respiration monitoring (CardioMem®, Getamed, GE). RESULTS: The study showed that age (Spearman's r = 0.207, p = 0.033) and parameters attributable to anaemia (RBC r = -0.205, p = 0.035, Hb r = -0.225, p = 0.02 and HCT r = -0.196, p = 0.044), atrial fibrillation and ischaemic changes in both brain hemispheres (p = 0.023 and 0.01, respectively) were correlated with the study outcomes. In terms of saturation parameters, we demonstrated that the 'total desaturation burden' (i.e. [100% minus actual measured SpO2%] x apnoea duration) and multiple apnoeas of longer than 20 seconds were correlated with worse functional outcomes. Measures of shorter desaturation episodes (i.e. SpO2 oxygen desaturation index (ODI) at 3% and 4%, and time-weighted desaturations below the determined thresholds (SpO2 from 95% to 85%) demonstrated non-significant associations with the study outcomes. CONCLUSIONS AND CLINICAL IMPLICATIONS: This study demonstrated that long-lasting desaturation episodes during the night, depicted by the 'total desaturation burden', were correlated with worse functional outcomes in AIS, while measures of shorter desaturation episodes were not correlated. In future clinical trials, indications for oxygen supplementation should include the methodology of personalised medicine and introduce individual approaches based on specially formulated, novel multifactorial algorithms.

Serum Proteome Alterations in Human Cystathionine ß-Synthase Deficiency and Ischemic Stroke Subtypes.

Ischemic stroke induces brain injury via thrombotic or embolic mechanisms involving large or small vessels. Cystathionine ß-synthase deficiency (CBS), an inborn error of metabolism, is associated with vascular thromboembolism, the major cause of morbidity and mortality in affected patients. Because thromboembolism involves the brain vasculature in these patients, we hypothesize that CBS deficiency and ischemic stroke have similar molecular phenotypes. We used label-free mass spectrometry for quantification of changes in serum proteomes in CBS-deficient patients (n = 10) and gender/age-matched unaffected controls (n = 14), as well as in patients with cardioembolic (n = 17), large-vessel (n = 26), or lacunar (n = 25) ischemic stroke subtype. In CBS-deficient patients, 40 differentially expressed serum proteins were identified, of which 18 were associated with elevated homocysteine (Hcy) and 22 were Hcy-independent. We also identified Hcy-independent differentially expressed serum proteins in ischemic stroke patients, some of which were unique to a specific subtype: 10 of 32 for cardioembolic vs. large-vessel, six of 33 for cardioembolic vs. lacunar, and six of 23 for large-vessel vs. lacunar. There were significant overlaps between proteins affected by CBS deficiency and ischemic stroke, particularly the cardioembolic subtype, similar to protein overlaps between ischemic stroke subtypes. Top molecular pathways affected by CBS deficiency and ischemic stroke subtypes included acute phase response signaling and coagulation system. Similar molecular networks centering on NFκB were affected by CBS deficiency and stroke subtypes. These findings suggest common mechanisms involved in the pathologies of CBS deficiency and ischemic stroke subtypes.

Spatial distribution of white matter degenerative lesions and cognitive dysfunction in relapsing-remitting multiple sclerosis patients.

AIM: The aim of this study was to assess degenerative lesion localisation in the course of relapsing-remitting multiple sclerosis (RRMS) and to identify the association between localisation and the frequency of T1-hypointense lesions (black holes) with cognitive dysfunction. We also searched for neuroradiological predictors of cognitive dysfunction in patients. The clinical rationale for the study was previous research, and our own findings suggest that lesion localisation plays an important role in cognitive performance and neurological disability of MS patients. MATERIAL AND METHODS: Forty-two patients were included in the study. All subjects underwent neuropsychological examination using Raven's Coloured Progressive Matrices, a naming task from the Brief Repeatable Battery of Neuropsychological Tests, and attention to detail tests. Magnetic resonance imaging (MRI) was acquired on 1.5 Tesla scanner and black holes were manually segmented on T1-weighted volumetric images using the FMRIB Software Library. Linear regression was applied to establish a relationship between black hole volume per lobe and cognitive parameters. Bonferroni correction of voxelwise analysis was used to correct for multiple comparisons. RESULTS: The following associations between black hole volume and cognition were identified: frontal lobes black hole volume was associated with phonemic verbal fluency (t = -4.013, p < 0.001), parietal black hole volume was associated with attention (t = -3.776, p < 0.001), and parietal and temporal black hole volumes were associated with nonverbal intelligence (p < 0.001). The volume of parietal black holes was the best predictor of cognitive dysfunction. CONCLUSIONS: Our approach, including measurement of focal axonal loss based on T1-volumetric MRI sequence and brief neuropsychological assessment, might improve personalised diagnostic and therapeutic decisions in clinical practice.

The Association between Serum Matricellular Protein: Secreted Protein Acidic and Rich in Cysteine-Like 1 Levels and Ischemic Stroke Severity.

BACKGROUND: The role of matricellular proteins like secreted protein acidic and rich in cysteine-like 1 (SC1) has been shown in important functions in the central nervous system, including the regulation of synaptic stability with upregulation throughout axonal regeneration. The aim of this study was to determine whether SC1 is related to ischemic stroke severity. METHODS: A total of 132 consecutively recruited patients admitted for acute ischemic stroke were included in this observational prospective study. Stroke severity was evaluated in the National Institutes of Health (NIHSS) scale on hospital admission. RESULTS: There was a positive correlation between SC1 levels and NIHSS score (r = .22, P = .009). Compared with patients with NIHSS scores lower than 5 at admission, patients with moderate and severe stroke (NIHSS ≥ 6) had significantly higher SC1 levels: 4.84 (2.53-11.58) ng/mL versus 3.31 (1.67-8.95) ng/mL (P = .01). SC1 was an independent predictor of stroke severity at admission (adjusted odds ratio =1.25; 95% confidence interval, 1.03-1.97; P = .04). CONCLUSION: SC1 levels were independently associated with ischemic stroke severity evaluated by the NIHSS.

Free thyroxine and TSH interact with secreted protein acidic and rich in cysteine-like 1 in ischemic stroke.

The role of the thyroid gland in ischemic stroke pathology is not well understood. As thyroid hormones modulate the extracellular matrix, we explored the possible link between them and secreted protein acidic and rich in cysteine like 1 (SC1) - one of the extracellular matrix molecules. In the 81 patients with acute ischemic stroke, serum SC1 levels were much higher compared with 30 control subjects: 4.47 vs 2.43ng/mL (p<0.001). Serum levels of free thyroxine (fT4) were higher in stroke subjects compared to those of controls (p=0.03). In stroke patients, TSH concentration was lower than in the control group (p=0.03). SC1 levels positively correlated with fT4 levels (p=0.02) and negatively with TSH (p=0.03) in stroke patients. Our results confirmed the association between thyroid hormones and SC1 - extracellular matrix protein.

Clinical recovery and health-related quality of life in ischaemic stroke survivors receiving thrombolytic treatment: a 1-year follow-up study.

The aims of this study were to examine prospectively the course of neurological and functional recovery and health related quality of life (HRQoL) in ischaemic stroke patients after intravenous thrombolysis, to assess the 1-year outcome and to determine the early predictors. A group of 53 consecutive patients were assessed at admission to the acute stroke unit (T0), before their discharge (T1), and at 3 (T2) and 12 (T3) months after hospital discharge. The National Institutes of Health Stroke Scale (NIHSS), the Barthel Index (BI) and the Stroke Specific Quality of Life Scale (SSQoL) were used to evaluate stroke severity, functional disability and health related quality of life (HRQoL). A good outcome was defined as simultaneous improvement in all three scales. At T0, 83 % of the patients had severe or moderate neurological impairment. Additionally, 77 % demonstrated very severe or severe disability when assessed by the BI. 74 and 79 % of the patients reported an acceptable HRQoL at 3 and 12 months following discharge, respectively. Neurological and functional status improved significantly over time with most changes occurring during hospitalization and the subsequent 3 months. At T3, 75.5 % of the patients had the good outcome which had been independently predicted by the level of stroke related disability at T0. A majority of the stroke survivors treated with thrombolysis achieved a good outcome. The measurement of stroke specific HRQoL, as a tool for gathering information from the patient, should be incorporated in the assessment of post-stroke recovery and outcome.

Reversal of antithrombotic treatment in intracranial hemorrhage--A review of current strategies and guidelines.

In the last few years, there has been a rapid increase in patients being treated with various anticoagulation and antiplatelet agents. In clinical neurology, these drugs are administered for primary and secondary stroke prevention or to avoid the consequences of immobilization of severe stroke patients. Additionally, thrombolytic intravenous therapy and, recently, intra-arterial therapy for stroke have been increasingly employed all over the world. These therapies are associated with an increased risk of hemorrhage, including the most dangerous, intracranial hemorrhage. The knowledge of the standards for the treatment of hemorrhagic complications in the central nervous system is crucial for doctors in neurology and stroke units as well as in emergency rooms. Therefore, we conducted a review of various guidelines and recommendations, including manufacturers' opinions contained in the summaries of product characteristics (Polish and British or European versions), in Guidelines of the Polish Neurological Society and in international and American guidelines i.e., European Stroke Organization (ESO) and American Heart Association/American Stroke Association (AHA/ASA). In addition, we compared these guidelines with expert opinions published in recent manuscripts and manuals on intensive care in neurology.

Homocysteine thiolactone and other sulfur-containing amino acid metabolites are associated with fibrin clot properties and the risk of ischemic stroke.

Homocysteine (Hcy) and Hcy-thiolactone (HTL) affect fibrin clot properties and are linked to cardiovascular disease. Factors that influence fibrin clot properties and stroke are not fully understood. To study sulfur-containing amino acid metabolites, fibrin clot lysis time (CLT) and maximum absorbance (Absmax) in relation to stroke, we analyzed plasma and urine from 191 stroke patients (45.0% women, age 68 ± 12 years) and 291 healthy individuals (59.7% women, age 50 ± 17 years). Plasma and urinary levels of sulfur-containing amino acid metabolites and fibrin clot properties were significantly different in stroke patients compared to healthy individuals. Fibrin CLT correlated with fibrin Absmax in healthy males (R2 = 0.439, P = 0.000), females (R2 = 0.245, P = 0.000), female stroke patients (R2 = 0.187, P = 0.000), but not in male stroke patients (R2 = 0.008, P = ns). Fibrin CLT correlated with age in healthy females but not males while fibrin Absmax correlated with age in both sexes; these correlations were absent in stroke patients. In multiple regression analysis in stroke patients, plasma (p)CysGly, pMet, and MTHFR A1298C polymorphism were associated with fibrin Absmax, while urinary (u)HTL, uCysGly, and pCysGly were significantly associated with fibrin CLT. In healthy individuals, uHTL and uGSH were significantly associated with fibrin Absmax, while pGSH, and CBS T833C 844ins68 polymorphism were associated with fibrin CLT. In logistic regression, uHTL, uHcy, pCysGly, pGSH, MTHFR C677T polymorphism, and Absmax were independently associated with stroke. Our findings suggest that HTL and other sulfur-containing amino acid metabolites influence fibrin clot properties and the risk of stroke.

Association of Metallic and Nonmetallic Elements with Fibrin Clot Properties and Ischemic Stroke.

Objectives-Metallic elements and fibrin clot properties have been linked to stroke. We examined metallic and nonmetallic elements, fibrin clot lysis time (CLT), and maximum absorbance (Absmax) in relation to ischemic stroke. Design-A case-control study of ischemic stroke patients vs. healthy individuals. Subjects and Methods-Plasma and serum were collected from 260 ischemic stroke patients (45.0% women; age, 68 ± 12 years) and 291 healthy controls (59.7% women; age, 50 ± 17 years). Fibrin CLT and Absmax were measured using a validated turbidimetric assay. Serum elements were quantified by inductively coupled plasma mass spectrometry (ICP-MS) and optical emission spectrometry (ICP-OES). Data were analyzed by bivariate correlations and multiple or logistic regression. Results-In female stroke patients, copper, lithium, and aluminum were significantly lower compared with controls; in male stroke patients, potassium was lower, and beryllium was elevated. In female and male stroke patients, iron, zinc, nickel, calcium, magnesium, sodium, and silicon were significantly lower, while strontium was elevated. Positive correlations between fibrin clot properties and metals, observed in healthy controls, were lost in ischemic stroke patients. In multivariate regression analysis, fibrin CLT and/or Absmax was associated with zinc, calcium, potassium, beryllium, and silicon in stroke patients and with sodium, potassium, beryllium, and aluminum in controls. In logistic regression analysis, stroke was independently associated with lithium, nickel, beryllium, strontium, boron, and silicon and with sodium, potassium, calcium, and aluminum but not with fibrin CLT/Absmax. Conclusions-Various elements were associated with fibrin clot properties and the risk of ischemic stroke. Lithium, sodium, calcium, and aluminum abrogated the association of fibrin clot properties with ischemic stroke.

Significance of pulse pressure variability in predicting functional outcome in acute ischemic stroke: a retrospective, single-center, observational cohort study.

This study aimed to determine the association between pulse pressure variability (PPV) and short- and long-term outcomes of acute ischemic stroke (AIS) patients. We studied 203 tertiary stroke center patients with AIS. PPV during 72 h after admission was analyzed using different variability parameters including standard deviation (SD). Patients' outcome was assessed after 30 and 90 days post-stroke with modified Rankin Scale. The association between PPV and outcome was investigated using logistic regression analysis with adjustment for potential confounders. The predictive significance of PPV parameters was determined using area under the curve (AUC) of receiver operating characteristics. In the unadjusted logistic regression analysis, all PPV indicators were independently associated with unfavorable outcome at 30 days (i.a. Odds ratio (OR) = 4.817, 95%CI 2.283-10.162 per 10 mmHg increase in SD, p = 0.000) and 90 days (i.a. OR = 4.248, 95%CI 2.044-8.831 per 10 mmHg increase in SD, p = 0.000). After adjustment for confounders, ORs for all PPV indicators remained statistically significant. On the basis of AUC values, all PPV parameters were found relevant outcome predictors (p < 0.01). In conclusion, elevated PPV during first 72 h after admission due to AIS is associated with unfavorable outcome at 30 and 90 days, independent of mean blood pressure levels.

Effect of Face Masks on Blood Saturation, Heart Rate, and Well-Being Indicators in Health Care Providers Working in Specialized COVID-19 Center.

This study aims to investigate whether wearing face masks (filtering facepieces, FFP class 2) with personal protective equipment (FPP2/PPE), while working a 12-h shift in a COVID-19 referral center, affects the blood saturation, heart rate (HR), and well-being of health care providers (HCPs). The study included a group of 37 HCPs. To perform continuous recordings of the SpO2 and heart rate (HR) in real time, we used a Nellcor PM10N (Covidien, Mansfield, MA, USA) portable monitoring system. SpO2, HR, and HCP well-being scales were measured during two 3-h shifts, while HCPs worked during a 12-h period. Additionally, each subject completed a questionnaire concerning their well-being. The difference in the SpO2 level between the 1st and 2nd working shifts while wearing an FFP2/PPE was small, with a median decrease in SpO2 of -1%. The scales of the well-being indicators increased within the shift. They were mainly fatigue and thirst with median scores of 2 out of 6 (range 0-4). We assume that during a 12-h period, a work scheme that consists of a 3-h shift in FFP2/PPE and a 3-h rest period (working without FPP2/PPE) is a reliable and safe solution for HCPs working in specialized COVID-19 referral hospitals.

The impact of FFP3 respirators on the blood saturation.

This study aims to investigate whether wearing a filtering facepiece class 3 respirators with personal protective equipment (FPP3/PPE) during work in the intensive care unit (ICU) affects the blood saturation (SpO2), the heart rate (HR), and the well-being of health care workers (HCWs). This preliminary study included a group of 21 volunteers (including 16 females (76%), with a median age of 23 years). Each worker served as his own control and performed the test two times: they wore the FFP3/PPE and did not wear it for a three-hour shift in the ICU. The working with an FFP3/PPE compared to not working with an FFP3/PPE caused a significant, but within normal ranges, influence on the level of SpO2 with a mean decrease of - 1.43%. The highest reduction in the SpO2 was - 2.29% and occurred after 150 min of work. All of the score scales of the well-being markers increased consecutively but moderately during the shift while wearing the FFP3/PPE. We assume that a 3-h shift rhythm is a safe and reliable solution, i.e., three hours of working in the FFP3/PPE in the ICU, followed by rest or working without an FFP3/PPE.

Serum paraoxonase/arylesterase activity affects outcome in ischemic stroke patients.

BACKGROUND: The severity of neurological deficits arising from ischemic stroke may be related to serum redox homeostasis. The aim of this study was to estimate the effect of serum paraoxonase (PON), arylesterase (ARE) activities and conjugated dienes (CD) on patient outcome during a 1-year follow-up period. METHODS: The study included 468 consecutive ischemic stroke patients (251 males, 217 females) with an average age of 67.5 ± 12.4 years. Clinical evaluation was based on vital signs, National Institutes of Health Stroke Scale (NIHSS) scored at the time of admission and on the 7th day after stroke, as well as modified Rankin scale (mRS) and Barthel index (BI) scored at 30, 90, 180 and 360 days after stroke onset. Serum PON, ARE activities and CD concentration were measured with the use of spectrophotometric methods. RESULTS: Serum PON activity alone correlated directly with a favorable outcome during a 3-month observation period. Serum ARE activity correlated directly only with the mRS score in a 1-year observation. PON/ARE ratio showed the strongest direct correlation with favorable stroke outcome expressed by BI and inverse correlation with mRS as compared to serum PON or ARE activities assessed alone. PON/ARE affected the NIHSS score on admission (rS = -0.119, p = 0.014) and on the 7th day after stroke (rS = 0.120, p = 0.015); it also showed an association with the BI and mRS on the 30th (rS = 0.145, p = 0.007 and rS = -0.098, p = 0.049, respectively), 90th (rS = 0.147, p = 0.009, rS = -0.133, p = 0.008, respectively), as well as 180th, and 360th day after stroke. We did not find correlations between the serum CD concentration and stroke outcome. CONCLUSION: The PON/ARE ratio is an important predictor of ischemic stroke outcome and can be used in clinical practice rather than evaluating either PON or ARE activity alone.

Educational level and cognitive impairment in patients with Parkinson disease.

BACKGROUND AND PURPOSE: Parkinson disease (PD) is a risk factor for dementia. In addition, specific cognitive deficits can occur in PD patients without dementia. A patient's level of education could have an influence on the development of cognitive impairment in PD. The aim of this study was to examine the relationship between the level of education and cognitive performance in non-demented patients with PD. MATERIAL AND METHODS: Thirty-seven consecutive, nondemented PD patients and 40 healthy controls fulfilled the inclusion criteria and were enrolled in the case-control study. Each of the controls and PD patients were classified, for the purpose of this study, into one of three groups (low, intermediate, higher), categorized by the number of years of education. There were no differences in education and age between the controls and PD patients. All of the subjects were evaluated with a battery of neuropsychological tests: Mini-Mental State Examination, Trail Making Tests, Stroop Test, Mental Rotation Test, and Verbal Fluency Test. RESULTS: Less (low and intermediate) education was correlated with poor results from tests. The comparison of all groups of PD patients and controls demonstrated that PD subjects received lower test scores, especially for the low and intermediate groups. However, no statistically significant difference was reached between educationally advanced PD patients and the appropriate control subjects. CONCLUSIONS: As compared to the controls, most non-demented PD patients presented executive-type cognitive dysfunction. The higher educational level, however, was associated with a lower risk of cognitive deterioration. We conclude that higher education might have protective effects in cognitive decline in PD.