CCR5 Δ32 and CTLA-4 +49 A/G Gene Polymorphisms and Interferon-ß Treatment Response in Croatian and Slovenian Multiple Sclerosis Patients.

The aim of the present study was to investigate the impact of CCR5 Δ32 and CTLA-4 polymorphisms on the response to IFN-ß treatment in our cohort of MS patients from Croatia and Slovenia. Genomic DNA was obtained from 295 MS patients (230 female; 65 male) classified as responders (n = 173) and non-responders (n = 122) based on clinical criteria for treatment efficacy. Genotyping was performed via PCR/PCR-RFLP. No significant differences in the genotype/allele frequencies of CCR5Δ32 and CTLA-4 +49 A/G were detected between male responders and non-responders. A significantly higher prevalence (p = 0.039) of the CTLA-4 +49 AA genotype was found in female responders (42.1%) compared to non-responders (28.9%). Using multiple forward regression analysis, the CTLA-4 +49 AA genotype significantly predicted a positive response to IFN-ß therapy in females (p = 0.011) and contributed to 4.5% of response variability. Furthermore, the combined presence of the CCR5Δ32 wtwt/CTLA-4 +49 AA genotype significantly predicted a positive response to treatment in females (p = 0.025). The age at disease onset, pretreatment relapse rate, and baseline EDSS score were not reliable predictors of treatment response in MS patients. Our results indicate that the presence of the CCR5Δ32 polymorphism was not associated with the response to IFN-ß treatment, whereas the CTLA-4 +49 polymorphism showed a positive correlation with an optimal response in female patients.

General neurology: Current challenges and future implications.

BACKGROUND AND PURPOSE: In the coming decades, the world will face an increasing burden of neurological disorders (ND) and an urgent need to promote brain health. These challenges contrast with an insufficient neurological workforce in most countries, as well as decreasing numbers of general neurologists and neurologists attracted to work in general neurology (GN). This white paper aims to review the current situation of GN and reflect on its future. METHODS: The European Academy of Neurology (EAN) task force (TF) met nine times between November 2021 and June 2023. During the 2023 EAN annual meeting, attendees were asked to answer five questions concerning the future of GN. The document was sent for suggestions and eventually approval to the board and the presidents of the 47 national societies of the EAN. RESULTS: The TF first identified four relevant current and future challenges related to GN: (i) definition, (ii) practice, (iii) education, and (iv) research. The TF then identified seven initiatives to further develop GN at both the academic and community level. Finally, the TF formulated 16 recommendations to promote GN in the future. CONCLUSIONS: GN will remain essential in the coming decades to provide rapid, accessible, and comprehensive management of patients with ND that is affordable and cost-effective. There is also a need for research, education, and other initiatives aiming to facilitate improved working conditions, recognition, and prestige for those pursuing a career in GN.

Decreased brain volume may be associated with the occurrence of peri-lead edema in Parkinson's disease patients with deep brain stimulation.

BACKGROUND: Peri-lead edema (PLE) is a poorly understood complication of deep brain stimulation (DBS), which has been described in patients presenting occasionally with profound and often delayed symptoms with an incidence ranging from 0.4% up to even 100%. Therefore, our study aims to investigate the association of brain and brain compartment volumes on magnetic resonance imaging (MRI) with the occurrence of PLE in Parkinson's disease (PD) patients after DBS implantation in subthalamic nuclei (STN). METHODS: This retrospective study included 125 consecutive PD patients who underwent STN DBS at the Department of Neurosurgery, Dubrava University Hospital from 2010 to 2022. Qualitative analysis was done on postoperative MRI T2-weighted sequence by two independent observers, marking PLE on midbrain, thalamus, and subcortical levels as mild, moderate, or severe. Quantitative volumetric analysis of brain and brain compartment volumes was conducted using an automated CIVET processing pipeline on preoperative MRI T1 MPRAGE sequences. In addition, observed PLE on individual hemispheres was delineated manually and measured using Analyze 14.0 software. RESULTS: In our cohort, PLE was observed in 32.17%, mostly bilaterally. Mild PLE was observed in the majority of patients, regardless of the level observed. Age, sex, diabetes, hypertension, vascular disease, and the use of anticoagulant/antiplatelet therapy showed no significant association with the occurrence of PLE. Total grey matter volume showed a significant association with the PLE occurrence (r = -0.22, p = 0.04), as well as cortex volume (r = -0.32, p = 0.0005). Cortical volumes of hemispheres, overall hemisphere volumes, as well as hemisphere/total intracranial volume ratio showed significant association with the PLE occurrence. Furthermore, the volume of the cortex and total grey volume represent moderate indicators, while hemisphere volumes, cortical volumes of hemispheres, and hemisphere/total intracranial volume ratio represent mild to moderate indicators of possible PLE occurrence. CONCLUSION: The results of our study suggest that the morphometric MRI measurements, as a useful tool, can provide relevant information about the structural status of the brain in patients with PD and represent moderate indicators of possible PLE occurrence. Identifying patients with greater brain atrophy, especially regarding grey matter before DBS implantation, will allow us to estimate the possible postoperative symptoms and intervene in a timely manner. Further studies are needed to confirm our findings and to investigate other potential predictors and risk factors of PLE occurrence.

GiOPARK Project: The Genetic Study of Parkinson's Disease in the Croatian Population.

Parkinson's disease is a neurological disorder that affects motor function, autonomic functions, and cognitive abilities. It is likely that both genetic and environmental factors, along with age, contribute to the cause. However, there is no comprehensive guideline for genetic testing for Parkinson's disease, and more research is needed to understand genetic variations in different populations. There has been no research on the genetic background of Parkinson's disease in Croatia so far. Therefore, with the GiOPARK project, we aimed to investigate the genetic variants responsible for Parkinson's disease in 153 Croatian patients with early onset, familial onset, and sporadic late-onset using whole-exome sequencing, along with multiplex ligation-dependent probe amplification and Sanger sequencing in select patients. We found causative variants in 7.84% of the patients, with GBA being the most common gene (4.58%), followed by PRKN (1.96%), ITM2B (0.65%), and MAPT (0.65%). Moreover, variants of uncertain significance were identified in 26.14% of the patients. The causative variants were found in all three subgroups, indicating that genetic factors play a role in all the analyzed Parkinson's disease subtypes. This study emphasizes the need for more inclusive research and improved guidelines to better understand the genetic basis of Parkinson's disease and facilitate more effective clinical management.

Applicability of clinical genetic testing for deep brain stimulation treatment in monogenic Parkinson's disease and monogenic dystonia: a multidisciplinary team perspective.

In this perspective article, we highlight the possible applicability of genetic testing in Parkinson's disease and dystonia patients treated with deep brain stimulation (DBS). DBS, a neuromodulatory technique employing electrical stimulation, has historically targeted motor symptoms in advanced PD and dystonia, yet its precise mechanisms remain elusive. Genetic insights have emerged as potential determinants of DBS efficacy. Known PD genes such as GBA, SNCA, LRRK2, and PRKN are most studied, even though further studies are required to make firm conclusions. Variable outcomes depending on genotype is present in genetic dystonia, as DYT-TOR1A, NBIA/DYTPANK2, DYT-SCGE and X-linked dystonia-parkinsonism have demonstrated promising outcomes following GPi-DBS, while varying outcomes have been documented in DYT-THAP1. We present two clinical vignettes that illustrate the applicability of genetics in clinical practice, with one PD patient with compound GBA mutations and one GNAL dystonia patient. Integrating genetic testing into clinical practice is pivotal, particularly with advancements in next-generation sequencing. However, there is a clear need for further research, especially in rarer monogenic forms. Our perspective is that applying genetics in PD and dystonia is possible today, and despite challenges, it has the potential to refine patient selection and enhance treatment outcomes.

Overlapping Neuroimmune Mechanisms and Therapeutic Targets in Neurodegenerative Disorders.

Many potential immune therapeutic targets are similarly affected in adult-onset neurodegenerative diseases, such as Alzheimer's (AD) disease, Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), and frontotemporal dementia (FTD), as well as in a seemingly distinct Niemann-Pick type C disease with primarily juvenile onset. This strongly argues for an overlap in pathogenic mechanisms. The commonly researched immune targets include various immune cell subsets, such as microglia, peripheral macrophages, and regulatory T cells (Tregs); the complement system; and other soluble factors. In this review, we compare these neurodegenerative diseases from a clinical point of view and highlight common pathways and mechanisms of protein aggregation, neurodegeneration, and/or neuroinflammation that could potentially lead to shared treatment strategies for overlapping immune dysfunctions in these diseases. These approaches include but are not limited to immunisation, complement cascade blockade, microbiome regulation, inhibition of signal transduction, Treg boosting, and stem cell transplantation.

Post-COVID-19 Syndrome in Neurology Patients: A Single Center Experience.

Our aim was to determine the frequency and characteristics of neurological post-COVID-19 syndrome and the diagnostic and therapeutic measures that were used for the treatment of these patients. Data were collected for 243 patients examined during the period of 11 May 2021 to 22 June 2022. The inclusion criteria were COVID-19 illness and neurological symptoms associated with COVID-19. The exclusion criteria were non-neurological symptoms, patients who did not suffer from COVID-19, and symptoms that occurred after vaccination against the SARS-CoV-2 virus. Data for 227 patients with neurological post-COVID-19 symptoms were analyzed. Most patients presented with multiple symptoms, most often headache, cognitive impairment, loss of smell, paresthesia, fatigue, dizziness, and insomnia. Patients were most often referred for consultative examinations, neuroradiological imaging, and EEG. The therapy was mostly symptomatic. Most patients had no change in their symptoms on follow-up visits (53.21%), while positive outcome was found in 44.95% of patients. This study found that neurological post-COVID-19 syndrome appears to be more common in women, and generally, the most common symptoms are headache and cognitive impairment. The gender distribution of symptoms was clearly visible and should be further investigated. There is a need for longitudinal follow-up studies to better understand the disease dynamic.

GPi DBS treatment outcome in children with monogenic dystonia: a case series and review of the literature.

Introduction: Dystonia is the third most common pediatric movement disorder and is often difficult to treat. Deep brain stimulation (DBS) of the internal pallidum (GPi) has been demonstrated as a safe and effective treatment for genetic dystonia in adolescents and adults. The results of DBS in children are limited to individual cases or case series, although it has been proven to be an effective procedure in carefully selected pediatric cohorts. The aim of our study was to present the treatment outcome for 7- to 9-year-old pediatric patients with disabling monogenic isolated generalized DYT-THAP1 and DYT-KMT2B dystonia after bilateral GPi-DBS. Patients and results: We present three boys aged <10 years; two siblings with disabling generalized DYT-THAP1 dystonia and a boy with monogenic-complex DYT-KMT2B. Dystonia onset occurred between the ages of 3 and 6. Significantly disabled children were mostly dependent on their parents. Pharmacotherapy was inefficient and patients underwent bilateral GPi-DBS. Clinical signs of dystonia improved significantly in the first month after the implantation and continued to maintain improved motor functions, which were found to have improved further at follow-up. These patients were ambulant without support and included in everyday activities. All patients had significantly lower Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) values, indicating >25% improvement over the first 15 months. However, there was a decline in speech and upper limb function, manifesting with bradylalia, bradykinesia, and dysphonia, which decreased after treatment with trihexyphenidyl. Conclusion: Although reports of patients with monogenic dystonia, particularly DYT-THAP1, treated with DBS are still scarce, DBS should be considered as an efficient treatment approach in children with pharmacoresistent dystonia, especially with generalized monogenic dystonia and to prevent severe and disabling symptoms that reduce the quality of life, including emotional and social aspects. Patients require an individual approach and parents should be properly informed about expectations and possible outcomes, including relapses and impairments, in addition to DBS responsiveness and related improvements. Furthermore, early genetic diagnosis and the provision of appropriate treatments, including DBS, are mandatory for preventing severe neurologic impairments.

The effects of microbiota abundance on symptom severity in Parkinson's disease: A systematic review.

Introduction: Parkinson's disease (PD) is neurodegenerative disease with a multifactorial etiopathogenesis with accumulating evidence identifying microbiota as a potential factor in the earliest, prodromal phases of the disease. Previous research has already shown a significant difference between gut microbiota composition in PD patients as opposed to healthy controls, with a growing number of studies correlating gut microbiota changes with the clinical presentation of the disease in later stages, through various motor and non-motor symptoms. Our aim in this systematic review is to compose and assess current knowledge in the field and determine if the findings could influence future clinical practice as well as therapy in PD. Methods: We have conducted a systematic review according to PRISMA guidelines through MEDLINE and Embase databases, with studies being selected for inclusion via a set inclusion and exclusion criteria. Results: 20 studies were included in this systematic review according to the selected inclusion and exclusion criteria. The search yielded 18 case control studies, 1 case study, and 1 prospective case study with no controls. The total number of PD patients encompassed in the studies cited in this review is 1,511. Conclusion: The link between gut microbiota and neurodegeneration is a complex one and it depends on various factors. The relative abundance of various microbiota taxa in the gut has been consistently shown to have a correlation with motor and non-motor symptom severity. The answer could lie in the products of gut microbiota metabolism which have also been linked to PD. Further research is thus warranted in the field, with a focus on the metabolic function of gut microbiota in relation to motor and non-motor symptoms.

A multicenter study of genetic testing for Parkinson's disease in the clinical setting.

Parkinson's disease (PD) guidelines lack clear criteria for genetic evaluation. We assessed the yield and rationale of genetic testing for PD in a routine clinical setting on a multicenter cohort of 149 early-onset and familial patients by exome sequencing and semi-quantitative multiplex ligation-dependent probe amplification of evidence-based PD-associated gene panel. We show that genetic testing for PD should be considered for both early-onset and familial patients alike, and a clinical yield of about 10% in the Caucasian population can be expected.

Treatment of relapsing multiple sclerosis - recommendations of the Croatian Neurological Society.

Untreated multiple sclerosis (MS) irretrievably leads to severe neurological impairment. In European health care systems, patient access to disease modifying therapies (DMT) is often confined to more advanced stages of the disease because of restrictions in reimbursement. A discrepancy in access to DMTs is evident between West and East European countries. In order to improve access to DMTs for people with MS (pwMS) living in Croatia, the Croatian Neurological Society issued new recommendations for the treatment of relapsing MS. The aim of this article is to present these recommendations. The recommendations for platform therapies are to start DMT as soon as the diagnosis is made. If poor prognostic criteria are present (≥9 T2 or FLAIR lesions on the initial brain and spinal cord magnetic resonance imaging [MRI] or ≥3 T1 lesions with postcontrast enhancement on the initial brain and spinal cord MRI or Expanded Disability Status Scale after treatment of the initial relapse ≥3), high-efficacy DMT should be initiated. If pwMS experience ≥1 relapse or ≥3 new T2 lesions while on platform therapies, they should be switched to high-efficacy DMT. Further efforts should be made to enable early and unrestricted access to high-efficacy DMT with a freedom of choice of an appropriate therapy for expert physicians and pwMS. The improvement of access to DMT achieved by the implementation of national treatment guidelines in Croatia can serve as an example to national neurological societies from other Eastern European countries to persuade payers to enable early and unrestricted treatment of pwMS.

Cognitive Impact of Deep Brain Stimulation in Parkinson's Disease Patients: A Systematic Review.

Introduction: Parkinson's disease (PD) patients have a significantly higher risk of developing dementia in later disease stages, leading to severe impairments in quality of life and self-functioning. Questions remain on how deep brain stimulation (DBS) affects cognition, and whether we can individualize therapy and reduce the risk for adverse cognitive effects. Our aim in this systematic review is to assess the current knowledge in the field and determine if the findings could influence clinical practice. Methods: We have conducted a systematic review according to PRISMA guidelines through MEDLINE and Embase databases, with studies being selected for inclusion via a set inclusion and exclusion criteria. Results: Sixty-seven studies were included in this systematic review according to the selected criteria. This includes 6 meta-analyses, 18 randomized controlled trials, 17 controlled clinical trials, and 26 observational studies with no control arms. The total number of PD patients encompassed in the studies cited in this review is 3677, not including the meta-analyses. Conclusion: Cognitive function in PD patients can deteriorate, in most cases mildly, but still impactful to the quality of life. The strongest evidence is present for deterioration in verbal fluency, while inconclusive evidence is still present for executive function, memory, attention and processing speed. Global cognition does not appear to be significantly impacted by DBS, especially if cognitive screening is performed prior to the procedure, as lower baseline cognitive function is connected to poor outcomes. Further randomized controlled studies are required to increase the level of evidence, especially in the case of globus pallidus internus DBS, pedunculopontine nucleus DBS, and the ventral intermediate nucleus of thalamus DBS, and more long-term studies are required for all respective targets.

Effect of the coronavirus disease 2019 pandemic on people with Parkinson's disease: experience from a Croatian regional center.

AIM: To assess the effect of social isolation due to the coronavirus disease 2019 (COVID-19) pandemic on physical and mental health of Parkinson's disease patients treated at the University Hospital Center Rijeka. METHODS: This cross-sectional telephone study involved Parkinson's disease patients who had at least one control examination at University Hospital Center Rijeka in 2020 and were Croatian citizens. A questionnaire was used to obtain data on the socio-demographic characteristics and the severity of motor, anxiety, depression, and non-motor symptoms. RESULTS: The final sample included 87 patients. Most patients reported subjective worsening of motor symptoms. Patients who lived alone had worse motor scores than those not living alone. The majority of patients reported worsening of anxiety symptoms. Significant worsening of anxiety symptoms was found in patients who lived alone, had a longer disease duration, and had avoided check-ups. Fewer patients had depression symptoms than motor and anxiety symptoms. Significantly higher Hamilton Depression Rating Scale scores were observed in patients with a longer disease duration. Significant worsening of non-motor symptoms was identified in patients who lived alone, were less educated, had a longer disease duration, and had a higher Charlson comorbidity index. CONCLUSION: Patients who live alone, have longer disease duration, are less educated, avoid check-ups, and have more comorbidities are more vulnerable to the negative effects of social isolation.

Reperfusion therapy in a patient with early recurrence of ischemic stroke.

BACKGROUND: Acute ischemic stroke (AIS) has a high risk of recurrence, particularly in the early stage. Recurrent ischemic stroke (RIS) is associated with adverse neurological outcomes but the phenomenon of early RIS in the endovascular thrombectomy era has not been frequently discussed. We report a case addressing this issue. CASE PRESENTATION: We present a patient who was successfully treated by mechanical thrombectomy (MT) for middle cerebral artery occlusion. Due to an early stroke recurrence, within 72 h after the first MT, he received systemic thrombolysis and repeated MT was performed with excellent clinical outcome. DISCUSSION: We discuss the aspects of reperfusion therapy for patients experiencing early stroke recurrence. Consideration was given to stroke etiology and off-label use of thrombolytic therapy. Also, effectiveness of repeated MT for early re-occlusion of initially reanalyzed vessel was evaluated in order to allow more patients with RIS to benefit from reperfusion therapy.

A Systematic Review of Parkinson's Disease Pharmacogenomics: Is There Time for Translation into the Clinics?

BACKGROUND: Parkinson's disease (PD) is the second most frequent neurodegenerative disease, which creates a significant public health burden. There is a challenge for the optimization of therapies since patients not only respond differently to current treatment options but also develop different side effects to the treatment. Genetic variability in the human genome can serve as a biomarker for the metabolism, availability of drugs and stratification of patients for suitable therapies. The goal of this systematic review is to assess the current evidence for the clinical translation of pharmacogenomics in the personalization of treatment for Parkinson's disease. METHODS: We performed a systematic search of Medline database for publications covering the topic of pharmacogenomics and genotype specific mutations in Parkinson's disease treatment, along with a manual search, and finally included a total of 116 publications in the review. RESULTS: We analyzed 75 studies and 41 reviews published up to December of 2020. Most research is focused on levodopa pharmacogenomic properties and catechol-O-methyltransferase (COMT) enzymatic pathway polymorphisms, which have potential for clinical implementation due to changes in treatment response and side-effects. Likewise, there is some consistent evidence in the heritability of impulse control disorder via Opioid Receptor Kappa 1 (OPRK1), 5-Hydroxytryptamine Receptor 2A (HTR2a) and Dopa decarboxylase (DDC) genotypes, and hyperhomocysteinemia via the Methylenetetrahydrofolate reductase (MTHFR) gene. On the other hand, many available studies vary in design and methodology and lack in sample size, leading to inconsistent findings. CONCLUSIONS: This systematic review demonstrated that the evidence for implementation of pharmacogenomics in clinical practice is still lacking and that further research needs to be done to enable a more personalized approach to therapy for each patient.

The Accuracy of Direct Targeting Using Fusion of MR and CT Imaging for Deep Brain Stimulation of the Subthalamic Nucleus in Patients with Parkinson's Disease.

INTRODUCTION: In 33 consecutive patients with Parkinson's disease (PD) undergoing awake deep brain stimulation (DBS) without microelectrode recording (MER), we assessed and validated the precision and accuracy of direct targeting of the subthalamic nucleus (STN) using preoperative magnetic resonance imaging (MRI) and stereotactic computed tomography (CT) image fusion combined with immediate postoperative stereotactic CT and postoperative MRI, and we report on the side effects and clinical results up to 6 months' follow-up. MATERIALS AND METHODS: Preoperative nonstereotactic MRI and stereotactic CT images were merged and used for planning the trajectory and final lead position. Immediate postoperative stereotactic CT and postoperative nonstereotactic MRI provided the validation of the final electrode position. Changes in the Unified Parkinson's Disease Rating Scale III (UPDRS III) scores and the levodopa equivalent daily doses (LEDD) and appearance of adverse side effects were assessed. RESULTS: The mean Euclidian distance (ED) error between the planned position and the final position of the lead in the left STN was 1.69 ± 0.82 mm and that in the right STN was 2.12 ± 1.00. The individual differences between planned and final position in each of the three coordinates were less than 2 mm. The UPDRS III scores improved by 75% and LEDD decreased by 45%. Few patients experienced complications, such as postoperative infection (n = 1), or unwanted side effects, such as emotional instability (n = 1). CONCLUSION: Our results confirm that direct targeting of an STN on stereotactic CT merged with MRI could be a valid method for placement the DBS electrode. The magnitude of our targeting error is comparable with the reported errors when using MER and other direct targeting approaches.

RANKL/RANK/OPG Axis Is Deregulated in the Cerebrospinal Fluid of Multiple Sclerosis Patients at Clinical Onset.

OBJECTIVES: Our study focused on the RANKL (receptor activator of nuclear factor-κB ligand)/RANK/OPG (osteoprotegerin) axis and selected proinflammatory/immunoregulatory upstream mediators in the peripheral blood (PBL) and cerebrospinal fluid (CSF) of multiple sclerosis (MS) patients. METHODS: PBL and CSF were collected from healthy controls (n = 35) and MS patients at the clinical onset of the disease (n = 33). In addition, PBL samples were obtained from relapse-remitting (RR)-MS patients (n = 30). Patients were assessed by means of the expanded disability status scale (EDSS) and routine laboratory parameters. Soluble (s)RANKL and OPG were measured in the CSF and plasma; gene expression was detected for RANKL, RANK, OPG, and selected cytokines/chemokines (interleukin [IL]-4, IL-10, IL-17, CCL2, and CXCL12) in PBL mononuclear cells. RESULTS: The OPG level in the CSF was lower in MS patients at clinical onset than in controls. Moreover, the sRANKL/OPG ratio was higher in the CSF of MS patients at clinical onset and in the plasma of RR-MS patients than in controls. Gene expression of RANKL/RANK/OPG in PBL mononuclear cells was higher only in RR-MS patients. IL-4, CCL2, and CXCL12 were positively correlated and IL-10 was negatively correlated with RANKL/RANK expression. OPG was negatively correlated with EDSS and alkaline phosphatase level. CONCLUSION: Our study revealed that changes of RANKL/RANK/OPG axis are associated with MS, particularly the decreased OPG level in the CSF at disease onset. Therefore, these factors may serve as disease biomarkers and molecular targets of novel therapeutic approaches.

Effect of clonidine on the cutaneous silent period during spinal anesthesia.

AIM: To investigate the effect of clonidine on the cutaneous silent period (CSP) during spinal anesthesia. METHODS: A total of 67 adult patients were included in this randomized, prospective, single-center, double-blind trial. They did not have neurological disorders and were scheduled for inguinal hernia repair surgery. This trial was registered on ClinicalTrials.gov (NTC03121261). The patients were randomized into two groups with regards to the intrathecally administered solution: (1) 15 mg of 0.5% levobupivacaine with 50 µg of 0.015% clonidine, or (2) 15 mg of 0.5% levobupivacaine alone. There were 34 patients in the levobupivacaine-clonidine (LC) group and 33 patients in the levobupivacaine (L) group. CSP and its latency were measured four times: prior to the subarachnoid block (SAB), after motor block regression to the 0 level of the Bromage scale, with ongoing sensory blockade, and both 6 and 24 h after SAB. RESULTS: Only data from 30 patients in each group were analyzed. There were no significant differences between the groups investigated preoperatively and after 24 h. The CSP of the L group at the time point when the Bromage scale was 0 was 44.8 ± 8.1 ms, while in the LC group it measured 40.2 ± 3.8 ms (P = 0.007). The latency in the L group at the time point when the Bromage scale was 0 was 130.3 ± 10.2 ms, and in the LC group it was 144.7 ± 8.3 ms (P < 0.001). The CSP of the L group after 6 h was 59.6 ± 9.8 ms, while in the LC group it was 44.5 ± 5.0 ms (P < 0.001). The latency in the L group after 6 h was 110.4 ± 10.6 ms, while in LC group it was 132.3 ± 9.7 ms (P < 0.001). CONCLUSION: Intrathecal addition of clonidine to levobupivacaine for SAB in comparison with levobupivacaine alone results in a diminished inhibitory tonus and shortened CSP.