Clinical Neuroscience

[Clinical neurophysiological methods in diagnosis and treatment of cerebrovascular diseases]

NAGY Ildikó, FABÓ Dániel

JANUARY 30, 2018

Clinical Neuroscience - 2018;71(01-02)


[Neurophysiological methods are gaining ground in the diagnosis and therapy of cerebrovascular disease. While the role of the EEG (electroencephalography) in the diagnosis of post-stroke epilepsy is constant, quantitative EEG para-meters, as new indicators of early efficiency after thrombolysis or in prognosis of patient’s condition have proved their effectiveness in several clinical studies. In intensive care units, continuous EEG monitoring of critically ill patients became part of neurointenzive care protocols. SSEP (somatosesnsory evoked potencial) and EEG performed during carotid endarterectomy, are early indicative intraoperativ neuromonitoring methods of poor outcome. Neurorehabilitation is a newly discovered area of neurophysiology. Clinical studies have demonstrated the effectiveness of repetitive transcranial magnetic stimulation (rTMS) in the rehabilitation of stroke patients. Brain computer interface mark the onset of modern rehabi-litation, where the function deficit is replaced by robotic tehnology. ]



Further articles in this publication

Clinical Neuroscience

Insights into the structure and function of the hippocampal formation: Relevance to Parkinson’s disease

GYÖRFI Orsolya, NAGY Helga, BOKOR Magdolna, KÉRI Szabolcs

The link between the hippocampus and declarative memory dysfunctions following the removal of the medial temporal lobe opened unexplored fields in neuroscience. In the first part of our review, we summarized current theoretical frameworks discussing the role of hippocampus in learning and memory. Several theories are highlighted suggesting that the hippocampus is responsible for assembling stimulus elements into a unitary representation that later can be utilized to simulate future events. The hippocampal formation has been implicated in a growing number of disorders, from neurodegenerative diseases to atypical cognitive ageing and depression. Recent neuroimaging studies provided new opportunities to study in detail the hippocampal formation’s role in higher levels of the nervous system. We will present data regarding the regional specialization of the hippocampus in experimental models developed for healthy and neurological conditions with a special focus on Parkinson’s disease. Combined evidence from neuroimaging studies suggested that hippocampal volume is reduced in non-demented, newly diagnosed patients with Parkinson’s disease, which is associated with impaired memory performance. These findings proposed that, beyond the well-known striatal dopamine loss, impaired hippocampal synaptic plasticity may contribute to cognitive and affective impairments in early Parkinson’s disease.

Clinical Neuroscience

[Effects of nasal provocation with a single-dose allergen on the explicit and implicit memory of physically active and inactive patients with ragweed allergy]

TOKODI Margaréta, CSÁBI Eszter, KIRICSI Ágnes, SCHULTZ Rebeka, MOLNÁR H Andor, ROVÓ László, BELLA Zsolt

[Background and purpose - Allergy is an endemic disease and has a considerable impact on the quality of life. This study aimed to measure the effect of active allergic rhinitis on memory functions of physically active and inactive patients with ragweed allergy. Methods - Memory functions were assessed before and after allergen exposure. Participants in both groups were provoked nasally with 30 IR/mL ragweed allergen in each nostril. Explicit memory was measured with story-recalling and implicit memory was investigated with reaction time task. Results - In neuropsychological assessments athletes performed significantly better, compared with the control group after allergen provocation in short-term and long-term memory functions. There was no difference between the groups in the implicit tasks. Athletes have achieved better results after provocation, comparing to the baseline test and the tests that measured short-term and long-term memory functions. Conclusion - Short-term disturbing factors, e.g. swollen nasal mucosa, sneezing, and watery eyes after provocation did have not caused deterioration in cognitive functions. A single-shot allergen in high doses have caused an increase of mental concentration, which was more pronounced in athletes.]

Clinical Neuroscience

Functional neurotoxicity and tissue metal levels in rats exposed subacutely to titanium dioxide nanoparticles via the airways

HORVÁTH Tamara, VEZÉR Tünde, KOZMA Gábor, PAPP András

Introduction and aims - Nanoparticles of titanium dioxide are suspected neurotoxic agents and have numerous applications possibly resulting in human exposure by several ways including inhalation. In the present work, rats were exposed to spherical TiO2 nanoparticles of two different sizes by the intratracheal route. It was investigated how the neuro-functional alterations, detected by electrophysiological and behavioral methods, were related to the concentration of Ti in the tissue samples and what the influence of the size of the NPs was. Materials and methods - Rats (young adult Wistar males, 10/group) were exposed to TiO2 nanoparticles of ca. 10 and 100 nm diameter (suspension medium: neutral PBS with 1% hydroxyethyl cellulose) by intratracheal instillation in 5 and 18 mg/kg b.w. dose; 5 days per week for 6 weeks. Controls were instilled with saline, and vehicle controls, with the suspension medium. To see general toxicity, body weight was checked daily, and organ weights were measured at the end of experiment. Grip strength test, to assess motor function damage, was done before and after the 6-week treatment. Finally, the rats were anesthetized with urethane, spontaneous cortical activity and sensory evoked potentials were recorded, then the rats were dissected and tissue samples were taken for Ti level measurement. Results - Body weight gain indicated no general toxicity, and no significant change in the relative organ weights, except that of the lungs, was seen. However, change of time-to-fall in the grip strength test, and latency of cortical evoked po­tentials, were altered in the treated groups, indicating functional damage. Correlation of these alterations with the cortical Ti level was dissimilar for the two sizes of nanoparticles. Conclusion - The results provided further support to the functional neurotoxicity of TiO2 nanoparticles. The exact role of particle size, and the mechanisms involved, remain to be elucidated.

Clinical Neuroscience

Electroclinical and prognostic characteristics of epilepsy patients with photosensitivity

YAZAR Olgun Hülya, GUL Gunay, YAZAR Tamer, EREN Fulya, KUSCU Yandım Demet, KIRBAS Dursun

Background - Epilepsy with photosensitivity (PSE) is one of the reflex epilepsy types with pathophysiology still unexplained. In our study we aimed to evaluate the clinical, electroencephalogram (EEG) and prognosis of patients with PSE diagnosis. Method - A total of 44 patients with PSE diagnosis according to international classification were included in this retrospective and cross-sectional study. The age, gender, syndrome, clinical and EEG characteristics of patients, and treatment response were investigated. Results - The mean age was 22.09±6.49 years for 28 females and 16 males included in the study. Of patients, 17 had idiopathic photosensitive occipital lobe epilepsy (IPOLE), 11 had juvenile myoclonic epilepsy (JME), 11 had other PSE and 5 had juvenile absence epilepsy (JAE), with the most common visual trigger factors television and sunlight. In terms of seizure type, the most common was generalized tonic clonic seizure (GTCS), with myoclonus, absence and other seizure types observed. There was family history present in 17 patients and valproic acid was most commonly used for treatment. Conclusion - As noted in the literature, our data show that PSE has defined age group and clinical presentation, good prognosis but requires correct choice of medication for treatment. It is thought that good description of these epilepsy types will reduce misdiagnosis and mistreatment rates.

Clinical Neuroscience

Alteration of mean platelet volume in the pathogenesis of acute ischemic stroke: cause or consequence?

AYAS Özözen Zeynep, CAN Ufuk

Introduction - Platelets have a crucial role on vascular disease which are involved in pathogenesis of ischemic stroke. Platelet size is measured as mean platelet volume (MPV) and is a marker of platelet activity. Platelets contain more dense granules as the size increases and produce more serotonin and tromboglobulin (b-TG) than small platelets. In this study, the alteration of MPV values were investigated in patients with acute stroke, who had MPV values before stroke, during acute ischemic stroke and 7 days after the stroke. The relationship between this alteration and risk factors, etiology and localization of ischemic stroke were also investigated. Methods - Sixty-seven patients with clinically and radiologically established diagnoses of ischemic stroke were enrolled into the study and stroke etiology was classified by modified Trial of Org 10 172 in Acute Stroke Treatment (TOAST) classification and, modified Bamford classification was used for localization and stroke risk factors were also evaluated. The platelet counts and MPV values from patient files in patients who had values before stroke (at examination for another diseases), within 24 hours of symptom onset and after 7 further days were analysed. Results - MPV values increased after stroke (10.59±2.26) compared with acute stroke values (9.84±1.64) and the values before stroke (9.59±1.72) (p<0.0001); this alteration of MPV values occured 7 days after stroke (p<0.016). There was a positive correlation between age and MPV values during acute stroke (r=0.270; p<0.05). Patients with atrial fibrillation had higher alteration in the time of MPV compared with patients without atrial fibrillation (p>0.006). We assessed for gender, men (n=38) had a higher alteration in the time of MPV compared with women (n=29) (p=0.013). Conclusion - Although there was no alteration of platelet counts, MPV values were increased 7 days after stroke in patients with acute ischemic stroke.

All articles in the issue

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Clinical Neuroscience

[Vinpocetin in neurological diseases]

SZAPÁRY László, KÉSMÁRKY Gábor, TÓTH Kálmán, MISNYOVSZKY Melinda, TÓTH Tímea, BALOGH Ágnes, NAGY Krisztián, NÉMETH György, FEHÉR Gergely

[Introduction - Stroke is the third leading cause of death worldwide (following cardiovascular and cancer mortality) and associated with serious disability for the vast majority of patients. There is no salvage therapy for irreversibly damaged brain areas, improving the circulation of the surrounding hypoperfused territories may be associated with benefitial clinical states. Cerebral hypoperfusion may play a role in the pathogenesis of other kind of neurological diseases, improvement of global circulation may have a preventive effect on these conditions. Aims - The aim of our study was to review the experimental and clinical articles focusing on the role of vinpocetin in different neurological conditions. Results - Vinpocetin appears to have several different mechanisms of action that allow for its antiinflammatory, antioxidant, vasodilating, antiepileptic and neuroprotective activities in experimental conditions. On the other hand, several meta-analysis of the existing studies in acute stroke examining short and long term fatality rates with vinpocetin was unable to assess efficacy. In chronic cerebrovascular patients, vinpocetin improves impaired hemorheological variables, has significant vasodilating properties, improves endothelial dysfunction, neuroimaging studies showed selective increase in cerebral blood flow and cerebral metabolic rate, all of which are potentially beneficial in cerebrovascular disease and may improve cognitive functions. Summary - Based on the above mentioned results vinpocetin plays an important role both in basic research and in clinical management of different neurological diseases.]

Clinical Neuroscience

[Dizziness - vertigo Warning symptoms in vertebrobasilar ischemia - Part I. ]


[Dizziness and vertigo - like headache - are the most common complaints which leads patients to visit the doctor. In spite of the headache - which may be primary (e.g. migraine) or symptomatic - dizziness and vertigo do not appear to be a separate nosologic entity but rather the symptoms of several neurological disorders. For differential diagnosis, interdisciplinary thinking and activity is needed because the vestibular, neurological and psychiatric disorders might have a common role in the development of symptoms and further overlapping can also occur. The vascular disorders of the vertebrobasilar system are discussed in detail in this review. The importance, occurrence and causes of vertigo as a warning symptom is in the focus. The author draws attention to life-threatening conditions with acute onset in cases of the posterior scale ischemia and emphasizes the importance of the correct and early diagnosis. The author tries to clear up the nihilistic aspect in treating of stroke and stresses the necessity of thrombolysis and interventional radiological procedures which may be the only chance for the recovery of the patients. The pharmacological prevention of recurrent vascular events is also important and obligatory for the clinicians.]

Clinical Neuroscience

Is stroke indeed a “Monday morning disease”?


Introduction - The therapeutic time window of acute stroke is short. Decision on the use of intravenous thrombolysis is based on well-defined criteria. Any delay in the transport to a designated stroke centre decreases the odds of therapeutic success. In Hungary, the admission rate of stroke patients peaks on Monday, the number gradually decreasing by the end of the week. This phenomenon has long been suggested to be due to the lack of emergency care approach. According to the literature, however, returning to work following a holiday is a risk factor for acute stroke. A similar phenomenon is well-known in veterinary medicine, a condition in horses referred to as ‘Monday morning disease’. In our study, we analysed the distribution of admissions due to acute stroke by the day of the week in 4 independent data sources. Patients and methods - The number of patients admitted to the Szent János Hospital, Budapest, Hungary with stroke and that of emergency ambulance transports in the whole city of Budapest due to acute stroke were analysed in the period between January 1 and March 31, 2009. The distribution of thrombolytic interventions reflecting hospitalizations for hyperacute stroke was analysed based on data of the Szent János Hospital in 2009-2012, and on national data from 2006-2012. Descriptive statistics was used to present the data. The variation between daily admission was compared by chi-square test. Results - The proportion of daily admission of stroke patients admitted to the Szent János Hospital was the highest at the beginning of the week (18% on Monday, and 21% on Tuesday) and the lowest on the weekend (9% and 9% on Saturday and Sunday, respectively). The distribution of ambulance transports in Budapest due to acute stroke tended to be similar (15% and 15% on Monday and Tuesday, whereas 13% and 12% on Saturday and Sunday, respectively) on different days of the week. No such Monday peak could be observed in a single centre regarding thrombolytic interventions: 18% and 19% of the total of 80 thrombolytic interventions in the Szent János Hospital were performed on Monday and Sunday, respectively. At the national level the higher Monday rate is obvious: during a 7-year period 16.0%, 12.7%, and 13.5% of all thrombolytic interventions in Hungary were performed on Monday, Saturday and Sunday, respectively. Conclusion - Monday preference of stroke is not exclusively caused by the lack of emergency care approach, and the phenomenon is not consistent at the individual hospital level in cases undergoing thrombolysis.

Clinical Neuroscience

[Neurorehabilitation, neurology, rehabilitation medicine]

URBÁN Edina, SZÉL István, FÁY Veronika, DÉNES Zoltán, LIPPAI Zoltán, FAZEKAS Gábor

[We have read several publications of great authority on the neurological profession in the last two years in which were expressed assessments of the current situation combined with opinions about neurology and the necessity to reorganize neurological patient care. These articles took up the question of neurorehabilitation too. The authors, who on a daily basis, deal with the rehabilitation of people with disabilities as a consequence of neurological conditions, summarize some important definitions of rehabilitation medicine and the present system of neurological rehabilitation, as it is defined by the rehabilitation profession.]

Clinical Neuroscience

[EEG investigations in cognitive impairments]


[The EEG is an indicator of all physiological and neuropsychological activity. The α rhythm was considered as a key phenomenon in research of human mentation from the discovery of EEG. Two methods are known for the estimation of cognitive deficit by the use of quantitative EEG (QEEG). The first is based on the hypothesis, that the mean values of the normal EEG from healthy volunters can be used as reference, and deviation from the normal values of EEG parameters may suggest disease. This kind of “neurometry” was elaborated by R. E. John. The second method asseses event related (ER) transients evoked by somatosensory and mental stimuli. Quantity and localization of signals may refer to the functional state of the cortex. These reactions depend strongly on the test-paradigms. Recognition of the attention-intention cycle disclosed the psysiological mechanism of ERD (event related desynchronisation) and ERS (event related synchronisation). In contrast with the classical “stimulus-reaction” model, both perception and voluntary movement are iniciated by the brain itself, and not by the environment. Human behavior and conscious actions depend on the intention. QEEG analysis proved that the attention and intention localize in segregate areas of the brain. Both “static” and “dinamic” neurometric methods are able to differenciate the EEG records of demented patients from healthy controls, furthermore some dementias from each other. We conclude that with the help of sofisticated methods of QEEG analysis minimal functional deficit of the electrogenesis can be recognized, which could be helpful in the differential diagnosis Notwithstanding the EEG can not explain the evolution neither the normal or the diseased mental processes. The only “instrument” which is able to approach the human mind is the human cogitation itself with the aids of appropriate tests. The QEEG can be conclusive in the analysis of particular processes of mental activity, such as timing, state of activation, hierarchical organisation of cortical territories and mechanism of electrogenesis.]