Clinical Neuroscience

[Physical and electrophysiological aspects of electroconvulsive therapy (review)]

GAZDAG Gábor

DECEMBER 20, 2003

Clinical Neuroscience - 2003;56(11-12)

[Personnel and technical conditions for ECT (electroconvulsive therapy) is legally determined. In this article the author reviews studies focused on the technical questions of ECT. After the comparison of the unilateral and bilateral electrode placement an analysis is given on the physical properties of the stimulus used to elicit seizures. After discussing the questions of dose, vaweform frequency and polarity, the anatomical and physiological factors of impedance are evaluated. The author then discuss gender, age and encephalopathy as factors influencing seizure threshold. The connection between symmetry, regularity, and postictal suppression registered on the EEG and efficacy is observed. The EEG and EMG concordance is supposed to be connected also with the efficacy. In the discussion the author gives recommendations based on the literature.]

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Clinical Neuroscience

[The role of studies of Janos Szentagothai in developmental neurology]

KATONA Ferenc, BERÉNYI Marianne

[The vestibulospinal system plays determining role in the activation processes of elementary sensorymotor patterns characterised by the verticalisation of the trunk and elevation of the head. In the thirties of the last century János Szentágothai proved that axons of the vestibulospinal tract reach the cervical and thoracic spinal cord and innervate the muscles of the neck. Later he verified existence of various connections among the labyrinth, the vestibular system, and the motor nuclei of the III., IV. and the VI. cranial nerves. His studies explain the functional neuroanatomic background of sitting up, sitting and balancing in the air, head-elevation and head control during the execution of a special elementary sensorymotor pattern: ”sitting in air”. All these functions can be activated by labyrinthine stimulation long before the maturation of the corticospinal tract.]

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HORVÁTH Mónika, FAZEKAS Gábor

[Kinesiological electromyography means the application of the surface EMG measurement technique during movement and locomotion. The authors investigated the motor impairments of the upper limb of patients with spastic hemiparesis. Surface EMG activity in musculus biceps brachii and musculus triceps brachii were recorded during voluntary elbow flexion and extension movements. In some cases even the raw EMG signals contain the accurate information but more often the recorded signals should further be processed to achieve more valuable data concerning muscle performance. The limitations of the technique underlines the importance of the several steps of the processing. The purpose of this study is to present a systematic description of the methods and the precise application of surface EMG. The authors give a comprehensive view of different processing methods and demonstrate the application areas of the kinesiological EMG.]

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[Serotonin dysfunctions and the „Seven Deadly Sins”]

JANKA Zoltán

[The symbolic characters of the Seven Deadly Sins can be traced from time to time in the cultural history of human mankind, being directly specified in certain artistic products. Such are, among others, the painting entitled „The Seven Deadly Sins and the Four Last Things” by Hieronymus Bosch and the poems Divina Commedia and The Faerie Queene by Dante Alighieri and Edmund Spenser, respectively. However, there are several paragraphs referring to these behaviours of the Seven Deadly Sins in the Bible and in the dramas of William Shakespeare. The objective of the present review is to propose that dysfunctions in the central serotonergic system might be involved in the the neurobiology of these ’sinful’ behaviour patterns. Evidences indicate that behaviour traits such as Accidia (Sloth), Luxuria (Lust, Lechery), Superbia (Pride), Ira (Wrath, Anger), Invidia (Envy), Avaritia (Greed, Avarice), and Gula (Gluttony) can relate to the functional alterations of serotonin in the brain. Results of biochemical and molecular genetic (polymorphism) studies on the human serotonergic system (receptor, transporter, enzyme), findings of functional imaging techniques, effects of depletion (or supplementation) of the serotonin precursor tryptophan, data of challenge probe investigations directed to testing central serotonergic functions, alterations in the peripheral serotonin measures (platelet), and the changes in the CSF 5-hydroxy-indoleacetic acid content indicate such serotonergic involvement. Furthermore, results of animal experiments on behaviour change (aggressive, dominant or submissive, appetite, alcohol preference) attributed to serotonin status modification and the clinically evidenced therapeutic efficacy of pharmacological interventions, based on the modulation and perturbation of the serotonergic system (e.g. selective serotonin reuptake inhibitors), in treating the ’sinful’ behaviour forms and analogous pathological states reaching the severity of psychiatric disorders (depression, sexual disturbances, social phobia, impulsivity-aggression, obsessive-compulsive and related spectrum disorders, paranoid jealousy, eating disorders) all strongly suggest the possibility that brain serotonin dysfunctions might underlie the neurophysiology of the Seven Deadly Sins.]

Clinical Neuroscience

[HIV infection and neurology - long term follow-up of HIV infected children]

KOLLÁR Katalin, JELENIK Zsuzsanna, HEGELSBERGER Edit

[Objectives - Before the widespread introduction of combined antiretroviral therapy (1995) complications from HIV and AIDS in the central nervous system had been reported in larger proportion in infants and children than in adults: 80-90% versus 60-70%. Particular clinical manifestations tend to occur at different stages during the evolution of HIV infection. The authors review the neurological aspects of HIV infection. Method - First, a summary of the protocol of the neurological examinations and related experience is given. Then authors present the evaluation of neuro-psychological development, prevalence of neurological impairment and neuro-imaging of nine HIV infected children (seven boys, two girls) for the period of ten years (1991-2001). Three/ten children had vertically transmitted HIV, six/nine were infected by a nosocomial route in their early childhood. Children were regularly followed up from the diagnosis of HIV. The median follow up time has been 79 month (range: 18-144 month). Four patients died during the study period. The neurological status, the motor and mental development were examined at three month intervals or monthly under one year of age. EEG was performed every six month and CT/MRI once a year. All patients received combined antiretroviral treatment and immunglobulin therapy continuously. Results - Three/nine children have normal development, one/nine has hyperactive and attention deficit disorder with normal IQ range, two/nine have slight, one/nine moderate and two/nine serious mental retardation. Mild neurological signs were found in two children, various moderate and serious neuro/psychological symptoms were found in four patients, one of them was treated with benign epilepsy too. There was also close correlation between the clinical symptoms and the results of EEG examination (diffuse background slowing) and results of neuroimaging studies (cortical atrophy, calcification of the basal ganglia, toxoplasma abscesses). According to the results of different examinations three/nine children were found to be symptom-free, one/nine case showed the static form, two/nine patients showed the plateau form, two/nine the rapid progressive form and one/nine the progressive infantile form of AIDS encephalopathy. The majority of the patients suffered from adapting problems and difficulties of socialisation since their families lives were damaged by isolation and rejection from the community. Conclusion - The regular neurological and psychological examinations completed with EEG, CT/MRI were very informative to follow the course of neuro-psychological problems of HIV infected children. Symptom-free patients have to face psychosocial problems too, which cause much more damage in their mental progress than HIV itself.]

Clinical Neuroscience

[Thallium poisoning induced polyneuropathy - clinical and electrophysiological data]

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[Introduction - The aim of the study was the electrophysiological investigation of thallium induced polyneuropathy. Beyond the rarity of the illness, the motivation of this work was the possibility of following up the pattern of neuronal damage. Thallium is one of the most toxic heavy metal and its wide use increases the chance of chronic or accidental acute poisoning. The entero-hepatic circulation makes the accumulation of this toxic agent in tissues possible, mostly in neurons, in the epithelial cells of the digestive tract, in the germinative cells of the skin and testicles. In addition to alopecia and digestive complaints, the clinical picture of thallium poisoning is dominated by neurological signs. Severe axonal polyneuropathy develops in almost all cases, with further damage to the retina and impairment of cognitive functions being not unusual. The diagnosis is confirmed by finding high levels of thallium in body fluids, especially in saliva and urine. Case report - Electrophysiological examination of our accidentally poisoned patient revealed severe, sensory-motor, predominant motor axonal polyneuropathy and pointed out some aspects of the pattern of neurotoxic process: the initially distal lesion, the dying-back course and the capacity for regeneration. Conclusion - Because thallium has the same molecular targets as potassium ion thus impairing the energetical supply of the nerve cell, the most effective treatment is carefully loading with potassium. If recognized and treated early, thallium poisoning has a favourable prognosis.]

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The yield of electroencephalography in syncope

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Clinical Neuroscience

[EEG-based cerebral networks in 14 neurological disorders]

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[Background - Brain networks have not been systematically investigated yet in most neurological disorders. Purpose - To investigate EEG functional connectivity (EEGfC) networks in 14 neurological disorders. Patients - Potentially eligible patients were collected from clinical and EEG databases. All the available clinical data and EEG records were critically revised. All the patients who suffered of a single neurological disorder (out of the 14) and had a good quality EEG recording entered the study. Confoundig factors as comorbidity and CNS-active drug effects were eliminated as far as possible. EEG analysis - Three minutes of resting-state, waking EEG activity were selected for analysis. Current source density (CSD) values were computed for 2394 cortical voxels by Low Resolution Electromagnetic Tomography (LORETA). Thereafter, Pearson correlation coefficients were computed between all pairs of 23 cortical regions of interest (ROI) in each hemisphere (LORETA Source Correlation, LSC software). Computation was carried out for conventional EEG broad bands and very narrow bands (1 Hz bandwidth) between 1 and 25 Hz as well. Correlation coefficients of each group were statistically compared to our normative EEG (LSC) database by two-talied t-tests. Bonferroni-corrected p<0.05 values were accepted as statistically significant, and were graphically displayed as topographical networks. Results and conclusion - Group-specific networks were demonstrated. However, non-specific networks, charasteristic for most groups, were detected as well. Common finding were: decreased connectivity in the alpha band and increased connectivity in the delta, theta bands and upper-beta band. Decreased alpha-band connectivity presumably reflected primary lesional effects and on the other hand, non-specific vulnerability of “rich club connections”. Increased connectivity in the slow bands presumably indicated adaptive-compensatory activity of brain homeostasis. ]

Clinical Neuroscience

[The significance of high-resolution ultrasonography in the diagnosis of peripheral nerve disorders]

SCHEIDL Erika, JOSEF Böhm, FARBAKY Zsófia, DEBRECZENI Róbert, BERECZKI Dániel, ARÁNYI Zsuzsanna

[High resolution ultrasonography is an emerging technique for the investigation of peripheral nerves and is increasingly used worldwide in the diagnosis of peripheral nerve disorders, however, until now it is not widespread in Hungary. According to the literature this method is especially useful in entrapment neuropathies, traumatic peripheral nerve injuries, tumors of the peripheral nerves and sonographically guided interventions. Ultrasonography allows precise morphological analysis and quantitative measurements of the nerves providing useful complementary information to electrodiagnostic data. In entrapment neuropathies ultrasound shows nerve swelling mainly proximal to the sites of compression and a focal change of echotexture. On longitudinal scan, an abrupt caliber change and spindle-like swelling of the compressed nerve segment can be seen. Evaluation of the anatomical background and visualisation of the postoperative and posttraumatic changes provide useful information for planning of the therapy. Ultrasound may be of significant help in localizing the pathological nerve segment when it is at an electrophysiologically inaccessible site or when substantial secondary axonal loss precludes precise electrophysiological localization and it might even show pathological changes when nerve conduction studies are normal. Contrary to electrophysiological investigation ultrasonography might discover neurotmesis in the akute phase of traumatic nerve injuries indicating the necessity of surgical intervention. We provide a summary of the main indications and further application areas of this method.]

Clinical Neuroscience

[The evaluation of paroxysmal events in neonates and infants]

NAGY Eszter, FARKAS Nelli, HOLLÓDY Katalin

[Introduction - Differential diagnosis of neonatal and infantile seizures based only on inspection poses a challenge even for specialists. Aims - To investigate the evaluations of neonatal and infantile paroxysmal events based only on inspection. Research question - Is there any difference in the opinion of neonatologists, paediatric neurologists and neurologists about the assessment of common paroxysmal events in infancy? Patients and methods - Video recordings about paroxysmal movements of 15 neonates or infants (aged 2 days- 5 months) were displayed for 47 paediatric neurologists, 35 neonatologists and nurses working in Neonatal or Perinatal Intensive Care Units and 43 neurologists. They had to decide without knowing the past medical history or EEG results whether events presented were epileptic or nonepileptic in nature. Results - Answers of neonatologists and paediatric neurologists were correct in 67% of cases (824/1230), no significant difference was found between their results. The largest uncertainty was in the judgement of discrete hand movements and very rapid clonus with epileptic origin, they were judged correctly by only one third of participants. The result of neurologists was only slightly, but not significantly different from that of paediatric neurologists. Conclusion - In most cases, the correct diagnosis of neonatal and infantile paroxysmal events requires video-EEG recording. No significant difference was revealed between the evaluation of neonatologists and paediatric neurologists about the differential diagnosis of movements. The ongoing cooperation of paediatric neurologists and neurologists going back to several decades facilitates the shaping of a common perspective.]

Clinical Neuroscience

[Kennedy’s syndrome - bulbo-spinal muscular atrophy]

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[Kennedy syndrome is a late-onset, bulbar-spinal type of muscular atrophy, with X-linked recessive inheritance. The characteristic features of the disease become prominent in the 4-5th decades: proximal muscle wasting and weakness, bulbar signs, fasciculations in skeletal muscles, subtle signs of endocrine dysfunction, such as gynaecomastia or testicular atrophy. The electrophysiological examinations are the keypoint to the diagnosis. Electroneurography shows normal conduction velocity in peripheral nerves, but the sensory nerves usually show axonal degeneration, which causes only very mild or subclinical neurological deficits. Electromyography shows chronic anterior horn cell degeneration in skeletal muscles. Molecular genetic diagnosis was introduced in 1991, when an abnormal expansion of CAG repeat was found in the first exon of the androgen receptor gene on chromosome X with a frequency of 100% in the affected population. Since the progression is very slow and these patients can expect a normal life span, it is essential to distinguish this syndrome from other, often more severe diseases, such as ALS. There is no proven therapy for Kennedy's disease yet. This is the first case of Kennedy's disease published in Hungary.]