Clinical Neuroscience

[The role of transcranial magnetic stimulation in clinical diagnosis: facial nerve neurography]

ARÁNYI Zsuzsanna, SIMÓ Magdolna

DECEMBER 20, 2002

Clinical Neuroscience - 2002;55(11-12)

[Facial nerve neurography involving magnetic stimulation techniques can be used to assess the intracranial segment of the facial nerve and the entire facial motor pathway, as opposed to the traditional neurography, involving only extracranial electric stimulation of the nerve. Both our own experience and data published in the literature underline the value of the method in localising facial nerve dysfunction and its role in clinical diagnosis. It is non-invasive and easy to perform. Canalicular hypoexcitability has proved to be the most useful and sensitive parameter, which indicates the dysfunction of the nerve between the brain stem and the facial canal. This is an electrophysiological finding which offers for the first time positive criteria for the diagnosis of Bell’s palsy. The absence of canalicular hypoexcitability practically excludes the possibility of Bell’s palsy. The technique is also able to demonstrate subclinical dysfunction of the nerve, which can be of considerable help in the etiological diagnosis of facial palsies. For example, in a situation where clinically unilateral facial weakness is observed, but facial nerve neurography demonstrates bilateral involvement, etiologies other than Bell’s palsy are more likely, such as Lyme’s disease, Guillain-Barré syndrome, meningeal affections etc. Furthermore, the technique differentiates reliably between peripheral facial nerve lesion involving the segment in the brain stem or the segment after leaving the brainstem.]

COMMENTS

0 comments

Further articles in this publication

Clinical Neuroscience

[Relationship between the efficacy of atypical antipsychotics and polymorphism of dopamine D3 receptor in schizophrenia]

SZEKERES György, JUHÁSZ Anna, KÉRI Szabolcs, RIMANÓCZY Ágnes, SZENDI István, SZABÓ Zoltán, JANKA Zoltán

[Object - Numerous relevant variants of dopamine receptors have been identified in schizophrenia. The Ser9Gly gene polymorphism of dopamine D3 receptor is known as a susceptibility factor for the disease. In addition, it has a role in the modification of therapeutic effect of antipsychotics. In this naturalistic study the authors investigated the relationship between this polymorphism and the therapeutic response to atypical antipsychotics. Method - 75 patients with schizophrenia according to DSM-IV and 45 healthy controlls were recruited. The patients were divided to responder and nonresponder subgroups, cut-off: >20 point improvement in Global Assessment of Functioning. By polymerase chain reaction the genotype of dopamine D3 receptor of every participant was determined. Results - The Ser9Ser genotype of dopamine D3 receptor was more frequent in the nonresponder subgroup (64%, p=0.0018). The Ser9 allele was overrepresented among nonresponder patients (82%, p=0.0172). Conclusion - Based on our results, the worse therapeutic response to atypical antipsychotics is associated with Ser9 variant of dopamine D3 receptor.]

Clinical Neuroscience

[Friedreich-ataxia - diagnosis after a decade. Differential diagnosis of inherited spinocerebellar ataxias]

VITASZIL Edina, JELENCSIK Ilona, SZIRMAI Imre

[The clinical diagnosis of inherited spinocerebellar ataxias is difficult, because phenotypes frequently overlap. The authors attempt to review the different inherited ataxia syndromes, discussing the most frequent one, Friedreich-ataxia in detail. The case of a patient with Friedreich-ataxia is presented, where the genetically supported diagnosis has been made more than ten years following the onset of the symptoms, after several hospitalizations and misdiagnosis. The correct diagnosis can be established based on the Geoffroy-Harding criteria and gene mutation analysis.]

Clinical Neuroscience

[The use of ECT for epileptic patient]

FARKAS Márta, BARAN Brigitta, KÁRPÁTI Róbert, RAJNA Péter

[Psychiatric disorders which indicate the use of electroconvulsive therapy (ECT) also occur in epileptic patients, but there is a lack of medical authority concerning the use of ECT in epileptic patients. This is surprising because in recent years it has been proved that ECT has an anti-convulsive effect to some degree. A case study of an epileptic patient is presented whose progress has been monitored for several years. Antiepileptic drugs were seemingly able to control his epilepsy but at the same time progressive behavioural disturbance (schizophreniform psychosis) accompanied by agitation and violent behaviour developed. Considering the recurrent psychotic decompensations and the relative ineffectiveness of antipsychotics, the authors decided to administer ECT. As a result they were able to bring about the longest symptom free balanced period in the patient. According to the data based on previous medical studies and the experience they can suppose that ECT is not immediately contraindicated by the presence of epilepsy with active interictal focus if the psychopathological condition makes it necessary. In view of the epileptogenic risk factors of classical neuroleptics, the epileptogenic effects of accompanying psychosis and the probable anticonvulsive potential of ECT in cases of severe psychiatric complications accompanying epilepsy ECT could be used more frequently.]

Clinical Neuroscience

[CONGRESS CALENDAR]

Clinical Neuroscience

[Hormonal abnormalities caused by intrasellar persistent trigeminal: PTA with hormonal dysfunction]

OSZTIE Éva, CZIRJÁK Sándor, RÁCZ Károly, MARTOS János

[Persistent trigeminal artery is a relatively frequent type of intracranial arterial developmental anomalies. The diagnostic tools for demonstration previously consisted of carotid angiography, later CT and DSA and nowadays MR and MRA. The practical benefit of the diagnosis is to avoid any hazard at the operation of associated hypophysis adenomas and aneurysms and could also give a possible explanation for apparent hormonal abnormalities. The authors support the latter possibility with a case report.]

All articles in the issue

Related contents

Clinical Neuroscience

[CLINICAL ANALYSIS OF PATIENTS WITH PERIPHERAL FACIAL PALSY]

ILNICZKY Sándor

[symptoms. In two thirds of the cases the cause is unknown, this is called “idiopathic peripheral facial palsy or Bell’s palsy”, but several different diseases have to be considered in the differential diagnosis. In this paper we reviewed the case histories of 110 patients treated for “peripheral facial palsy” in the Department of Neurology, Semmelweis University, Budapest in a five year period, 2000-2004. We studied the age, gender distribution, seasonal occurance, comorbidities, sidedness, symptoms, circumstances of referral to the hospital, the initial diagnoses and therapeutic options. We also discuss the probable causes and consequences of diagnostic failures. Results: the proportion of males and females was equal. There was no considerable difference between sexes regarding agedistribution. Of the 110 patients 106 was diagnosed with idiopathic Bell’s palsy, three cases with otic herpes zoster and one patient with Lyme disease. In our material, peripheral facial palsy was significantly more frequent in the cold period of late autumn, winter, and early spring. Diabetes mellitus and hypertension were more frequent than in the general population. 74% of the patients were admitted within two days from the onset of the symptoms. In 37% preliminary diagnosis was unavailable. In 15% cerebrovascular insult was the first, incorrect diagnosis, the correct diagnosis of “Bell’s palsy” was provided only in 16%. The probable causes of diagnostic failures may be the misleading symptoms and accompanying conditions. We examined the different therapies applied and reviewed the literature in this topic. We conclude that intravenous corticosteroid treatment in the early stage of the disease is the therapy of choice.]

Clinical Neuroscience

[Non-invasive brain stimulation for relieving acute and chronic pain]

CSIFCSÁK Gábor, ANTAL Andrea

[Controlling pain has always been one of the biggest challenges of medical science. Despite pharmacological developments, still many patients suffer from long-lasting pain. During the last 40 years several surgical interventions have been used to modulate the activity of the central nervous system in order to control chronic, pharmacoresistant pain. Because such interventions may involve very serious adverse events, safer and at least equally efficient methods are still required. In the 90’s new techniques of non-invasive brain stimulation have been introduced that enable the facilitation or inhibition of distinct cortical areas. These methods are based on the electrical stimulation of brain structures and to date they have been successfully used to modulate perceptual, cognitive and motor functions in healthy subjects and various diseases as well. In this review we describe such techniques of non-invasive brain stimulation, namely repeated transcranial magnetic stimulation and transcranial direct current stimulation and review the current literature about their efficacy in controlling acute and chronic pain.]

Clinical Neuroscience

[The role of transcranial magnetic stimulation in clinical diagnosis: motor evoked potential (MEP)]

ARÁNYI Zsuzsanna, SIMÓ Magdolna

[Transcranial magnetic stimulation allows painless, non-invasive stimulation, neurophysiological evaluation of nervous structure covered by bone or difficult to access for other reasons. In the clinical setting the technique is mainly used for the investigation of the corticospinal tract (motor evoked potential: MEP). Based upon our experience with patients examined over the course of four years, we have attempted to highlight the clinical situations, where diagnostic help is provided by this technique. MEP in general has proved to be a sensitive and reliable examination. Its significance is apparent mainly in situations where clinical signs of corticospinal tract dysfunction are not evident, or they are masked by lower motoneurone involvement, and where neuroimaging techniques are not informative. The demonstration of subclinical corticospinal lesion is often essential to establish the diagnosis in multiple sclerosis and amyotrophic lateral sclerosis. The technique however received little attention so far with respect to its role in the diagnosis of various spinal cord disorders, and in the demonstration of intact corticospinal function in case of weakness, psychogenic in origin. We have endeavoured to provide further evidence in support of this, and thereby advocating a wider clinical application of the technique.]

Clinical Neuroscience

[TRANSCRANIAL MAGNETIC STIMULATION: PHYSIOLOGY AND APPLICATIONS]

ARÁNYI Zsuzsanna

[Transcranial magnetic stimulation (TMS) is a relatively new technique that allows painless activation of cortical motor neurons. In the clinical setting, TMS is primarily used for the investigation of the corticospinal tract in various neurological diseases, being especially useful in the detection of subclinical dysfunction. In addition to the motor cortex, TMS can be applied to examine other structures inaccessible to electrical stimulation, such as the canalicular portion of the facial nerve. In healthy individuals, TMS can be utilized to monitor excitability changes of the motor system in various situations and muscles, providing valuable information to the understanding of the physiology of motor control. Furthermore, TMS can be used to explore interhemispheric connections as well as intracortical inhibitory and excitatory processes both in health and disease. Finally, with the help of TMS cortical maps of the representation areas of muscles can be constructed, giving insight to both short and long-term cortical plasticity and to the reorganisation of the motor cortex following damage to the brain or acquisition of new motor skills]

Clinical Neuroscience

Unanswered questions in the transcranial magnetic stimulation treatment of patients with depression

MORVAI Szabolcs, NAGY Attila, KOVÁCS Attila, MÓRÉ Csaba, BERECZ Roland, FRECSKA Ede

According to the WHO fact sheet depression is a common mental disorder affecting 350 million people of all ages worldwide. Transcranial Magnetic Stimulation (TMS) is a technique which allows the investigator to stimulate and study cortical functions in healthy subjects and patients suffering from various mental and neurological disorders. In the early 1990s, studies revealed that it is possible to evoke long term mood changes in healthy volunteers by rapid rate repetitive, TMS (rTMS) over the frontal cortex. Subsequent studies involving depressed patients found frontal cortical rTMS administered daily to be clinically effective. In the past two decades, numerous trials examined the therapeutic potential of rTMS application in the treatment of mood disorders with constantly evolving treatment protocols. The aim of this paper is to review the literature of the past two decades, focusing on trials addressing the efficacy and safety of rTMS in depressed patients. Our primary goal is to evaluate the results in order to direct future studies which may help investigators in the development of treatment protocols suitable in hospital settings. The time is not far when TMS devices will be used routinely by practitioners primarily for therapeutic purpose rather than clinical research. To our knowledge, a widely accepted “gold standard" that would offer the highest efficacy, with the best tolerability has not been established yet. In order to approach this goal, the most important factors to be addressed by further studies are: localization, frequency, intensity, concurrent medication, maintenance treatments, number of pulses, trains, unilateral, or bilateral mode of application.