Neurophysiological Tests (neurophysiological + test)

Distribution by Scientific Domains


Selected Abstracts


Neurophysiological tests and neuroimaging procedures in non-acute headache: guidelines and recommendations

EUROPEAN JOURNAL OF NEUROLOGY, Issue 4 2004
G. Sandrini
The use of instrumental examinations in headache patients varies widely. In order to evaluate their usefulness, the most common instrumental procedures were evaluated, on the basis of evidence from the literature, by an EFNS Task Force (TF) on neurophysiological tests and imaging procedures in non-acute headache patients. The conclusions of the TF regarding each technique are expressed in the following guidelines for clinical use. 1Interictal electroencephalography (EEG) is not routinely indicated in the diagnostic evaluation of headache patients. Interictal EEG is, however, indicated if the clinical history suggests a possible diagnosis of epilepsy (differential diagnosis). Ictal EEG could be useful in certain patients suffering from hemiplegic and basilar migraine. 2Recording of evoked potentials is not recommended for the diagnosis of headache disorders. 3There is no evidence to justify the recommendation of autonomic tests for the routine clinical examination of headache patients. 4Manual palpation of pericranial muscles, with standardized palpation pressure, can be recommended for subdividing patient groups but not for diagnosis. Pressure algometry and electromyography (EMG) cannot be recommended as clinical diagnostic tests. 5In adult and paediatric patients with migraine, with no recent change in attack pattern, no history of seizures, and no other focal neurological signs or symptoms, the routine use of neuroimaging is not warranted. In patients with atypical headache patterns, a history of seizures and/or focal neurological signs or symptoms, magnetic resonance imaging (MRI) may be indicated. 6If attacks can be fully accounted for by the standard headache classification [International Headache Society (IHS)], a positron emission tomography (PET) or single-photon emission computerized tomography (SPECT) and scan will generally be of no further diagnostic value. 7Nuclear medicine examinations of the cerebral circulation and metabolism can be carried out in subgroups of headache patients for diagnosis and evaluation of complications, when patients experience unusually severe attacks, or when the quality or severity of attacks has changed. 8Transcranial Doppler examination is not helpful in headache diagnosis. Although many of the examinations described are of little or no value in the clinical setting, most of the tools have a vast potential for further exploring the pathophysiology of headaches and the effects of pharmacological treatment. [source]


Implementation and evaluation of existing guidelines on the use of neurophysiological tests in non-acute migraine patients: a questionnaire survey of neurologists and primary care physicians

EUROPEAN JOURNAL OF NEUROLOGY, Issue 8 2009
P. Rossi
Background and purpose:, The main aims of this study were to evaluate: the diffusion, use and perception of the usefulness of the 2004 EFNS guidelines on neurophysiological testing in non-acute headache patients; the frequency with which the different neurophysiological tests were recommended in non-acute migraine patients by physicians aware or unaware of the guidelines; and the appropriateness of the reasons given for recommending neurophysiological tests. Methods:, One hundred and fifty physicians selected amongst the members of the Italian societies of general practitioner (GPs), neurologists and headache specialists were contacted via e-mail and invited to fill in a questionnaire specially created for the study. Results:, Ninety-two percent of the headache specialists, 8.6% of the neurologists and 0% of the GPs were already aware of the EFNS guidelines. A significantly higher proportion of headache specialists had not recommended any neurophysiological tests to the migraine patients they had seen in the previous 3 months, whereas these tests had frequently been prescribed by the GPs and neurologists. Overall, 80%, 42% and 42.6% of the reasons given by headache specialists, neurologists and GPs, respectively, for recommending neurophysiological testing in their migraine patients were appropriate (P < 0.01). Conclusions:, The diffusion of the EFNS guidelines on neurophysiological tests and neuroimaging procedures was found to be very limited amongst neurologists and GPs. The physicians aware of the EFNS guidelines recommended neurophysiological tests to migraine patients less frequently and more appropriately than physicians who were not aware of them. The most frequent misconceptions regarding neurophysiological tests concerned their perceived capacity to discriminate between migraine and secondary headaches or between migraine and other primary headaches. [source]


Neurophysiological tests and neuroimaging procedures in non-acute headache: guidelines and recommendations

EUROPEAN JOURNAL OF NEUROLOGY, Issue 4 2004
G. Sandrini
The use of instrumental examinations in headache patients varies widely. In order to evaluate their usefulness, the most common instrumental procedures were evaluated, on the basis of evidence from the literature, by an EFNS Task Force (TF) on neurophysiological tests and imaging procedures in non-acute headache patients. The conclusions of the TF regarding each technique are expressed in the following guidelines for clinical use. 1Interictal electroencephalography (EEG) is not routinely indicated in the diagnostic evaluation of headache patients. Interictal EEG is, however, indicated if the clinical history suggests a possible diagnosis of epilepsy (differential diagnosis). Ictal EEG could be useful in certain patients suffering from hemiplegic and basilar migraine. 2Recording of evoked potentials is not recommended for the diagnosis of headache disorders. 3There is no evidence to justify the recommendation of autonomic tests for the routine clinical examination of headache patients. 4Manual palpation of pericranial muscles, with standardized palpation pressure, can be recommended for subdividing patient groups but not for diagnosis. Pressure algometry and electromyography (EMG) cannot be recommended as clinical diagnostic tests. 5In adult and paediatric patients with migraine, with no recent change in attack pattern, no history of seizures, and no other focal neurological signs or symptoms, the routine use of neuroimaging is not warranted. In patients with atypical headache patterns, a history of seizures and/or focal neurological signs or symptoms, magnetic resonance imaging (MRI) may be indicated. 6If attacks can be fully accounted for by the standard headache classification [International Headache Society (IHS)], a positron emission tomography (PET) or single-photon emission computerized tomography (SPECT) and scan will generally be of no further diagnostic value. 7Nuclear medicine examinations of the cerebral circulation and metabolism can be carried out in subgroups of headache patients for diagnosis and evaluation of complications, when patients experience unusually severe attacks, or when the quality or severity of attacks has changed. 8Transcranial Doppler examination is not helpful in headache diagnosis. Although many of the examinations described are of little or no value in the clinical setting, most of the tools have a vast potential for further exploring the pathophysiology of headaches and the effects of pharmacological treatment. [source]


A New Simple Neurophysiological Method (Through Conventional Electrical Stimulation) To Assess Function Of Tactile Receptors And Related Nerve Fibers

JOURNAL OF THE PERIPHERAL NERVOUS SYSTEM, Issue 1 2001
L Padua
Sometimes standard sensory nerve conduction studies show normal results in patients with definite symptoms of sensory polyneuropathy. This is usually explained because standard neurophysiological tests evaluate only large myelinated fibers and do not assess the slowest conducting fibers, more distal segments of the nerves and tactile receptors. Tactile stimulation is a test, not routinely available, that assesses the function of tactile receptors and conduction of fibers that are depolarized by these receptors. During conventional sensory nerve conduction studies (in patients and healthy subjects) through surface electrodes, where we slowly increased the intensity of the stimulus, we occasionally observed a sensory response characterized by a particular morphology with two peaks. After several experiments (performed in the neurophysiological laboratories of Catholic University of Rome and of University of Uppsala) we argued that the double component of the response is the expression of the stimulation of tactile receptors (and depolarization of their related fibers). Therefore an electrical stimulation through conventional EMG equipment allows us to assess function of tactile receptors (and related nerve fibers). This observation may have important diagnostic application in clinical practice to evaluate suspected polyneuropathies negative to neurophysiological conduction studies. [source]


Opportunities afforded by the study of unmyelinated nerves in skin and other organs

MUSCLE AND NERVE, Issue 6 2004
William R. Kennedy MS
Abstract Neurological practice is mainly focused on signs and symptoms of disorders that involve functions governed by myelinated nerves. Functions controlled by unmyelinated nerve fibers have necessarily remained in the background because of the inability to consistently stain, image, or construct clinically applicable neurophysiological tests of these nerves. The situation has changed with the introduction of immunohistochemical methods and confocal microscopy into clinical medicine, as these provide clear images of thin unmyelinated nerves in most organs. One obvious sign of change is the increasing number of reports from several laboratories of the pathological alterations of cutaneous nerves in skin biopsies from patients with a variety of clinical conditions. This study reviews recent methods to stain and image unmyelinated nerves as well as the use of these methods for diagnosing peripheral neuropathy, for experimental studies of denervation and reinnervation in human subjects, and for demonstrating the vast array of unmyelinated nerves in internal organs. The new ability to examine the great variety of nerves in different organs opens opportunities and creates challenges and responsibilities for neurologists and neuroscientists. Muscle Nerve 756,767, 2004 [source]


Sural nerve biopsy may predict future nerve dysfunction

ACTA NEUROLOGICA SCANDINAVICA, Issue 1 2009
S. Thrainsdottir
Objective,,, Sural nerve pathology in peripheral neuropathy shows correlation with clinical findings and neurophysiological tests. The aim was to investigate progression of nerve dysfunction over time in relation to a baseline nerve biopsy. Methods,,, Baseline myelinated nerve fiber density (MNFD) was assessed in sural nerve biopsies from 10 men with type 2 diabetes, 10 with impaired and 10 with normal glucose tolerance. Nerve conduction and quantitative perception thresholds were estimated at baseline and follow-up (7,10 years later). Results,,, Subjects with low MNFD (,,4700 fibers/mm2) showed decline of peroneal amplitude (P < 0.02) and conduction velocity (P < 0.04), as well as median nerve sensory amplitude (P < 0.05) and motor conduction velocity (P < 0.04) from baseline to follow-up. In linear regression analyses, diabetes influenced decline of nerve conduction. MNFD correlated negatively with body mass index (r = ,0.469; P < 0.02). Conclusion,,, Low MNFD may predict progression of neurophysiological dysfunction and links obesity to myelinated nerve fiber loss. [source]