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STUDY DESIGN: Repetitive transcranial magnetic stimulation study. OBJECTIVES: The analgesic effects of repetitive transcranial magnetic stimulation (rTMS) in chronic pain have been the focus of several studies. In particular, rTMS of the premotor cortex/dorsolateral prefrontal cortex (PMC/DLPFC) changes pain perception in healthy subjects and has analgesic effects in acute postoperative pain, as well as in fibromyalgia patients. However, its effect on neuropathic pain in patients with traumatic spinal cord injury (SCI) has not been assessed. SETTING: Merano (Italy) and Salzburg (Austria). METHODS: In this study, we performed PMC/DLPFC rTMS in subjects with SCI and neuropathic pain. Twelve subjects with chronic cervical or thoracic SCI were randomized to receive 1250 pulses at 10 Hz rTMS (n=6) or sham rTMS (n=6) treatment for 10 sessions over 2 weeks. The visual analog scale, the sensory and affective pain rating indices of the McGill Pain Questionnaire (MPQ), the Hamilton Depression Rating Scale and the Hamilton Anxiety Rating Scale were used to assed pain and mood at baseline (T0), 1 day after the first week of treatment (T1), 1 day (T2), 1 week (T3) and 1 month (T4) after the last intervention. RESULTS: Subjects who received active rTMS had a statistically significant reduction in pain symptoms in comparison with their baseline pain, whereas sham rTMS participants had a non-significant change in daily pain from their baseline pain. CONCLUSION: The findings of this preliminary study in a small patient sample suggest that rTMS of the PMC/DLPFC may be effective in relieving neuropathic pain in SCI patients.
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Dolor Crónico/terapia , Corteza Motora , Neuralgia/terapia , Traumatismos de la Médula Espinal/complicaciones , Estimulación Magnética Transcraneal/métodos , Adulto , Análisis de Varianza , Vértebras Cervicales , Dolor Crónico/etiología , Dolor Crónico/fisiopatología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Corteza Motora/fisiopatología , Neuralgia/etiología , Neuralgia/fisiopatología , Dimensión del Dolor , Traumatismos de la Médula Espinal/fisiopatología , Traumatismos de la Médula Espinal/rehabilitación , Vértebras Torácicas , Factores de Tiempo , Estimulación Magnética Transcraneal/efectos adversos , Resultado del TratamientoRESUMEN
STUDY DESIGN: Topical review of the literature. OBJECTIVE: The objective of this review article was to assess indications and usefulness of various neurophysiological techniques in diagnosis and management of cervical spondylogenic myelopathy (CSM). METHODS: The MEDLINE, accessed by Pubmed and EMBASE electronic databases, was searched using the medical subject headings: 'compressive myelopathy', 'cervical spondylotic myelopathy (CSM)', 'cervical spondylogenic myelopathy', 'motor evoked potentials (MEPs)', 'transcranial magnetic stimulation', 'somatosensory evoked potentials (SEPs)', 'electromyography (EMG)', 'nerve conduction studies (NCS)' and 'cutaneous silent period (CSP)'. RESULTS: SEPs and MEPs recording can usefully supplement clinical examination and neuroimaging findings in assessing the spinal cord injury level and severity. Segmental cervical cord dysfunction can be revealed by an abnormal spinal N13 response, whereas the P14 potential is a reliable marker of dorsal column impairment. MEPs may also help in the differential diagnosis between spinal cord compression and neurodegenerative disorders. SEPs and MEPs are also useful in follow-up evaluation of sensory and motor function during surgical treatment and rehabilitation. EMG and NCS improve the sensitivity of cervical radiculopathy detection and may help rule out peripheral nerve problems that can cause symptoms that are similar to those of CSM. CSP also shows a high sensitivity for detecting CSM. CONCLUSION: Neuroimaging, especially magnetic resonance imaging, represents the procedure of choice for the diagnosis of CSM, but a correct interpretation of morphological findings can be achieved only if they are correlated with functional data. The studies reported in this review highlight the crucial role of the electrophysiological studies in diagnosis and management of CSM.
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Manejo de la Enfermedad , Neurofisiología , Traumatismos de la Médula Espinal , Espondilosis , Animales , Electromiografía , Potenciales Evocados/fisiología , Humanos , Conducción Nerviosa/fisiología , Neurofisiología/tendencias , Traumatismos de la Médula Espinal/diagnóstico , Traumatismos de la Médula Espinal/fisiopatología , Traumatismos de la Médula Espinal/terapia , Espondilosis/diagnóstico , Espondilosis/fisiopatología , Espondilosis/terapiaRESUMEN
STUDY DESIGN: Transcranial magnetic stimulation study. OBJECTIVES: To further investigate the corticospinal excitability changes after spinal cord injury (SCI), as assessed by means of transcranial magnetic stimulation (TMS). SETTING: Merano (Italy) and Salzburg (Austria). METHODS: We studied resting motor threshold (RMT), motor evoked potential (MEP) amplitude and recruitment curve in five subjects with good recovery after traumatic incomplete cervical SCI. RESULTS: RMT did not differ significantly between patients and controls, whereas the slope of MEP recruitment curve was significantly increased in the patients. CONCLUSION: This abnormal finding may represent an adaptive response after SCI. The impaired ability of the motor cortex to generate proper voluntary movement may be compensated by increasing spinal excitability. The easily performed measurement of MEP recruitment curve may provide a useful additional tool to improve the assessment and monitoring of motor cortical function in subjects with SCI. Increasing our knowledge of the corticospinal excitability changes in the functional recovery after SCI may also support the development of effective therapeutic strategies.
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Médula Cervical/lesiones , Potenciales Evocados Motores/fisiología , Corteza Motora/fisiopatología , Tractos Piramidales/fisiopatología , Traumatismos de la Médula Espinal/fisiopatología , Estimulación Magnética Transcraneal/métodos , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Proyectos PilotoRESUMEN
Several Transcranial Magnetic Stimulation (TMS) techniques can be applied to noninvasively measure cortical excitability and brain plasticity in humans. TMS has been used to assess neuroplastic changes in Alzheimer's disease (AD), corroborating findings that cortical physiology is altered in AD due to the underlying neurodegenerative process. In fact, many TMS studies have provided physiological evidence of abnormalities in cortical excitability, connectivity, and plasticity in patients with AD. Moreover, the combination of TMS with other neurophysiological techniques, such as high-density electroencephalography (EEG), makes it possible to study local and network cortical plasticity directly. Interestingly, several TMS studies revealed abnormalities in patients with early AD and even with mild cognitive impairment (MCI), thus enabling early identification of subjects in whom the cholinergic degeneration has occurred. Furthermore, TMS can influence brain function if delivered repetitively; repetitive TMS (rTMS) is capable of modulating cortical excitability and inducing long-lasting neuroplastic changes. Preliminary findings have suggested that rTMS can enhance performances on several cognitive functions impaired in AD and MCI. However, further well-controlled studies with appropriate methodology in larger patient cohorts are needed to replicate and extend the initial findings. The purpose of this paper was to provide an updated and comprehensive systematic review of the studies that have employed TMS/rTMS in patients with MCI and AD.
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Enfermedad de Alzheimer/terapia , Disfunción Cognitiva/terapia , Estimulación Magnética Transcraneal/métodos , Enfermedad de Alzheimer/fisiopatología , Animales , Encéfalo/fisiopatología , Disfunción Cognitiva/fisiopatología , Humanos , Plasticidad NeuronalRESUMEN
STUDY DESIGN: Experimental neurophysiological study. OBJECTIVES: The hepatic myelopathy (HM) is characterized by progressive weakness and spasticity of the lower extremities, while there are only a few reports of sensory impairment. However, sensory function has been poorly explored in HM. We believe that an electrophysiological assessment of dorsal columns by somatosensory evoked potentials (SEPs) and of cortico-spinal lateral tracts by motor evoked potentials (MEPs) should be of considerable value in the functional evaluation of the spinal cord involvement in patients with HM. SETTING: Salzburg (Austria) and Merano (Italy). METHODS: Eight patients diagnosed with HM were studied with MEPs and SEPs. Neurological examination revealed different degrees of cortico-spinal tract involvement in all patients and sensory abnormalities in three patients. RESULTS: Central motor conduction to lower limb muscles was abnormal in all patients, while central sensory conduction was abnormal in seven out of the eight patients. Both central motor and sensory conduction to upper limbs are normal in all patients. CONCLUSION: The main finding is that electrophysiological evidence of central sensory involvement is present in a very high percentage of patients with HM, and that the threshold for electrophysiological abnormalities is below that for clinical manifestations. Therefore, central sensory and motor conduction studies are sensitive methods for detecting, localizing and monitoring spinal cord damage in HM.
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Cirrosis Hepática/fisiopatología , Conducción Nerviosa/fisiología , Enfermedades de la Médula Espinal/fisiopatología , Adulto , Anciano , Potenciales Evocados Motores , Potenciales Evocados Somatosensoriales , Femenino , Humanos , Extremidad Inferior/fisiopatología , Masculino , Persona de Mediana Edad , Músculo Esquelético/fisiopatología , Examen Neurológico , Tractos Piramidales/fisiopatología , Extremidad Superior/fisiopatologíaRESUMEN
STUDY DESIGN: Topical review of the literature. OBJECTIVES: The evaluation of patients with myelopathies requires radiological investigations; however, for the correct interpretation of the neuroimaging findings, the functional assessment of corticospinal conduction is helpful or even mandatory in many conditions. The objective of this review article was to assess the utility of the motor evoked potentials (MEPs) in diagnosis and management of the most frequent spinal cord disorders. SETTING: Salzburg (Austria) and Merano (Italy). METHODS: A MEDLINE search was performed using following terms: 'motor evoked potentials', 'transcranial magnetic stimulation', 'central motor conduction', 'compressive myelopathy', 'spinal cord infarction', 'spinal cord injury', 'syringomyelia', 'myelitis', 'hereditary spastic paraparesis', 'subacute combined degeneration' and 'hepatic myelopathy'. RESULTS: Central motor conduction abnormalities can be detected also in the absence of neuroradiological abnormalities-for example, in patients with subacute combined degeneration or hepatic myelopathy. In the most frequent patients with compressive myelopathies, MEPs were found to be very helpful in determining the functional significance of neuroimaging findings. MEP recording can supplement clinical examination and neuroimaging findings also in the assessment of the spinal cord injury level. In patients with spinal cord infarction, the MEP study can demonstrate spinal involvement even when radiological evidence for spinal cord damage is absent or equivocal, thus allowing an important early diagnosis. CONCLUSION: MEPs represent a highly sensitive and accurate diagnostic tool in many different spinal cord disorders. MEPs can also be useful in follow-up evaluation of motor function during treatment and rehabilitation.
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Electrodiagnóstico/métodos , Potenciales Evocados Motores , Enfermedades de la Médula Espinal/diagnóstico , Enfermedades de la Médula Espinal/terapia , Humanos , Médula Espinal/fisiopatología , Enfermedades de la Médula Espinal/fisiopatologíaRESUMEN
STUDY DESIGN: Randomized, double-blind, crossover, sham-controlled trial. OBJECTIVES: Repetitive transcranial magnetic stimulation (rTMS) over the primary motor cortex (M1) leads to a significant reduction of spasticity in subjects with spinal cord injury (SCI), but the physiological basis of this effect is still not well understood. The purpose of this study was to evaluate the disynaptic reciprocal Ia inhibition of soleus motoneurons in SCI patients. SETTING: Department of Neurology, Merano, Italy and TMS Laboratory, Paracelsus Medical University, Salzburg, Austria. METHODS: Nine subjects with incomplete cervical or thoracic SCI received 5 days of daily sessions of real or sham rTMS applied over the contralateral M1. We compared the reciprocal inhibition, the Modified Ashworth Scale and the Spinal Cord Injury Assessment Tool for Spasticity at baseline, after the last session and 1 week later in the real rTMS and sham stimulation groups. RESULTS: We found that real rTMS significantly reduced lower limb spasticity and restored the impaired excitability in the disynaptic reciprocal inhibitory pathway. CONCLUSIONS: In a small proof-of-concept study, rTMS strengthened descending projections between the motor cortex and inhibitory spinal interneuronal circuits. This reversed a defect in reciprocal inhibition after SCI, and reduced leg spasticity.
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Corteza Motora/fisiología , Espasticidad Muscular/terapia , Inhibición Neural/fisiología , Trastornos de Estrés Traumático/terapia , Estimulación Magnética Transcraneal/métodos , Adulto , Anciano , Estudios Cruzados , Método Doble Ciego , Electromiografía , Potenciales Evocados Motores/fisiología , Femenino , Reflejo H/fisiología , Humanos , Masculino , Persona de Mediana Edad , Neuronas Motoras/fisiología , Espasticidad Muscular/etiología , Músculo Esquelético/patología , Inhibición Neural/efectos de la radiación , Trastornos de Estrés Traumático/complicaciones , Índices de Gravedad del TraumaRESUMEN
STUDY DESIGN: Case report. OBJECTIVE: Reveal the evolution of the magnetic resonance imaging (MRI) pattern in a patient with a posterior spinal artery infarction, which belongs to a subgroup of spinal cord ischemia syndromes and presents a rare cause of spinal cord injury. Our report underlines that diagnosis of spinal cord ischemia and thus clinical decision making remains challenging. SETTING: University Hospital of Innsbruck and University Hospital of Salzburg, Austria. METHODS: Here we present clinical, electrophysiological and imaging data in the acute, subacute and chronic phase of a woman who developed signs and symptoms related to a bilateral posterior spinal cord infarction. RESULTS: At the clinical nadir (24 h after symptom onset), MRI did not exhibit T2 hyperintensities. However, such MRI changes were detected 8 days after symptom onset and persisted until the latest follow-up at 5 months. CONCLUSIONS: Repeated MRI constitutes an indispensable diagnostic and follow-up tool for spinal cord ischemia. The imaging data in accordance with the electrophysiological measurements correlated well with the clinical presentation in the subacute und chronic phase. Therefore, further studies might allow using MRI following spinal cord ischemia as a prognostic marker for an individual outcome.
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Isquemia de la Médula Espinal/diagnóstico , Anciano , Femenino , Humanos , Imagen por Resonancia MagnéticaRESUMEN
Natalizumab is a humanized monoclonal antibody directed against the alpha-4 integrin subunit of very late activation antigen-4 (VLA-4). Natalizumab neutralizing antibodies (NAB) have been found to significantly reduce beneficial effects of natalizumab treatment in multiple sclerosis. We investigated interactions of NAB with natalizumab by serial measurements of alpha-4 integrin levels on peripheral blood mononuclear cells using flow cytometry. In addition, serum concentrations of soluble vascular cell adhesion molecule-1 (sVCAM-1), the endothelial ligand of VLA-4, and serum NAB were serially determined. Natalizumab infusion led to a transient reduction in alpha-4 integrin levels on immune cells and serum sVCAM-1 levels along with serum negativity of NAB lasting for a few days post-infusion. Apparently, the high-dose effect of freshly infused natalizumab resulted in a transient neutralization of NAB possibly involving a transient therapeutic effectiveness.
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Anticuerpos Monoclonales Humanizados/uso terapéutico , Anticuerpos Neutralizantes/uso terapéutico , Esclerosis Múltiple Recurrente-Remitente/tratamiento farmacológico , Esclerosis Múltiple Recurrente-Remitente/inmunología , Adulto , Anticuerpos Monoclonales Humanizados/inmunología , Anticuerpos Neutralizantes/inmunología , Femenino , Citometría de Flujo , Humanos , Integrina alfa4beta1/inmunología , Leucocitos Mononucleares/inmunología , Leucocitos Mononucleares/metabolismo , Natalizumab , Molécula 1 de Adhesión Celular Vascular/sangreRESUMEN
BACKGROUND: The diagnosis of the isolated leptomeningeal involvement of a primary central nervous system B-cell lymphoma without parenchyma lesions may be difficult. Patients with leptomeningeal meningeosis lymphomatosa can present with various neurologic deficits. AIMS OF THE STUDY: To demonstrate the impact of cerebrospinal fluid (CSF) flow cytometry in the diagnosis of an isolated leptomeningeal manifestation of B-cell lymphoma by presenting an interesting case report. METHODS: Flow cytometric analysis of B-cell monoclonality of the CSF was performed as complementary diagnostic procedure in addition to CSF cytology. Final diagnosis was confirmed by necropsy. RESULTS: We suspected isolated leptomeningeal manifestation of B-cell lymphoma with palsy of the VI and VII cranial nerves in a 79-year-old male, because of mononuclear pleocytosis in CSF. Interestingly, the decisive diagnostic hint was given by implementation of flow cytometry of the CSF. Diagnosis was confirmed by postmortem autopsy. CONCLUSION: Our case shows that flow cytometry of the CSF in addition to conventional CSF cytology has the potential to accelerate diagnosis of lymphomeningeal infiltration of B-cell lymphoma.
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Neoplasias del Sistema Nervioso Central/patología , Citometría de Flujo , Linfoma no Hodgkin/patología , Neoplasias Meníngeas/diagnóstico , Neoplasias Meníngeas/secundario , Anciano , Neoplasias del Sistema Nervioso Central/líquido cefalorraquídeo , Técnicas Citológicas , Humanos , Linfoma no Hodgkin/líquido cefalorraquídeo , Masculino , Neoplasias Meníngeas/líquido cefalorraquídeo , Necrosis/diagnósticoRESUMEN
BACKGROUND: Natalizumab is the first monoclonal antibody therapy approved for multiple sclerosis (MS). Its therapeutic mechanism is the blockade of the α4-integrin subunit of the adhesion molecule (AM) very late activation antigen-4 (VLA-4), which leads to an inhibition of immune cell extravasation into the central nervous system (CNS). METHODS: We investigated changes in the expression levels of unblocked α4-integrin and further AM (intercellular adhesion molecule-1, -2, -3 (cICAM-1, -2, -3), leukocyte function associated antigen-1 (LFA-1)) on peripheral blood mononuclear cells (PBMC) determined by flow cytometry from 25 patients with MS before the first natalizumab infusion and before the fourth infusion. In 15 MS patients AM expression was evaluated every 3 months over 1 year. RESULTS: We found a significant decrease (p < 0.0001) of unblocked α4-integrin cell surface expression on all investigated PBMC subsets (T cells -61.7%, B cells -69.1%, monocytes/macrophages -46.4%) in the blood of MS patients after 3 months of natalizumab treatment. Moreover, a continuous decrease (p < 0.05) of unblocked α4-integrin expression levels was seen after 3, 6, 9, and 12 months. As a secondary effect, expression levels of the other investigated AM were differentially affected. CONCLUSIONS: Results show a sustained decrease of unblocked α4-integrin expression not only in all patients but also in all investigated PBMC subsets. This probably results in a continuously decreasing transmigration of PBMC into the CNS and may explain the improved clinical efficacy in the second treatment year and also the increasing risk of progressive multifocal leukoencephalopathy during long-term natalizumab therapy. We conclude that AM expression profiles are promising candidates for the development of a biomarker system to determine both natalizumab treatment response and patients at risk for opportunistic CNS infections.
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Anticuerpos Monoclonales/administración & dosificación , Moléculas de Adhesión Celular/sangre , Factores Inmunológicos/administración & dosificación , Leucocitos Mononucleares/efectos de los fármacos , Esclerosis Múltiple Recurrente-Remitente/tratamiento farmacológico , Adolescente , Adulto , Anticuerpos Monoclonales Humanizados , Antígenos CD/sangre , Austria , Biomarcadores/sangre , Niño , Femenino , Citometría de Flujo , Humanos , Integrina alfa4/sangre , Molécula 1 de Adhesión Intercelular/sangre , Leucocitos Mononucleares/inmunología , Antígeno-1 Asociado a Función de Linfocito/sangre , Masculino , Persona de Mediana Edad , Esclerosis Múltiple Recurrente-Remitente/sangre , Esclerosis Múltiple Recurrente-Remitente/inmunología , Natalizumab , Estudios Prospectivos , Factores de Tiempo , Resultado del Tratamiento , Adulto JovenRESUMEN
PURPOSE: Comparative evaluation of regional brain perfusion measured by HMPAO-SPECT of patients with mild cognitive impairment (MCI), dementia of Alzheimer's type (DAT) and depression with cognitive impairment (DCI). METHODS: A total of 736 patients were investigated because of suspected cognitive dysfunction. After exclusion of patients with other forms of dementia than DAT or relevant accompanying disorders, SPECT data from 149 MCI, 131 DAT and 127 DCI patients, and 123 controls without any cognitive impairment, were analysed. Relative cerebral blood flow of 34 anatomical regions was assessed with automated analysis software (BRASS). RESULTS: Calculation of global forebrain perfusion discriminated demented from nondemented patients. Compared to controls DCI patients showed hypoperfusion of the thalamus, lentiform nucleus and medial temporal cortex. MCI patients differed significantly from controls concerning perfusion in both hemispheric temporal and parietal areas, and in the (right hemispheric) posterior part of the cingulate gyrus. MCI and DCI patients differed in the parietal, temporal superior and right hemispheric cingulate gyrus posterior cortices. Global forebrain and regional perfusion was more extensively reduced in DAT patients and discriminated them from controls, and MCI and DCI patients. Frontal perfusion disturbance was only present in DAT patients. CONCLUSION: Automated analysis of HMPAO-SPECT data from MCI patients showed significant perfusion deficits in regions also involved in DAT patients, but ROC analysis demonstrated only moderate sensitivity and specificity for differentiating DAT patients from controls and DCI patients. Frontal hypoperfusion seems to correspond with conversion from MCI to DAT. Finally, the results in DCI patients again raise the question of depression as an early symptom of neurodegeneration.
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Enfermedad de Alzheimer/complicaciones , Enfermedad de Alzheimer/diagnóstico , Encéfalo/patología , Trastornos del Conocimiento/complicaciones , Trastornos del Conocimiento/diagnóstico , Depresión/complicaciones , Depresión/diagnóstico , Tomografía Computarizada de Emisión de Fotón Único/métodos , Anciano , Enfermedad de Alzheimer/patología , Automatización , Trastornos del Conocimiento/patología , Depresión/patología , Diagnóstico por Computador , Femenino , Humanos , Masculino , Persona de Mediana Edad , Enfermedades Neurodegenerativas/diagnóstico , Enfermedades Neurodegenerativas/patología , Perfusión , Curva ROCRESUMEN
BACKGROUND: Growing evidence suggests that pathological processes leading to Alzheimer's disease occurs gradually and begins to develop decades before the earliest clinical symptoms occur. The use of biomarkers has been proposed to detect evidence of preclinical Alzheimer's pathologic change in asymptomatic subjects. Subjective cognitive complaints (SCC) i.e. self-reported cognitive decline with normal cognition have been reported as an indicator of future cognitive decline, however, this condition is unspecific. OBJECTIVE: In the present study we used the regional brain perfusion measured by HMPAO-SPECT as Biomarker of neurodegeneration to compare the regional brain perfusion of patient with subjective cognitive complaints with and without minimal cognitive dysfunction (SCC+ and SCC- respectively) in respect to patients with mild cognitive impairment (MCI). METHODS: We retrospectively examined 736 Patients who referred to our Memory Clinic because of suspected cognitive dysfunction. After exclusion of patients with overt dementia, automated, quantitatively assessed relative cerebral blood flow of 10 forebrain regions (thalamus, parietotemporal, medial temporal, posterior temporal, posterior cingulate gyrus, each region left hemispheric and right hemispheric) and neuropsychological assessment of 64 SCC (32 SCC+; 32 SCC-) and 28 MCI subjects were analysed. RESULTS: .The most relevant differences between groups in cognitive performance concerned verbal memory. Left hemispheric medial temporal region could significantly discriminate between all three groups, with a progressive decrease n perfusion from SCC towards MCI. Area under the curve of left medial temporal region showed a sensitivity of 0,61 and a specificity of 0,78 for discriminating MCI from SCC. CONCLUSION: Automated analysis of HMPAO-SPECT data of MCI and SCC+ patients showed significant perfusion differences in medial temporal region and impaired verbal memory, both of which are known features of Alzheimer's disease. Perfusion patterns and verbal memory performance in SCC+ are more similar to MCI than SCC-. Thus, SPECT analysis could distinguish those subjects whose perfusion pattern resembles that of an MCI from those who do not. In our opinion, this could identify two populations with a different risk of progression to AD, with SCC+ subjects needing further diagnostic examination and repeated follow-up.
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Encéfalo/diagnóstico por imagen , Trastornos del Conocimiento/diagnóstico por imagen , Tomografía Computarizada de Emisión de Fotón Único , Anciano , Encéfalo/metabolismo , Circulación Cerebrovascular , Trastornos del Conocimiento/metabolismo , Diagnóstico Diferencial , Autoevaluación Diagnóstica , Femenino , Humanos , Interpretación de Imagen Asistida por Computador , Masculino , Memoria , Pruebas Neuropsicológicas , Níquel , Oximas , Reconocimiento de Normas Patrones Automatizadas , Radiofármacos , Estudios Retrospectivos , TitanioRESUMEN
Sex differences in mental rotation tasks, favoring men, have been noted in behavioral studies and functional imaging studies. In the present study ten female and ten male volunteers underwent functional magnetic resonance imaging in a conventional block design. Regions of activation were detected after performance of a mental rotation task inside the scanner. In contrast to previous studies, confounding factors such as performance differences between genders or high error rates were excluded. Men showed significantly stronger parietal activation, while women showed significantly greater right frontal activation. Our results point to gender specific differences in the neuropsychological processes involved in mental rotation tasks.
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Encéfalo/fisiología , Cognición , Percepción Visual , Mapeo Encefálico , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Rotación , Factores SexualesRESUMEN
Sex differences in executive speech tasks, favoring women, have been noted in behavioral studies and functional imaging studies. In the present study ten female and ten male volunteers underwent functional magnetic resonance imaging in a conventional block design. All subjects were selected on the basis of high performance on the verbal fluency task. Regions of activation were detected after performance of a covert lexical verbal fluency task inside the scanner. Men and women who did not differ significantly in verbal fluency task performance showed a very similar pattern of brain activation. Our data argue against genuine between-sex differences in cerebral activation patterns during lexical verbal fluency activities when confounding factors like performance differences are excluded.
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Encéfalo/fisiología , Pruebas del Lenguaje/estadística & datos numéricos , Imagen por Resonancia Magnética/métodos , Caracteres Sexuales , Adulto , Femenino , Humanos , MasculinoRESUMEN
This investigation was designed to study the characteristics of a marker for harmonic processing and to test whether it could be used for differentiating harmonic processing capabilities. The first three chords of an ordinary musical cadenca were presented to the left ear to establish a harmonic context followed by a harmonic or non-harmonic target tone. Cadencas were presented rapidly and randomly in different keys to render the task difficult. Results showed a specific P3m (magnetic P300) effect to the non-harmonic targets which was only visible in subjects with low target recognition errors. Low resolution electro-magnetic tomography current density maps showed P3m sources in the right temporoparietal, left temporoparietal and frontocentral brain areas with right temporoparietal sources being strongest and most reliable. The results offer new possibilities to selectively study harmonic variables in music processing.
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Corteza Cerebral/fisiología , Música/psicología , Adulto , Audiometría de Respuesta Evocada/métodos , Biomarcadores , Mapeo Encefálico , Potenciales Relacionados con Evento P300/fisiología , Potenciales Evocados Auditivos/fisiología , Femenino , Humanos , Magnetoencefalografía , MasculinoRESUMEN
Epilepsy surgery is a successful therapeutic approach in patients with medically intractable epilepsy. The presurgical evaluation aims to detect the epileptogenic brain area by use of different diagnostic techniques. In this review article the current diagnostic procedures applied for this purpose are described. The diagnostic armamentarium can be divided conceptually into three different groups: assessment of function/dysfunction, structural/morphologic imaging methods and functional neuroimaging techniques. Properties, diagnostic power and limits of all diagnostic tools used in the diagnostic evaluation are discussed. In addition, future perspectives and the diagnostic value of new technologies are mentioned. Some are increasingly gaining acceptance in the routine preoperative diagnostic procedure like MR volumetry or MR spectroscopy of the hippocampus in patients with temporal lobe epilepsy. Some, on the other hand, like MEG and 11C-flumazenil PET, still remain experimental diagnostic tools as they are technically demanding and cost intensive. Besides the refinement of established techniques, co-registration of different modalities like spike-triggered functional MRI will play an important role in the non-invasive detection of the epileptic seizure focus and may change the regimen of the preoperative diagnostic work up of epilepsy patients in the future.
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Encefalopatías/cirugía , Diagnóstico por Imagen , Epilepsia/cirugía , Magnetoencefalografía , Encefalopatías/diagnóstico , Mapeo Encefálico , Epilepsia/diagnóstico , Epilepsia del Lóbulo Temporal/diagnóstico , Epilepsia del Lóbulo Temporal/cirugía , HumanosRESUMEN
In this study oxygen saturation was measured at the presenting part of the fetus during labour. We used two different reflectance sensors together with two different pulse oximeters. The Baxter Asat 100 displayed a 25% lower functional oxygen saturation of haemoglobin (SaO2) compared to the Ohmeda Biox 3700 pulse oximeter. The mean duration of application using the Ohmeda Biox 3700 together with an adapted finger sensor was 36 min (SD +/- 17 min), an effective measurement was achieved for 15 min (SD +/- 9 min). The mean duration of application using the Baxter Asat 100 together with a commercial Baxter reflex sensor was 88 min (SD +/- 96 min), an effective measurement was attained for 73 min (SD +/- 77 min).
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Monitoreo Fetal/instrumentación , Oximetría/instrumentación , Adulto , Asfixia Neonatal/sangre , Asfixia Neonatal/prevención & control , Cardiotocografía/instrumentación , Femenino , Humanos , Concentración de Iones de Hidrógeno , Recién Nacido , Masculino , Oxígeno/sangre , Embarazo , Valores de ReferenciaRESUMEN
Inflammatory serum parameters are intensely investigated in the search of biomarkers for disease activity and treatment response in multiple sclerosis (MS). A reason for contradictory results might be the timing of blood collection for analyzing serum concentrations of inflammatory parameters which are subject to diurnal changes. We included 34 untreated patients with relapsing-remitting MS and 34 age- and sex-matched healthy controls. 12 MS patients showed acute disease activity in corresponding MRI scans. Blood samples were obtained at 7.00, 11.00 am, 2.30, 6.00 and 9.30 pm within 1 day. We determined serum levels of cortisol and inflammatory markers including soluble tumor necrosis factor-beta (sTNF-ß), soluble TNF-Receptor-1 (sTNF-R1) and -2 (sTNF-2), soluble vascular adhesion molecule-1 (sVCAM-1) and soluble intercellular adhesion molecule-1 (sICAM-1) by ELISA. We observed significantly higher serum levels of sTNF-R1 (p < 0.001) and sTNF-R2 (p < 0.001) in the morning and a significant decline of sICAM-1 (p < 0.005) and sVCAM-1 (p < 0.001) in the afternoon in both, MS patients and healthy controls. Comparison of diurnal serum levels between MS patients with active versus with non-active disease revealed significantly higher serum levels of sVCAM-1 (p < 0.05) around noon and in the early afternoon in MS patients with active disease. A significant decline of sICAM-1 (p < 0.05) in the afternoon was seen in MS patients with active and non-active disease. Our data indicate that increased awareness of potential diurnal serum concentration changes of biomarkers can eliminate one major cause of biased data as they occur in most of the investigated immunological parameters.
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Biomarcadores/sangre , Ritmo Circadiano/fisiología , Inflamación/sangre , Esclerosis Múltiple/sangre , Esclerosis Múltiple/fisiopatología , Adulto , Estudios de Casos y Controles , Femenino , Humanos , Hidrocortisona/sangre , Inflamación/etiología , Molécula 1 de Adhesión Intercelular/sangre , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Receptores del Factor de Necrosis Tumoral/sangre , Factor de Necrosis Tumoral alfa/sangre , Molécula 1 de Adhesión Celular Vascular/sangreRESUMEN
PURPOSE: We explore the relationship of aqueductal flow of cerebrospinal fluid (CSF) and the changes of the anatomical configuration of the cerebral aqueduct (AC) in patients with communicating hydrocephalus (CH) in a routine MRI setting. METHODS/PATIENTS: We performed a retrospective evaluation of different anatomical configurations of the AC on midsaggital MRI images in 43 patients (medial age 67 years, median 68 years, range from 14 to 85, 25 women) with suspected communicating hydrocephalus and compared the anatomical form of the AC on the sagittal sequences with MRI CSF flow data. The measured acqueductal cross sectional area was correlated (Pearson's correlation coefficient, which is a measure of the linear dependence between two variables, is 0.747. From 0.7 to 1 correlation is strong, from 0.7 to 0.5 moderate correlation, from 0.5 to 0.3 weak correlation, and 0.3 to 0 means no correlation) with MRI CSF flow data based on phase contrast measurements. RESULTS: Two independent neuroradiologists were blinded to the patients' diagnosis. In 53% (Rater I) and 67% (Rater II) the anatomical appearance of the AC on sagittal MRI was tubular shaped and in 47% (Rater I) and 33% (Rater II) trumpet shaped. Highly elevated CSF flow correlated with a dilated and trumpet shaped AC lumen area. CONCLUSION: The anatomical morphology of the AC in midsagittal MRI sequences may be a significant diagnostic sign for suspected communicating hydrocephalus, already discernible on routine MRI scans; consequently, this may also be a sensitive method of supporting the clinical diagnosis of communicating hydrocephalus and moreover supports patients' selection for further CSF flow measurements.