ABSTRACT
The purpose of this study was to assess whether a visual examination of 1H spectroscopic images could correctly lateralize patients with intractable temporal lobe epilepsy. 20 patients with intractable temporal lobe epilepsy and 10 volunteers were included in this study. Spectroscopic images were analysed using a protocol based on visual inspection. Images of the metabolites N-acetyl aspartate (NAA), choline (Cho), creatine (Cr) and lactate were obtained from a transverse plane oriented along the sylvian fissure. Images from each individual were evaluated independently by six reviewers. Results of the lateralization procedure obtained from the visual examinations were compared with those obtained from quantitative analysis of the spectra and with those obtained by magnetic resonance imaging (MRI), positron emission tomography (PET), neuropsychological examinations, and electroencephalographic (EEG) recordings. NAA images were found to be the most effective, amongst metabolite images, in lateralizing the epileptogenic lobe. Using the site selected for resection as the definition of the correct lateralization, 70% of the patients who underwent temporal lobectomy were correctly lateralized by the majority of the examiners using the visual inspection protocol. Based on the results of this study it is concluded that visual examination of 1H spectroscopic images is potentially valid in lateralizing patients with intractable temporal lobe seizures. Confidence in the visual interpretation increased as the difference in NAA signal intensity between the temporal lobes increased. The threshold above which the majority of the examiners correctly lateralized the patients was approximately 15% in NAA signal loss in the ipsilateral lobe.
Subject(s)
Epilepsy, Temporal Lobe/diagnosis , Adolescent , Adult , Case-Control Studies , Chronic Disease , Clinical Protocols , Epilepsy, Temporal Lobe/physiopathology , Epilepsy, Temporal Lobe/therapy , Humans , Magnetic Resonance Spectroscopy , Middle Aged , Observer Variation , Protons , Treatment FailureABSTRACT
The WHO launched a multicentre study to explore the nature and prevalence of HIV-1-associated neurological, psychiatric, and neuropsychological abnormalities in persons living in different geographical and sociocultural contexts. The study is being conducted in Brazil, Germany, Kenya, Thailand, the United States of America, and Zaire. A comprehensive instrument for the collection of neuropsychiatric data (including a battery of neuropsychological tests suitable for cross-cultural use) has been developed, and the feasibility of the recruitment and assessment procedure designed for the main phase has now been demonstrated.
Subject(s)
Cross-Cultural Comparison , HIV Infections/diagnosis , HIV-1 , Neuropsychological Tests , World Health Organization , Attention , HIV Infections/psychology , Humans , Mental Recall , Pilot Projects , Psychomotor Performance , Verbal Behavior , Verbal LearningABSTRACT
Averaging is the primary method for detecting small evoked potentials in the midst of surrounding electrical noise. Not all types of noise can be removed by averaging, however. The condition of the patient, electrodes, amplifiers, and filters are equally important for successful recording.