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Clin EEG Neurosci [journal]
- Lacrimation as an Ictal Autonomic Event in a Patient With Seizures Originating From the Right Hemisphere. [JOURNAL ARTICLE]
- Clin EEG Neurosci 2014 Aug 26.
In dacrystic seizures lacrimation has previously been reported as an ictal autonomic event accompanying emotional and somatic signs. However, it has not been observed as an isolated event in autonomic seizures. We report a patient experiencing complex partial seizures characterized by lacrimation as the initial and most prominent ictal event, with no sign of crying. The patient's ictal electroencephalogram (EEG) suggested a focus in the right hemisphere, along with interictal single-photon emission computed tomographic (SPECT) and positron emission tomographic (PET) studies demonstrating hypoperfusion-hypometabolism in the right temporoparietal lobe. Magnetic resonance imaging (MRI) did not show any structural abnormalities. Involvement of the temporal lobe has been suggested for dacrystic seizures, and both dominant and nondominant hemispheric foci were detected in such cases. Therefore, partially in concordance with previous reports, our case may point to neurobiologic interaction, between the temporoparietal region and the hypothalamus, for mediating lacrimation.
- Three-Dimensional Electroencephalographic Changes on Low-Resolution Brain Electromagnetic Tomography (LORETA) During the Sleep Onset Period. [JOURNAL ARTICLE]
- Clin EEG Neurosci 2014 Aug 21.
Electroencephalographic (EEG) patterns during sleep are markedly different from those measured during the waking state, but the process of falling asleep is not fully understood in terms of biochemical and neurophysiological aspects. We sought to investigate EEG changes that occur during the transitional period from wakefulness to sleep in a 3-dimensional manner to gain a better understanding of the physiological meaning of sleep for the brain. We examined EEG 3-dimensionally using LORETA (low-resolution electromagnetic tomography), to localize the brain region associated with changes that occur during the sleep onset period (SOP). Thirty-channel EEG was recorded in 61 healthy subjects. EEG power spectra and intracortical standardized LORETA were compared between 4 types of 30-second states, including the wakeful stage, transition stage, early sleep stage 1, and late sleep stage 1. Sleep onset began with increased delta and theta power and decreased alpha-1 power in the occipital lobe, and increased theta power in the parietal lobe. Thereafter, global reductions of alpha-1 and alpha-2 powers and greater increases of theta power in the occipito-parietal lobe occurred. As sleep became deeper in sleep stage 1, beta-2 and beta-3, powers decreased mainly in the frontal lobe and some regions of the parieto-temporo-limbic area. These findings suggest that sleep onset includes at least 3 steps in a sequential manner, which include an increase in theta waves in the posterior region of the brain, a global decrease in alpha waves, and a decrease in beta waves in the fronto-central area.
- Reflex Epilepsy Triggered by Smell. [JOURNAL ARTICLE]
- Clin EEG Neurosci 2014 Jul 9.
Reflex epilepsies can be provoked by various types of external stimuli, but triggered by smell is rare in the literature. In this case report, we present a patient whose reflex epilepsy is triggered by smell. Physical examination findings and electrophysiologic studies of the patient are discussed.
- Cortical Brain Connectivity and B-Type Natriuretic Peptide in Patients With Congestive Heart Failure. [JOURNAL ARTICLE]
- Clin EEG Neurosci 2014 Jul 3.
The brain has a high level of complexity and needs continuous oxygen supply. So it is clear that any pathological condition, or physiological (aging) change, in the cardiovascular system affects functioning of the central nervous system. We evaluated linear aspects of the relationship between the slowness of cortical rhythms, as revealed by the modulation of a graph connectivity parameter, and congestive heart failure (CHF), as a reflection of neurodegenerative processes. Eyes-closed resting electroencephalographic (EEG) data of 10 patients with CHF were recorded by 19 electrodes positioned according the international 10-20 system. Graph theory function (normalized characteristic path length λ) was applied to the undirected and weighted networks obtained by lagged linear coherence evaluated by eLORETA software, therefore getting rid of volumetric propagation influences. The EEG frequency bands of interest were: delta (2-4 Hz), theta (4-8 Hz), alpha 1 (8-10.5 Hz), alpha 2 (10.5-13 Hz), beta 1 (13-20 Hz), beta 2 (20-30 Hz), and gamma (30-40 Hz). The analysis between B-type natriuretic peptide (BNP) values and λ showed positive correlation in delta, associated with a negative correlation in alpha 2 band. Namely, the higher the severity of the disease (as revealed by the BNP vales), the higher the λ in delta, and lower in alpha 2 band. Results suggest that delta and alpha λ indices are good markers of the severity of CHF.
- Agenesis of the Corpus Callosum and Generalized Epilepsy. [JOURNAL ARTICLE]
- Clin EEG Neurosci 2014 Jul 3.
The corpus callosum is the main band of interhemispheric axonal fibers in the human brain. Corpus callosum agenesis has widely varying symptoms, mainly associated with epilepsy, cognitive failure, and different neuropsychiatric disorders. Our case of corpus callosum agenesis includes eyelid myoclonia with absences. In the literature, there is no reported case of this combination. We report this case because it is rare, and relevant for the understanding of interhemispheric communications, based on our electrophysiological findings.
- Creutzfeldt-Jakob-Like Syndrome due to Hypercalcemic Encephalopathy. [JOURNAL ARTICLE]
- Clin EEG Neurosci 2014 Jun 27.
Hypercalcemia can cause a subacute syndrome of progressive dementia and marked changes in the electroencephalogram (EEG). We report a case of iatrogenic hypercalcemia with a close correlation between the clinical course and the EEG changes. A 73-year-old woman presented with a subacute syndrome of progressive dementia and bursts of 1.5 to 2 Hz intermittent rhythmic delta activity superimposed on a low-voltage background activity in the EEG. Clinical and EEG abnormalities rapidly resolved after normalization of serum calcium levels. As part of the diagnostic workup of a subacute progressive dementia, a serum calcium level and an EEG should be obtained to detect a Creutzfeldt-Jakob like syndrome in hypercalcemia. Unlike in Creutzfeldt-Jakob disease, and Creutzfeldt-Jakob-like syndrome induced by lithium intoxication, there are rarely myoclonic jerks and periodic discharges in hypercalcemic encephalopathy.
- Use of EEG Beta-1 Power and Theta/Beta Ratio Over Broca's Area to confirm Diagnosis of Attention Deficit/Hyperactivity Disorder in Children. [JOURNAL ARTICLE]
- Clin EEG Neurosci 2014 Jun 26.
The Food and Drug Administration has approved a medical device using the electroencephalogram (EEG) theta/beta ratio (tbr) to help assess pediatric attention deficit/hyperactivity disorder (ADHD). Tbr is reported to be higher in ADHD, with increased theta and decreased beta. This study examined theta and beta-1 power differences between ADHD and normal children, during tasks of selective attention, and elucidated topographical differences. EEGs were collected from 28 normal and 58 ADHD children, aged 6 to 14 years, using 31 scalp electrodes during auditory and visual tasks requiring selective attention. Spectral analysis was performed. Tbr was higher in ADHD than in normal children (2.60 vs 2.25, P = .007), with lower beta-1 (3.66 vs 4.22, P = .01), but no difference in theta power. There was lower beta-1 (P < .001) and higher tbr (P = .002) over Broca's area (electrode locations F7 and FC5). Beta-1 power over Broca's area was the best diagnostic test, with sensitivity 0.86 and specificity 0.57. Tbr is higher and beta-1 power lower in ADHD than in normal children, especially over Broca's area. Beta-1 power and tbr assist in confirming the diagnosis of ADHD in a sample with moderate pretest probability of ADHD.
- Deep Brain Stimulation in Intractable Epilepsy: Role of Pulse Width in Neuromodulation. [LETTER]
- Clin EEG Neurosci 2014 Jun 22.
- Improvement of Neurofeedback Therapy for Improved Attention Through Facilitation of Brain Activity Using Local Sinusoidal Extremely Low Frequency Magnetic Field Exposure. [JOURNAL ARTICLE]
- Clin EEG Neurosci 2014 Jun 16.
Traditional neurofeedback (NF) is a training approach aimed at altering brain activity using electroencephalography (EEG) rhythms as feedback. In NF training, external factors such as the subjects' intelligence can have an effect. In contrast, a low-energy NF system (LENS) does not require conscious effort from the subject, which results in fewer attendance sessions. However, eliminating the subject role seems to eliminate an important part of the NF system. This study investigated the facilitating effect on the theta-to-beta ratio from NF training, using a local sinusoidal extremely low frequency magnetic field (LSELF-MF) versus traditional NF. Twenty-four healthy, intelligent subjects underwent 10 training sessions to enhance beta (15-18 Hz), and simultaneously inhibit theta (4-7 Hz) and high beta (22-30 Hz) activity, at the Cz point in a 3-boat-race video game. Each session consisted of 3 statuses, PRE, DURING, and POST. In the DURING status, the NF training procedure lasted 10 minutes. Subjects were led to believe that they would be exposed to a magnetic field during NF training; however, 16 of the subjects who were assigned to the experimental group were really exposed to 45 Hz-360 µT LSELF-MF at Cz. For the 8 other subjects, only the coil was located at the Cz point with no exposure. The duty cycle of exposure was 40% (2-second exposure and 3-second pause). The results show that the theta-to-beta ratio in the DURING status of each group differs significantly from the PRE and POST statuses. Between-group analysis shows that the theta-to-beta ratio in the DURING status of the experimental group is significantly (P < .001) lower than in the sham group. The result shows the effect of LSELF-MF on NF training.
- A Wavelet-Statistical Features Approach for Nonconvulsive Seizure Detection. [JOURNAL ARTICLE]
- Clin EEG Neurosci 2014 Jun 16.
The detection of nonconvulsive seizures (NCSz) is a challenge because of the lack of physical symptoms, which may delay the diagnosis of the disease. Many researchers have reported automatic detection of seizures. However, few investigators have concentrated on detection of NCSz. This article proposes a method for reliable detection of NCSz. The electroencephalography (EEG) signal is usually contaminated by various nonstationary noises. Signal denoising is an important preprocessing step in the analysis of such signals. In this study, a new wavelet-based denoising approach using cubical thresholding has been proposed to reduce noise from the EEG signal prior to analysis. Three statistical features were extracted from wavelet frequency bands, encompassing the frequency range of 0 to 8, 8 to 16, 16 to 32, and 0 to 32 Hz. Extracted features were used to train linear classifier to discriminate between normal and seizure EEGs. The performance of the method was tested on a database of nine patients with 24 seizures in 80 hours of EEG recording. All the seizures were successfully detected, and false positive rate was found to be 0.7 per hour.