Epileptiform and periodic EEG activities induced by rapid sevoflurane anaesthesia induction.

Objectives: The aim of the study was to compare the EEG findings and haemodynamic parameters of adult male patients while undergoing mask induction with sevoflurane anaesthesia with either controlled hyperventilation (CH) or spontaneous breathing (SB).

Methods: Twenty male patients, aged 23-52 (mean 42) years were anaesthetized randomly with either spontaneous breathing or mild controlled hyperventilation via mask. EEG was recorded using a full 10-20 electrode set.

Long-term influence of recurrent acute otitis media on neural involuntary attention switching in 2-year-old children.

Background: A large group of young children are exposed to repetitive middle ear infections but the effects of the fluctuating hearing sensations on immature central auditory system are not fully understood. The present study investigated the consequences of early childhood recurrent acute otitis media (RAOM) on involuntary auditory attention switching.

Methods: By utilizing auditory event-related potentials, neural mechanisms of involuntary attention were studied in 22-26 month-old children (N = 18) who had had an early childhood RAOM and healthy controls (N = 19).

Event-related brain potentials to change in the frequency and temporal structure of sounds in typically developing 5-6-year-old children.

The brain's ability to recognize different acoustic cues (e.g., frequency changes in rapid temporal succession) is important for speech perception and thus for successful language development.

Atypical central auditory speech-sound discrimination in children who stutter as indexed by the mismatch negativity.

Purpose: Recent theoretical conceptualizations suggest that disfluencies in stuttering may arise from several factors, one of them being atypical auditory processing. The main purpose of the present study was to investigate whether speech sound encoding and central auditory discrimination, are affected in children who stutter (CWS).

Methods: Participants were 10 CWS, and 12 typically developing children with fluent speech (TDC).

Electrophysiological correlates of cross-linguistic semantic integration in hearing signers: N400 and LPC.

We explored semantic integration mechanisms in native and non-native hearing users of sign language and non-signing controls. Event-related brain potentials (ERPs) were recorded while participants performed a semantic decision task for priming lexeme pairs. Pairs were presented either within speech or across speech and sign language.

Infra-slow EEG fluctuations are correlated with resting-state network dynamics in fMRI.

Ongoing neuronal activity in the CNS waxes and wanes continuously across widespread spatial and temporal scales. In the human brain, these spontaneous fluctuations are salient in blood oxygenation level-dependent (BOLD) signals and correlated within specific brain systems or "intrinsic-connectivity networks." In electrophysiological recordings, both the amplitude dynamics of fast (1-100 Hz) oscillations and the scalp potentials per se exhibit fluctuations in the same infra-slow (0.

Effects of recurrent acute otitis media on cortical speech-sound processing in 2-year old children.

Objectives: To investigate at the age of 2 years the effects of childhood recurrent acute otitis media (RAOM) on central auditory processing by using cortical event-related potentials elicited by syllable stimuli.

Design: During a 1-year period, 22- to 26-month-old children fulfilling the criteria for tympanostomy tube insertion in Oulu University Hospital, Oulu, Finland, were recruited to the RAOM group (N = 20). The control group (N = 19) was matched by age, sex, and mother's educational level.

Linguistic multi-feature paradigm as an eligible measure of central auditory processing and novelty detection in 2-year-old children.

This study evaluated whether the linguistic multi-feature paradigm with five types of speech-sound changes and novel sounds is an eligible neurophysiologic measure of central auditory processing in toddlers. Participants were 18 typically developing 2-year-old children. Syllable stimuli elicited significant obligatory responses and syllable changes significant MMN (mismatch negativity) which suggests that toddlers can discriminate auditory features from alternating speech-sound stream.

HRV and EEG based indicators of stress in children with Asperger syndrome in audio-visual stimulus test.

Asperger syndrome (AS) is a neurobiological condition which is characterized by poor skills in social communication, and restricted and repetitive patterns of behavior and interests. We studied whether stress-related indices of heart rate variability (HRV) and electroencephalography (EEG) are different in children with AS than normal controls. We analyzed retrospectively the data of the test where audiovisual stimuli were used.

Evaluation of Heart Rate Variation Analysis during Rest and Tilting in Patients with Temporal Lobe Epilepsy.

Objective. To evaluate spectral heart rate (HR) variation using short-term ECG recordings at rest and during the tilt table test. Methods.

A characteristic time sequence of epileptic activity in EEG during dynamic penicillin-induced focal epilepsy--a preliminary study.

Penicillin-induced focal epilepsy is a well-known model in experimental epilepsy. However, the dynamic evolution of waveforms, DC-level changes, spectral content and coherence are rarely reported. Stimulated by earlier fMRI findings, we also seek for the early signs preceding spiking activity from frequency domain of EEG signal.

Coherence in depth electrodes during induction of deep anesthesia.

Our aim was to explore time-varying coherence values versus spacing and referencing of electrode contacts in thalamic level from human encephalographic (EEG) data. Data has been acquired during induction of propofol anesthesia until burst-suppression level in scalp EEG. Results are shown from coherence analysis applied to EEG signals from selected depth electrode contacts pair-wise of three subjects.

Automatic classification of penicillin-induced epileptic EEG spikes.

Penicillin-induced focal epilepsy is a well-known model in epilepsy research. In this model, epileptic activity is generated by delivering penicillin focally to the cortex. The drug induces interictal electroencephalographic (EEG) spikes which evolve in time and may later change to ictal discharges.

Atypical perceptual narrowing in prematurely born infants is associated with compromised language acquisition at 2 years of age.

Background: Early auditory experiences are a prerequisite for speech and language acquisition. In healthy children, phoneme discrimination abilities improve for native and degrade for unfamiliar, socially irrelevant phoneme contrasts between 6 and 12 months of age as the brain tunes itself to, and specializes in the native spoken language. This process is known as perceptual narrowing, and has been found to predict normal native language acquisition.

Sudomotor dysfunction in patients with optic neuritis.

Objectives: Optic neuritis (ON) is a frequent initial manifestation of multiple sclerosis (MS). Autonomic failure affecting the pupillary function is known to exist in ON patients, and patients with MS are known to have more widespread autonomic dysfunction. For example, sudomotor dysfunction is well known in MS.

Perception of basic emotions from speech prosody in adolescents with Asperger's syndrome.

Asperger's syndrome (AS) belongs to the group of autism spectrum disorders and is characterized by deficits in social interaction, as manifested e.g. by the lack of social or emotional reciprocity.

Processing of affective speech prosody is impaired in Asperger syndrome.

Many people with the diagnosis of Asperger syndrome (AS) show poorly developed skills in understanding emotional messages. The present study addressed discrimination of speech prosody in children with AS at neurophysiological level. Detection of affective prosody was investigated in one-word utterances as indexed by the N1 and the mismatch negativity (MMN) of auditory event-related potentials (ERPs).

BOLD signal increase preceeds EEG spike activity--a dynamic penicillin induced focal epilepsy in deep anesthesia.

In 40-60% of cases with interictal activity in EEG, fMRI cannot locate any focus or foci with simultaneous EEG/fMRI. In experimental focal epilepsy, a priori knowledge exists of the location of the epileptogenic area. This study aimed to develop and to test an experimental focal epilepsy model, which includes dynamic induction of epileptic activity, simultaneous EEG/fMRI, and deep anesthesia.

BOLD-contrast functional MRI signal changes related to intermittent rhythmic delta activity in EEG during voluntary hyperventilation-simultaneous EEG and fMRI study.

Differences in the blood oxygen level dependent (BOLD) signal changes were studied during voluntary hyperventilation (HV) between young healthy volunteer groups, (1) with intermittent rhythmic delta activity (IRDA) (N = 4) and (2) controls (N = 4) with only diffuse arrhythmic slowing in EEG (normal response). Subjects hyperventilated (3 min) during an 8-min functional MRI in a 1.5-T scanner, with simultaneous recording of EEG (successful with N = 3 in both groups) and physiological parameters.

Nocturnal cardiac autonomic regulation in Parkinson's disease.

Diminished heart rate (HR) variability has been reported in patients with early phase Parkinson's disease (PD) using standardized cardiovascular reflex tests. However, limited data exist on HR variability during sleep; thus the present study was performed to investigate the characteristics of HR variability during different sleep stages. The HR variability of 21 newly diagnosed and untreated PD patients and of 22 control subjects was evaluated by using time domain, frequency domain and non-linear methods and by analyzing HR reactions to body movements during the different sleep stages (non-REM stages S1-4 and the REM stage).

Neurophysiologic correlates of deficient phonological representations and object naming in prematurely born children.

Objective: The aim of this follow-up study was to evaluate the development of object naming ability and auditory processing in prematurely born children. Furthermore, we investigated whether the mismatch negativity (MMN) parameters at the age of 4 years correlate with the MMN parameters and naming ability at the age of 6 years.

Methods: Twelve very low birth weight (VLBW) preterm children (mean age 5 years 7 months) and matched controls were studied.

Deficient speech-sound processing, as shown by the electrophysiologic brain mismatch negativity response, and naming ability in prematurely born children.

Very low birth weight (VLBW, <1500 g) preterm birth has been associated with anatomic abnormalities in brain development and cognitive and language disorders. We examined object naming ability, and an electrophysiologic index of auditory sensory discrimination of speech sounds (the mismatch negativity, MMN) in 4-year-old VLBW prematurely born children. We found that half of the VLBW children were inferior to their controls in the object naming ability.

Deficient auditory processing in children with Asperger Syndrome, as indexed by event-related potentials.

Asperger Syndrome (AS) is characterized by normal language development but deficient understanding and use of the intonation and prosody of speech. While individuals with AS report difficulties in auditory perception, there are no studies addressing auditory processing at the sensory level. In this study, event-related potentials (ERP) were recorded for syllables and tones in children with AS and in their control counterparts.

Functional magnetic resonance imaging of swine brain during change in thiopental anesthesia into EEG burst-suppression level--a preliminary study.

Deepening anesthesia produces well known changes in electroencephalogram (EEG) and evoked potentials, differing in pathological and normal brain. Yet, it is not known how the T2*-weighted signal changes in the healthy brain during deepening anesthesia. We studied the effect of thiopental bolus on functional magnetic resonance imaging (fMRI) in the healthy brain using porcine model.