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PubMed2026

Comparison of the clinical efficacy, safety and EEG functional connectivity changes between 18-Hz rTMS and iTBS of accelerated dTMS treatment for major depressive disorder: a randomized controlled trial.

Although the antidepressant efficacy of 18-Hz deep transcranial magnetic stimulation (dTMS) has been validated, its prolonged treatment duration has considerable limitations for treatment capacity and patient adherence. Therefore, novel short-course protocols such as accelerated dTMS and intermittent theta burst stimulation (iTBS) present promising alternative options. Here we addressed the question of whether iTBS of accelerated dTMS achieves comparable therapeutic and electrophysiological effects to accelerated dTMS with the conventional 18-Hz rTMS protocol in patients with major depressive disorder (MDD). In a randomized controlled trial (n = 73), participants received either 18-Hz rTMS of accelerated dTMS (rTMS-dTMS group), iTBS of accelerated dTMS (iTBS-dTMS group), or pharmacotherapy alone (drug group). Both dTMS protocols were administered twice daily for 10 days targeting the left lateral prefrontal cortex including the dorsolateral region. Results showed that Hamilton Depression Rating Scale (HAMD) score of the iTBS-dTMS group decreased significantly from 22.5 ± 3.7 before treatment to 8.2 ± 4.1 after treatment (t = 15.900, p < 0.001). HAMD score of the rTMS-dTMS group decreased significantly from 21.3 ± 2.9 before treatment to 8.0 ± 3.8 after treatment (t = 17.232, p < 0.001). The drug group also exhibited significantly improved patients' mood symptoms, and the HAMD score decreased from 24.7 ± 6.8 to 14.0 ± 5.0 (t = 6.363, p < 0.001). The treatment response rate was 85.7% in the iTBS-dTMS group and 76.9% in the rTMS-dTMS group, which was much higher than that of the drug group (42.1%). The remission rate was 50.0% in the iTBS-dTMS group and 42.3% in the rTMS-dTMS group, which was significantly higher than 10.5% of the drug group. We demonstrate here that both accelerated dTMS protocols significantly reduced HAMD scores, improved the response rates, and remission rates, outperforming pharmacotherapy alone. Resting-state EEG analysis further revealed unique frequency-specific functional connectivity (FC) modulation effects: the rTMS-dTMS group primarily exhibited weakened alpha-band functional connectivity within the fronto-occipital, fronto-temporal and fronto-central networks after treatment, whereas the iTBS-dTMS group predominantly demonstrated reduced theta-band functional connectivity within the fronto-parietal, fronto-occipital and fronto-temporal pathways after treatment. These findings indicate that iTBS of accelerated dTMS demonstrates comparable efficacy and tolerability to 18-Hz rTMS of accelerated dTMS, whilst inducing treatment-specific network-level neurophysiological alterations. In the rTMS-dTMS group, relative changes in FC between the frontal and temporal/precentral regions showed significant negative correlation with HAMD score reduction rates, while relative changes in FC between the frontal lobe and parietal lobe showed a significant positive correlation with the rate of HAMD score reduction for the iTBS-dTMS group. This study revealed novel mechanisms by which accelerated dTMS protocols modulate brain networks, providing evidence for the clinical application of accelerated iTBS-dTMS as an efficient, evidence-based treatment for MDD.

Humans↗

PubMed2026

Targeting cortico-striatal-amygdalar networks via theta-band frontoparietal synchronization in opioid use disorder: a randomized tACS-fMRI Trial.

Theta-band oscillation is integral to fronto-parietal connectivity in the executive control network and its top-down regulation on subcortical areas. External frontoparietal synchronization using theta-frequency transcranial alternating current (tACS) is a technology to potentially engage this network. In this pre-registered, triple-blind, sham-controlled trial (NCT03907644), we tested this intervention targeting the right frontoparietal network in people with opioid use disorder (OUD) to measure network engagement and behavioral outcomes. Sixty male participants with OUD were randomized to receive 20 min of active or sham 6 Hz tACS (HD electrodes over F4 and P4). Structural, resting-state, task-based fMRI drug cue reactivity, and repeated cue-induced craving assessments were collected immediately before and after stimulation. Pre-registered outcome measures were analyzed using time × group interaction models to examine (1) modulation of drug cue-related brain activity, (2) changes in craving, (3) alterations in functional connectivity, and (4) relationship between electric field, neural responses, and craving behavior. (1) A significant Time × Group interaction revealed decreased post-stimulation opioid cue-related activity in the active group relative to sham, involving key nodes in reward processing (ventral striatum, amygdala and ventral tegmental area) (FWE corrected α = 0.05) (2) subjective craving did not differ significantly between groups (3) Group by time generalized psychophysiological interaction analyses showed increased right frontoparietal network engagement (β = 2.63, p= 0.0308) following stimulation, and increased top-down inhibitory regulation of frontoparietal network on right ventral striatum (β = 1.99, p= 0.037) and left medial amygdala (β = 1.97, p= 0.039) (4) Electric field strength in the right frontal/parietal node predicted frontoparietal network engagement in the active group (r = 0.43, p= 0.02). Together, these findings demonstrate that theta-band frontoparietal tACS can modulate activity and task-dependent coupling within cortical-subcortical circuits in OUD, supporting network-targeted neuromodulation as a potential intervention for addiction.

Humans↗

PubMed2026

Personalized functional topography-based multisite brain age prediction modeling reveals divergent neurodevelopment in major depression.

Major depressive disorder (MDD) is associated with widespread alterations in functional brain networks across the lifespan. However, heterogeneity in atypical brain development among patients with MDD remains largely uncharacterized. Using a multisite resting-state functional MRI dataset consisting of 1,105 MDD patients and 1,065 healthy controls, we constructed a harmonized multicenter brain age prediction model based on individualized functional topography and identified two patient subgroups with positive or negative brain age gaps (BAGs). In patients with a positive BAG (BAG+), expansion of the salience network (SAL) into the dorsolateral prefrontal and ventrolateral prefrontal cortices, in addition to contraction of the sensorimotor and dorsal attention networks (DAN), contributes to accelerated brain aging. Conversely, in the negative BAG (BAG-) group, SAL expansion into the orbitofrontal cortex (OFC) and contraction of the visual and sensorimotor networks (SMN) were linked to delayed brain development. These subgroups also exhibited distinct neurodevelopmental trajectories. Clinically, BAG+ patients showed stronger associations between higher-order network topography and mood symptoms, whereas BAG- patients exhibited links between visual/default mode network topography and insomnia. At the molecular level, both groups showed enrichment of genes related to synaptic signaling but displayed distinct expression patterns and divergent expression trajectories in key neurodevelopmental gene sets. Notably, antidepressant treatment modulated the brain in ways that were specific to each subgroup. These findings reveal heterogeneous neurodevelopmental profiles in MDD with distinct biological and clinical signatures, offering insights into personalized precision medicine for this disorder.

Humans↗

PubMed1986

Focal physiological uncoupling of cerebral blood flow and oxidative metabolism during somatosensory stimulation in human subjects.

Coupling between cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2) was studied using multiple sequential administrations of 15O-labeled radiotracers (half-life, 123 sec) and positron emission tomography. In the resting state an excellent correlation (mean r, 0.87) between CBF and CMRO2 was found when paired measurements of CBF and CMRO2 from multiple (30-48) brain regions were tested in each of 33 normal subjects. Regional uncoupling of CBF and CMRO2 was found, however, during neuronal activation induced by somatosensory stimulation. Stimulus-induced focal augmentation of cerebral blood flow (29% mean) far exceeded the concomitant local increase in tissue metabolic rate (mean, 5%), when resting-state and stimulated-state measurements were obtained in each of 9 subjects. Stimulus duration had no significant effect on response magnitude or on the degree of CBF-CMRO2 uncoupling observed. Dynamic, physiological regulation of CBF by a mechanism (neuronal or biochemical) dependent on neuronal firing per se, but independent of the cerebral metabolic rate of oxygen, is hypothesized.

Adult↗

PubMed1995

Crystal structure of a complement factor D mutant expressing enhanced catalytic activity.

Complement factor D is a serine protease regulated by a novel mechanism that depends on conformational changes rather than cleavage of a zymogen for expression of proteolytic activity. The conformational changes are presumed to be induced by the single natural substrate, C3bB, and to result in reversible reorientation of the catalytic center and of the substrate binding site of factor D, both of which have atypical conformations. Here we report that replacement of Ser94, Thr214, and Ser215 of factor D (chymotrypsinogen numbering has been used for comparison purposes) with the corresponding residues of trypsin, Tyr, Ser, and Trp, is sufficient to induce substantially higher catalytic activity associated with a typical serine protease alignment of the catalytic triad residues His57, Asp102, and Ser195. These results provide a partial structural explanation for the low reactivity of "resting-state" factor D toward synthetic substrates.

Amino Acid Sequence↗

PubMed1988

Cerebral metabolic effects of a verbal fluency test: a PET scan study.

Sixteen normal volunteers were studied with [F-18] fluorodeoxyglucose and positron emission tomography scans during behavioral activation with a verbal fluency test, and 35 age-matched controls were studied with resting-state scans. There was an overall increase of the cerebral glucose metabolic rate of 23.3% during verbal fluency activation, compared to the resting state, with the greatest activation in bilateral temporal and frontal lobes. A negative correlation between test performance scores and indices of metabolism was found in frontal, temporal, and parietal regions. Damage to the left frontal lobe maximally affects scores on verbal fluency tests, but performing the test activates a network of regions, of which the left frontal lobe is only one. Proficient performance in verbal fluency seems to require less metabolic activation than poor performance, perhaps because of the efficiency of cognitive strategies employed.

Adult↗

PubMed1995

A PET study of the functional neuroanatomy of writing impairment in Alzheimer's disease. The role of the left supramarginal and left angular gyri.

A dissociation in the central processes of spelling, with preferentially lexical over phonological impairment, frequently affects patients with early Alzheimer's disease. The aim of this work was to test whether dissociations in the language domain in Alzheimer's disease can be exploited with PET to assess the neural basis of cognition. To this end, we studied the functional neuroanatomy of writing impairment in Alzheimer's disease by means of PET measurements of the local cerebral glucose utilization and neuropsychological tests specially designed to assess the phonological and lexical components of writing. We analysed the performance in written spelling of irregular words and non-words of 11 right-handed patients with mild-to-moderate Alzheimer's disease. For each patient, we calculated a residual phonological score and a residual lexical score, based on a cognitive interpretation of the errors according to the item category. In each of these 11 patients, using PET, we measured the resting-state utilization of glucose in the left supramarginal gyrus and the left angular gyrus, two cortical regions selected a priori because of their presumed role in the central processes for spelling, and identified on CT scans obtained according to stereotaxic references and coregistered with PET. To assess the relationships between the neuropsychological scores and the metabolic data, we used the 'ratio paradigm', the sensitivity of which has been previously documented in cognitive-metabolic correlative PET studies of Alzheimer's disease that were less focused than the present study in both cognitive and anatomical terms. We found a highly significant positive correlation between phonological score:lexical score neuropsychological ratios and corresponding supramarginal gyrus:angular gyrus metabolic ratios. These findings further support the role of these two left-sided temporo-parietal regions in the central processes of writing and show that the neuropsychological dissociations in early Alzheimer's diseases can be exploited to further our understanding of the functional neuroanatomy of cognitive operations. The role of focal, as compared with more diffuse, brain damage in the development of impaired written language of central origin in Alzheimer's disease is also discussed.

Aged↗

PubMed1993

Effects of halothane and isoflurane on cytosolic calcium ion concentrations and contraction in the vascular smooth muscle of the rat aorta.

BACKGROUND: Halothane and isoflurane have been reported to suppress the contraction of vascular smooth muscle, although the exact mechanism has not been explained fully. This study examined the effect of halothane and isoflurane on cytosolic calcium ion (Ca2+) concentrations ([Ca2+]cyt), which was measured simultaneously with muscle tension in the vascular smooth muscle of the rat aorta to improve the understanding of the anesthetic's effect on vascular smooth muscle. METHODS: Isolated spiral strips of rat thoracic aorta were suspended for isometric tension recordings in physiologic salt solution. The [Ca2+]cyt was measured concomitantly by using fura-2-Ca2+ fluorescence. During exposure to 0%, 1%, 2%, or 3% halothane or 0%, 2%, or 4% isoflurane, increases in muscle tension and [Ca2+]cyt induced by 32.8 mM K+ or 30 nM norepinephrine were measured and compared with the reference values. In the other series, the 3% halothane-induced increase in [Ca2+]cyt was measured in Ca2+)-free solution without and with a pretreatment of ryanodine, caffeine, or norepinephrine. RESULTS: Halothane and isoflurane increased resting-state [Ca2+]cyt, although only 3% halothane elicited a transient increase in muscle tension during the resting state. By contrast, both anesthetic agents attenuated the high K(+)- and norepinephrine-induced increases in [Ca2+]cyt and muscle tension in a concentration-dependent manner. During 3% halothane or 4% isoflurane exposure, the pretreatment of the muscle strip with a 10(-6)-M dose of Bay K 8644 augmented the high K(+)-induced increase in [Ca2+]cyt to the level observed in the control (0% anesthetic exposure) state. However, the increase in muscle tension in the presence of Bay K 8644 was low; it was still attenuated from the control level during 3% halothane or 4% isoflurane administration. These results indicate that, not only [Ca2+]cyt-dependent, but also [Ca2+]cyt-independent, mechanisms are involved in the anesthetic-induced suppression of smooth muscle contraction. A 3% halothane-induced increase in [Ca2+]cyt was observed in the Ca(2+)-free solution even when the muscle strip was pretreated with a 10(-6)-M dose of ryanodine and a 20-mM dose of caffeine, whereas it was abolished completely after the muscle strip was pretreated with ryanodine, caffeine, and 100 nM norepinephrine. These results indicate that halothane can release Ca2+ from an intracellular Ca2+ store other than the caffeine-releasable site. CONCLUSIONS: Halothane and isoflurane have multiple effects on the [Ca2+]cyt and induce [Ca2+]cyt-dependent and [Ca2+]cyt-independent suppression of the contraction in the vascular smooth muscle.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗

PubMed1992

Reduction of cerebral blood flow in chronic schizophrenia: relation to age.

The effect of age on resting-state cerebral blood flow (CBF) was studied in 40 medicated patients with chronic schizophrenia aged 20 to 57 and 32 age- and sex-matched normal controls, using the regional CBF with the xenon-133 inhalation technique. Global CBF (average of 16 cerebral regions) and the left prefrontal flow ratio (left prefrontal/global CBF) were significantly lower in schizophrenics aged 20-29 than in age-matched controls. Both global CBF and the left prefrontal flow ratio correlated with age in controls, but neither of such correlations was found in schizophrenics. Therefore, the CBF deficits in chronic schizophrenia appear to be unaffected by the aging process.

Adult↗

PubMed1987

Biphasic inotropic effects of a Ca2+ channel activator CGP28392 in rat myocardium: possible relation to intracellular Ca2+ release.

1. The inotropic effect of a Ca2+-entry stimulator, CGP28392, (CGP) was compared in rat and frog myocardium in a concentration- and time-dependent manner. 2. Frog preparations exhibited a persistent positive inotropic effect following prolonged treatment with CGP. 3. Compared to amphibian myocardium, rat ventricular muscle exhibited a biphasic time-dependent response to CGP: an initial increase in the twitch tension amplitude of 30% was changed to a reduction of 80% below the control level during prolonged exposure to CGP (stimulation frequency, 0.2 Hz). 4. Following prolonged incubation with CGP, the resting-state contraction was decreased and the negative force-frequency relation was converted into a positive one in rat muscle. 5. Since sarcoplasmic reticulum (SR) is the major source of Ca2+ in a rested-state contraction, inhibition by CGP suggests an additional, intracellular action of the Ca2+ channel activator on SR-Ca2+ release in rat myocardium.

Action Potentials↗

PubMed1990

Obsessive-compulsive disorder: a clinical, neuropsychological and positron emission tomography study.

The authors compared 16 nondepressed obsessive-compulsive patients (OCS) with 8 normal controls (NC) of similar age for resting-state regional cerebral glucose metabolic rates (rCMRglu) using positron emission tomography with the fluorodeoxyglucose method. OCS were rated for clinical data, and a neuropsychological battery was administered to 14 patients on the day of the scan. Absolute rCMRglu for whole cortex, and normalized prefrontal lateral cortex metabolic rates, were both significantly lower in OCS than in NC. No significant difference between treated (n = 10) and drug-free (n = 6) OCS was found for those variables. OCS were significantly impaired in the neuropsychological tasks assessing memory and attention. The rCMRglu for prefrontal lateral cortex were negatively correlated to Stroop-test subscores. This "frontal-oriented" task assessed the ability of OCS to inhibit immediate but inappropriate responses. These results suggest, in OCS, a modification of the general activating systems of cortical function and a relationship between the lateral prefrontal rCMRglu decrease and a selective attention deficit.

Adult↗

PubMed1988

Nonoxidative glucose consumption during focal physiologic neural activity.

Brain glucose uptake, oxygen metabolism, and blood flow in humans were measured with positron emission tomography, and a resting-state molar ratio of oxygen to glucose consumption of 4.1:1 was obtained. Physiological neural activity, however, increased glucose uptake and blood flow much more (51 and 50 percent, respectively) than oxygen consumption (5 percent) and produced a molar ratio for the increases of 0.4:1. Transient increases in neural activity cause a tissue uptake of glucose in excess of that consumed by oxidative metabolism, acutely consume much less energy than previously believed, and regulate local blood flow for purposes other than oxidative metabolism.

Brain↗

PubMed2025

Glaucoma and brain functional networks: a bidirectional Mendelian randomisation study.

OBJECTIVE: Glaucoma is a complex neurodegenerative ocular disorder accompanied by brain functional abnormalities that extend beyond the visual system. However, the causal association between the two remains unclear at present. This study aimed to investigate the potential causal relationships between glaucoma and brain functional networks in order to provide novel insights into the neuropathic mechanism of glaucoma. METHODS AND ANALYSIS: Based on the genome-wide association studies data of glaucoma and resting-state functional MRI (Rs-fMRI), a bidirectional Mendelian randomisation (MR) analysis was conducted between glaucoma and brain functional networks. Inverse variance weighting was applied as the primary method to estimate causality with false discovery rate correction. Additional sensitivity analyses were conducted to evaluate the robustness of the results. RESULTS: Forward MR analysis suggested that glaucoma was causally associated with two brain networks between the subcortical cerebellum and the attention or visual network (p=0.022), as well as the default mode and central executive network (p=0.008), but without significance after false discovery rate correction (q>0.1). Reverse MR analysis revealed 19 Rs-fMRI traits related to glaucoma risk, including the salience or central executive network in the frontal region (p=0.0005, q=0.08) and the motor network (p=0.0009, q=0.08) with significant causality. CONCLUSIONS: This MR study revealed potentially causal relationships between glaucoma and brain functional networks. Especially, the functional connectivity of the motor network between the postcentral or precentral areas may potentially lead to increased risk of glaucoma.

Humans↗

PubMed1989

X-ray absorption spectroscopic investigations of cytochrome c oxidase structure and function.

Although the low sensitivity of the XAS technique imposes difficulties upon the study of an enzyme that is often heterogeneous, significant progress has been made in elucidation of the structures of the functional metal sites of cytochrome c oxidase. Figure 8 summarizes interpretations of the resting-state enzyme based on the XAS results obtained over the past decade by the two main groups involved. Aside from several persisting minor differences in distances and precise ligand compositions of the metal sites, the biggest difference between the two interpretations involves the binuclear O2 interaction site, especially the nature of the bridging ligand and its precise attachments to Fea3 and CuB. However, the structural models presented by the two groups have been converging recently, and there is hope that the next few years will see a resolution of the remaining differences. Other XAS approaches (e.g. studies on oriented multilayers) and other techniques will doubtless contribute to this resolution.

Animals↗

PubMed1990

Left prefrontal glucose hypometabolism in the depressed state: a confirmation.

The resting-state cerebral metabolic rates for glucose of 10 severely depressed patients (seven bipolar and three unipolar) were compared, before and after treatment with tricyclic antidepressants, to those of 10 control subjects of similar age by means of positron emission tomography and the fluorodeoxyglucose method. Significant left-right prefrontal asymmetry was present in the patients before but not after successful treatment, suggesting that medication can reduce this asymmetry. Also, significant hypofrontality and whole-cortex hypometabolism were found in the patients in the depressed state and persisted in the treated state, despite clinical improvement, suggesting that these abnormalities are not state dependent.

Adult↗

PubMed1987

Mapping human somatosensory cortex with positron emission tomography.

Positron emission tomography measurements of regional cerebral blood flow were used to detect focal neuronal activation in the first somatosensory cortex (SI) of humans induced by cutaneous vibratory stimulation. Intravenously administered water labeled with oxygen-15 (H2(15)O) was used as a blood flow tracer to obtain five stimulated-state and two resting-state blood flow images in each of eight normal volunteers. Three cutaneous surfaces were tested: lips, fingers, and toes. Intense, highly focal SI responses were seen during all 39 stimulated-state trials. The SI responses from the three stimulation sites were anatomically distinct and formed a medial-to-lateral homonculus in every subject. Response magnitudes (increase in local blood flow) and response locales (expressed as proportionately measured bicommissural stereotaxic coordinates) were highly consistent among subjects and on repeated trials for each subject. These findings suggest that eliciting cerebral blood flow responses by cutaneous vibration provides a safe, rapid, and reproducible tool for locating and assessing the functional status of somatosensory cortex, and offers potential clinical and research utility. This study has established normative values for future applications of this experimental paradigm.

Brain Mapping↗

PubMed2026

Genetic Correlation Between Brain Imaging Phenotypes and Externalizing Behavior: A Large-Scale LDSC Analysis of UK Biobank IDPs.

Externalizing has been associated with differences in brain structure and function; however, it remains unclear whether these associations reflect shared common-variant genetic influences. Cross-trait linkage disequilibrium score regression was used to estimate genome-wide genetic correlations between externalizing genome-wide association study (GWAS) results and 3,935 brain imaging-derived phenotypes from the UK Biobank BIG40 resource. The imaging phenotypes covered structural magnetic resonance imaging (MRI), diffusion MRI, susceptibility-weighted imaging, resting-state functional MRI, and task-based functional MRI. Results were included in the primary analysis when the imaging phenotype had positive single-nucleotide polymorphism (SNP) heritability, a heritability Z statistic of at least 1.96, a mean GWAS chi-square statistic of at least 1.02, at least 200,000 regression SNPs, and a complete LDSC result without a fatal error. Technical imaging quality-control phenotypes were excluded from biological inference. Individual results were corrected using the Benjamini-Hochberg false discovery rate procedure. Aggregated Cauchy association tests (ACATs) were used to evaluate evidence across all imaging phenotypes and within predefined imaging categories. Statistical power, simultaneous confidence bounds, and alternative quality-control definitions were examined in sensitivity analyses. Of the 3,935 imaging phenotypes, 3,716 produced estimable genetic correlations, 2,980 met the primary LDSC quality-control criteria, and 2,967 were classified as biological imaging phenotypes. No individual phenotype survived false discovery rate correction. The smallest unadjusted P value was 0.0005, and the minimum adjusted q value was 0.486. The distribution of genetic correlations was centered near zero, with a median genetic correlation of 0.0014 and a median absolute genetic correlation of 0.0338. ACAT provided no evidence of an aggregate association across all biological imaging phenotypes (P = 0.302), and no predefined imaging category survived multiple-testing correction. The median minimum detectable genetic correlation at 80% power was 0.216. Bonferroni-adjusted simultaneous confidence intervals were fully contained within the interval [-0.30, 0.30] for 80.0% of phenotypes in the primary analysis and 88.0% under the stringent heritability quality-control definition. Broad and stringent sensitivity analyses produced the same overall conclusions. In this study, no statistically robust evidence of genome-wide genetic correlations between externalizing and individual UK Biobank brain imaging phenotypes was found. Nevertheless, small, localized, mixed-direction, or developmentally specific genetic effects remain possible.

Journal Article↗

PubMed1987

[The timing of crisis and day-night distribution of paroxysmal EEG activities: a study on 197 epileptic patients].

The purpose of the present study was to determine whether paroxysmal EEG activity (PA) occurs randomly over time and whether seizures arise at time of maximum PA. 204 ambulatory recordings (A/EEG) in 197 adult epileptic outpatients have been were included. The patients' seizures were grouped according to ILAE classification: Simple partial seizures; complex partial seizures (CPS), isolated or secondarily generalized; idiopathic generalized seizures: epilepsy with myoclonic absences, generalized tonic-clonic seizures (GTCS) on awakening, GTCS with photo-sensitivity; undetermined epilepsies: "grand mal morpheique", epilepsies with generalized PA without photosensitivity or with All recordings were performed with a 8-channel 24 h cassette recorder system (Medilog 9,000). The video play-back speed used was 20 times the recording speed to allow good detection, characterization and localization of PA. Counting was accomplished by visual analysis. No PA during A/EEG was noted in 24.5 p. 100 of all cases. A diurnal distribution in wakefulness was found in 59 p. 100 of idiopathic generalized epilepsies, PA usually occurring on awakening whatever the specific time of day; in 27 p. 100 of CPS and 20 p. 100 of undetermined epilepsies, with peak PA occurrence at late morning and 6 pm. During resting-state and afternoon-naps, PA occurrence was mainly seen in CPS. PA occurring only in overnight sleep was observed in 17 p. 100 of CPS and 20 p. 100 of undetermined epilepsies. PA distribution pattern in both CPS and undetermined epilepsies suggests an ultradian rhythm (time-dependent). On the other hand, PA pattern in idiopathic generalized epilepsies support the hypothesis of a circadian rhythm linked to sleep/wake--or light/dark--cycle (state-dependent).

Adolescent↗