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- Is a hypothalamic hamartoma always a suspect in gelastic seizures? A source functional connectivity studyPublication . Borges, Daniel Filipe; Leal, AlbertoGelastic seizures are rare manifestations of epilepsy that are often associated with hypothalamic hamartomas (HH). In the absence of HH, location of the origin is more difficult and there are several less well-established possibilities. Non-invasive assessment is often complicated by the deep localization of the epileptogenic area and the complex dynamics of spike activity. Robust neurophysiological methods and careful validation of intrinsically epileptogenic lesions detected by RM can improve the validity of scalp EEG analysis. This presentation will discuss a case report analysing the dynamics of epileptic activity in gelastic seizures associated with cortical dysplasia. The clinical case was a 26-year-old girl with daily refractory gelastic seizures since the age of 6 who underwent neurophysiological examination with long-term EEG recordings and MRI of the brain. She had previously been rejected in an epilepsy surgery programme because no structural brain lesion had been found and the EEG information was not conclusive enough. A recent 3T MRI showed cortical dysplasia in the cingulate gyrus, which was highly suspicious as an epileptogenic focus. We analysed the 31-channel EEG (ictal and interictal) using source and functional connectivity methods to obtain a solid computer model of the origin and dynamics of the epileptic activity and correlate it with the anatomical information of the MRI. Source analysis of the interictal activity revealed multiple sources that dominated at different time points, suggesting considerable dynamics that prevented clear identification of the source. The ictal recordings showed little late rhythmic activity over the frontal areas, but no early focalization. Connectivity analysis, which revealed the flow of information between cortical sources, showed a consistent origin of epileptic activity near the cortical dysplasia for both interictal and ictal activity. EEG connectivity analysis significantly improves the performance of non-invasive methods for determining the intracranial dynamics of epileptic activity and correlation with structural lesions.
- The sound of silence: Quantification of typical absence seizures by sonifying EEG signals from a custom‐built wearable devicePublication . Borges, Daniel Filipe; Fernandes, João; Soares, Joana Isabel; Casalta‐Lopes, João; Carvalho, Daniel; Beniczky, Sándor; Leal, AlbertoObjective: To develop and validate a method for long- term (24- h) objective quantification of absence seizures in the EEG of patients with childhood absence epilepsy (CAE) in their real home environment using a wearable device (waEEG), comparing automatic detection methods with auditory recognition after seizure sonification. Methods: The waEEG recording was acquired with two scalp electrodes. Automatic analysis was performed using previously validated software (Persyst® 14) and then fully reviewed by an experienced clinical neurophysiologist. The EEG data were converted into an audio file in waveform format with a 60- fold time compression factor. The sonified EEG was listened to by three inexperienced observers and the number of seizures and the processing time required for each data set were recorded blind to other data. Quantification of seizures from the patient diary was also assessed. Results: Eleven waEEG recordings from seven CAE patients with an average age of 8.18 ± 1.60 years were included. No differences in the number of seizures were found between the recordings using automated methods and expert audio assessment, with significant correlations between methods (ρ > .89, p < .001) and between observers (ρ > .96, p < .001). For the entire data set, the audio assessment yielded a sensitivity of .830 and a precision of .841, resulting in an F1 score of .835. Significance: Auditory waEEG seizure detection by lay medical personnel provided similar accuracy to post- processed automatic detection by an experienced clinical neurophysiologist, but in a less time- consuming procedure and without the need for specialized resources. Sonification of long- term EEG recordings in CAE provides a user- friendly and cost- effective clinical workflow for quantifying seizures in clinical practice, minimizing human and technical constraints.
- The effects of 24-hour sleep deprivation on the human brain: a multimodal neurophysiological approachPublication . Gonçalves, Alice; Pinto, Sara; Ferreira, Simão; Borges, Daniel FilipeIntroduction: Sleep is an important aspect of human health and well-being and influences various physiological and cognitive functions such as learning and attention. On the other hand, sleep deprivation activates the sympathetic nervous system, negatively impacting blood pressure, heart rate, glucose metabolism, cortisol, and hormones. It alters mood, behaviour, and reduces awareness leading to a poor performance, hence the importance of studying the neurophysiological and neurocognitive effects of 24h sleep deprivation. Objective: Our main goal is to investigate the effects of acute sleep deprivation on the cerebral cortex in healthy university students using a multimodal approach and neurocognitive scales. Methods: This study will use a magnetic stimulator to assess neurophysiological changes, while actigraphy will verify sleep deprivation in the intervention group. Neuropsychological assessments include the Trail Making Test (TMT), measuring visual processing speed and cognitive flexibility, the Psychomotor Vigilance Task (PVT), assessing sustained attention through reaction times to unpredictable stimuli and N-Back test measuring working memory by requiring participants to recall objects presented a few steps earlier. EEG data will be recorded using a cap with 32 channels during. This integrated approach provides a comprehensive analysis of the effects of sleep deprivation on cognitive and neurophysiological functions. Expected Results: Hypothetically, there will be a significant decline in cognitive performance, with impairments in key areas such as visual attention, processing speed and cognitive flexibility. These results will likely manifest in longer reaction times, more frequent errors and overall lower task execution.
- Spike detection in the wild: Screening of suspected temporal lobe epilepsy cases using a tailored 2-channel wearable EEGPublication . Borges, Daniel Filipe; Soares, Joana Isabel; Dias, Daniela; Cordeiro, Helena; Leal, Alberto; Borges, Daniel FilipeTo clinically validate the contribution of a custom-built-wearable device (waEEG) compared to a full 10–20 electrode array ambulatory EEG (aEEG) for screening epilepsy cases in patients with suspected temporal lobe epilepsy (TLE) but negative routine EEGs. Patients (aged 16–91 years) with clinically suspected TLE who were referred for a 24 h aEEG were fitted with an additional 2-channel bipolar waEEG device and prospectively enrolled in the study until 20 TLE diagnoses were confirmed by aEEG. 41 patients were included and their waEEG was blindly reviewed by two experienced clinical neurophysiologists and a semi-automated spike detection software to categorize patients into TLE (spikes present) and non-TLE (no spikes) groups. The experts achieved good sensitivity (95%–100%) and accuracy (98%–93%) with excellent interrater agreement (kappa>0.80) in patient labelling. The semi-automated software performed poorly (40% sensitivity, 68% accuracy) and failed to classify TLE in more than half the cases. Classification was not affected by restricting spike detection to the evening and night time, which reduced the average length of the analyzed EEG from 23.4 to 10.4 h. Three false-positive spike detections were thoroughly analyzed and reclassified as artifacts due to eye and body movements and electrocardiographic contamination. To better control cardiac artifacts, the addition of an ECG channel to the waEEG is recommended. Detection of spikes with waEEG allows accurate detection of epilepsy in suspected TLE cases, with less technical and professional effort and improved acceptance. This screening tool could improve the yield of follow-up with a conventional aEEG and provide an accessible method for monitoring interictal epileptiform activity in TLE. Epilepsy is a chronic short circuit in the brain. In adults, it most often affects the temporal lobes, resulting in temporal lobe epilepsy (TLE). Seizures are infrequent but difficult to treat. Electroencephalography (EEG) is the best method to detect the electrical disturbances and is crucial to distinguish epilepsy from other non-epileptic disorders. Developing simple, inexpensive and easily accessible portable EEG methods that complement in-hospital assessment could significantly impact patient care. Our study aims to clinically validate a wearable epilepsy screening device to aid in TLE management, reduce delays in diagnosis and enable straightforward assessment of epileptic activity.
- The prevalence of post-therapy epilepsy in patients treated for high-grade glial tumors: a systematic review and meta-analysisPublication . Ferreira, Marta Pereira; Carvalho, Ruben Lopes; Soares, Joana Isabel; Casalta‑Lopes, João; Borges, Daniel Filipe; Borges, Daniel Filipe; Soares, Joana I.Gliomas are the most prevalent type of primary brain tumor of the adult central nervous system. High-grade gliomas (HGG) are the most common type of glioma. Epilepsy is often the first clinical manifestation of HGG. Since epilepsy leads to increased morbidity and mortality rates, seizure control is one of the main therapeutic goals for patients with glioma-related epilepsy. Post-therapy epilepsy is observed in a significant percentage of patients, hence, this work aimed to quantify the prevalence of post-therapy epilepsy after HGG treatment. Our search was conducted across PubMed®, EMBASE®, Web of Science™, Cochrane Library, Sicelo and Scopus, adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. This review included articles published in Portuguese or English that evaluate adult patients with newly diagnosed HGG, who were treated with at least surgery or radiation. Thirty-six studies reporting on 4036 HGG patients were included in our meta-analysis. The mean age ranged from 44 to 73 years. Glioblastoma was the most commonly observed HGG, representing 77,8% of all glioma patients. The pre-treatment seizure frequency was observed in 21,2%. All patients underwent surgery as the main therapy, and 1842 patients received standard adjuvant therapy. We also observed a pooled prevalence of post-therapy seizures of 25.5% (95% confidence interval of [19.9%; 31.1%]). Substantial heterogeneity in all assessed variables was observed. Conducting larger prospective studies with suitable epilepsy diagnostic methods would help provide a more precise estimate of the number of HGG patients who develop post-therapy epilepsy.
- The Dianalund experience: A review of the 6th ILAE School on Advanced EEG and EpilepsyPublication . Borges, Daniel Filipe; Primicerio, Giulia; Perjoc, Radu‐Ștefan; Bloch, Lars Ølgaard; Cacic Hribljan, MelitaThe 6th International League Against Epilepsy (ILAE)School on Advanced EEG and Epilepsy (DSSEE6) tookplace between July 20 and 28, 2024. It is a biennial courseheld in Dianalund @ Danish Epilepsy Center—Filadelfia,Denmark, since 2012. This year's event was hosted in ahybrid format and was organized under the auspices ofthe ILAE Academy and the Danish Epilepsy Society.
- Ictal and interictal source connectivity during gelastic seizures in a focal cortical dysplasia of the cingulate gyrusPublication . Borges, Daniel Filipe; Dias, Daniela; Cordeiro, Helena; Leal, AlbertoGelastic seizures are rare manifestations of epilepsy often associated with hypothalamic hamartomas (HH). In the absence of HH, localization of the origin is more difficult and there are several less well-established possibilities. Non-invasive assessment is often complicated by the deep localization of the epileptogenic area and the complex dynamics of spike activity. Robust neurophysiologic methods and careful validation of intrinsically epileptogenic lesions detected by RM can improve the validity of scalp EEG analysis. To analyze the dynamics of epileptic activity in gelastic seizures associated with cortical dysplasia. A 26-year-old girl with daily refractory gelastic seizures since the age of 6 underwent a neurophysiological assessment with long-term EEG recordings (24h, 31 channels) and an MRI of the brain. She had previously been rejected in an epilepsy surgery program because no structural brain lesion had been found and the EEG information was not informative enough. A recent 3T MRI showed cortical dysplasia in the cingulate gyrus, which was highly suspicious as an epileptogenic focus. We analyzed the 31-channel EEG (ictal and interictal) using source and functional connectivity methods to obtain a solid computer model of the origin and dynamics of epileptic activity and correlate it with the anatomical information of the MRI. Source analysis of interictal activity revealed multiple sources that dominated at different time points, indicating considerable dynamics that prevented clear source identification. The ictal recordings demonstrated barely late rhythmic activity over the frontal areas, but no early focalization. Connectivity analysis, which revealed the flow of information between cortical sources, showed a consistent origin of epileptic activity in the vicinity of cortical dysplasia for both interictal and ictal activity. EEG connectivity analysis significantly improves the performance of non-invasive methods for determining intracranial dynamics of epileptic activity and correlation with structural lesions.
- Reading epilepsy and hyperexcitability of the visual word form areaPublication . Borges, Daniel Filipe; Leal, AlbertoReading epilepsy recruits critical language-related areas, with synchronization and subsequent spreading of excitation in response to the epileptogenic stimulus. The mechanism by which possible generalized discharges result in the expression of bilateral or unilateral clinical symptoms remains controversial. The cortical and subcortical areas involved may constitute part of the normal reading network, such as the visual word form area (VWFA). A right-handed, 59-year-old man was diagnosed with epilepsy at the age of 15 after tonic-clonic seizures. Later, the patient described myoclonic jerks of the masticatory and perioral muscles while reading. A multimodal approach with magnetic resonance imaging and ambulatory and video-electroencephalogram was used for seizure characterization and source analysis. A left hemisphere spontaneous occipitotemporal epileptic focus, activated by reading, was observed, spreading broadly throughout frontal and temporal language networks. There was an abnormally increased cortical response to visual word presentation in comparison to pseudowords. Spatial localization of spike sources suggested a close association between the primary epileptic focus and the VWFA. This epileptiform activity seems to be selectively triggered at an early stage of lexical processing, with a functional connection between the epileptic network and the VWFA. This multimodal and functional connectivity approach could be helpful in determining the epileptic network in reading epilepsy.
- Technology, Sleep and Rest: what effects do they have on the brain?Publication . Borges, Daniel FilipeThis lecture dealt with various topics relating to technology, neurobiology and the function of sleep as well as the characteristics of rest. In a pragmatic way, an original approach was taken by trying to answer several story-related questions, such as: - When we talk about technology, we inevitably think about access to and use of the internet. How can we measure the impact of technology today in Portugal and in the world? - Should we be concerned about the exponential growth in the use of social networks and e-commerce? - Can the reported statistical data be the ground truth, or is there a certain subjectivity that must be taken into account when analysing it? - Today there are smartwatches and a variety of technologies that allow us to track our sleep. There is a lot of talk about "quantity versus quality". Do we know how to interpret the results? - How can we tell if our sleep was effective without needing a detailed diagnosis? - Are we sufficiently informed about what sleep is and what it does to us? How would you explain in a simple way how this element, which is so important for our health, works? - We often wake up with the feeling that we haven’t rested enough and take it for granted – it’s the “new normal”. Is that dangerous? - Will the overuse of technology that is directly related to light exposure render the sleep cycle ineffective? - There is a lot of talk about blue light. It's often associated with sleep and falling asleep. What are the consequences of exposure to this light? - We are used to only talking about the negative effects of using technology on the brain. But are there also benefits? - The exponential growth in the use of technology can now even be seen in schools. Teenagers are the most affected by this technological phenomenon. What tips would be helpful to protect yourself from the surge we are experiencing? - How can this decline in emotional intelligence affect the critical minds of young people? - What does the future of sleep health look like?
- The sound of silence: Quantification of typical absence seizures by sonifying EEG signals from a custom‐built wearable devicePublication . Borges, Daniel Filipe; Fernandes, João; Soares, Joana Isabel; Casalta‐Lopes, João; Carvalho, Daniel; Beniczky, Sándor; Leal, AlbertoTo develop and validate a method for long-term (24-h) objective quantification of absence seizures in the EEG of patients with childhood absence epilepsy (CAE) in their real home environment using a wearable device (waEEG), comparing automatic detection methods with auditory recognition after seizure sonification. The waEEG recording was acquired with two scalp electrodes. Automatic analysis was performed using previously validated software (Persyst® 14) and then fully reviewed by an experienced clinical neurophysiologist. The EEG data were converted into an audio file in waveform format with a 60-fold time compression factor. The sonified EEG was listened to by three inexperienced observers and the number of seizures and the processing time required for each data set were recorded blind to other data. Quantification of seizures from the patient diary was also assessed. Eleven waEEG recordings from seven CAE patients with an average age of 8.18 ± 1.60 years were included. No differences in the number of seizures were found between the recordings using automated methods and expert audio assessment, with significant correlations between methods (ρ > .89, p < .001) and between observers (ρ > .96, p < .001). For the entire data set, the audio assessment yielded a sensitivity of .830 and a precision of .841, resulting in an F1 score of .835. Auditory waEEG seizure detection by lay medical personnel provided similar accuracy to post-processed automatic detection by an experienced clinical neurophysiologist, but in a less time-consuming procedure and without the need for specialized resources. Sonification of long-term EEG recordings in CAE provides a user-friendly and cost-effective clinical workflow for quantifying seizures in clinical practice, minimizing human and technical constraints.