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In patients with a first seizure, the identification of early sensitive and specific biomarkers for formulating a diagnosis of epilepsy is fundamental. Sleep deprivation (SD) has long been used as a means of enhancing EEG sensitivity in the diagnostic process. However, huge methodological differences among the studies addressing this topic have led to highly variable results and often confusing assumptions. Here, we provide a detailed description of the correlations between SD and epilepsy, along with their putative mechanistic explanations derived from experimental studies in animals and humans. We also outline the clinical studies evaluating the role of SD EEG and discuss them critically in terms of: (a) study design and SD EEG methodology; (b) EEG sensitivity and specificity; (c) the role of drug-induced sleep EEG and EEG during spontaneously occurring sleep; and (d) the relevance of patient features, syndromes, and subsyndromes, as well as their correlations with neuroimaging details. Finally, we propose specific studies that might increase the role of SD EEG in the diagnosis and prognosis of epilepsy. [ABSTRACT FROM AUTHOR]

Purpose Sleep deprivation (SD) increases the occurrence of interictal epileptiform discharges (IED) compared to basal EEG in temporal lobe epilepsy (TLE). In adults, EEG after SD is usually performed in the morning after SD. We aimed to evaluate whether morning sleep after SD bears additional IED-inducing effects compared with nocturnal physiological sleep, and whether changes in sleep stability (described by the cyclic alternating pattern-CAP) play a significant role. Methods Adult patients with TLE underwent in-lab night polysomnography (n-PSG) and, within 7 days from n-PSG, they underwent also a morning EEG after night SD (SD-EEG). We included only TLE patients in which both recordings showed IED. SD-EEG consisted of waking up patients at 2:00 AM and performing video EEG at 8:00 AM. For both recordings, we obtained the following markers for the first sleep cycle: IED/h (Spike Index, SI), sleep macrostructure, microstructure (NREM CAP rate; A1, A2 and A3 Indices), and SI association with CAP variables. Results The macrostructure of the first sleep cycle was similar in n-PSG and morning SD-EEG, whereas CAP rate and SI were significantly higher in SD-EEG. SI increase was selectively associated with CAP phases. Conclusions SD increases the instability of morning recovery sleep compared with n-PSG, and particularly enhances CAP A1 phases, which are associated with the majority of IED. Thus, higher instability of morning recovery sleep may account at least in part for the increased IED yield in SD-EEG in TLE patients. [ABSTRACT FROM AUTHOR]

EEG after sleep deprivation (SD-EEG) iswidely used in many epilepsy centers as an important tool in the epilepsy diagnosis process. However, aftermore than 40 years of use, there are a number of issueswhich still need to be clarified concerning its features and role. In particular, the many scientific papers addressing its role in epilepsy diagnosis often differ remarkably from each other in terms of the type of patients assessed, their description and study design. Furthermore, also the length and the type of EEG performed after SD, as well as the length of SD itself, vary dramatically from one study to another. In this paper we shortly underscore the abovementioned differences among the different reports, as well as some interpretations of the findings obtained in the different studies. This analysis emphasizes, if needed, how SD-EEG still represents a crucial step in epilepsy diagnosis, and how additional, controlled studies might further shape its precise diagnostic/prognostic role. [ABSTRACT FROM AUTHOR]

Highlights: [•] We assessed retrospectively the role of a simple method of EEG after sleep deprivation (SD-EEG) on a large population of de novo patients evaluated for suspected seizures, bearing a normal basal EEG. [•] In these patients SD-EEG often reveals interictal abnormalities and bears a high specificity in epilepsy diagnosis. [•] Interictal abnormalities are different in generalized versus focal epilepsies, and in the latter the interictal abnormalities yield in SD-EEG is higher than in a repeated routine EEG. [Copyright &y& Elsevier]

Our aim was to evaluate the EEG and clinical modifications induced by the new antiepileptic drug lacosamide (LCM) in patients with epilepsy.We evaluated 10 patients affected by focal pharmacoresistant epilepsy in which LCM (mean 250mg/day) was added to the preexisting antiepileptic therapy, which was left unmodified. Morning waking EEG recording was performed before (t0) and at 6 months (t1) after starting LCM. At t0 and t1, patients were also administered questionnaires evaluating mood, anxiety, sleep, sleepiness, and fatigue (Beck Depression Inventory; State-Trait Anxiety Inventory Y1 and Y2; Pittsburgh Sleep Quality Index; Epworth Sleepiness Scale; Fatigue Severity Scale). We performed a quantitative analysis of EEG interictal abnormalities and background EEG power spectrum analysis. LCMas an add-on did not significantly affect anxiety, depression, sleepiness, sleep quality, and fatigue scales. Similarly, adding LCM to preexisting therapy did not modify significantly patient EEGs in terms of absolute power, relative power, mean frequency, and interictal abnormalities occurrence. In conclusion, in this small cohort of patients, we confirmed that LCM as an add-on does not affect subjective parameters which play a role, among others, in therapy tolerability, and our clinical impression was further supported by evaluation of EEG spectral analysis. [ABSTRACT FROM AUTHOR]

Introduction Although Myasthenia gravis (MG) is the most common autoimmune disease associated with thymoma, a small proportion of thymomatous patients can suffer from limbic autoimmune encephalitis (LE). LE is usually characterized by rapid progressive short-term memory deficits, psychiatric symptoms, and seizures. Patients can present antibodies against cell surface antigens, including contactin-associated protein-like 2 (CASPR2) and a-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR). Our aim was to analyze the EEG findings of these patients to find possible EEG homologies among their patterns. Methods Clinical information was obtained from a retrospective review of medical records and EEG recordings of three patients with thymoma and LE: two with seropositivity for AMPAR antibodies and one for CASPR2 antibodies. Results The first case was a 37 years-old man with a subacute onset of memory loss, confusion, anxiety and behavioral disorders in the setting of an invasive thymoma (type B2-B3). Brain MRI and dosage of acetylcholine receptor antibodies (AChR-Abs) were normal. EEG showed bilateral fronto-temporal spikes together with slow theta and delta activity. Clinical suspicion of a paraneoplastic neurological syndrome associated with thymoma was confirmed by the serological presence of AMPAR-Abs. The second case was a 47 years-old female patient with Myasthenia Gravis (MG) and seropositivity for AChR-Abs, treated for recurrent thymoma (type B2). She presented three episodes of generalized seizures, together with mental disorientation, impairment of recent memory and insomnia. Brain MRI was normal. EEG showed a peculiar pattern, comprising lateralized right fronto-temporal spikes and generalized sharp waves. Serological tests detected the presence of antibodies to CASPR2. The third case was a 52 years-old female patient with thymoma (type B2-B3) who developed confusion, short-term memory loss and psychomotor agitation after thymectomy. Cerebrospinal fluid (CSF) examination showed a mild blood-CSF barrier damage and brain MRI revealed increased T2 signal involving mesio-temporal cortical areas. EEG showed electrical abnormalities in the fronto-temporal regions. Antibodies to the glutamate receptor 1 (GluR1) and GluR3 subunits of AMPAR were detected both in serum and CSF. Conclusion Limbic autoimmune encephalitis should be suspected in patients with invasive thymoma and subacute onset of confusion, memory loss and seizures. In all these three cases EEG showed epileptiform activity, especially in the fronto-temporal regions, together with slow theta and delta activity, without a pathognomonic pattern. Our results strongly emphasize the importance of testing biological samples when a possible autoimmune CNS involvement is suspected. Even if antibody testing remains the cornerstone in the diagnostic pathway, EEG is paramount in the differential diagnosis with similar disorders, in orienting toward limbic encephalopathy, especially when MRI is inconclusive. [ABSTRACT FROM AUTHOR]