Distinguishing seizures in autoimmune limbic encephalitis from mesial temporal lobe epilepsy with hippocampal sclerosis: Clues of a temporal plus network

• Published in: Journal of the neurological sciences Vol. 467; p. 123288
• Main Authors: Morano, Alessandra, Cerulli Irelli, Emanuele, Fortunato, Francesco, Casciato, Sara, Panzini, Chiara, Milano, Chiara, Versace, Salvatore, Orlando, Biagio, Iorio, Raffaele, Tinelli, Emanuele, Ruffolo, Gabriele, Pizzanelli, Chiara, Vogrig, Alberto, Quarato, Pierpaolo, Giallonardo, Anna Teresa, Di Gennaro, Giancarlo, Gambardella, Antonio, Di Bonaventura, Carlo
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.12.2024
• Subjects: Adult; Aged; Autoimmune Diseases - complications; Autoimmune Diseases - physiopathology; Autoimmune limbic encephalitis; Diagnosis; Diagnosis, Differential; Electroencephalography; Epilepsy, Temporal Lobe - complications; Epilepsy, Temporal Lobe - diagnosis; Epilepsy, Temporal Lobe - diagnostic imaging; Female; Hippocampal Sclerosis; Hippocampus - diagnostic imaging; Hippocampus - pathology; Humans; Limbic Encephalitis - complications; Limbic Encephalitis - diagnosis; Limbic Encephalitis - diagnostic imaging; Limbic Encephalitis - physiopathology; Magnetic Resonance Imaging; Male; Mesial temporal lobe epilepsy; Middle Aged; Neurology; Peri-sylvian; Retrospective Studies; Sclerosis; Seizures; Seizures - diagnosis; Seizures - etiology; Temporal plus epilepsy; Young Adult; AE; MTLE; AAE; FBDS; LCA; Peri-sylvian; TLE; Mesial temporal lobe epilepsy; Autoimmune limbic encephalitis; HV; Temporal plus epilepsy; TPOJ; SEEG; aBIC; SSW; ALE; Diagnosis; AIC; NTLE; MTLE-HS; Seizures; faciobrachial dystonic seizures; aikake information criterion; temporo-parieto-occipital junction; latent class analysis; autoimmune-associated epilepsy; hyperventilation; neocortical temporal lobe epilepsy; sequential spikes/spikes-and-slow waves/sharp waves; temporal lobe epilepsy; Adjusted baikake information criterion; autoimmune encephalitis; mesial temporal lobe epilepsy with hippocampal sclerosis; stereo-EEG
• ISSN: 0022-510X; 1878-5883; 1878-5883
• DOI: 10.1016/j.jns.2024.123288

Diagnosing autoimmune limbic encephalitis (ALE) in adults with new-onset seizures can be challenging, especially when seizures represent the predominant manifestation and MRI findings are not straightforward. By comparison with mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS), this study aimed to identify ictal electro-clinical features that might help clinicians recognize ALE-related seizures. This retrospective, multi-centre study analysed the ictal semiology and EEG correlate of 116 video-EEG-captured seizures in 40 ALE patients and 45 ones recorded in 21 MTLE-HS subjects. The proportion of patients presenting each clinical feature on at least one occasion was compared between the study groups. Latent class analysis (LCA) was also performed. Ictal features were overall more numerous in ALE than in MTLE-HS (33 vs 22), and LCA confirmed the intrinsic variability of ALE-related seizures. Hyperventilation served as a trigger only in ALE (4/40). Awareness impairment (p = 0.032), limb dystonic posturing (p = 0.009) and manual automatisms (p < 0.001) were significantly less common in ALE cases. Conversely, piloerection was observed only in ALE subjects, although it did not reach statistical significance (p = 0.289), as was the case for déjà-vu (p = 0.084), and sensory symptoms (p = 0.079). Regarding EEG, the type of ictal pattern differed significantly (p = 0.007). This study shows that, despite the wide overlap with MTLE-HS, some ictal electro-clinical features could help clinicians suspect the autoimmune origin of adult-onset seizures. Moreover, autoimmune limbic seizures apparently shared similarities with ‘temporal plus’ epilepsy, which could partly account for the poor surgical outcomes and provide an interesting conceptual framework for future research. •If seizures are prominent, diagnosing autoimmune limbic encephalitis (ALE) is challenging.•Some differences emerged by comparing ictal semeiology/EEG of ALE and MTLE-HS.•Awareness impairment, limb dystonia, manual automatisms were less common in ALE.•Piloerection, déjà-vu, sensory symptoms and HV sensitivity occurred more in ALE.•ALE seizures shared similarities with ‘temporal plus’ epilepsy.