ABSTRACT
The absence of speech is a clinical phenotype seen across neurodevelopmental syndromes, offering insights for neural language models. We present a case of bilateral perisylvian polymicrogyria (BPP) and complete absence of speech with considerable language comprehension and production difficulties. We extensively characterized the auditory speech perception and production circuitry by employing a multimodal neuroimaging approach. Results showed extensive cortical thickening in motor and auditory-language regions. The auditory cortex lacked sensitivity to speech stimuli despite relatively preserved thalamic projections yet had no intrinsic functional organization. Subcortical structures implicated in early stages of processing exhibited heightened sensitivity to speech. The arcuate fasciculus, a suggested marker of language in BPP, showed similar volume and integrity to a healthy control. The frontal aslant tract, linked to oromotor function, was partially reconstructed. These findings highlight the importance of assessing the auditory cortex beyond speech production structures to understand absent speech in BPP. Despite profound cortical alterations, the intrinsic motor network and motor-speech pathways remained largely intact. This case underscores the need for comprehensive phenotyping using multiple MRI modalities to uncover causes of severe disruption in language development.
Subject(s)
Abnormalities, Multiple , Auditory Cortex , Intellectual Disability , Malformations of Cortical Development , Polymicrogyria , Speech Perception , Humans , Auditory Cortex/physiology , Speech/physiology , Speech Perception/physiology , Magnetic Resonance Imaging/methods , PhenotypeABSTRACT
Many neurodevelopmental conditions imply absent or severely reduced language capacities at school age. Evidence from functional magnetic resonance imaging is highly limited. We selected a series of five cases scanned with the same fMRI paradigm and the aim of relating individual language profiles onto underlying patterns of functional connectivity (FC) across auditory language cortex: three with neurogenetic syndromes (Coffin-Siris, Landau-Kleffner, and Fragile-X), one with idiopathic intellectual disability, one with autism spectrum disorder (ASD). Compared to both a group with typical development (TD) and a verbal ASD group (total N = 110), they all showed interhemispheric FC below two standard deviations of the TD mean. Children with higher language scores showed higher intrahemispheric FC between Heschl's gyrus and other auditory language regions, as well as an increase of FC during language stimulation compared to rest. An increase of FC in forward vs. reversed speech in the posterior and middle temporal gyri was seen across all cases. The Coffin-Siris case, the most severe, also had the most anomalous FC patterns and showed reduced myelin content, while the Landau-Kleffner case showed reduced cortical thickness. These results suggest potential for neural markers and mechanisms of severe language processing deficits under highly heterogeneous etiological conditions.
Subject(s)
Auditory Cortex , Autism Spectrum Disorder , Auditory Cortex/diagnostic imaging , Brain Mapping/methods , Child , Humans , Language , Magnetic Resonance Imaging/methods , Neural Pathways , Temporal LobeABSTRACT
BACKGROUND: We aimed to prospectively analyze memory and executive and social cognitive functioning in patients with drug-resistant frontal lobe epilepsy (FLE) and temporal lobe epilepsy (TLE) with focal lesions and isolate the impact of intellectual ability on specific deficits. METHODS: A neuropsychological evaluation was performed in 23 children with FLE, 22 children with TLE, and 36 healthy pediatric controls (HCs). Patients in the epilepsy groups had a range of lesions, including low-grade epilepsy-associated tumors (LEAT), focal cortical dysplasia (FCD) type II, and mesial temporal sclerosis (MS). RESULTS: There were no significant differences between children with FLE and TLE regarding memory, executive, or social cognitive functioning. General Ability Index (GAI) was a predictor of memory, executive function, and social cognition scores and was influenced by age at onset, duration of epilepsy, and number of antiepileptic drugs (AEDs) prescribed at the time of assessment. Working Memory Index scores of patients with TLE, which measure verbal mnesic processing, were significantly lower than those of HCs and patients with TLE. The greatest differences in both clinical groups compared to HCs were recorded in cognitive executive functions, and patients with FLE had lower scores in this domain. Regarding behavioral executive functions, patients with TLE presented impaired emotional control and impulse inhibition and patients with FLE exhibited decreased flexibility. CONCLUSION: Consistent with previous research, our findings provide further detailed evidence of small differences in cognitive performance among children with FLE and TLE. These differences emerge on analysis of the factors with which deficits are associated.
Subject(s)
Epilepsy, Frontal Lobe , Epilepsy, Temporal Lobe , Child , Cognition , Epilepsy, Temporal Lobe/complications , Executive Function , Humans , Neuropsychological TestsABSTRACT
Introducción. Las displasias corticales focales (DCF) son la primera etiología de cirugía de la epilepsia pediátrica. La evaluación prequirúrgica en DCF a menudo es compleja, ya que son lesiones que pueden ser altamente epileptógenas y, a la vez, conservar función neurológica, y no visualizarse en la resonancia magnética. El éxito de la cirugía depende, en gran medida, de la adecuada identificación de la lesión y de la posibilidad de realizar una resección completa del tejido displá- sico. En este trabajo se revisa la bibliografía relacionada con el tema, en relación con la experiencia de los autores. Desarrollo. Se revisan algunos avances relacionados con la evaluación prequirúrgica y el abordaje neuroquirúrgico de la epilepsia en niños con DCF; se comentan los resultados de las series quirúrgicas en relación con las clasificaciones de DCF y los factores de pronóstico posquirúrgico; se describen algunos fenotipos anatomoelectroclínicos distintivos en niños con DCF y su abordaje quirúrgico; y se comentan brevemente los actuales retos y el futuro del tratamiento quirúrgico de la epilepsia en DCF. Conclusiones. El avance los métodos de diagnóstico prequirúrgico y de procedimientos quirúrgicos está permitiendo ofrecer un tratamiento exitoso en edades tempranas a pacientes con DCF previamente considerados no lesionales y a pacientes con lesiones localizadas en la corteza elocuente. La identificación de fenotipos anatomoelectroclínicos de DCF permite establecer abordajes quirúrgicos y expectativas de pronóstico posquirúrgico adecuadas a cada situación, mejor en las DCF IIb transmantle y en las displasias de fondo de surco que en las DCF multilobares, en su mayoría DCF I (AU)
Introduction. Focal cortical dysplasias (FCD) are the first cause of surgery in paediatric epilepsy surgery. The pre-surgical assessment in FCD is often complex, since they are lesions that can be highly epileptogenic and at the same time can preserve neurological functioning and may not be displayed in magnetic resonance imaging. The success of the operation largely depends on the proper identification of the lesion and the possibility of performing a complete resection of the dysplastic tissue. In this work we review the literature related with this topic, in relation to the authors experience. Development. The study reviews some of the advances made as regards the pre-surgical assessment and the neurosurgical management of epilepsy in children with FCD; results from the surgical series regarding the classifications of FCD and the post-surgical prognostic factors are commented on; some anatomo-clinical phenotypes that are distinctive in children with FCD and their surgical management are described; and current challenges and the future of the surgical treatment of epilepsy in FCD are also briefly discussed. Conclusions. The advances being made in the methods of pre-surgical diagnosis and surgical procedures are making it possible to offer successful treatment at earlier ages in patients with FCD who were previously considered non-lesional and in patients with localised lesions in the eloquent cortex. The identification of anatomo-electro-clinical phenotypes of FCD makes it possible to establish surgical approaches and post-surgical prognostic expectations that are well suited to each situation, which are better in the transmantle-type FCD IIb and in bottom-of-sulcus dysplasias than in multilobe FCD, which are mostly FCD I (AU)
Subject(s)
Humans , Child , Epilepsies, Partial/classification , Epilepsies, Partial/diagnosis , Epilepsies, Partial/pathology , Epilepsies, Partial/surgery , Malformations of Cortical Development/classification , Malformations of Cortical Development/diagnosis , Malformations of Cortical Development/pathology , Malformations of Cortical Development/surgery , Neurosurgical Procedures/methods , Brain/surgery , Prognosis , Forecasting , Magnetic Resonance Imaging , Neuroimaging , Perioperative Care , Treatment OutcomeABSTRACT
INTRODUCTION: Focal cortical dysplasias (FCD) are the first cause of surgery in paediatric epilepsy surgery. The pre-surgical assessment in FCD is often complex, since they are lesions that can be highly epileptogenic and at the same time can preserve neurological functioning and may not be displayed in magnetic resonance imaging. The success of the operation largely depends on the proper identification of the lesion and the possibility of performing a complete resection of the dysplastic tissue. In this work we review the literature related with this topic, in relation to the authors' experience. DEVELOPMENT: The study reviews some of the advances made as regards the pre-surgical assessment and the neurosurgical management of epilepsy in children with FCD; results from the surgical series regarding the classifications of FCD and the post-surgical prognostic factors are commented on; some anatomo-clinical phenotypes that are distinctive in children with FCD and their surgical management are described; and current challenges and the future of the surgical treatment of epilepsy in FCD are also briefly discussed. CONCLUSIONS: The advances being made in the methods of pre-surgical diagnosis and surgical procedures are making it possible to offer successful treatment at earlier ages in patients with FCD who were previously considered 'non-lesional' and in patients with localised lesions in the 'eloquent cortex'. The identification of anatomo-electro-clinical phenotypes of FCD makes it possible to establish surgical approaches and post-surgical prognostic expectations that are well suited to each situation, which are better in the transmantle-type FCD IIb and in bottom-of-sulcus dysplasias than in multilobe FCD, which are mostly FCD I.
TITLE: Cirugia de la epilepsia en niños con displasias corticales focales.Introduccion. Las displasias corticales focales (DCF) son la primera etiologia de cirugia de la epilepsia pediatrica. La evaluacion prequirurgica en DCF a menudo es compleja, ya que son lesiones que pueden ser altamente epileptogenas y, a la vez, conservar funcion neurologica, y no visualizarse en la resonancia magnetica. El exito de la cirugia depende, en gran medida, de la adecuada identificacion de la lesion y de la posibilidad de realizar una reseccion completa del tejido displasico. En este trabajo se revisa la bibliografia relacionada con el tema, en relacion con la experiencia de los autores. Desarrollo. Se revisan algunos avances relacionados con la evaluacion prequirurgica y el abordaje neuroquirurgico de la epilepsia en niños con DCF; se comentan los resultados de las series quirurgicas en relacion con las clasificaciones de DCF y los factores de pronostico posquirurgico; se describen algunos fenotipos anatomoelectroclinicos distintivos en niños con DCF y su abordaje quirurgico; y se comentan brevemente los actuales retos y el futuro del tratamiento quirurgico de la epilepsia en DCF. Conclusiones. El avance los metodos de diagnostico prequirurgico y de procedimientos quirurgicos esta permitiendo ofrecer un tratamiento exitoso en edades tempranas a pacientes con DCF previamente considerados 'no lesionales' y a pacientes con lesiones localizadas en la 'corteza elocuente'. La identificacion de fenotipos anatomoelectroclinicos de DCF permite establecer abordajes quirurgicos y expectativas de pronostico posquirurgico adecuadas a cada situacion, mejor en las DCF IIb transmantle y en las displasias de fondo de surco que en las DCF multilobares, en su mayoria DCF I.
Subject(s)
Epilepsies, Partial/surgery , Malformations of Cortical Development/surgery , Neurosurgical Procedures/methods , Brain/surgery , Child , Craniofacial Abnormalities , Epilepsies, Partial/classification , Epilepsies, Partial/diagnosis , Epilepsies, Partial/pathology , Forecasting , Humans , Magnetic Resonance Imaging , Malformations of Cortical Development/classification , Malformations of Cortical Development/diagnosis , Malformations of Cortical Development/pathology , Neuroimaging , Preoperative Care , Prognosis , Treatment OutcomeABSTRACT
Magnetic resonance imagine (MRI) is the essential tool for the diagnosis and evaluation of epileptic patients due to the possibility of it identifying the epileptogenic substrate and the decisive value for the selection of surgical candidates in cases of refractory epilepsy. Because the main role of MRI in epilepsy relates to the detection of a structural injury, the quality of the image clearly determines the results. In structural studies, it can contribute to detecting small hippocampal alterations that may be missed with conventional techniques, and it is a more reliable tool for detecting small focal cortical dysplasias (FCD), which constitute the most frequent cause of dual injury. 3-Tesla MRI also provides relevant information in functional studies. Its advantages rely on the rise in signal-to-noise ratio and its higher T2 contrast, and also, in the case of MR spectroscopy, on its higher chemical shift, which in general increases both the quality and the rapidity of acquisition. Finally, epilepsy is one of the main indications for obtaining cerebral activation maps, usually using the blood oxygen level dependent (BOLD) technique, which is one of the techniques that most benefits from the magnetic field increase.
