Clinical, functional, and neurophysiologic assessment of dysplastic cortical networks: Implications for cortical functioning and surgical management

• Published in: Epilepsia (Copenhagen) 2009-10, Vol.50 (s9), p.19-27
• Main Author: Duchowny, Michael
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Cerebral Cortex - physiopathology; Cerebral Cortex - surgery; Cognition Disorders - diagnosis; Cognition Disorders - physiopathology; Cortical dysplasia; Disease-Free Survival; Electroencephalography - statistics & numerical data; Epilepsy - diagnosis; Epilepsy - physiopathology; Epilepsy - surgery; Headache. Facial pains. Syncopes. Epilepsia. Intracranial hypertension. Brain oedema. Cerebral palsy; Humans; Intractable epilepsy; Magnetic Resonance Imaging - methods; Magnetic Resonance Imaging - statistics & numerical data; Malformations of Cortical Development - diagnosis; Malformations of Cortical Development - physiopathology; Malformations of Cortical Development - surgery; Malformations of the nervous system; Medical sciences; Nerve Net - physiopathology; Nerve Net - surgery; Nervous system (semeiology, syndromes); Neural network; Neurology; Neurons - pathology; Neurophysiology - statistics & numerical data; Neuropsychological Tests; Prognosis; Treatment Outcome
• ISSN: 0013-9580; 1528-1167
• DOI: 10.1111/j.1528-1167.2009.02291.x

Summary Cortical malformations are highly epileptogenic lesions associated with complex, unanticipated, and often aberrant electrophysiologic and functional relationships. These relationships are inextricably linked to widespread cortical networks subserving eloquent functions, particularly language and motor ability. Cytomegalic neurons but not balloon cells in Palmini type 2 dysplastic cortex are intrinsically hyperexcitable and contribute to local epileptogenesis and functional responsiveness. However, there is much evidence that focal cortical dysplasia is rarely a localized or even regional process, and is a functionally, electrophysiologically, and ultimately clinically integrated neural network disorder. Not surprisingly, malformed cortex is implicated in cognitive dysfunction, particularly disturbances of linguistic processing. An understanding of these relationships is critical for successful epilepsy surgery. Gains in surgical prognosis rely on multiple diagnostic modalities to delineate complex anatomic, electrophysiologic, and functional relationships in magnetic resonance imaging (MRI)–negative patients with rates of seizure‐freedom roughly comparable to lesional patients