Cognitive fMRI and neuropsychological assessment in patients with secondarily generalized seizures

• Published in: Clinical neurology and neurosurgery 2008-05, Vol.110 (5), p.441-450
• Main Authors: Vlooswijk, Marielle C.G, Jansen, Jacobus F.A, Reijs, Rianne P, de Krom, Marc C.T.F.M, Kooi, M. Eline, Majoie, H.J.Marian, Hofman, Paul A.M, Backes, Walter H, Aldenkamp, Albert P
• Format: Article
• Language: English
• Subjects: Adult; Biological and medical sciences; Brain Mapping; Cognition; Cognition Disorders - complications; Cognition Disorders - diagnosis; Epilepsy; Epilepsy, Tonic-Clonic - complications; Epilepsy, Tonic-Clonic - physiopathology; Female; fMRI; Frontal Lobe - physiopathology; Humans; Intelligence Tests; Linear Models; Magnetic Resonance Imaging; Male; Medical sciences; Memory, Short-Term; Middle Aged; Neurology; Neuropsychological Tests; Neurosurgery; Prefrontal Cortex - physiopathology; Problem Solving; Seizures - complications; Seizures - physiopathology; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Temporal Lobe - physiopathology; Tonic-clonic seizures
• ISSN: 0303-8467; 1872-6968
• DOI: 10.1016/j.clineuro.2008.01.007

Abstract Objectives Cognitive dysfunction is a frequent comorbid disorder in epilepsy which has been associated with high seizure frequency. We examined the effect of secondarily generalized tonic-clonic seizures (SGTCS) on cognitive dysfunction using neuropsychological assessment and fMRI. Patients and methods Sixteen patients with localization-related epilepsy of varying etiologies and SGTCS underwent extensive neuropsychological assessment. Functional MRI was performed probing the frontal and temporal lobes with two paradigms aimed at investigating speed of mental processing and working memory. Results A high number of total lifetime SGTCS was associated with lower intelligence scores. Moreover, a trend towards cognitive decline related to the number of SGTCS was observed. A relatively increased prefrontal activation related to the number of SGTCS was demonstrated, plus a trend towards a decreased activation in the frontotemporal areas. Conclusion High numbers of SGTCS are associated with a drop in intelligence scores and altered prefrontal brain activation. A shift from frontotemporal to prefrontal activation seems to have occurred, suggesting that a functional reorganization of working memory is induced by a high number of SGTCS. It remains uncertain if this reorganization reflects a compensation mechanism, or the underlying pathological processes of cognitive dysfunction.