Original ArticlesCognitive deterioration associated with focal cortical dysplasia
Introduction
Because focal cortical dysplasia (FCD) is highly and intrinsically epileptogenic [1], [2], neurosurgery has been used when medical treatment has failed [3], [4], [5], [6]. However, unsatisfactory outcomes occur after incomplete removal of the lesions or in patients with lesions in the extratemporal lobes [6], [7], [8]. Therefore, it is important to identify how the epileptogenic lesions relate to the structural abnormality in the functional cortex before surgery [3], [9].
The authors describe the case of an 11-year-old female with FCD in the left parieto-occipital lobes. Because she manifested daily focal seizures and cognitive impairment, the authors discuss the relationship between an epileptic focus and the functional cortex. The epileptic focus was identified by ictal electroencephalographic (EEG) video monitoring, ictal technetium-99m-ethyl cysteinate dimer single-photon emission computed tomography (SPECT) superimposed on magnetic resonance imaging [10], and magnetoencephalogram [11]. Her intellectual abilities, obtained from Wechsler Intelligence Scale of Children-Revised (WISC-R) during the interictal state, were compared with findings of serial N-isopropyl-p-iodoamphetamine (123I-IMP). SPECT scans were performed using a Hitachi SPECT 2000 H-40 (Hitachi Medico, Tokyo, Japan) equipped with high-resolution collimators. Acquisition data were collected using 64 total steps of 15 seconds each into a 64 × 64 matrix, yielding a pixel size of 4 mm, and axial, sagittal, and coronal images with an 8-mm thickness were reconstructed. Computer-automated square regions of interest (16.8 × 16.8 mm) were created over the frontal, parietal, temporal, and occipital cortices and cerebellar hemicortices. The average pixel values in each region of interest were normalized to the cerebellar value. Also, somatosensory/auditory cortices were investigated by evoked magnetic dipoles [9], [12].
Section snippets
Case report
A right-handed female was admitted to the authors’ hospital at 11 years, 8 months of age because of daily epileptic seizures and verbal cognitive impairment. Physical examination revealed mild gum hypertrophy and hirsutism but no paralysis, hemianopsia, or cutaneous lesions of tuberous sclerosis. She was born at term after an uncomplicated pregnancy, weighing 2,940 gm. She had one older healthy sibling. There was no family history of epilepsy or mental disorder. Her early development was
Discussion
The long-term effects of seizures on the developing brain are a difficult problem to study because cognitive impairment may be related to the etiologic agent responsible for the seizures, age at the time of onset of seizures, or the antiepileptic drugs used to treat the seizures [14]. The authors’ patient demonstrated an increased subcortical signal on T2-weighted images, compatible with FCD, mainly in the left parietal lobe. She manifested three symptoms of Gerstmann syndrome even during a
Acknowledgements
The authors thank Professor Akimasa Okuno for review of the manuscript, Mr. Yukio Ishikawa and Mr. Junichi Satou for technical assistance in performing SPECT examinations, and Dr. Yutaka Watanabe for examining the patient with magnetoencephalogram.
References (19)
Neuroimaging in the evaluation of children and adolescents with intractable epilepsy: II. Neuroimaging and pediatric epilepsy surgery
Pediatr Neurol
(1997)- et al.
Functional localization of bilateral auditory cortices using an MRI-linked whole head magnetoen- cephalography (MEG) system
Electroencephalogr Clin Neurophysiol
(1995) The long-term effects of seizures on the developing brainClinical and laboratory issues
Brain Dev
(1991)- et al.
Positive epileptiform discharges in children with neuronal migration disorders
Pediatr Neurol
(1997) - et al.
Abnormal local-circuit neurons in epilepsia partialis continua associated with focal cortical dysplasia
Acta Neuropathol (Berl)
(1992) - et al.
Seizure-like discharges recorded in human dysplastic neocortex maintained in vitro
Neurology
(1995) - et al.
Operative strategies for patients with cortical dysplastic lesions and intractable epilepsy
Epilepsia
(1994) - et al.
Surgical treatment of epilepsy due to cortical dysplasiaClinical and EEG findings
J Neurol Neurosurg Psychiatry
(1993) - et al.
Focal cortical dysplasia and epilepsy surgery
No To Hattatsu
(1997)
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