Papers by Giuseppe Didato
Epilepsia, 2011
Sleep-related complex motor seizures are a common feature of nocturnal frontal lobe epilepsy. Nev... more Sleep-related complex motor seizures are a common feature of nocturnal frontal lobe epilepsy. Nevertheless, recent studies also suggest that sleep-related hypermotor seizures can originate in the insula. The present study describes the electroclinical features of eight drug-resistant epileptic patients with insular-opercular seizures manifesting with nocturnal complex motor seizures. Patients underwent a comprehensive presurgical evaluation, which included history, interictal electroencephalography (EEG), scalp video-EEG monitoring, high-resolution magnetic resonance imaging (MRI), and intracerebral recording by stereo-EEG. Almost all patients reported an initial sensation consisting of viscerosensitive or somatosensory symptoms. Ictal clinical signs were represented by tonic-dystonic asymmetric posturing and/or hyperkinetic automatisms, including bimanual/bipedal activity and ballistic movements. Some patients exhibited dysarthric speech, hypersalivation, and apnea. Interictal and ...
Early post-operative convulsive status epilepticus in a patient with drug-refractory temporal lobe epilepsy and type I focal cortical dysplasia
Seizure, 2014
ABSTRACT Status epilepticus (SE) early after epilepsy surgery is rarely described in case series ... more ABSTRACT Status epilepticus (SE) early after epilepsy surgery is rarely described in case series partly because the current seizure outcome classification does not allow its proper recognition. However, recent data indicating de novo SE in about 2% of patients undergoing surgery because of drug-refractory focal epilepsy suggest that, although rare, SE may be an important condition with causative factors mechanistically related to long-term seizure relapses. We describe the case of a patient with drug-refractory, magnetic resonance-negative temporal lobe epilepsy who developed a refractory generalised convulsive SE immediately after a left-sided anterior temporal lobectomy. Neuropathological examination of the surgical specimens revealed type IC focal cortical dysplasia. The resection margins were free from dysplasia, and the hippocampus did not show any signs of sclerosis. Surgical complications, the co-existence of different epilepsy types, multifocal epilepsy, perioperative alterations in the plasma levels of anti-epileptic drugs and, most importantly, the sub-total surgical removal of the dysplastic lesion were excluded as possible causes of post-surgical SE in this patient. The appearance of generalised epileptic activity after anterior temporal lobectomy may be due to an imbalance in the epileptic network containing the epileptogenic zone that probably exceeds the anatomical limits of the lesion. The surgical removal of a dysplastic lesion may activate previously dormant cortical areas predisposed to epilepsy that may be mechanistically related to long-term seizure relapses.
7T MRI features in control human hippocampus and hippocampal sclerosis: An ex vivo study with histologic correlations
Epilepsia, 2014
Hippocampal sclerosis (HS) is the major structural brain lesion in patients with temporal lobe ep... more Hippocampal sclerosis (HS) is the major structural brain lesion in patients with temporal lobe epilepsy (TLE). However, its internal anatomic structure remains difficult to recognize at 1.5 or 3 Tesla (T) magnetic resonance imaging (MRI), which allows neither identification of specific pathology patterns nor their proposed value to predict postsurgical outcome, cognitive impairment, or underlying etiologies. We aimed to identify specific HS subtypes in resected surgical TLE samples on 7T MRI by juxtaposition with corresponding histologic sections. Fifteen nonsclerotic and 18 sclerotic hippocampi were studied ex vivo using an experimental 7T MRI scanner. T2 -weighted images (T2wi) and diffusion tensor imaging (DTI) data were acquired and validated using a systematic histologic analysis of same specimens along the anterior-posterior axis of the hippocampus. In nonsclerotic hippocampi, differences in MR intensity could be assigned to seven clearly recognizable layers and anatomic boundaries as confirmed by histology. All hippocampal subfields could be visualized also in the hippocampal head with three-dimensional imaging and angulated coronal planes. Only four discernible layers were identified in specimens with histopathologically confirmed HS. All sclerotic hippocampi showed a significant atrophy and increased signal intensity along the pyramidal cell layer. Changes in DTI parameters such as an increased mean diffusivity, allowed to distinguish International League Against Epilepsy (ILAE) HS type 1 from type 2. Whereas the increase in T2wi signal intensities could not be attributed to a distinct specific histopathologic substrate, that is, decreased neuronal or increased glial cell densities, intrahippocampal projections and fiber tracts were distorted in HS specimens suggesting a complex disorganization of the cellular composition, fiber networks, as well as its extracellular matrix. Our data further advocate high-resolution MRI as a helpful and promising diagnostic tool for the investigation of hippocampal pathology along the anterior-posterior extent in TLE, as well as in other neurologic and neurodegenerative disorders.
Long-term outcome after limited cortical resections in two cases of adult-onset Rasmussen encephalitis
Epilepsia, 2014
Rasmussen encephalitis (RE) is a progressive inflammatory disorder characterized by brain hemiatr... more Rasmussen encephalitis (RE) is a progressive inflammatory disorder characterized by brain hemiatrophy, unilateral focal deficits, and drug-refractory focal epilepsy. Epilepsia partialis continua (EPC) is a hallmark of the disease. Several immunomodulatory treatments may slow but not halt the disease progression. The treatment of choice still relies on surgical hemispheric disconnection, which is burdened by heavy neurologic morbidity. More limited cortical resections, although more tolerable, are usually considered to be, at best, only transiently effective in RE. Hemispheric disconnections may be not feasible when neurologic functions are preserved and the dominant hemisphere is affected. Adult patients with a milder RE course that preserves neurologic function for a long period are particularly at risk of developing severe deficits after surgery. In this study we present the histories of two patients with adult-onset RE who have undergone selective cortical resections to control EPC, avoiding, at the same time, the severe postsurgical deficits that may be induced by hemispheric disconnective surgery. The good result obtained on EPC has been stable over a prolonged period; however, this result was not paralleled by the stop of neurologic progression in one of the two cases. A PowerPoint slide summarizing this article is available for download in the Supporting Information section http://dx.doi.org/10.1111/epi.12596/supinfo.
Purpose: Sleep-related complex motor seizures are a common feature of nocturnal frontal lobe epil... more Purpose: Sleep-related complex motor seizures are a common feature of nocturnal frontal lobe epilepsy. Nevertheless, recent studies also suggest that sleeprelated hypermotor seizures can originate in the insula. The present study describes the electroclinical features of eight drug-resistant epileptic patients with insularopercular seizures manifesting with nocturnal complex motor seizures. Methods: Patients underwent a comprehensive presurgical evaluation, which included history, interictal electroencephalography (EEG), scalp video-EEG monitoring, high-resolution magnetic resonance imaging (MRI), and intracerebral recording by stereo-EEG. Key Findings: Almost all patients reported an initial sensation consisting of viscerosensitive or somatosensory symptoms. Ictal clinical signs were represented by tonicdystonic asymmetric posturing and/or hyperkinetic automatisms, including bimanual/bipedal activity and ballistic movements. Some patients exhibited dysarthric speech, hypersalivation, and apnea. Interictal and ictal EEG provided lateralizing information in the majority of patients. In three patients, MRI showed a focal anatomical
Purpose: To analyze the topography of the epileptogenic zone (EZ) and the etiologic substrate as ... more Purpose: To analyze the topography of the epileptogenic zone (EZ) and the etiologic substrate as risk factors for sleep-related focal epilepsy. Methods: Three hundred three patients (172 males and 131 females, mean age at surgery 25.6 ± 13.1 years), who were seizure-free after resective surgery for drug-resistant focal epilepsy, were retrospectively reviewed. Statistical analysis was conducted to evaluate the risk of presenting sleep-related epilepsy (SRE) against topography of resection (assumed to correspond or to include the EZ) and results of histology. Results: Thirty-nine patients (12.8% %) presented with an SRE. At bivariate analysis, a higher frequency of SRE was associated with a frontal lobe EZ (p = 1.94 · 10 )9 ) and Taylor's FCD (TFCD, p = 2.20 · 10 )16 ), whereas architectural FCD (p = 0.00977), ganglioglioma (p = 0.02508), and mesial temporal sclerosis (p = 2.47 · 10 )5 ) were correlated with a reduced frequency of SRE. Multivariate analysis demonstrated that the only variable significantly associated with SRE was the presence of a TFCD, which increased 14-fold the risk of SRE [p = 1.66 · 10 )10 ; risk ratio (RR) = 14.44]. Discussion: In this study, we have demonstrated a significant and strong association between SRE and TFCD in a select population of patients with drug-resistant focal epilepsy submitted to surgical resection of the EZ. Although our results cannot be applied to the entire spectrum of SRE, the presence of TFCD as the underlying etiology should be considered when evaluating patients with SRE, because surgery can provide excellent results on seizures in these cases.
Sleep, 2009
Arousal parasomnias are expressions of sleep/ wake state dissociations in which wakefulness and N... more Arousal parasomnias are expressions of sleep/ wake state dissociations in which wakefulness and NREM sleep seem to coexist. We describe the results of a neurophysiological (intracerebral EEG) investigation that captured an episode of confusional arousal. Observational analysis. Tertiary sleep center. A 20-year-old male with refractory focal epilepsy. The intracerebral EEG findings documented the presence of a local arousal of the motor and cingulate cortices associated with increased delta activity in the frontoparietal associative cortices; these findings were noted preceding the onset and persisting throughout the episode. The presence of dissociated sleep/wake states in confusional arousals is the expression not of a global phenomenon, but rather of the coexistence of different local states of being: arousal of the motor and cingulate cortices and inhibition of the associative ones. Whether this is an exclusive feature of NREM parasomnias, or a common substrate on which other tri...
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Papers by Giuseppe Didato