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Multimodal human brain mapping has been proposed as an integrated approach capable of improving the recognition of the cortical correlates of specific neurological functions. We used simultaneous EEG-fMRI (functional magnetic resonance imaging) and EEG-TD-fNIRS (time domain functional near-infrared spectroscopy) recordings to compare different hemodynamic methods with changes in EEG in ten patients with progressive myoclonic epilepsy and 12 healthy controls. We evaluated OHb, HHb and Blood oxygen level-dependent (BOLD) changes and event-related desynchronization/synchronization (ERD/ERS) in the α and β bands of all of the subjects while they performed a simple motor task. The general linear model was used to obtain comparable fMRI and TD-fNIRS activation maps. We also analyzed cortical thickness in order to evaluate any structural changes. In the patients, the TD-NIRS and fMRI data significantly correlated and showed a significant lessening of the increase in OHb and the decrease in BOLD. The post-movement β rebound was minimal or absent in patients. Cortical thickness was moderately reduced in the motor area of the patients and correlated with the reduction in the hemodynamic signals. The fMRI and TD-NIRS results were consistent, significantly correlated and showed smaller hemodynamic changes in the patients. This finding may be partially attributable to mild cortical thickening. However, cortical hyperexcitability, which is known to generate myoclonic jerks and probably accounts for the lack of EEG β-ERS, did not reflect any increased energy requirement. We hypothesize that this is due to a loss of inhibitory neuronal components that typically fire at high frequencies. [ABSTRACT FROM AUTHOR]

Electrophysiological studies indicate that Unverricht-Lundborg's disease (ULD), the most common form of progressive myoclonus epilepsy in Europe, is characterized by the involvement of multiple cortical regions in degenerative changes that lead to enhanced excitation and deficient inhibition. We searched for the haemodynamic correlates of these effects using functional MRI (fMRI) of self-paced index extensions, a well-accepted task highlighting significant differences. EEG and fMRI were simultaneously acquired in 11 ULD patients and 16 controls, performing the index extensions individually (event-related task) as well as repetitively (block task). ERD/ERS analysis was performed for the EEG data in the alpha and beta bands. fMRI time-series were analyzed using the traditional general linear model, as well as with an assumption-free approach, and by means of cross-region correlations representing functional connectivity. In line with the existing literature, ULD patients had enhanced desynchronization in the alpha band and reduced post-movement synchronization in the beta band. By contrast, fMRI did not reveal any difference between the two groups; there were no activation intensity, latency or extent effects, no significant engagement of additional regions, and no changes to functional connectivity. We conclude that, so long as the patients are executing a task which does not induce obvious action myoclonus, the hypothesized abnormalities in pyramidal neuron and interneuron dynamics are relatively subtle, embodied in processes which are not metabolically-demanding and take place at a time-scale invisible to fMRI. [ABSTRACT FROM AUTHOR]

Mutations in the epsilon-sarcoglycan (SGCE) gene have been associated with DYT11 myoclonus-dystonia syndrome (MDS). The aim of this study was to characterize myoclonus in 9 patients with DYT11-MDS presenting with predominant myoclonus and mild dystonia by means of neurophysiological techniques. Variously severe multifocal myoclonus occurred in all of the patients, and included short (mean 89.1 +/- 13.3 milliseconds) electromyographic bursts without any electroencephalographic correlate, sometimes presenting a pseudo-rhythmic course. Massive jerks could be evoked by sudden stimuli in 5 patients, showing a 'startle-like' muscle spreading and latencies consistent with a brainstem origin. Somatosensory evoked potentials and long-loop reflexes were normal, as was silent period and long-term intracortical inhibition evaluated by means of transcranial magnetic stimulation; however, short-term intracortical inhibition revealed subtle impairment, and event-related synchronization (ERS) in the beta band was delayed. Blink reflex recovery was strongly enhanced. Myoclonus in DYT11-MDS seems to be generated at subcortical level, and possibly involves basal ganglia and brainstem circuitries. Cortical impairment may depend from subcortical dysfunction, but it can also have a role in influencing the myoclonic presentation. The wide distribution of the defective SCGE in DYT11-MDS may justify the involvement of different brain areas. [ABSTRACT FROM AUTHOR]

Abstract Knockout Otx1 mice present a microcephalic phenotype mainly due to reduced deep neocortical layers and spontaneous recurrent seizures. We investigated the excitable properties of layer V pyramidal neurons in neocortical slices prepared from Otx1–/– mice and age-matched controls. The qualitative firing properties of the neurons of Otx1–/– mice were identical to those found in wild-type controls, but the proportion of intrinsically bursting (IB) neurons was significantly smaller. This is in line with the lack of the Otx1 gene contribution to the generation and differentiation of neurons destined for the deep neocortical layers, in which IB neurons are located selectively in wild-type rodents. The pyramidal neurons recorded in Otx1–/– mice responded to near-threshold electrical stimulation of the underlying white matter, with aberrant polysynaptic excitatory potentials often leading to late action potential generation. When the strength of the stimulus was increased, the great majority of the Otx1–/– neurons (78%) responded with a prominent biphasic inhibitory postsynaptic potential that was significantly larger than that observed in the wild-type mice, and was often followed by complex postinhibitory depolarizing events. Both late excitatory postsynaptic potentials and postinhibitory excitation were selectively suppressed by NMDA receptor antagonists, but not by AMPA antagonists. We conclude that the cortical abnormalities of Otx1–/– neocortex due to a selective loss of large projecting neurons lead to a complex rearrangement of local circuitry, which is characterized by an excess of N-methyl-d-aspartate-mediated polysynaptic excitation that is counteracted by GABA-mediated inhibition in only a limited range of stimulus intensity. Prominent postsynaptic inhibitory potentials may also act as a further pro-epileptogenic event by... [ABSTRACT FROM AUTHOR]

We report the electroencephalographic (EEG) features of 22 patients with neuronal ceroid lipofuscinoses (NCL) who were referred to the Neurological Institute of Milan between 1984 and 1998. The EEG data were reviewed, taking into account the different forms of NCL on the basis of age at onset, clinical features and morphological appearance. The study group included patients with infantile NCL (one case), late-infantile NCL (ten cases), juvenile NCL (seven cases) and adult NCL (four cases). We looked for the presence of homogeneous EEG features associated with these different forms, particularly in the early phases of the disease. Our data indicate that the EEG characteristics of late-infantile NCL and of the myoclonic form of adult NCL are quite distincitve, and that their particular spontaneous epileptiform anomalies and response to intermittent light stimulation can be considered relevant diagnostic clues at an early disease stage. [ABSTRACT FROM AUTHOR]

Copyright of Italian Journal of Neurological Sciences is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Italian Journal of Neurological Sciences is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

One hundred and twenty-eight adult patients presenting with and operated on for supratentorial neoplasms were studied. Sixty-five had preoperative seizures and were treated with anti-epileptic drugs (AEDs). Among the 63 patients without preoperative epileptic fits, 41 were given AEDs (either phenobarbital or phenytoin) as prophylactic treatment and 22 were not treated. The preoperative epilepsy course was considered with respect to tumour site and histological type. Early and late postoperative seizure occurrence was considered in the different groups of patients. The results suggest the usefulness of a short term preventive treatment with AEDs after surgey in patients without preoperative seizures. In patients with preoperative epilepsy, AEDs should be continued after surgery. However long-term AEDs treatment should not be recommended in patients without preoperative epilepsy. In fact, no significant difference in late seizure occurrence was found between preventively treated and untreated patients. [ABSTRACT FROM AUTHOR]

Neurological derangement has been reported in haemodialysed patients receiving intravenous desferrioxamine (DFO) for aluminium-related disorders. The possible direct effects of desferrioxamine on EEG recordings were investigated in ten haemodialysed patients who underwent a DFO test 2 h after the end of dialysis. According to a commonly accepted protocol, 40 mg/kg body-weight of desferrioxamine was infused in 60 min. EEG recording was continuously performed, starting 30 min before and stopping 30 min after the desferrioxamine infusion. Besides visual inspection, EEG records were digitised, tapered, and spectrally analysed with Digital PDP 11/73 microcomputer. Basal EEG recording was normal in all patients. In three patients a progressive EEG slowing was detected by visual inspection during desferrioxamine infusion; in these cases automatic analysis revealed a 50% increase in power of slower frequencies 30 min after starting the infusion, when no changes in plasma aluminium concentrations are detected; a complete recovery was observed 30 min after desferrioxamine withdrawal. In one patient bilateral paroxysms of slow waves appeared, so we stopped desferrioxamine infusion. Two of the three patients who developed EEG abnormalities also had an increased aluminium body burden (positive DFO test).Results indicated that desferrioxamine per se can modify EEG in haemodialysis patients and that its effect is not mediated by acute increases of plasma aluminium concentrations. The finding of a positive DFO test in two of three patients with EEG changes may suggest that an aluminium-induced blood-brain barrier derangement could have played a role. However, prompt recovery after ceasing desferrioxamine infusion strongly suggests a direct role of desferrioxamine in the induction of EEG changes. These findings contribute to a better understanding of the acute impairment in neurological status when high doses of desferrioxamine are infused in haemodialysis patients with aluminium overload. [ABSTRACT FROM PUBLISHER]