Cortical inhibitory dysfunction in epilepsia partialis continua: A high frequency oscillation somatosensory evoked potential study

ObjectiveThe pathophysiology of epilepsia partialis continua (EPC) is still unclear, a thalamo-cortical circuit dysfunction has been hypothesized.The aim of present study is the functional evaluation of the thalamo-cortical network in EPC by means of the study of low- and high-frequency somatosensory evoked potentials (LF-SEP and HF-SEP).MethodsMedian LF-SEP and HF-SEP were recorded in 3 patients with EPC and in 2 patients with rolandic lesions without EPC (non-EPC). Recording electrodes were placed on P3, C3, F3 and P4, C4, F4 of scalp regions. HF-SEP were obtained by an offline 400–800 Hz filtering of P3-F3 and P4-F4 traces.ResultsIn EPC patients, we found a significant suppression of post-synaptic HF-SEP burst and an amplitude reduction of the P24 wave of the LF-SEPs. Both these components are related to cortical inhibitory interneuron activity. HF-SEP and LF-SEP were normal in non-EPC patients.ConclusionThe different results obtained in patients with a rolandic lesion with and without EPC supports the hypothesis that EPC might be correlated to a dysfunction of gabaergic interneurons of a cortical sensory-motor network.SignificanceOur results might contribute to the understanding of the physiological basis of the cortical dysfunction causing epilepsia partialis continua.     

Altered predictive contextual processing of emotional faces versus abstract stimuli in adults with Autism Spectrum Disorder

ObjectivesWe investigated the proposition that Autism Spectrum Disorder (ASD) is associated with predictive contextual processing deficits.MethodsWe recorded electroencephalography (EEG) in adults with ASD and controls during the performance of a predictive contextual processing task, using either triangles or emotional faces. Targets were preceded by either randomized sequences (R) or by sequences including a predictive sequence (P).ResultsASD subjects showed an attenuated behavioral facilitation (P versus R) compared with controls (faces). P3b amplitudes of P, R and the predictive sequence (n-1) were attenuated in ASD compared with controls. However, the attenuation of n-1 was more pronounced during the processing of faces. Controls demonstrated shorter peak P3b latencies of P versus R, while this facilitation was absent in ASD subjects. ASD subjects demonstrated functional connectivity alterations during the processing of random (triangles and faces) and predicted targets (faces). These changes were associated with weaker, more randomised, functional connections between frontal and parietal regions in ASD.ConclusionsWe found predictive contextual processing alterations in ASD, which were more pronounced during the processing of emotional faces compared with abstract stimuli.SignificanceWe provide novel evidence for the proposition that ASD is associated with deficits of top-down predictions.     

Subthalamic and pallidal oscillatory activity in patients with Neurodegeneration with Brain Iron Accumulation type I (NBIA-I)

ObjectivesNeurodegeneration with Brain Iron Accumulation type I (NBIA-I) is a rare hereditary neurodegenerative disorder with pallidal degeneration leading to disabling generalized dystonia and parkinsonism. Pallidal or subthalamic deep brain stimulation can partially alleviate motor symptoms. Disease-specific patterns of abnormally enhanced oscillatory neuronal activity recorded from the basal ganglia have been described in patients with movement disorders undergoing deep brain stimulation (DBS). Here we studied oscillatory activity recorded from the internal globus pallidus (GPi) and the subthalamic nucleus (STN) to characterize neuronal activity patterns in NBIA-I.MethodsWe recorded local field potentials (LFP) from DBS electrodes in 6 juvenile patients with NBIA-I who underwent functional neurosurgery. Four patients were implanted in the STN and two patients in the GPi. Recordings were performed during wakeful rest. An FFT-based approach was used to analyze the power spectrum in the target area.ResultsIn all patients we found distinct peaks in the low frequency (7–12 Hz) and in 5 out 6 also in the beta frequency range (15–30 Hz) with the largest beta peak in the patient that presented with the most prominent bradykinesia. No distinct peaks occurred in the gamma frequency range (35–100 Hz). The oscillatory pattern did not differ between STN and GPi.ConclusionsHere we show for the first time the oscillatory activity pattern in the STN and the GPi in juvenile patients with dystonia plus syndrome due to NBIA-I. The low frequency peak we found is in line with previous studies in patients with isolated idiopathic dystonia. In our cohort, the pallidal beta band activity may be related to more severe motor slowing in dystonia plus syndrome such as NBIA-I.SignificanceOur results further support the link between hyperkinetic motor symptoms such as dystonia and enhanced basal ganglia low frequency activity irrespective of the underlying etiology of dystonia.     

The impact of accelerated high frequency rTMS on brain neurochemicals in treatment-resistant depression: Insights from 1H MR spectroscopy

Objective

Although accelerated repetitive transcranial magnetic stimulation (rTMS) designs seem to be able to alleviate mood over a relatively short period of time, no studies yet examined the cellular effects on neurochemicals with regard to working mechanisms, safety and neural integrity.

Assessment of the technical usability and efficacy of a new portable dry-electrode EEG recorder: First results of the HOMEONE study

ObjectivesThe HOME project is intended to provide evidence of diagnostic and therapeutic yield of a patient-controlled EEG home-monitoring for neurological outpatients.MethodsThis study evaluated the technical and practical usability and efficacy of a new portable dry-electrode EEG recorder in comparison to conventional EEG devices based on technical assessments and inter-rater comparisons of EEG record examinations of office-based practitioners and two experienced neurologists.ResultsThe technical assessment was based on channel-wise comparisons of band power values derived from power spectra as observed in two recording modalities. Slight yet significant differences were observed only in the Delta-frequency band (1.5–4 Hz). The fraction of automatically detected artifact segments was larger in the new portable recordings than in conventional recordings (20% vs. 11%, median). Overall, 93% of raters’ stated diagnostic findings gathered from conventional devices were concordant with stated diagnostic findings gathered from the new portable device.ConclusionThe new EEG device was shown to have technical comparability to and a high concordance rate of diagnostic findings with conventional EEG devices.SignificanceThe new portable dry-electrode EEG device is suitable to meet the HOME projects’ goal of establishing a patient-controlled EEG home-monitoring in the routine care of neurological outpatients.Trial registrationDRKS DRKS00012685. Registered 09 August 2017, retrospectively registered.     

Identification of small intensely fluorescent (SIF) cells as chromaffin cells in bullfrog sympathetic ganglia.

Small intensely fluoresent (SIF) cells were investigated in the ninth and tenth paravertebral sympathetic ganglia of the bullfrog using histochemical and electron microscopic techniques. Fluorescence histochemistry revealed that clusters of SIF cells are sparsely distributed in the ninth and tenth ganglia; the clusters were usually located in the vicinity of blood vessels. Fluorescent processes were not observed emanating from SIF cells. The clusters stained positively for the chromaffin reaction indicating that SIF cells are chromaffin cells. Ultrastructurally, the SIF-chromaffin cells in the sympathetic ganglia appeared virtually identical to the chromaffin cells in the adrenal gland; this includes two cell types that appear morphologically the same as the epinephrine and norepinephrine containing chromaffin cells in the adrenal gland. Efferent synapses from the SIF-chromaffin cells in sympathetic ganglia to sympathetic ganglia to sympathetic neurons were not observed. The SIF-chromaffin cells in bullfrog sympathetic ganglia did not have the morphological characteristics of interneurons; it is suggested that they may function as extra-adrenal chromaffin tissue.     

De novo variant in SCN4A causes neonatal sodium channel myotonia with general muscle stiffness and respiratory failure

Variants of the skeletal muscle sodium channel gene SCN4A are associated with different neuromuscular disorders including sodium channel myotonia. Here, we report an infant with a de novo variant in SCN4A presenting with neonatal onset of severe muscle stiffness with involvement of facial and eyelid muscles, and life-threatening events with respiratory failure due to severe apnoea and thorax rigidity. The boy dramatically improved in both respiratory and motor function under carbamazepine therapy.     

Neurodevelopmental disorders in children with macrocephaly: A prevalence study and PTEN gene analysis

Purpose

To clarify the relationship between macrocephaly and neurodevelopmental disorders, as well as identify the prevalence of PTEN mutations in autism spectrum disorders with macrocephaly in Japan.

The effects of 7-week cognitive training in patients with vascular cognitive impairment,no dementia (the Cog-VACCINE study): A randomized controlled trial

IntroductionEvidence for the efficacy of cognitive training in patients with subcortical vascular cognitive impairment no dementia is still lacking.MethodsA randomized, active controlled design using multidomain, adaptive, computerized cognitive training for 30 minutes, 5 days/week for 7 weeks. Assessments included global cognitive function and executive function (primary outcomes) and brain functional connectivity and structural changes (secondary outcomes).ResultsSixty patients were randomized across three medical centers in Beijing. At the end of the intervention, the cognitive training group showed significant improvement in Montreal Cognitive Assessment relative to the active control group (P = .013) and significantly increased functional connectivity between the left dorsolateral prefrontal cortex and medial prefrontal cortex, which was significantly correlated with Montreal Cognitive Assessment change (P = .017).DiscussionComputerized cognitive training significantly improved global cognitive function, which was supported by the improved brain plasticity. Incorporation of biomarkers should be implemented in cognitive training trials.