Multifocal visual-evoked potentials in patients with schizophrenia during treatment

Role of Multifocal Visually Evoked Potential as a Biomarker of Demyelination, Spontaneous Remyelination, and Myelin Repair in Multiple Sclerosis

Multiple sclerosis (MS) is a complex disease of the central nervous system (CNS), characterized by inflammation, demyelination, neuro-axonal loss, and gliosis. Inflammatory demyelinating lesions are a hallmark of the disease. Spontaneous remyelination, however, is often incomplete and strategies that promote remyelination are needed. As a result, accurate and sensitive in vivo measures of remyelination are necessary. The visual pathway provides a unique opportunity for in vivo assessment of myelin damage and repair in the MS-affected brain since it is highly susceptible to damage in MS and is a very frequent site of MS lesions. The visually evoked potential (VEP), an event-related potential generated by the striate cortex in response to visual stimulation, is uniquely placed to serve as a biomarker of the myelination along the visual pathway. The multifocal VEP (mfVEP) represents a most recent addition to the array of VEP stimulations. This article provides a current view on the role of mfVEP as a biomarker of demyelination, spontaneous remyelination, and myelin repair in MS.

Classification of ADHD and BMD patients using visual evoked potential

OBJECTIVES

Children with Bipolar Mood Disorder (BMD) and those with Attention Deficit Hyperactivity Disorder (ADHD) share many clinical signs and symptoms; therefore, achieving an accurate diagnosis is still a challenge, especially in the first interview session. The main focus of this paper is to quantitatively classify the ADHD and BMD patients using their Visual Evoke Potential (VEP) features elicited from their Electroencephalogram (EEG) signals.

METHODS AND MATERIALS

In this study, 36 subjects were participated including 12 healthy ones, 12 patients with ADHD and 12 ones with BMD. The age of ADHD patients was 16.92±6.29 and for the BMD ones was 17.85±3.68. Their scalp EEG signals in the presence of visual stimulus were recorded using 22 silver electrodes located according to the 10-20 international recording protocol. To extract their VEP, first a preprocessing step was executed to remove the power line and movement artifacts. Afterward, the wavelet denoising and synchronous averaging were applied to the preprocessed trials in order to elicit the P100 component. To obtain interpretable features from the evoked patterns, amplitude and latency were extracted and applied to the 1-Nearest Neighbor (1NN) classifier due to the locally scattered distribution of the VEP features.

RESULTS

The evaluation was performed according to leave-one(subject)-out method and the experimental results were led to 92.85% classification accuracy which is a fairly promising achievement to distinguish the BMD, ADHD, and healthy subjects from each other.

CONCLUSION

From the physiological point of view, this result point out to the existence of significant difference in the neural activities of their visual system in the ADHD, BMD, and healthy subjects in response to a periodic optical stimulus.

Obstetric complications and neurological soft signs in male patients with schizophrenia

Bersani G, Clemente R, Gherardelli S, Bersani FS, Manuali G. Obstetric complications and neurological soft signs in male patients with schizophrenia.

Objective: The study investigated the relationship between neurological soft signs (NSS) and obstetric complications (OCs) in patients with schizophrenia.

Methods: Sixty-three male patients with schizophrenia were divided into two subgroups, based on the OCs presence or absence, which were compared in relation to NSS prevalence. After that, a Person's correlation test was performed to explore the correlation between NSS and OCs severity.

Results: The subgroup with OCs showed more NSS, but there were not significant correlations between NSS and OCs severity.

Conclusions: It seems that any OC, without distinction in typology and severity, could unspecifically impair the neurodevelopment and inducing NSS expression. Our findings confirm the hypothesis that neurodevelopment alterations, such as those probably induced by OCs, can contribute to a premorbid brain dysfunctional state expressed by NSS.