[Pattern VECPs in optic neuritis caused by multiple sclerosis].

To interpret the flash evoked potential (FVEP) as dynamic high-order responses to natural and experimental stimulation in healthy preterm infants, waveform analysis of FVEP in 36 healthy preterm infants (postconceptional age 28~42 weeks) were performed using an autoregressive analysis. Based on the histogram of damping frequency of different component impulse response waveforms, the waveforms were divided into 4 groups: group I (0 ~ <2 Hz), group II (2 ~ <6.5 Hz), group III (6.5 ~ <12.0 Hz) and group IV (12~25 Hz). The total power, power of component impulse responses (group I~IV), and damping time (group II~IV) changed significantly with increasing postconceptional age (P<0.01 or P<0.05). Identification of an impulse response component with dominant frequency which undergoes a well-identified change with age is considered to be a useful tool for discriminating between normal and abnormal changes in the FVEP with age in healthy preterm infants.

Evoked Potentials, Visual↗

PubMed2002

How distributed is visual category information in human occipito-temporal cortex? An fMRI study.

We used fMRI to study the distribution of object category information in the ventral visual pathway. Extending the findings of, we find that categories of stimuli can be distinguished by the pattern of activation they elicit across this entire pathway, even when the stimuli within a category differ in viewpoint, exemplar, or image format. However, regions within the ventral visual pathway are neither interchangeable nor equipotential. Although the FFA and PPA permit excellent discrimination between preferred versus nonpreferred stimuli (e.g., faces-bottles and houses-bottles, respectively), we find that neither region alone permits accurate discrimination between pairs of nonpreferred stimuli (e.g., bottles-shoes). These findings indicate that the ventral visual pathway is not homogeneous, but contains some regions (including FFA and PPA) that are primarily involved in the analysis of a single class of stimulus.

Evoked Potentials, Visual↗

PubMed2002

Cranial nerve lesions and abnormal visually evoked potentials associated with the M694V mutation in familial Mediterranean fever.

A 52-year-old Turkish man with familial Mediterranean fever (FMF) due to the homozygous M694V mutation in the MEFV-gene on chromosome 16p13.3, newly developed hemicrania, blurred and double vision, ptosis, ophthalmoparesis and peripheral facial nerve palsy. Except for double vision, all the other abnormalities disappeared spontaneously within 10 days after onset. Markedly prolonged latencies of the visually evoked potentials were also found. At follow-up, 8 months after onset of the neurological abnormalities, right-sided bradydiadochokinesia, right-sided discrete weakness and right-sided hypaesthesia were found. After the exclusion of other hereditary fever syndromes, migraine, stroke, Molaret's meningitis, Behçet's syndrome and mitochondriopathy by clinical, serological, CSF investigations, funduscopy, electroencephalography, and cerebral MRI and MRI angiography, the described neurological abnormalities were regarded as CNS and PNS manifestation of vasculitis or amyloidosis in FMF.

Evoked Potentials, Visual↗