Alteration of early components of the visual evoked potential in amyotrophic lateral sclerosis

Abstract

Evoked potentials were recorded in three different visual experiments in 14 patients with amyotrophic lateral sclerosis (ALS) and 14 matched control subjects. Control subjects' evoked potentials (EPs) were characterized by an initial positivity in the 90-140 ms range (P1) at the temporo-occipital site. This component was absent from the group average of the ALS patients as well as the individual patients' EPs. As the P1 is known to emanate from inferior occipito-temporal areas, this finding provides electrophysiological evidence for a cortical involvement in ALS including visual areas.

Differential Loss of Prolyl Isomerase or Chaperone Activity of Ran-binding Protein 2 (Ranbp2) Unveils Distinct Physiological Roles of Its Cyclophilin Domain in Proteostasis

“…Hence, even though the PPIase activity of CY of Ranbp2 regulates the proteostasis of hnRNPA2/B1 without impairing their nucleocytoplasmic shuttling, it is likely that other domains and partners of Ranbp2 modulate this shuttling process (63). Finally, ALS patients also present profound changes in VEPs before the clinical onset of motor symptoms ensue (107). Thus, it will be important to find whether similar or analogous Ranbp2-dependent pathomechanisms are shared between ganglionic retinal and motor neurons and the contribution of other factors modulated by Ranbp2, such as HDAC4, to disease expression.…”

“…Disturbances in transmission through this pathway are manifested in neurodegenerative diseases, such as ALS, multiple sclerosis, optic atrophies, and several retinopathies (107)(108)(109)(110). We examined cone and rod photoreceptor functions by light-and dark-adapted ERGs and transmission through the visual pathway, including retinal ganglion cells, in VEPs.…”

The brain–computer interface cycle

“…One consideration is that a system, which is designed and tested for healthy subjects, does not necessarily generalize to the patient population. For example, some studies have reported that about 45% of patients suffering from ALS reveal some form of cognitive impairment [94,95] as well as modified EEG signatures [96]. A possible reason for this cognitive impairment may be the enduring immobility, but the disease may also have effects on brain functioning that have not yet been properly clarified [97].…”

Degeneration of the Human Nervous System and Magnetic Resonance Neuroimaging

“…This increase in activity was correlated with loss of movement ability: The higher the physical restrictions were, the higher was the activity in those areas of third order sensory processing in ALS patients (Figure 3). Structural analysis of white matter integrity in this study measured with DTI provided evidence for a disruption of sensory nerve fibres in those ALS patients (Lulé et al, 2010 Auditory processing underlying stimulus detection measured by MEG and subsequent memory-based comparison processes were abnormal in ten ALS patients with bulbar signs (Pekkonen et al, 2004), and a reduced response to auditory and visual stimuli was observed in ALS patients compared to healthy controls using EEG (Münte et al, 1998;Vieregge et al, 1999). This finding may indicate a changed sensory processing capacity as well as reduced attention capacity (Pinkhardt et al, 2008), an ability assigned to the frontal cortex known to be involved in ALS (Ludolph et al, 1992;Kew et al, 1993b).…”