They found that patients with the bulbar-onset type showed marked prolongation of P3 latency
compared to patients with the limb-onset type and controls. Furthermore, correlation studies revealed that the relative bulbar functional rating scale correlated with prolonged P3 latency and low P3 amplitude. These results further suggested that patients with bulbar-onset ALS had consistently poorer cognitive test performance than those with Inhibitors,research,lifescience,medical limb-onset ALS (Schreiber et al. 2005). In addition, a significant correlation was found between the respiratory function tests and P3 amplitude, by suggesting that ventilatory impairment overrides cognitive impairment caused by the disease itself. The described evidences with regard to the P300 component of the ERPs in ALS patients suggest the presence of an impairment of novelty detection mechanisms, which are associated with the dorsofrontal–orbitofrontal Inhibitors,research,lifescience,medical and anterior cingulate cortices. Such results confirm the dysfunction of the frontal network in ALS, according to neuropsychological, neuroimaging, neuropathological, and genetic evidences and with the hypothesis of an overlapping between ALS and FTD. The discussed abnormalities in brain structures and functions and in LEE011 mouse psychophysiology
observed in ALS, which turn into an impaired cognitive profile in a consistent Inhibitors,research,lifescience,medical proportion of patients, apparently represent a challenge for the use of P300 as an input signal in BCIs. However, some studies have investigated this issue, providing encouraging results against the hypothesis of a generalized “ALS illiteracy.” Inhibitors,research,lifescience,medical In particular, (Kübler and Birbaumer 2008) investigated the relationship between the level of motor and physical impairment and the ability to use brain computer interface, by comparing three different Inhibitors,research,lifescience,medical BCI systems (P300, SCP, and sensorimotor rhytms [SMRs]). They found no continuous decrement in BCI performance with physical decline, even if in completed locked in state (CLIS) no communication was possible. According to these evidences, the major challenge remains the use of BCI-based systems with CLIS patients, who have the
greatest need for a BCI in order to communicate. Cognitive assessment of ALS and locked-in syndrome (LIS) patients through BCI-based AAC systems BCIs have been studied with the primary motivation of providing assistive technologies for people with severe motor disabilities, particularly locked-in syndrome (LIS) caused by neurodegenerative disease such as ALS 4-Aminobutyrate aminotransferase or by stroke. These patients are conscious and alert but they are unable to use their muscles and therefore can not communicate neither vocally nor by writing (Kubler et al. 2001b). In LIS, vertical eye movements and eye blinks are spared while in the complete LIS (CLIS) patient lose any control of the eye muscular response. BCI usually requires a training that can be physically and emotionally very exhausting for patients, especially when they show some degree of cognitive impairment.