Recognition memory deficits in amyotrophic lateral sclerosis assessed with event-related brain potentials

Abstract

Objectives ‐ Amyotrophic lateral sclerosis (ALS) has been shown to cause neuropsychological deficits. The present investigation sought to delineate memory deficits by recording cognitive event‐related potentials (ERPs). Subjects and methods ‐ Eight ALS patients and 8 matched controls were subjected to a 2‐phase recognition memory test. During the first phase words were presented consecutively on a video‐screen with one‐third of the words being repeated. The subject had to press buttons according to whether a word had been repeated or not. During the second phase (delay 1 h) a second list containing 33% old items from phase 1 and 66% new words was shown with an old/new decision required. Results ‐ ALS patients showed less accurate recognition in the second phase. The ERPs of the controls showed a reliable difference between old and new items in both phases. This difference was nearly absent in the patients in both phases. Conclusion ‐ The ERP pattern suggests abnormal memory processes in ALS. The results are compared with data from similar experiments in Huntington's and Alzheimer's disease and are interpreted in terms of an encoding deficit in ALS.

Memory deficits in amyotrophic lateral sclerosis are not exclusively caused by executive dysfunction: a comparative neuropsychological study of amnestic mild cognitive impairment

“…Although this was an experimental set up, results can be compared to the recognition test that was used in this study (RAVLT). Similar to our observations, Muente et al [50] reported a recognition deficit in patients with ALS that was related to an absent recognition associated event-related potential. Interestingly, this effect was not observed in patients with Alzheimer's Disease which completed a comparable task [54].…”

“…However, given the results yielded in the present study, memory deficits in ALS seem to be disease specific and can be differentiated from other neurodegenerative diseases such as AD when assessed specifically. Recognition deficits in patients with ALS were found the most obvious memory deficit and have been reported before [17,50], although such deficits have been mostly associated with executive dysfunction [17,29]. In our cohort, executive impairment could only account for 20.5% of memory performance in ALS, which supports the emerging notion that executive function is only one of several cognitive domains impaired in ALS [7,16].…”

“…Thus, recognition judgements can be based on the recollection of details about previous events or on the assessment of stimulus familiarity [53]. In ALS, only one study so far investigated recognition memory and its underlying neuronal mechanisms [50]. The paradigm consisted of a verbal recognition task, where the subjects had to decide whether a word was presented before or not.…”

Frontotemporal dementia and motor neurone disease: Overlapping clinic-pathological disorders

“…63,64 Memory problems involve primarily immediate recall, 49,65 but visual memory also has been implicated. 53,66 In a cohort of 146 sporadic MND cases, 20% of the patients performed below cut off (5th percentile) on the California Verbal Learning Test, with difficulties on the free recall learning trials, meanwhile on the Delayed Verbal Recognition Memory Test the performance was good.…”

A Review on Effect of Physical Activity as an Exogenous Factor and Cognitive Change in Motor Neuron Disease

“…[16] "Furthermore, a study using event-related brain potentials revealed that recognition memory deficiencies were caused by poor encoding rather than poor retention over time, which is consistent with a frontal lobe interpretation." [17] "The findings show no evidence of faster forgetting in patients than in controls, but they do point to a problem with initial information assimilation. These memory results, along with those from previous investigations, are consistent with an interpretation based on poor encoding mechanisms as a result of frontal lobe dysfunction.…”