A neurophysiological analysis of working memory in amyotrophic lateral sclerosis

Hammer, Anke; Vielhaber, Stefan; Rodrı́guez-Fornells, Antoni; Mohammadi, Bahram; Münte, Thomas F.

doi:10.1016/j.brainres.2011.09.010

Cited by 27 publications

(38 citation statements)

References 49 publications

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“…In agreement with these data, we observed cognitive deficits in more than 40% of our patients – predominantly but not exclusively in the form of executive dysfunctions. Moreover, comparable to earlier studies (Hammer et al, 2011; Mantovan et al, 2003; Phukan et al, 2012; Raaphorst et al, 2010), 14–21% also exhibited deficits in the memory domain.…”

Section: Discussionsupporting

confidence: 88%

“…While only a proportion of ALS patients develop actual clinical signs of frontotemporal dementia (Lomen-Hoerth et al, 2002), milder cognitive and behavioral impairments occur in up to 50% of the patients (Hammer et al, 2011; Lomen-Hoerth et al, 2002; Phukan et al, 2012; Raaphorst et al, 2010). In agreement with these data, we observed cognitive deficits in more than 40% of our patients – predominantly but not exclusively in the form of executive dysfunctions.…”

Section: Discussionmentioning

confidence: 99%

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Structural and functional hallmarks of amyotrophic lateral sclerosis progression in motor- and memory-related brain regions

Stoppel

Vielhaber

Eckart

et al. 2014

NeuroImage: Clinical

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Previous studies have shown that in amyotrophic lateral sclerosis (ALS) multiple motor and extra-motor regions display structural and functional alterations. However, their temporal dynamics during disease-progression are unknown. To address this question we employed a longitudinal design assessing motor- and novelty-related brain activity in two fMRI sessions separated by a 3-month interval. In each session, patients and controls executed a Go/NoGo-task, in which additional presentation of novel stimuli served to elicit hippocampal activity. We observed a decline in the patients' movement-related activity during the 3-month interval. Importantly, in comparison to controls, the patients' motor activations were higher during the initial measurement. Thus, the relative decrease seems to reflect a breakdown of compensatory mechanisms due to progressive neural loss within the motor-system. In contrast, the patients' novelty-evoked hippocampal activity increased across 3 months, most likely reflecting the build-up of compensatory processes typically observed at the beginning of lesions. Consistent with a stage-dependent emergence of hippocampal and motor-system lesions, we observed a positive correlation between the ALSFRS-R or MRC-Megascores and the decline in motor activity, but a negative one with the hippocampal activation-increase. Finally, to determine whether the observed functional changes co-occur with structural alterations, we performed voxel-based volumetric analyses on magnetization transfer images in a separate patient cohort studied cross-sectionally at another scanning site. Therein, we observed a close overlap between the structural changes in this cohort, and the functional alterations in the other. Thus, our results provide important insights into the temporal dynamics of functional alterations during disease-progression, and provide support for an anatomical relationship between functional and structural cerebral changes in ALS.

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Section: Discussionsupporting

confidence: 88%

Section: Discussionmentioning

confidence: 99%

Structural and functional hallmarks of amyotrophic lateral sclerosis progression in motor- and memory-related brain regions

Stoppel

Vielhaber

Eckart

et al. 2014

NeuroImage: Clinical

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“…For example, it is suggested that the presubiculum is involved in processing spatial information, which is in line with the deficits on spatial working memory tasks observed in ALS patients (Hammer et al, 2011;Jarrard et al, 2004). With respect to the other hippocampal subfields, it is important to note that no volume change of the CA1 was observed at baseline or during follow-up, which is in accordance with clinical observations.…”

Section: Discussionsupporting

confidence: 56%

Subcortical structures in amyotrophic lateral sclerosis

Westeneng

Verstraete

Walhout

et al. 2015

Neurobiology of Aging

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“…In addition to motor impairment, patients with ALS may also experience respiratory dysfunction, disrupted sleep, and fatigue [23], which in turn may limit attentional and working memory performance [24]. However, it is unclear how relevant these findings are in an applied setting; some studies reporting P300 amplitudes comparable between healthy participants and ALS patients, and others showing reduced P300 amplitudes in patients with ALS [25–27]. Similarly, some studies found prolonged latencies in ALS [27, 28], while others revealed no such difference [29, 30].…”

Section: Introductionmentioning

confidence: 99%

Circadian course of the P300 ERP in patients with amyotrophic lateral sclerosis - implications for brain-computer interfaces (BCI)

et al. 2017

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BackgroundAccidents or neurodegenerative diseases like amyotrophic lateral sclerosis (ALS) can lead to progressing, extensive, and complete paralysis leaving patients aware but unable to communicate (locked-in state). Brain-computer interfaces (BCI) based on electroencephalography represent an important approach to establish communication with these patients. The most common BCI for communication rely on the P300, a positive deflection arising in response to rare events. To foster broader application of BCIs for restoring lost function, also for end-users with impaired vision, we explored whether there were specific time windows during the day in which a P300 driven BCI should be preferably applied.MethodsThe present study investigated the influence of time of the day and modality (visual vs. auditory) on P300 amplitude and latency. A sample of 14 patients (end-users) with ALS and 14 healthy age matched volunteers participated in the study and P300 event-related potentials (ERP) were recorded at four different times (10, 12 am, 2, & 4 pm) during the day.ResultsResults indicated no differences in P300 amplitudes or latencies between groups (ALS patients v. healthy participants) or time of measurement. In the auditory condition, latencies were shorter and amplitudes smaller as compared to the visual condition.ConclusionOur findings suggest applicability of EEG/BCI sessions in patients with ALS throughout normal waking hours. Future studies using actual BCI systems are needed to generalize these findings with regard to BCI effectiveness/efficiency and other times of day.

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A neurophysiological analysis of working memory in amyotrophic lateral sclerosis

Cited by 27 publications

References 49 publications

Structural and functional hallmarks of amyotrophic lateral sclerosis progression in motor- and memory-related brain regions

Structural and functional hallmarks of amyotrophic lateral sclerosis progression in motor- and memory-related brain regions

Subcortical structures in amyotrophic lateral sclerosis

Circadian course of the P300 ERP in patients with amyotrophic lateral sclerosis - implications for brain-computer interfaces (BCI)

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