PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-4 (4)
 

Clipboard (0)
None

Select a Filter Below

Journals
Year of Publication
Document Types
1.  Anti-saccade performance predicts executive function and brain structure in normal elders 
Objective
To assess the neuropsychological and anatomical correlates of anti-saccade (AS) task performance in normal elders.
Background
The AS task correlates with neuropsychological measures of executive function and frontal lobe volume in neurological diseases, but has not been studied in a well-characterized normal elderly population. Because executive dysfunction can indicate an increased risk for cognitive decline in cognitively normal elders, we hypothesized that AS performance might be a sensitive test of age-related processes that impair cognition.
Method
The percentage of correct AS responses was evaluated in forty-eight normal elderly subjects and compared with neuropsychological test performance using linear regression analysis and gray matter volume measured on MRI scans using voxel-based morphometry.
Results
The percentage of correct AS responses was associated with measures of executive function, including modified trails, design fluency, Stroop inhibition, abstraction, and backward digit span, and correlated with gray matter volume in two brain regions involved in inhibitory control: the left inferior frontal junction and the right supplementary eye field. The association of AS correct responses with neuropsychological measures of executive function was strongest in individuals with fewer years of education.
Conclusions
The AS task is sensitive to executive dysfunction and frontal lobe structural alterations in normal elders.
doi:10.1097/WNN.0b013e318223f6c6
PMCID: PMC3775477  PMID: 21697711
anti-saccade; normal aging; executive function; frontal lobe; cognitive reserve
2.  Saccade abnormalities in autopsy-confirmed frontotemporal lobar degeneration and Alzheimer’s disease 
Archives of neurology  2012;69(4):509-517.
Objective
Deficits in the generation and control of saccades have been described in clinically-defined frontotemporal dementia (FTD) and Alzheimer’s disease (AD). Because clinical FTD syndromes can correspond to a number of different underlying neuropathologic FTD and non-FTD diagnoses, we sought to determine the saccade abnormalities associated with autopsy-defined cases of FTLD and AD.
Participants and design
An infrared eye tracker was used to record visually guided saccades to ten degree targets and antisaccades in 28 autopsy-confirmed FTD and 10 AD subjects, an average of 35.6 ± 10 months prior to death and 27 age-matched normal controls (NC). 12 FTD subjects had FTLD-TDP pathology, 15 had FTLD-tau pathology and one showed FTLD-FUS pathology. Receiver operating curve (ROC) statistics were used to determine diagnostic value of oculomotor variables. Neuroanatomical correlates of oculomotor abnormalities were investigated using voxel-based morphometry (VBM).
Results
All FTD and AD subjects were impaired relative to NC on the antisaccade task. However, only FTLD-tau and AD cases displayed reflexive visually-guided saccade abnormalities. AD cases displayed prominent increases in horizontal saccade latency that differentiated them from FTD cases. Impairments in velocity and gain were most severe in individuals with Progressive Supranuclear Palsy (PSP) but were also present in other tauopathies. Vertical and horizontal saccade velocity and gain were able to differentiate PSP cases from other patients. Vertical saccade velocity was strongly correlated with dorsal midbrain volume.
Conclusion
Decreased visually-guided saccade velocity and gain are suggestive of underlying tau pathology in FTD, with vertical saccade abnormalities most diagnostic of PSP.
doi:10.1001/archneurol.2011.1021
PMCID: PMC3423186  PMID: 22491196
Frontotemporal Dementia; Corticobasal Degeneration; Progressive Supranuclear Palsy; Ocular Motility
3.  Clinical, neuroimaging and neuropathological features of a new chromosome 9p-linked FTD-ALS family 
Background
Frontotemporal dementia-amyotrophic lateral sclerosis (FTD-ALS) is a heritable form of FTD, but the gene(s) responsible for the majority of autosomal dominant FTD-ALS cases have yet to be found. Previous studies have identified a region on chromosome 9p that is associated with FTD and ALS.
Methods
The authors report the clinical, volumetric MRI, neuropathological and genetic features of a new chromosome 9p-linked FTD-ALS family, VSM-20.
Results
Ten members of family VSM-20 displayed heterogeneous clinical phenotypes of isolated behavioural-variant FTD (bvFTD), ALS or a combination of the two. Parkinsonism was common, with one individual presenting with a corticobasal syndrome. Analysis of structural MRI scans from five affected family members revealed grey- and white-matter loss that was most prominent in the frontal lobes, with mild parietal and occipital lobe atrophy, but less temporal lobe atrophy than in 10 severity-matched sporadic bvFTD cases. Autopsy in three family members showed a consistent and unique subtype of FTLD-TDP pathology. Genome-wide linkage analysis conclusively linked family VSM-20 to a 28.3 cM region between D9S1808 and D9S251 on chromosome 9p, reducing the published minimal linked region to a 3.7 Mb interval. Genomic sequencing and expression analysis failed to identify mutations in the 10 known and predicted genes within this candidate region, suggesting that next-generation sequencing may be needed to determine the mutational mechanism associated with chromosome 9p-linked FTD-ALS.
Conclusions
Family VSM-20 significantly reduces the region linked to FTD-ALS on chromosome 9p. A distinct pattern of brain atrophy and neuropathological findings may help to identify other families with FTD-ALS caused by this genetic abnormality.
doi:10.1136/jnnp.2009.204081
PMCID: PMC3017222  PMID: 20562461
4.  Visual search patterns in semantic dementia show paradoxical facilitation of binding processes 
Neuropsychologia  2011;49(3):468-478.
While patients with Alzheimer’s disease (AD) show deficits in attention, manifested by inefficient performance on visual search, new visual talents can emerge in patients with frontotemporal lobar degeneration (FTLD), suggesting that, at least in some of the patients, visual attention is spared, if not enhanced. To investigate the underlying mechanisms for visual talent in FTLD (behavioral variant FTD [bvFTD] and semantic dementia [SD]) patients, we measured performance on a visual search paradigm that includes both feature and conjunction search, while simultaneously monitoring saccadic eye movements. AD patients were impaired relative to healthy controls (NC) and FTLD patients on both feature and conjunction search. BvFTD patients showed less accurate performance only on the conjunction search task, but slower response times than NC on all three tasks. In contrast, SD patients were as accurate as controls and had faster response times when faced with the largest number of distracters in the conjunction search task. Measurement of saccades during visual search showed that AD patients explored more of the image, whereas SD patients explored less of the image before making a decision as to whether the target was present. Performance on the conjunction search task positively correlated with gray matter volume in the superior parietal lobe, precuneus, middle frontal gyrus and superior temporal gyrus. These data suggest that despite the presence of extensive temporal lobe degeneration, visual talent in SD may be facilitated by more efficient visual search under distracting conditions due to enhanced function in the dorsal frontoparietal attention network.
doi:10.1016/j.neuropsychologia.2010.12.039
PMCID: PMC3046767  PMID: 21215762
Alzheimer’s disease; frontotemporal dementia; conjunction search; voxel-based morphometry; eye movements

Results 1-4 (4)