Search tips
Search criteria

Results 1-2 (2)

Clipboard (0)

Select a Filter Below

Year of Publication
Document Types
1.  Novel brain imaging approaches to understand acquired and congenital neuro-ophthalmological conditions 
Current opinion in neurology  2014;27(1):92-97.
Purpose of review
The arrival of large datasets and the on-going refinement of neuroimaging technology have led to a number of recent advances in our understanding of visual pathway disorders. This work can broadly be classified into two areas, both of which are important when considering optimal management strategies. The first looks at delineation of damage, teasing out subtle changes to (specific components of) the visual pathway, which may help evaluate severity and extent of pathology. The second uses neuroimaging to investigate neuroplasticity, via changes in connectivity, cortical thickness, and retinotopic maps within the visual cortex.
Recent findings
Here we give consideration to both acquired and congenital patients with damage to the visual pathway, and how they differ. Congenital disorders of the peripheral visual system can provide insight into the large-scale reorganisation of the visual cortex: these are investigated with reference to disorders of the optic chiasm and anophthalmia (absence of the eyes). In acquired conditions, we consider recent work describing patterns of degeneration, both following single insult and in neurodegenerative conditions. We also discuss developments in functional neuroimaging, with particular reference to work on hemianopia and the controversial suggestion of cortical reorganisation following acquired retinal injury.
Techniques for comparing neuro-ophthalmological conditions with healthy visual systems provide sensitive metrics to uncover subtle differences in gray and white matter structure of the brain. It is now possible to compare the massive reorganisation present in congenital conditions with the apparent lack of plasticity following acquired damage.
PMCID: PMC3983755  PMID: 24300791
hemianopia; optic chiasm; neuroimaging; fMRI; blindness
2.  Fornix microstructure correlates with recollection but not familiarity memory 
The fornix is the main tract between the medial temporal lobe (MTL) and medial diencephalon, both of which are critical for episodic memory. The precise involvement of the fornix in memory, however, has been difficult to ascertain since damage to this tract in human amnesics is invariably accompanied by atrophy to surrounding structures. We used diffusion-weighted imaging to investigate whether individual differences in fornix white matter microstructure in neurologically healthy participants were related to differences in memory as assessed by two recognition tasks. Higher microstructural integrity in the fornix tail was found to be associated with significantly better recollection memory. In contrast, there was no significant correlation between fornix microstructure and familiarity memory or performance on two non-mnemonic tasks. Our findings support the idea that there are distinct MTL-diencephalon pathways that subserve differing memory processes.
PMCID: PMC2825810  PMID: 19940194
Recognition Memory; Fornix; Hippocampal function; Memory; Hippocampus; Imaging

Results 1-2 (2)