Finger Agnosia in Alzheimer Disease

Posterior Cortical Atrophy with Right Lower Egocentric Quadrantic Neglect and Lower Vertical Allocentric Neglect

BACKGROUND/OBJECTIVES

Whereas rare cases of hemispatial visual neglect have been reported in patients with a neurodegenerative disease, quadrantic visuospatial neglect has not been described. We report a patient with probable posterior cortical atrophy who demonstrated lower right-sided quadrantic visuospatial neglect, together with allocentric vertical neglect.

METHODS/RESULTS

A 68-year-old man initially noted deficits in reading and writing. Subsequently, he developed other cognitive deficits. On vertical line bisections, he deviated upward, and on horizontal line bisections, he deviated to the left. These deviations together suggest that this man's neglect might be most severe in his right (head/body-centered) lower (below eye level) visual space. When attempting to perform vertical line bisections in all four egocentric quadrants, his upward deviations were largest in the right lower quadrant. On a cancelation test, he revealed bilateral lower (ventral) allocentric neglect but not egocentric neglect. This patient's magnetic resonance imaging revealed cortical atrophy, most prominent in the left parietal lobe.

DISCUSSION

Previous research in stroke patients has demonstrated that the parietal lobes are important in mediating attention to contralateral and inferior visual space. The presence of left parietal atrophy may have induced this right lower (ventral) egocentric inattention as well as bilateral ventral allocentric inattention. Although to our knowledge there have been no prior reports of a patient with right lower quadrantic and lower vertical allocentric visuospatial neglect, patients are rarely tested for these forms of neglect, and this patient illustrates the importance of evaluating patients for these and other forms of neglect.

Finger agnosia and cognitive deficits in patients with Alzheimer's disease

The purpose of this study was to examine the presence of finger agnosia in patients with Alzheimer's disease (AD) and to determine if level of finger agnosia was related to cognitive impairment. Finger agnosia is a sensitive measure of cerebral impairment and is associated with neurofunctional areas implicated in AD. Using a standardized and norm-referenced approach, results indicated that patients with AD evidenced significantly decreased performance on tests of bilateral finger agnosia compared with healthy age-matched controls. Finger agnosia was predictive of cognitive dysfunction on four of seven domains, including: Crystallized Language, Fluid Processing, Associative Learning, and Processing Speed. Results suggest that measures of finger agnosia, a short and simple test, may be useful in the early detection of AD.