Spatial Perseveration in Dementia with Lewy Bodies

An 80 y.o. right-handed man presented with a left bradykinesia, cognitive fluctuations, unexplained falls, disrupted sleep, complex visual hallucinations and delusions evolving for 10 months. Instrumental activities of daily living were impaired for finances and shopping abilities. He was alert, oriented and very slow. On neurological exam, he had a positive glabellar response and left predominant akinetorigid syndrome. Mini Mental Status Examination was 20/30. The clock drawing test (CDT Fig. 1A), and subsequent writing (Fig. 1B), disclosed a peculiar type of perseveration that was apparently restricted to the compulsion to reproduce spatial representational schemas (draw a circle etc). Extensive neuropsychological testing demonstrated attentional, executive, visuospatial and episodic memory deficits. Moderate corticosubcortical atrophy was noted on MRI. Final diagnosis met all criteria for probable dementia with Lewy bodies (DLB) [1]. The CDT is quick to administer, relatively independent of culture, language and education, easy to score for research purposes [2], and valid as a screening tool for moderate to severe cognitive impairment in older adults [3]. Patients are asked to draw a clock-face, showing all the numbers, and the hands to set the clock