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Correspondence to: Dr L R Moo †, Department of Neurology, Johns Hopkins University, 600 N Wolfe Street, Meyer 100, Baltimore, MD, USA; [email protected]
Formal neurocognitive test batteries provide invaluable information regarding specific cognitive domains, allow for comparison to established norms, and reveal patterns of deficits consistent with a variety of neurological diagnoses. Their use is often limited because they require a trained person and lengthy time to administer. Simple screening tests that can be incorporated into the bedside or office based neurological examination are useful if they ascertain whether or not more detailed investigations are indicated.
While a general impression regarding level of consciousness, orientation, and language can often be made while taking a history, casual assessment of functions predominantly subserved by the parietal lobes is more difficult. A variety of formal cognitive tests can assess parietal lobe function, and typically include visual-constructional tasks (for example, Rey-Osterrieth Complex Figure, drawing interlocking polygons (as on the MMSE), clock drawing/setting), visual perceptual tasks (for example, time perception, Benton Judgement of Line orientation, Ravens Progressive Matrices, Hooper Visual Organization test), right-left orientation, and arithmetic/calculations (WAIS-R performance subtest).1 However, most of these tests require considerable time and expertise to administer in addition to equipment that may not be available in a clinic or emergency department setting.
Imitation of finger and hand figures has been used to test visual-spatial skills,2–5 although without clear anatomical localisation or correlations to other standardised tests. Non-symbolic gesture imitation is frequently used as it has been shown to be impaired more frequently than imitation of learned gestures or those with symbolic meaning (for example, saluting, hitchhiking).4 Imitation of finger configurations specifically, in contrast with whole hand gestures, has been found to be impaired with equal frequency in both left and right brain damaged patients,6 and thus seems to have little cerebral lateralisation.
We hypothesised that a task that entails imitation of a series of finger gestures without symbolic meaning would require visual-spatial integration and correlate highly with other measures of parietal lobe function for the following reasons: (1) single cell recording results in non-human primates indicate that posterior parietal lobe structures are responsible for the integration of visual information, upper extremity movement and proprioception,7 (2) there is evidence...