Quantitative assessment of impairment in constructional ability by cube copying in patients with aphasia.

Constructional apraxia was evaluated in patients with aphasia using a cube-copying task. It was assessed whether quantitative assessment of cube copying could be used to estimate the performance intelligence quotient (IQ) according to neuropsychological tests. Abnormality in the cube-copying test was observed in 42 of 46 patients (91.3%). Performance according to Raven's coloured progressive matrices and the revised Wechshler adult intelligence scale (WAIS-R) in patients with poor cube copying was significantly lower than in the other four patients. Numbers of the connections completed and plane-orientation errors made in the cube-copying test were significantly correlated with performance IQ on the WAIS-R, correlating particularly with block design, digit symbol, and object assembly in performance IQ subtests. The quantitatively scored cube-copying test, then, can roughly predict non-verbal IQ in patients with aphasia.