The contribution of computerized tomography to the differential diagnosis of confusion in elderly patients

Two hundred and eighty elderly patients who were referred because of a principal problem of confusion were investigated by computerized tomography; 94% were suffering from a 'dementia syndrome' and unrecognized receptive dysphasia was the commonest problem in the remainder. One hundred and twenty-four patients were suffering from senile dementia of the Alzheimer type, and 79 from multi-infarct dementia. Space-occupying lesions (tumour, subdural haematoma or hygroma) were found in 32 (11%). Of the 25 with other intracranial and extracranial causes, 64% had potentially treatable lesions (PTL). In only four cases was no diagnosis made. PTL were found in 31% of 170 patients with a duration of confusion of less than a year compared with 1% of 110 patients with a longer duration. In 48 of the former group, confusion was an isolated phenomenon; 12 of these (25%) had a PTL, as had 27 of 88 with confusion and a focal neurological deficit (31%). All five patients with recognized seizures, and six of 15 of those with reduced alertness had PTL. Twenty of 37 patients with neurosurgical lesions underwent surgery.