Neuroimaging guidelines in cognitive impairment: lessons from 3 cases of meningiomas presenting as isolated dementia

We report three cases of large intracranial meningiomas who presented with dementia alone and no accompanying focal neurological deficits. The meningiomas were detected solely as a result of a policy of routinely scanning the brains of patients presenting with early dementia. Dramatic improvements in the cognitive functions were noted following the excision of the tumours in two of the patients (the third passed away in the perioperative period). The implications of these cases with regard to deciding when to order a brain scan for patients presenting with isolated dementia are discussed in this article and a brief review of the relevant medical literature on this topic is also presented.