Isolated dementia in two patients with posterior intraventricular meningiomas

Although patients with brain lesions of neurosurgical interest may sometimes present with a cognitive profile very similar to a primary dementia, they usually have a history and/or a neurologic examination which alert the clinician. The occurrence of mass lesions with purely isolated cognitive deterioration has been mainly reported for locations at the level of the frontal lobes. A potentially positive prognosis is advocated in these cases, in terms of even complete reversibility of the mental impairment when surgical removal is feasible and successful. We report two rare cases of posterior intraventricular meningiomas presenting with isolated cognitive and behavioural changes consistent with a frontal type dementia; the outcome was favourable in one patient, whereas the second one suffered from massive intracerebral bleeding during the neurosurgical removal and required prolonged hospitalization and subsequent intensive neurorehabilitative efforts. By comparing our cases with previously published decision-rules regarding neuroimaging in dementia, we suggest that criteria should be enlarged, especially those regarding the age of the subject and the time elapsed from the first signs of the cognitive deterioration.