Dementia in Elderly Outpatients: A Prospective Study

Abstract

We prospectively studied the evaluation of dementia in 107 unselected outpatients; 83 had so-called "irreversible" dementias, including 74 who had an Alzheimer-type dementia. Fifteen patients had potentially reversible dementias, of which hypothyroidism and drug toxicity were the commonest causes. Distinguishing features of reversible dementia were shorter duration, use of more prescription drugs, and less severe dementia. Almost half of the patients had other previously unrecognized treatable medical diseases. Most diagnoses were made from patient history and physical and mental status examination. Patients with reversible dementia improved but rarely reverted to normal. Objective improvement occurred in 25 patients after treating unrecognized coexistent medical and psychiatric diseases, or stopping unnecessary medication. Careful clinical observation is the most useful part of the evaluation and extensive testing may not be required for all patients. Overemphasis on distinguishing reversible from irreversible forms of dementia may detract from recognition of commoner, treatable causes of dysfunction and suffering.

The Recognition, Assessment and Management of Dementing Disorders: Conclusions from the Canadian Consensus Conference on Dementia

“…A structured clinical approach will help to establish the presence of dementia and enable the physician to distinguish underlying causes, including the presence of reversible conditions which may aggravate or even cause cognitive decline. 17,18 Substance abuse, adverse drug effects, depression, metabolic disorders and systemic illnesses are among the most common of these. 19,20 The history should describe onset, duration and evolution of symptoms and precipitating factors such as stroke.…”

Differential Diagnosis of Idiopathic Normal Pressure Hydrocephalus from Other Dementias Using Diffusion Tensor Imaging

“…1,2 Accurate diagnosis of normal pressure hydrocephalus is important, however, because it is a treatable cause of dementia. Although patients with normal pressure hydrocephalus usually present with a triad of typical symptoms and signs, such as gait disturbance, progressive cognitive impairment, and urinary incontinence, the clinical decision as to whether a patient with INPH would benefit from shunt surgery is challenging.…”

“…Although morphologic patterns seen with CT and MR imaging have been investigated, including increased Evans index, less sulcal enlarge-ment, white matter signal-intensity change, and aqueductal flow void, the role of structural neuroimaging in selecting surgical candidates has remained limited. 5 More recently, various cerebral perfusion-imaging methods, including cerebral angiography, xenon-enhanced CT, technetium Tc99m-hexamethylpropyleneamine oxime SPECT, iodine 123 N-isopropyl-p-iodoamphetamine-SPECT, perfusion-weighted MR imaging, and H 2 15 O positron-emission tomography, have shown positive correlations between increased cerebral blood flow and clinical improvement after CSF shunt surgery. [6][7][8] These methods, however, cannot differentiate INPH from subcortical vascular dementia, which can clinically mimic INPH despite its distinct pathologic features.…”

Systematic Review of Clinical Prediction Rules for Neuroimaging in the Evaluation of Dementia

“…Of the 57 articles obtained for in-depth review, 7 met eligibility criteria for inclusion in this analysis 13,14,16,17,[20][21][22][23][28][29][30][31] ( Table 2). One study evaluated 4 different prediction rules with the use of the same patient population, 13 whereas another study compared 2 prediction rules in the same patient population.…”