[Reversible dementia in neurology outpatient clinics]

The dementias are one of the commonest conditions seen in Neurology Clinics. Potentially reversible causes are described amongst the various aetiologies although there are doubts as to whether the use of indiscriminate testing to detect them is worthwhile.

In a group of demented persons to determine how many had a potentially reversible condition and how many improved, in a prospective, descriptive study in a Neurology Outpatient Clinic.

Using the Mini-Mental State Examination of Folstein and the DSM-III-R criteria for dementia, 121 demented patients were selected. An ordinary biochemical study was made (vitamin B12, thyroid hormones), serology (lues) and neuroimaging (cerebral CT), and when a potentially reversible condition was found, each case was treated. The patients treated were followed-up periodically for an average of 9.6 months (range 2 to 24 months).

A potentially reversible condition was seen in 19.8% of the patients. On prospective evaluation only 3.3% had reversible symptoms and in no case were these completely reversed. Improvement was seen in conditions of depressive pseudo-dementia.

Since some causes of dementia are reversible, the neurologist is obliged to investigate and seek these possible aetiologies. This study should be individualized according to clinical criteria to improve profitability of the complementary tests. Our results suggest that there are doubts as to the usefulness of indiscriminate investigation of possible reversible causes of the cases of dementia referred to Outpatient neurologists.