Extrapyramidal symptoms and signs in Alzheimer's disease: prevalence and correlation with the first symptom

To determine the prevalence and clinical correlates of extrapyramidal signs (EPS) in outpatients with probable Alzheimer's disease (AD); to examine the appearance of EPS in association with the first symptom that led the patient or family to ask for medical help; to examine the association of the prevalence of EPS with gender, age at onset of the disease, duration of the disease, severity of dementia, functional disability, and potential use of neuroleptics; and to address the issue of the possible role of EPS as a predictive factor for the clinical course of the disease. We examined 126 patients meeting NINCDS-ADRDA* criteria for probable AD and 29 healthy, nondementia controls of comparable age and gender. Thirteen of the patients taking neuroleptics at the time of the examination were excluded from the main study group and formed a separate subgroup of AD/neuroleptics-positive. Twenty-eight of the AD/neuroleptics-free patients were re-examined during an 18-month period in order to determine the possible role of EPS as a predictive factor of the clinical course of the disease. Only 8 percent of the AD/neuroleptics-free patients were free of EPS, while the corresponding percentage in the control group was 61.5 percent. The most common types of EPS presented in the patient group were hypomimia ([facial mask] 60 percent), difficulty in talking (53.66 percent), bradykinesia (51.4 percent), postural instability (47.33 percent), abnormal gait (34.66), and rigidity (26 percent), respectively. No significant differences were found when examining for the presence of resting tremor, other tremors, dystonias, and dyskinesias. With regard to the presence of EPS and the first symptom, no significant difference was found among patients whose first complaint was memory disorder (probable AD) and patients with other symptoms. When examining the association between the prevalence of EPS and gender or age at onset of the disease, no special correlation was detected. However, such a correlation was found between the prevalence of EPS and duration of the disease, as indicated by the fact that EPS appear in 78.9 percent of the patients with a duration of illness less than two years, but in 97 percent of the patients with a corresponding duration of two years or more. The mean duration of the disease in patients appearing with EPS is found to be 2.68 +/- 1.98 years. The presence of EPS increases proportionally with the progression of the disease and cognitive and functional d