Freezing phenomenon in patients with parkinsonian syndromes.

Freezing is a common symptom in parkinsonian syndromes, but its association with different causes of parkinsonism as well as with other symptoms has never been investigated. We conducted a database survey of the occurrence of freezing in parkinsonism. Of 347 patients with a clinical diagnosis of parkinsonism other than idiopathic Parkinson's disease and with specific data regarding freezing, 158 patients had freezing (46%). Freezing was significantly associated with progression of the disease as rated on the Hoehn & Yahr scale [odds ratio (OR), 1.69; p < 0.004]. Gender was not a risk factor for the development of freezing. Patients with drug-induced parkinsonism were at a very low risk for developing freezing (p < 0.00001; OR, 0.1). Freezing was found in a high frequency in patients with vascular parkinsonism (57%), normal-pressure hydrocephalus (56%), and generally in the group of patients who had parkinsonism resulting from neurodegenerative diseases (progressive supranuclear palsy, multiple system atrophy, and corticobasal ganglionic degeneration; 45%). Freezing was significantly associated with the presence of dementia, incontinence, and tachyphemia (OR, 2.01, 1.7, and 5.09, respectively).