Freezing of gait is an early clinical feature of progressive supranuclear palsy

BACKGROUND AND AIM Early clinical diagnosis of progressive supranuclear palsy (PSP) remains challenging. AIM We attempted to identify any sign or symptom to diagnose PSP earlier. METHODS A total of 401 patients, 40 with PSP and 361 with other neurodegenerative disorders, were included. We followed these patients for at least 1 year since 2009. We reviewed the signs and symptoms of patients with PSP in a standardized manner, and observed four manifestations: "vertical supranuclear gaze abnormality," "movement disorders," "pseudobulbar palsy" and "dementia of frontal type." Features, such as symmetric parkinsonism, freezing of gait, postural instability, dysarthria and/or dysphagia, or dementia of frontal type, were considered core clinical features. RESULTS In patients with PSP, "movement disorders" was the most common manifestation, whereas "vertical supranuclear gaze abnormality" was uncommon during the early disease course. A total of 16 patients fulfilled the National Institute for Neurological Disorders and Stroke and Society for PSP criteria for possible PSP at their first clinic visit. Of the remaining 24 patients, 15 presented with one or more core clinical features before fulfilling the criteria for possible PSP; nine patients had a clinical diagnosis of PSP but never fulfilled the criteria. A total of 49 of the 361 patients with other neurodegenerative disorders had core clinical features. A comparison showed that freezing of gait differentiated the groups the best over the disease course. CONCLUSION Freezing of gait is an early feature that might improve the clinical diagnosis of PSP, whereas vertical supranuclear gaze abnormality is not.