Frontal presentation in progressive supranuclear palsy

Background: Progressive supranuclear palsy (PSP) is a progressive hypokinetic rigid disorder with supranuclear gaze palsy and frequent falls. Although clinical consensus criteria are available, an atypical presentation may lead to clinical misdiagnosis in the initial phase. In the present study we investigated the clinical presentation of PSP and its relationship to initial clinical diagnosis and survival. Methods: We ascertained patients with PSP in a prospective cohort by nationwide referral from neurologists and nursing home physicians. All patients underwent a structural interview and clinical examination before entering the study. Medical records were reviewed for the presence of symptoms during the first 2 years. Results: A total of 152 patients ascertained between 2002 and 2005 fulfilled the international consensus criteria for PSP. Categorical principal component analysis of clinical symptoms within the first 2 years showed apart from a cluster of typical PSP symptoms, the clustering of cognitive dysfunction and behavioral changes. Further analysis showed that 20% of patients had a predominant frontal presentation with less than two other PSP symptoms. Survival analysis showed that this subgroup had a similar prognosis to that of the total group of patients with PSP. Conclusions: There exists a subgroup of patients with progressive supranuclear palsy (PSP) with a predominant frontal presentation, who progressed into typical PSP over the course of the disease.