Objective: To review the available literature regarding the presence and properties of square wave jerks (SWJs) in Progressive Supranuclear Palsy (PSP) and Parkinson’s Disease (PD).
Background: Oculomotor testing is an essential component of the neurological assessment in patients with movement disorders, especially in PD and Parkinsonian syndromes. The presence of SWJs in earlier stages of disease is believed to be helpful in differentiating PSP from PD. However, little is known about the data supporting this clinical observation.
Method: We performed a systematic search using MEDLINE, Embase, Web of Science for studies describing SWJs in PD and PSP. With search terms of “((ocular fixation) OR (square wave jerk) OR (SWJ) OR (saccadic intrusions)) AND ((parkinson) OR ((PSP) OR (Progressive Supranuclear Palsy)))”. Only publications in English were reviewed.
Results: In total, 137 manuscripts were screened, seven met inclusion criteria. Among the five studies with unduplicated SWJs data, there is heterogeneity in measures used to identify SWJs, which ranged from video tape review of eye movements to infrared or video-based eye movement monitoring programs. The average study sample size was 8.5 (range: 5-12) for PSP group and 23.2 (range: 4-85) for PD group. One study (Clanet et al. 1991) showed a higher prevalence of SWJs in PSP (7/8) than in PD (13/85), while other studies focused on the characteristics of SWJs. All studies found that the average rate of SWJs (number of SWJs/minute) was higher in PSP (range: 33.8-54/minute) than in PD (range: 10.3-45/minute).
Conclusion: Data on SWJs in PSP and PD are limited and heterogeneous. The presence and frequency of SWJs may potentially act as a clinical biomarker in differentiating PSP from PD. Larger studies with standardized methods of measuring oculomotor movements are required to determine the potential prognostic value of SWJs in PSP and PD.
To cite this abstract in AMA style:
Y. Xu, N. Bellacicco, E. Feinstein. Can Square Wave Jerks Differentiate Progressive Supranuclear Palsy from Parkinson’s Disease? A Scoping Review [abstract]. Mov Disord. 2024; 39 (suppl 1). https://www.mdsabstracts.org/abstract/can-square-wave-jerks-differentiate-progressive-supranuclear-palsy-from-parkinsons-disease-a-scoping-review/. Accessed June 15, 2025.« Back to 2024 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/can-square-wave-jerks-differentiate-progressive-supranuclear-palsy-from-parkinsons-disease-a-scoping-review/