The Box Task: A novel tool to differentiate the primary progressive aphasias

Area of Science:

• Neurology
• Cognitive Neuroscience

Background:

• Primary progressive aphasia (PPA) diagnosis is complex, particularly distinguishing logopenic (lv-PPA) and non-fluent (nfv-PPA) variants.
• Visuospatial memory deficits are increasingly recognized as potential diagnostic markers for PPA subtypes.

Purpose of the Study:

• To evaluate the diagnostic utility of a novel computerised visuospatial working memory test, the Box Task.
• To differentiate between the three PPA variants (lv-PPA, nfv-PPA, sv-PPA) and Alzheimer's disease (AD).

Main Methods:

• Recruited participants included 18 lv-PPA, 14 nfv-PPA, 23 sv-PPA, 33 AD patients, and 32 healthy controls.
• Administered the computerised Box Task and WMS-III Spatial Span to assess visuospatial working memory.

Main Results:

• The lv-PPA group exhibited significantly more errors on the Box Task compared to nfv-PPA, sv-PPA, and control groups.
• Logistic regression achieved 72% accuracy in classifying lv-PPA and 79% in classifying nfv-PPA using Box Task variables.
• The Box Task demonstrated higher sensitivity than Spatial Span in differentiating lv-PPA from nfv-PPA.

Conclusions:

• The computerised Box Task is a promising tool for the differential diagnosis of PPA variants.
• Visuospatial working memory assessment, specifically using the Box Task, can aid in distinguishing lv-PPA from other PPA subtypes.