In evaluating potential cognitive impairment in ALS, which neuropsychological test is most useful?

• A. Grooved Pegboard
• B. JLO
• C. CVLT-2
• D. COWAT

Answer: (D)

In ALS, cognitive problems often show up as problems with executive control over language—how we search, retrieve, and monitor words under time pressure. Verbal fluency tests are especially good at tapping that frontline, frontal-executive function. The Controlled Oral Word Association Test asks you to produce as many words as possible from a given letter (or category) within a short time, which requires rapid retrieval, set-shifting, strategic searching, and monitoring of output. These processes rely on frontal and frontostriatal circuits that ALS frequently affects, so performance on this task is particularly sensitive to cognitive impairment in this population.

Grooved Pegboard mainly measures fine motor dexterity and speed, which can be directly impacted by ALS motor weakness and tremor, confounding any attempt to infer cognitive status from its results. JLO assesses visuospatial skills, which are less typically affected early and can miss the common executive profile of ALS. CVLT-2 gauges verbal learning and memory, while valuable for memory assessment, may not detect the executive dysfunction that tends to accompany ALS cognitive impairment as readily as a verbal fluency measure does. Therefore, the COWAT serves as the most useful single screen for detecting the kind of cognitive impairment seen in ALS.