Predicting the severity of HD

Predicting the Severity of Imminent Huntington Disease

An important study has led to the development of a cognitive assessment tool that could help predict the severity of Huntington disease (HD) in those close to onset.

Huntington disease (HD) - a condition that affects one’s movement, cognition, and behavior—manifests fully in adulthood.

While a genetic test can predict HD early on, clinical diagnosis relies on testing a person’s motor function and often overlooks the subtle cognitive and behavioral changes associated with HD. Adults with HD-linked mutations do, however, display an early premanifest-prodromal phase close to the onset of first symptoms. They do not exhibit specific neurological signs during this phase, but predicting future HD severity at this stage can ensure rehabilitative and nutritional interventions are started early.

We thus developed a Composite Cognitive Score (CCS) to predict the severity of future HD symptoms in individuals during the early premanifest-prodromal phase. We looked at cognitive test data from 21,343 subjects enrolled in the global ENROLL-HD study to create this CCS. We focused on individuals in the premanifest-prodromal stage, who later developed HD, and aimed to see if their CCS scores could accurately predict the severity of their HD symptoms during follow-up visits.   

The CCS stands out from other scoring scales by incorporating essential cognitive measures often absent in existing indices. It integrates four tests—The Symbol Digit Modality Test, Categorical Verbal Fluency Test, Stroop Color Naming test, and Stroop Word Reading test. An MS Excel model that can calculate an individual’s CCS is also available on request.

“Our findings indicate that individuals with a lower CCS during the premanifest-prodromal phase exhibit more severe HD symptoms later in life”, stated Dr. Ferdinando Squitieri, the corresponding author of the study, published on Movement Disorders Clinical Practices “Conversely, individuals with a higher CCS would display a slower progression of motor symptoms in HD”, he continued.

The CCS could thus be used to predict how severe HD symptoms will be early on, allowing for better timing of rehabilitation and interventions, such as clinical trials.

To learn more, see the attached article and watch the video.