Time perception is impaired in patients with Huntington’s disease, even in pre- or early-symptomatic stages of the disease, and is correlated with disease severity and progression, Swiss researchers found.
Huntington’s disease is a genetic neurodegenerative disorder characterized by loss of movement coordination, and intellectual, behavior and memory impairments.
Movement coordination requires accurate time perception, or the ability to sense the duration of consecutive events. This capacity is controlled by the striatum — one of the brain regions that composes the basal ganglia, which is responsible for motor coordination.
Although previous studies had already suggested time perception deficits could be a major contributor for the lack of movement coordination in Huntington’s, no study ever addressed the impact of this process before patients started to experience the first motor symptoms associated with the condition, or during the early stages of the disease.
Now, researchers analyzed time perception in 21 Huntington’s mutation carriers without motor signs (HD-premotor group) and 10 early-symptomatic (HD-motor group) patients, and compared it with 27 age- and sex-matched healthy control subjects.
Time was assessed using two different perception tasks: Task A involved absolute, duration-based time perception, which evaluates the measurement of precise time intervals. Task B is relative, beat-based time perception, which evaluates the measurement of precise time intervals relative to events that occur at a regular pace in time, such as sound beats.
For both tasks, participants were asked if the perceived timing was the same or diﬀerent.
Patients from the HD-motor group performed poorly in both tasks compared to patients from the HD-premotor group and control subjects.
Researchers also found a positive correlation between disease severity (CAP score) and thresholds of time perception for both tasks in all participants carrying genetic mutations linked to Huntington’s, indicating that gradual changes in time perception start to occur even before patients experience the first motor symptoms of disease.
The team also found that time perception deficits were linked with other types of cognitive impairments.
“Our study data show impairment of time perception in correlation with the disease burden in a cohort comprising [Huntington’s disease] patients in the motor pre-symptomatic stages and early stages of motor impairment,” researchers wrote.
“Assessment of time perception may be a marker for progression, and could be used in clinical trials,” they added.