Background Putamen atrophy is widely assumed to be associated with several motor symptoms of HD but less so cognitive impairment. This study specifically examines two cognitive functions associated with the putamen and potentially affected in HD, namely emotion recognition and associative learning.

Aims A novel cognitive test of putamen function was designed alongside imaging measures (putamen, caudate and whole-brain volumes). Cross-sectional and longitudinal change will be investigated in both domains along with the interactions between them.

Method 15 early HD and 15 controls will be tested, 13 with follow-up at 9 months. A novel forced-choice multi-modal emotion recognition task is followed by an associative learning task in which participants learn to pair shapes with numbers. Manual segmentation of T1 scans is conducted in MIDAS.

Results Preliminary results suggest that emotion recognition deficits correlate with striatal and whole-brain volumes. Patients find auditory emotion recognition more difficult than the visual modalities, with fear and anger recognition scoring the most errors in the HD group. A general deficit in facial recognition (as assessed by the Benton Facial Recognition Test) is also seen. Associative learning is impaired in early HD but error rates do not clearly correlate with imaging measures.

Conclusions Further cross-sectional and additional longitudinal data will help clarify questions such as: do cognitive measures correlate with cross-sectional and longitudinal putamen change? Are some emotions/emotion modalities more impaired than others?

Funding This work has been supported by the European Union–PADDINGTON project, contract n. HEALTH-F2-2010-261358. FP7 logos and/or EU emblem has been used according to European Commission guideline and recommendations. http://www.paddingtonproject.eu/.