Objective: The neural correlates of emotion processing in Huntington’s Disease (HD) have only
been investigated in premanifest HD by means of functional MRI (fMRI) focusing on
disgust processing1. Using an fMRI paradigm with more emotional valences, we aimed to investigate the
functional correlates of emotion perception in manifest HD, while taking account of
structural atrophy. Methods: Event-related fMRI and anatomical images were acquired with a 3T Siemens MR Scanner
in 14 HD patients (stages2 I-III) and 14 age- and gender-matched healthy controls. An emotion recognition task
displayed video-sequences of trained actors performing one of six facial expressions
(sadness, happiness, disgust, fear, anger, neutral). Structural changes between patients
and controls were assessed by means of voxel-based morphometry. Differences in BOLD-response
were analyzed for emotion-related regions of interest (ROI) with and without including
grey matter values of respective ROIs as covariates (SPM8). Results: HD patients performed significantly worse than controls in recognizing negative emotions.
During the perception of sadness, the amygdala, parahippocampal gyrus, putamen and
posterior cingulate showed increased activity in patients compared to controls. The
insula was more strongly recruited during disgust and sadness. Less activity was observed
in parahippocampal regions for happiness, in orbitofrontal and lateral prefrontal
cortices for all emotions. Taking account of grey matter changes, hyperactivity in
most regions decreased, while hypoactivity remained constant and was further observed
in the amygdala and parahippocampal gyrus for fear. Conclusion: Increased emotion-related activity seems to represent primarily dysfunctions due
to degeneration processes in limbic regions3, which may along with frontal hypoactivity underlie emotion processing deficits in
HD. Our results emphasize the need of considering structural changes in the investigation
of functional activity in HD.
Literatur: 1. Hennenlotter A, Schroeder U, Erhard P, Haslinger B, Stahl R, Weindl A, von Einsiedel
HG, Lange KW, Ceballos-Baumann AO (2004), ‘Neural correlates associated with impaired
disgust processing in pre-symptomatic Huntington's disease’, Brain, vol. 127, no.
6, pp. 1446-53. 2. Shoulson I, Fahn S (1979), ‘Huntington disease: clinical care and
evaluation’, Neurology, vol. 29, no. 1, pp. 1-3. 3. Georgiou-Karistianis N (2009),
‘A peek inside the Huntington's brain: will functional imaging take us one step closer
in solving the puzzle?’, Exp Neurol, vol. 220, no. 1, pp. 5-8.