| 1. |
- Follin, Cecilia, et al.
(författare)
-
Hypothalamic dysfunction revealed by magnetic resonance diffusion tensor imaging in childhood leukemia survivors treated with cranial radiotherapy but not in craniopharyngeoma survivors
- 2016
-
Konferensbidrag (refereegranskat)abstract
- Background: Metabolic complications with obesity are frequent in childhood acute lymphoblastic leukemia (ALL) survivors treated with cranial radiotherapy (CRT). Childhood onset Craniopharyngioma (CP) survivors without hypothalamic (HT) involvement are spared gross obesity. Magnetic resonance diffusion tensor imaging (DTI) provides information of microstructure function of the brain and quantified as fractional anisotrophy (FA), mean diffusivity (MD), axial and radial diffusivity (AD, RD). Since MD in HT is reportedly impaired (increased) in obese compared to non-obese subjects, we investigated DTI in the HT.Methods: Twenty nine ALL survivors on hormone supplementation were investigated 34 years after CRT (24 Gy). 17 CO-CP survivors with hormone supplementation but without HT damage were investigated. Comparisons were made with these two patient populations to 27 matched controls regarding DTI parameters in the HT and for BMI, fat mass, fat free mass and waist/hip measurements.Results: We recorded reduced FA (0.27 vs 0.29, P=0.04), and increased MD (1.13 vs 1.00, P<0.001), AD (1.41 vs 1.25, P<0.001), and RD (0.99 vs 0.86, P<0.001) in the right HT and increased MD (1.42 vs 1.25, P<0.001), AD (1.75 vs 1.58, P<0.001), and RD (1.25 vs 1.04, P<0.001) in left HT in ALL survivors compared to matched controls. The CPs showed no difference in the HT for these parameters compared to controls. ALL survivors with a BMI ≥ 25 showed elevated MD (P=0.03) and AD (P=0.02) compared to ALL survivors with a BMI < 25 and compared to controls with BMI ≥ 25 in the right HT. This was not the case in CP survivors or in controls.Conclusions: Thirty four years after CRT for ALL, DTI measures are deranged in the HT. ALL survivors with a BMI ≥ 25 were presented with worse HT dysfunction. CP survivors were unaffected. The present data suggests changes in the microstructure of the HT in these ALL survivors.
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
|
|
| 5. |
|
|
| 6. |
|
|
| 7. |
|
|
| 8. |
|
|
| 9. |
- Söderström, Pelle, et al.
(författare)
-
Anticipating morphological and syntactic structures : investigating the pre-activation negativity
- 2017
-
Konferensbidrag (refereegranskat)abstract
- It is known that listeners can predict upcoming words based on constraining contexts (e.g. DeLong et al., 2005). In a recent study, we proposed a left frontal brain potential, the pre-activation negativity, PrAN (Söderström et al., 2016), thought to reflect pre-activation of expected word continuations. Time-locked to word-initial fragments, PrAN’s amplitude was found to increase in a 136-280 ms time window as the number of possible continuations decreased, suggesting that PrAN increased with increased predictive certainty about a word’s ending. In the present study, we tested whether a similar effect could be found for pre-activation of expected syntactic structures. In Swedish, intonation is used to signal whether an unfolding embedded clause is a main or subordinate clause. Specifically, a clause-initial word with a low boundary tone cues only subordinate clause structure. Conversely, a corresponding high tone signals that any kind of embedded main clause structure may follow, i.e. it cues a more open set of structures. Test participants listened to complex sentences and judged the word order of the verb (V) and negation (NEG) after the boundary tone as quickly as possible (NEG–V word order occurs in subordinate clauses and V–NEG in main clauses). ERPs were time-locked to the tone-bearing syllable. A repeated-measures ANOVA showed a negativity in left anterior electrodes at 136-280 ms for low initial boundary tones, which cue only subordinate clauses. We propose that this effect is a PrAN, but that it here reflects pre-activation of syntactic structures rather than possible word endings.
|
|
| 10. |
|
|
