Amelioration of Parkinsonian tremor evoked by DBS: which role play cerebello-(sub)thalamic fiber tracts?

BACKGROUND: Current pathophysiological models of Parkinson's disease (PD) assume a malfunctioning network being adjusted by the DBS signal. As various authors showed a main involvement of the cerebellum within this network, cerebello-cerebral fiber tracts are gaining special interest regarding the mediation of DBS effects. OBJECTIVES: The crossing and non-decussating fibers of the dentato-rubro-thalamic tract (c-DRTT/nd-DRTT) and the subthalamo-ponto-cerebellar tract (SPCT) are thought to build up an integrated network enabling a bidimensional communication between the cerebellum and the basal ganglia. The aim of this study was to investigate the influence of these tracts on clinical control of Parkinsonian tremor evoked by DBS. METHODS: We analyzed 120 electrode contacts from a cohort of 14 patients with tremor-dominant or equivalence-type PD having received bilateral STN-DBS. Probabilistic tractography was performed to depict the c-DRTT, nd-DRTT, and SPCT. Distance maps were calculated for the tracts and correlated to clinical tremor control for each electrode pole. RESULTS: A significant difference between "effective" and "less-effective" contacts was only found for the c-DRTT (p = 0.039), but not for the SPCT, nor the nd-DRTT. In logistic and linear regressions, significant results were also found for the c-DRTT only (pmodel logistic = 0.035, ptract logistic = 0,044; plinear = 0.027). CONCLUSIONS: We found a significant correlation between the distance of the DBS electrode pole to the c-DRTT and the clinical efficacy regarding tremor reduction. The c-DRTT might therefore play a major role in the mechanisms of alleviation of Parkinsonian tremor and could eventually serve as a possible DBS target for tremor-dominant PD in future.

Food allergy in infants assessed in two German birth cohorts 10 years after the EuroPrevall Study.

BACKGROUND: The prevalence of food allergies (FA) in children increased rapidly at the turn of the century. The EuroPrevall study identified Germany as a country with very high prevalence of FA at that time. Using two large German birth cohorts, we provide an update of the status quo 10 years later. METHODS: KUNO Kids and Ulm SPATZ Health studies are two ongoing prospective birth cohorts. Information on FA was obtained by questionnaires at birth and after 6, 12, and 24 months. Univariable and multivariable logistic regression analyses were performed to investigate risk factors during pregnancy, birth, and early childhood. RESULTS: In 1139 and 1006 children from KUNO Kids and SPATZ, the point prevalence of parent-reported FA symptoms at the ages of 1 and 2 years was 13.2% (95% CI: 11.2-15.2) and 13.9% (95% CI: 11.5-17.2) in KUNO Kids. Doctor's diagnosed FA at 1 and 2 years was 2.4% (95% CI: 1.6-3.4) and 2.7% (95% CI: 1.2-4.3) in KUNO Kids and 2.3% (95% CI: 1.3-3.6) and 3% (95% CI: 2.0-4.5) in SPATZ. Cow's milk and citrus fruits were most frequently suspected by parents to cause FA symptoms. Atopy in the child was associated with a higher frequency of FA at any time, whereas atopy in first-degree relatives was only associated with FA at year 1. Smoke exposure during pregnancy was a risk for FA at age 2. CONCLUSION: The prevalence of food allergy seems to have plateaued in the last 10 years in Germany. FA is often suspected by parents but only rarely diagnosed by oral food challenge. Risk factor analysis may help to establish personalized health approaches.