Hypermetabolism of Olivary Nuclei in a Patient with Progressive Ataxia and Palatal Tremor

Background: The pathophysiology of the movement disorder progressive ataxia with palatal tremor (PAPT) is unclear. Case report: A 77-year-old male presented with dysarthria, ataxia, and 1–2 Hz palatal tremor. A diagnosis of probable sporadic PAPT was established. Brain magnetic resonance imaging was normal at the presymptomatic phase but later showed olivary hypertrophy. Brain [18F]-fludeoxyglucose (FDG) positron emission tomography (PET) showed bilateral hypermetabolism in the olivary nuclei. Discussion: This second reported patient with PAPT and FDG-PET shows that olivary hypertrophy is paralleled with hypermetabolism. The olivary nuclei pathology also appears to be temporally associated with symptom onset

PET aivosairauksissa

Positroniemissiotomografia (PET) kuvastaa käytetyn merkkiaineen mukaan aivojen verenkiertoa, aineenvaihduntaa, välittäjäainejärjestelmien toimintaa tai tiettyjen proteiinien kertymää. Neurologisten sairauksien diagnostiikassa PET-kuvantamista hyödynnetään eniten muisti- ja liikehäiriösairauksien erotusdiagnostiikassa sekä epilepsiapesäkkeen paikantamisessa selvitettäessä epilepsian leikkaushoidon mahdollisuuksia. PET-kuvantamista käytetään laajasti myös psykiatristen sairauksien tutkimustyössä, mutta sen rooli kliinisessä työssä on toistaiseksi vähäinen.</p

Sublingual administration of detomidine to calves prior to disbudding: a comparison with the intravenous route.

Objective: To study the effects of oromucosal detomidine gel administered sublingually to calves prior to disbudding, and to compare its efficacy with intravenously administered detomidine. Study design: Randomised, prospective clinical study. Animals: Twenty dairy calves aged 12.4 ± 4.4 days (mean ± SD), weight 50.5 ± 9.0 kg. Methods: Detomidine at 80 μg kg-1 was administered to ten calves sublingually (GEL) and at 30 μg kg-1 to ten control calves intravenously (IV). Meloxicam (0.5 mg kg-1) and  local anaesthetic (lidocaine 3 mg kg-1) were administered before heat cauterization of horn buds. Heart rate (HR), body temperature and clinical sedation were monitored over  240 minutes. Blood was collected during the same period for drug concentration  analysis. Pharmacokinetic variables were calculated from the plasma detomidine  concentration-time data using non-compartmental methods.  Results: The maximum plasma detomidine concentration after GEL was 2.1 ± 1.2 ng  mL-1 (mean ± SD) and the time of maximum concentration was 66.0 ± 36.9 minutes. The bioavailability of detomidine was approximately 34% with GEL. Similar sedation  scores were reached in both groups after administration of detomidine, but maximal sedation was reached earlier in the IV group (10 minutes) than in the GEL group (40 minutes). HR was lower after IV than GEL from 5 to 10 minutes after administration. All animals were adequately sedated, and we were able to administer local anaesthetic without resistance to all of the calves before disbudding. Conclusions and clinical relevance: Oromucosally administered detomidine is an  effective sedative agent for calves prior to disbudding.Peer reviewe

Cerebral grey matter density is associated with neuroreceptor and neurotransporter availability: A combined PET and MRI study

Positron emission tomography (PET) can be used for in vivo measurement of specific neuroreceptors and transporters using radioligands, while voxel-based morphometric analysis of magnetic resonance images allows automated estimation of local grey matter densities. However, it is not known how regional neuroreceptor or transporter densities are reflected in grey matter densities. Here, we analyzed brain scans retrospectively from 328 subjects and compared grey matter density estimates with neuroreceptor and transporter availabilities. µ-opioid receptors (MORs) were measured with [11C]carfentanil (162 scans), dopamine D2 receptors with [11C]raclopride (92 scans) and serotonin transporters (SERT) with [11C]MADAM (74 scans). The PET data were modelled with simplified reference tissue model. Voxel-wise correlations between binding potential and grey matter density images were computed. Regional binding of all the used radiotracers was associated with grey matter density in region and ligand-specific manner independently of subjects’ age or sex. These data show that grey matter density and MOR and D2R neuroreceptor / SERT availability are correlated, with effect sizes (r2) ranging from 0.04 to 0.69. This suggests that future studies comparing PET outcome measure different groups (such as patients and controls) should also analyze interactive effects of grey matter density and PET outcome measures

Atlas of type 2 dopamine receptors in the human brain: Age and sex dependent variability in a large PET cohort

BackgroundThe dopamine system contributes to a multitude of functions ranging from reward and motivation to learning and movement control, making it a key component in goal-directed behavior. Altered dopaminergic function is observed in neurological and psychiatric conditions. Numerous factors have been proposed to influence dopamine function, but due to small sample sizes and heterogeneous data analysis methods in previous studies their specific and joint contributions remain unresolved.MethodsIn this cross-sectional register-based study we investigated how age, sex, body mass index (BMI), as well as cerebral hemisphere and regional volume influence striatal type 2 dopamine receptor (D2R) availability in the human brain. We analyzed a large historical dataset (n=156, 120 males and 36 females) of [11C]raclopride PET scans performed between 2004 and 2018.ResultsStriatal D2R availability decreased through age for both sexes (2-5 % in striatal ROIs per 10 years) and was higher in females versus males throughout age (7-8% in putamen). BMI and striatal D2R availability were weakly associated. There was no consistent lateralization of striatal D2R. The observed effects were independent of regional volumes. These results were validated using two different spatial normalization methods, and the age and sex effects also replicated in an independent sample (n=135).ConclusionsD2R availability is dependent on age and sex, which may contribute to the vulnerability of neurological and psychiatric conditions involving altering D2R expression.​​​​​​​</ul

SNCA mutation p.Ala53Glu is derived from a common founder in the Finnish population

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Interindividual variability and lateralization of mu-opioid receptors in the human brain

Alterations in the brain's mu-opioid receptor (MOR) system have been associated with several neuropsychiatric disorders. Central MOR availability also varies considerably in healthy individuals. Multiple epidemiological factors have been proposed to influence the MOR system, but due to small sample sizes the magnitude of their influence remains inconclusive. We compiled [C-11] carfentanil positron emission tomography scans from 204 individuals with no neurologic or psychiatric disorders, and estimated the effects of sex, age, body mass index (BMI) and smoking on [C-11]carfentanil binding potential using between-subject regression analysis. We also examined hemispheric differences in MOR availability. Older age was associated with increase in MOR availability in frontotemporal areas but decrease in amygdala, thalamus, and nucleus accumbens. The age-dependent increase was stronger in males. MOR availability was globally lowered in smokers but independent of BMI. Finally, MOR availability was higher in the right versus the left hemisphere. The presently observed variation in MOR availability may explain why some individuals are prone to develop MOR-linked pathological states, such as chronic pain or psychiatric disorders. Lateralized MOR system may reflect hemispheric work specialization in central emotion and pain processes

Seasonal variation in the brain μ-opioid receptor availability

Seasonal rhythms influence emotion and sociability. The brain μ-opioid receptor (MOR) system modulates a multitude of seasonally varying socioemotional functions, but its seasonal variation remains elusive with no previously reported in vivo evidence. Here, we first conducted a cross-sectional study with previously acquired human [11C]carfentanil PET imaging data (132 male and 72 female healthy subjects) to test whether there was seasonal difference in MOR availability. We then investigated experimentally whether seasonal variation in daylength causally influences brain MOR availability in rats. Rats (six male and three female rats) underwent daylength cycle simulating seasonal changes; control animals (two male and one female rats) were kept under constant daylength. Animals were scanned repeatedly with [11C]carfentanil PET imaging. Seasonally varying daylength had an inverted U-shaped functional relationship with brain MOR availability in humans. Brain regions sensitive to daylength spanned the socio-emotional brain circuits, where MOR availability formed a spring-like peak. In rats, MOR availabilities in the brain neocortex, thalamus and striatum peaked at intermediate daylength. Varying daylength also affected the weight gain and stress hormone. We conclude that the in vivo brain MOR availability in humans and rats shows significant seasonal variation, which is predominately associated with seasonal photoperiodic variation. Given the intimate links between MOR signaling and socioemotional behavior, these results suggest that the MOR system might underlie seasonal variation in human mood and social behavior.</p

Oxycodone does not affect placental circulatory physiology during the early first stage of labor-A randomized trial

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