Modified cued recall test in the French population with Down syndrome: A retrospective medical records analysis.

BACKGROUND: Adults with Down syndrome (DS) are at increased risk of developing Alzheimer's disease (AD) due to genetic predisposition. Identification of patients with AD is difficult since intellectual disabilities (ID) may confound diagnosis. The objective of this study was to evaluate the ability of the French version of the modified cued recall test (mCRT) to distinguish between subjects with and without AD in the adult DS population. METHODS: This was a retrospective, single-centre, medical records study including data between March 2014 and July 2020. Adults aged ≥30 years with DS who had at least one mCRT record available were eligible. Age, sex and ID level were extracted, and subjects were attributed to three groups: patients with AD, patients with co-occurring conditions that may impact cognitive function and subjects without AD. mCRT scores, adjusted by sex, age and ID level, were compared between groups. The optimal cut-off value to distinguish between patients with and without AD was determined using the receiver operating characteristic curve. The impact of age and ID level on mCRT scores was assessed. RESULTS: Overall, 194 patients with DS were included: 12 patients with AD, 94 patients with co-occurring conditions and 88 healthy subjects. Total recall scores were significantly lower (P < 0.0001) in patients with AD compared with healthy subjects. The optimal cut-off value to discriminate between patients with AD and healthy subjects was 22, which compares well with the cut-off value of 23 originally reported for the English version of the mCRT. Patients aged 30-44 years had higher mCRT total recall scores compared with patients aged ≥45 years (P = 0.0221). Similarly, patients with mild ID had higher mCRT scores compared with patients with severe ID (P < 0.0001). INTERPRETATION: The mCRT is a sensitive tool that may help in the clinical diagnosis of AD in subjects with DS. Early recognition of AD is paramount to deliver appropriate interventions to this vulnerable population.

Feeding problems and gastrointestinal diseases in Down syndrome.

BACKGROUND AND METHOD: Feeding problems and gastrointestinal disorders are the most common anomalies in people with Down syndrome (DS) and have a significant impact on their daily life. This study lists the various anomalies on the basis of 504 references selected from a PubMed search in October 2018. RESULTS: The anomalies are grouped into three categories: anatomical anomalies: duodenal atresia and stenosis (3.9%), duodenal web and annular pancreas; aberrant right subclavian artery (12% of children with DS with cardiac anomaly); Hirschsprung's disease (2.76%); anorectal malformation (1.16%); congenital vascular malformations of the liver; orofacial cleft, bifid uvula (4.63%), and submucous orofacial cleft; esophageal atresia (0.5-0.9%); pyloric stenosis (0.3%); diaphragmatic hernia; malrotation of small intestine or duodenum inversum; omphalocele, gastroschisis or anomalies of the median line, anomalies of the umbilical vein; biological, immunological, and infectious anomalies: neonatal cholestasis (3.9%); neonatal hepatic fibrosis; Helicobacter pylori infection (75.8% in institutionalized children with DS, between 29.2 and 19.5% in non-institutionalized); non-alcoholic fatty liver disease (NAFLD; 82% in obese and 45% in non-obese); biliary lithiasis (6.9% under 3 years); celiac disease (6.,6%); geographical tongue (4%); hepatitis B virus sensitivity; autoimmune hepatitis and cholangitis; Crohn's disease, inflammatory bowel disease (IBD); pancreatitis; vitamin D deficiency (45.2% in Italy); functional disorders: suction, swallowing and chewing disorders (13 of 19 children with DS under 4 years); gastroesophageal reflux (47% in children with sleep apnea); achalasia (0,5% in adults); obesity (51.6% of males and 40.0% of females in Ireland) and overweight (32.0% and 14.8%); constipation (19.0%). Based on their practice, the authors insist on the following points: malformations are sometimes detected late (chronic vomiting after the introduction of food pieces, resistant constipation despite appropriate measures); prescription of preventive doses of vitamin D is advised; jaundice in a baby with DS may be retentional; in the event of transient leukemoid reaction it is vital to monitor liver function; the patient with geographic tongue must be reassured; for celiac serology there is no consensus on the staring age and the frequency, we propose every year from the age of 2; we advise to test people with DS for H. pylori infection if they are attending specialized institutions; abdominal ultrasounds must be systematic during the first months of life; detection of NAFLD is recommended; people with DS must be vaccinated against hepatitis B; breastfeeding is possible with maternal support; it is important to start speech therapy very early; feeding difficulties are often overlooked by the family and educators; gastroesophageal reflux is often pathological; preventing obesity must start from birth using body mass index for the general population; it is necessary to do everything for their meals to be joyful.

PKR downregulation prevents neurodegeneration and ß-amyloid production in a thiamine-deficient model.

Brain thiamine homeostasis has an important role in energy metabolism and displays reduced activity in Alzheimer's disease (AD). Thiamine deficiency (TD) induces regionally specific neuronal death in the animal and human brains associated with a mild chronic impairment of oxidative metabolism. These features make the TD model amenable to investigate the cellular mechanisms of neurodegeneration. Once activated by various cellular stresses, including oxidative stress, PKR acts as a pro-apoptotic kinase and negatively controls the protein translation leading to an increase of BACE1 translation. In this study, we used a mouse TD model to assess the involvement of PKR in neuronal death and the molecular mechanisms of AD. Our results showed that the TD model activates the PKR-eIF2α pathway, increases the BACE1 expression levels of Aß in specific thalamus nuclei and induces motor deficits and neurodegeneration. These effects are reversed by PKR downregulation (using a specific inhibitor or in PKR knockout mice).