The reliability and validity of DSM 5 diagnostic criteria for neurocognitive disorder and relationship with plasma neurofilament light in a down syndrome population.

The validity of dementia diagnostic criteria depends on their ability to distinguish dementia symptoms from pre-existing cognitive impairments. The study aimed to assess inter-rater reliability and concurrent validity of DSM-5 criteria for neurocognitive disorder in Down syndrome. The utility of mild neurocognitive disorder as a distinct diagnostic category, and the association between clinical symptoms and neurodegenerative changes represented by the plasma biomarker neurofilament light were also examined. 165 adults with Down syndrome were included. Two clinicians independently applied clinical judgement, DSM-IV, ICD-10 and DSM-5 criteria for dementia (or neurocognitive disorder) to each case. Inter-rater reliability and concurrent validity were analysed using the kappa statistic. Plasma neurofilament light concentrations were measured for 55 participants as a marker of neurodegeneration and between group comparisons calculated. All diagnostic criteria showed good inter-rater reliability apart from mild neurocognitive disorder which was moderate (k = 0.494). DSM- 5 criteria had substantial concurrence with clinical judgement (k = 0.855). When compared to the no neurocognitive disorder group, average neurofilament light concentrations were higher in both the mild and major neurocognitive disorder groups. DSM-5 neurocognitive disorder criteria can be used reliably in a Down syndrome population and has higher concurrence with clinical judgement than the older DSM-IV and ICD-10 criteria. Whilst the inter-rater reliability of the mild neurocognitive disorder criteria was modest, it does appear to identify people in an early stage of dementia with underlying neurodegenerative changes, represented by higher average NfL levels.

Diagnostic value of a negative single complete compression ultrasound of the lower limbs to exclude the diagnosis of deep venous thrombosis in pregnant or postpartum women: a retrospective hospital-based study.

OBJECTIVE: We aimed at determining whether a negative single complete compression ultrasonography (CUS) of the lower limbs veins is a safe and accurate diagnostic method to rule out the diagnosis of deep venous thrombosis in pregnant and early postpartum women. DESIGN: Hospital-based retrospective study. SETTING: The gynaecology and vascular ultrasound units of three general hospitals in western France. PATIENTS: We identified from the hospitals databases all pregnant or up to three months postpartum women who underwent CUS for a suspicion of deep venous thrombosis between January 2002 and December 2004. METHODS: Questionnaires were sent to all women with a negative CUS. Their medical records were also checked. MAIN OUTCOME MEASURES: We assessed the three-month thromboembolic risk and its 95% percent confidence interval in women left untreated on the basis of a negative single complete CUS of the lower limbs. RESULTS: During the study period, 162 pregnant or postpartum women underwent CUS for a suspicion of deep venous thrombosis. It was positive in 44 (27%). The 118 women who had a negative CUS were sent the questionnaire. Information about the three-month follow-up was found for 107 patients (91%). None of them experienced a thromboembolic event during follow-up: 0.0% (95% CI: 0.0-3.6). CONCLUSIONS: Single complete CUS of lower limbs veins appears to be a safe method to rule out the diagnosis of deep venous thrombosis in pregnant or early postpartum women. This has to be confirmed by a prospective management study with a formal follow-up.