Discriminant Performance of Dysexecutive and Frontal Release Signs for Delirium in Patients With High Dementia Prevalence: Implications for Neural Network Impairment.

BACKGROUND: Prevalence of signs of abnormal executive function (EF) and primitive reflexes (PR) with delirium in older hospitalized patients with or without comorbid dementia has not been reported. OBJECTIVE: To describe prevalence of signs of EF deficits and PR in older inpatients and their discriminant value for delirium while accounting for dementia. METHODS: Participants were evaluated for delirium using the Diagnostic and Statistical Manual of Mental Disorders 5th edition and the Delirium Rating Scale Revised-98, dementia using Informant Questionnaire on Cognitive Decline in the Elderly, and signs of PR (n = 5) and EF deficits (n = 3) using bedside neuropsychiatric examination. Three indices (PR, EF, and Combined) and 4 diagnostic groups were created for correlational and discriminant analyses. RESULTS: Correlations of indices were higher with the Delirium Rating Scale Revised-98 than with the Informant Questionnaire on Cognitive Decline in the Elderly and even higher in those with dementia, especially the Combined index (Delirium Frontal Index). Among individual signs, glabellar and Simple Luria Hand Sequence were most common in delirium and the best for delirium discrimination irrespective of dementia status. The Combined index had about 80% sensitivity and specificity at the ≥2 cutoff in the whole cohort (positive and negative predictive values and likelihood ratios: PPV 50.0%, NPV 93.8%, +LR 3.82, -LR 0.25). The Combined index also had the best performance on discriminating delirium in dementia patients at the ≥3 cutoff, with about 80% for both sensitivity and specificity. CONCLUSIONS: PR and EF deficit signs are consistent with reduced neural network integration during delirium, even worse in those with dementia whose baseline structural injury impairs network connectivity with frontal regions. We recommend simple bedside assessment of PR and EF signs to help assess for delirium as an indicator of cerebral cortical neural network impairment in older persons.

Delirium diagnostic tool-provisional (DDT-Pro) scores in delirium, subsyndromal delirium and no delirium.

OBJECTIVE: To evaluate whether the Delirium Diagnostic Tool-Provisional (DDT-Pro), a 0-9 point scale with three items each representing symptoms from delirium's three core domains, differentiates subsyndromal delirium (SSD) from delirium and no delirium. METHODS: We applied cluster analyses of DDT-Pro scores from 200 consecutive inpatients using three reference standards for delirium diagnosis to determine DDT-Pro cutoff values for delirium, SSD and no delirium groups. Clinical validators and DDT-Pro item scores were compared among groups. RESULTS: DDT-Pro SSD range was 6-7 (n = 54), with no delirium having higher scores (n = 98) and delirium lower (n = 48). Dementia prevalence in the SSD group (40.7%) was intermediate between no delirium (20.4%) and delirium (66.7%). SSD and delirium groups were more affected than no delirium regarding medical comorbidities, hospital stay (no delirium <1 week, SSD and delirium >1 week) and mortality (SSD = 7.4%, delirium = 18.8%, no delirium = 1%). Values for motor subtypes, frontal lobe signs, and DRS-R98 in the SSD group were intermediate between no delirium and delirium, as well as for the DDT-Pro items (all p < 0.05). CONCLUSIONS: All DDT-Pro items, which represent the three delirium core domains, are important for SSD diagnosis. Patients scoring in the SSD 6-7 range have significant clinical and prognostic features and deserve clinical attention.

Validation of the Delirium Diagnostic Tool-Provisional (DDT-Pro) With Medical Inpatients and Comparison With the Confusion Assessment Method Algorithm.

OBJECTIVE: Delirium remains underdetected as a result of its broad constellation of symptoms and the inadequate neuropsychiatric expertise of most medical-surgical clinicians. Brief, accurate tools are needed to enhance detection. METHODS: The authors extended validation of the Delirium Diagnostic Tool-Provisional (DDT-Pro), originally validated in a study of inpatients with traumatic brain injury for diagnosis of delirium by nonexpert clinicians, for 200 general medical inpatients in Colombia. The three structured, quantitatively rated items in DDT-Pro represent the three core delirium domains. RESULTS: High interrater reliability between physician and nurse (0.873) administrators, internal consistency (>0.81), and content validity were found. Compared with independent reference standard diagnosis with DSM-5 or the Delirium Rating Scale-Revised-98, the area under the receiver operating characteristic (ROC) curve (global diagnostic accuracy) range was 93.8%-96.3%. ROC analysis revealed the same cutoff score (≤6) as that for the original study, with somewhat lower sensitivities of 88.0%-90.0% and specificities of 85.3%-81.2% (independent expert physician or nurse ratings). Even when rated by a trained expert physician, the original version of the Confusion Assessment Method algorithm (CAM-A) performed moderately, with lower sensitivities (61.8%-70.0%) than the DDT-Pro (88.0%-100%) and somewhat higher specificities (84.8%-95.3% versus 67.4%-86.7%), with values depending on dementia status, reference standard, and rater type. Accuracies for the DDT-Pro and CAM-A were comparable (DDT-Pro: 83.0%-87.5% versus CAM-A: 87.5%-88.5%), although lower in the dementia subgroup, especially for CAM-A. However, these tools were significantly discordant, especially in negative cases, which suggests that they do not detect diagnosis of patients in the same way. CONCLUSIONS: The DDT-Pro had high validity and reliability in provisional delirium diagnosis by physicians and nonexpert clinicians, although further validation is warranted before widespread use can be recommended.