A longitudinal study of motor subtypes in delirium: frequency and stability during episodes.

OBJECTIVE: Motor-defined subtypes are a promising means of identifying clinically relevant patient subgroups but little is known about their course and stability during a delirium episode. METHODS: We assessed 100 consecutive adult palliative care patients with DSM-IV delirium twice weekly during their episodes using the Delirium Motor Subtype Scale (DMSS), Delirium Rating Scale-Revised-98 (DRS-R98) and Cognitive Test for Delirium (CTD). DMSS subtypes were assigned for each assessment and analysed for stability within patients during episodes. RESULTS: Across all assessments (n=303; mean 3 per patient, range 2-9), subtype occurrence was hypoactive (35%), mixed (26%), hyperactive (15%) and no subtype (24%). "No subtype" was associated with significantly lower DRS-R98 severity scores, of which 80% were subsyndromal, whereas mixed subtype assessments were the most impaired on the DRS-R98 and CTD. Subtypes were stable within delirium episodes in 62% of patients: 29% hypoactive, 18% mixed, 10% hyperactive and 6% no-subtype. The DRS-R98 noncognitive subscale scores differed across groups whereas cognitive subscale scores did not (p<0.001). CONCLUSIONS: We conclude that motor subtypes occur in nearly all patients with full syndromal delirium and are often stable during an episode. Subtypes exhibited comparable levels of cognitive impairment but differed in non-cognitive symptoms, supporting the importance of cognitive testing to detect delirium in less overt cases.

A longitudinal study of motor subtypes in delirium: relationship with other phenomenology, etiology, medication exposure and prognosis.

OBJECTIVE: Motor subtypes have promise as a means of identifying clinically relevant delirium subgroups. Little is known about their relationship to etiologies, medication exposure, and outcomes. METHODS: Consecutive cases of DSM-IV delirium in palliative care patients were assessed twice-weekly throughout their delirium episodes using the Delirium Motor Subtype Scale (DMSS), Delirium Etiology Checklist (DEC) and Delirium Rating Scale Revised-98 (DRS-R98). RESULTS: 100 patients [mean age 70.2 ± 10.5] were assessed on 303 visits [range 2-9]. Over the entire episode, mean DRS-R98 Severity scores were 16.2 ± 5.7. The mean number of etiologies per case was 3.4 ± 1.2. Motor subtypes were no subtype throughout (6%), hypoactive subtype throughout (28%), mixed subtype throughout (18%), hyperactive subtype throughout (10%) and variable subtype (38%). DRS-R98 Total and Severity scales differed significantly across categories (highest in mixed) but only motor, sleep-wake cycle, perceptual and language disturbance items differed. The Generalized Estimating Equations (GEE) approach was used to explore the relationship between subtype profile and symptoms, medication exposure and etiology. This showed that apart from motor items, only delusions, affective lability, metabolic disturbance and CVA related to any subtype. Cross-sectional assessments indicated greater use of benzodiazepine and antipsychotics in hyperactive patients but GEE analyses did not identify major associations between motor subtype and medication exposure. Patients with sustained hypoactive subtype were significantly more likely to die within one month of study entry. CONCLUSIONS: Motor profile in delirium is relatively consistent over episode course and relates more closely to delirium phenomenology than to etiology or medication exposure. Motor subtypes have comparable disturbance of key diagnostic features such as cognitive and thought process abnormalities. Although mixed subtype is the most phenomenologically intense, hypoactives have the poorest prognosis.

Phenomenological and neuropsychological profile across motor variants of delirium in a palliative-care unit.

Studies using composite measurement of cognition suggest that cognitive performance is similar across motor variants of delirium. The authors assessed neuropsychological and symptom profiles in 100 consecutive cases of DSM-IV delirium allocated to motor subtypes in a palliative-care unit: Hypoactive (N=33), Hyperactive (N=18), Mixed (N=26), and No-Alteration motor groups (N=23). The Mixed group had more severe delirium, with highest scores for DRS-R-98 sleep-wake cycle disturbance, hallucinations, delusions, and language abnormalities. Neither the total Cognitive Test for Delirium nor its five neuropsychological domains differed across Hyperactive, Mixed, and Hypoactive motor groups. Most patients (70%) with no motor alteration had DRS-R-98 scores in the mild or subsyndromal range even though they met DSM-IV criteria. Motor variants in delirium have similar cognitive profiles, but mixed cases differ in expression of several noncognitive features.

A comparison of neuropsychiatric and cognitive profiles in delirium, dementia, comorbid delirium-dementia and cognitively intact controls.

PURPOSE: Delirium and dementia have overlapping features that complicate differential diagnosis. Delirium symptoms overshadow dementia symptoms when they co-occur, but delirium phenomenology in comorbid cases has not been compared to both conditions alone. METHODS: Consecutive adults with DSM-IV delirium, dementia, comorbid delirium-dementia and cognitively intact controls were assessed using the Revised Delirium Rating Scale (DRS-R98) and Cognitive Test for Delirium (CTD). RESULTS: Delirium and comorbid delirium-dementia groups had comparable DRS-R98 and CTD total scores, which were greater than in dementia or control groups. On the DRS-R98, multiple non-cognitive symptoms, inattention and disorientation were more severe in delirium groups compared with dementia-alone. Patients with dementia differed from both delirium groups on the CTD test of attention. Spatial span backwards was significantly lower in all patients with cognitive impairment (delirium, comorbid delirium-dementia, dementia alone) compared to controls, whereas spatial span forwards distinguished delirium groups from dementia. CONCLUSIONS: Delirium phenomenology is similar with or without comorbid dementia. A wide range of neuropsychiatric symptoms distinguish delirium from dementia. Spatial span forward is disproportionately diminished in delirium suggesting usefulness as a differentiating screening test.

Validating a new clinical subtyping scheme for delirium with electronic motion analysis.

The usefulness of motor subtypes of delirium is unclear due to inconsistency in sub-typing methods and a lack of validation with objective measures of activity. The activity of 40 patients was measured with 24 h accelerometry monitoring. Patients with Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) delirium (n=30) were allocated into hyperactive, hypoactive and mixed motor subtypes. Delirium subtypes differed in relation to overall amount of activity, including movement in both sagittal and transverse planes. Differences were greater in the daytime and during the early evening 'sundowning' period. Frequency of postural changes was the most discriminating measure examined. Clinical subtypes of delirium defined by observed motor behaviour on the ward differ in electronically measured activity levels.

Motion analysis in delirium: a novel method of clarifying motoric subtypes.

The usefulness of motor subtypes of delirium is unclear due to inconsistency in subtyping methods and a lack of validation with objective measures of motor activity levels. We studied patients with hyperactive, hypoactive, and mixed presentations of delirium were studied with 24-h accelerometer-based monitoring. The procedures were well tolerated and motor presentations were readily distinguished using the accelerometer-based measurements. The system was capable of identifying static versus dynamic activity and the frequency of changes in posture. Electronic motion analysis concurs with observed gross movement and can distinguish motorically defined subtypes according to quantitative and qualitative aspects of movement.