This study evaluated the outcomes of ischemic stroke patients according to delirium motor subtype.
This study included patients who were admitted to the stroke unit between August 2017 and March 2019 and met the DSM-5 diagnostic criteria for delirium. Patients were assessed twice weekly throughout their delirium episodes using the Korean version of the Delirium Motor Subtype Scale (K-DMSS) and the Korean version of the Delirium Rating Scale-Revised-98 (K-DRS-98). The clinical characteristics and short-term outcomes of the patients were also assessed.
A total of 943 stroke patients were included; the rate of incident delirium was 10.18%. Of the 95 delirium patients, 34 were classified as the hyperactive subtype, 30 as the mixed subtype, 25 as the hypoactive and six as no subtype. Among the subtype groups, the hypoactive subtype had the highest initial scores on the National Institutes of Health Stroke Scale (NIHSS; 6.72±4.75, p=0.02) and the modified Rankin Scale (mRS; 3.96±1.24, p<0.01). Additionally, the mixed and hypoactive subtypes had longer durations (p<0.01) and more severe symptoms of delirium (p=0.03) than the other motor subtypes, and the hypoactive subtype group had a significantly longer hospital stay (36.88±27.71 days, p<0.01) than the other subtype groups. After adjusting for baseline covariates in a multiple linear regression analysis, these differences remained significant.
The present results suggest that the motor subtype of delirium is associated with different characteristics and outcomes in ischemic stroke patients.
Delirium is a syndrome characterized by disturbances in attention and cognition that develop over a short period and tend to fluctuate in severity during the course of a day [
The incidence of delirium is higher in post-stroke patients (13–48%) than in patients admitted to general internal medicine wards (10–25%) [
Delirium is almost invariably complicated by disturbances of motor activity, which have been the focus of greatest interest in studies of its clinical subtypes. Lipowski [
Therefore, the aim of this study was to evaluate clinical characteristics and outcomes according to delirium motor subtypes in patients with ischemic stroke admitted to the stroke unit (SU) of a tertiary referral hospital.
The study population was drawn from patients with cerebral infarction who developed delirium after admission to the SU of Chungnam National University Hospital, Daejeon, Korea, between August 2017 and March 2019. Because patients with global aphasia, sensory aphasia, and coma could not be appropriately assessed for delirium, we excluded them from the study. We also excluded patients who were admitted to the intensive care unit (ICU) and those who refused to participate. The procedures and rationale for this study, as well as the right to withdraw, were fully explained to all patients and their family members. Due to the nature of the study, informed consent was obtained from patients when possible, and proxy consent from caregivers when necessary. The study protocol was approved by the Institutional Review Board (IRB No: 2017-07-058).
Patients were screened for delirium every day beginning on the day of SU admission. Screening was performed at the same time every day (4 p.m.) by trained SU nurses, and the Confusion Assessment Method (CAM) was used for the delirium screening. The SU nurses were trained to perform the CAM by a psychiatrist (the first author of the present study) prior to the first registration.
Patients who met the CAM criteria for delirium were assessed by a trained psychiatrist within 24 h. Diagnosis was based on the Diagnostic and Statistical Manual of Mental Disorders (DSM)-5 criteria for delirium. The severity of delirium symptoms was assessed using the Korean version of the Delirium Rating Scale-Revised-98 (K-DRS-98). The Korean version of the DMSS (K-DMSS) was also applied to classify delirium motor subtypes.
After the initial assessment, the presence of delirium was assessed daily and symptom severity and delirium motor subtype were reassessed twice weekly by the psychiatrist who performed the initial assessment for up to 3 weeks, or until the delirium resolved or until the patient died. This frequency of assessments allowed for consistency in the time frame between assessments, sustained observations of the motor activity profile, and the minimization of any tendency toward missing or incomplete data. For patients who were discharged with delirium, outcomes such as duration of delirium and subsequent institutionalization were evaluated through follow-up calls and visits.
Data were collected regarding demographic factors and comorbidities, including hypertension, diabetes mellitus, dyslipidemia, renal failure, hepatic failure, atrial fibrillation, ischemic heart disease, cardiac valve disease, respiratory system disorder, thyroid disease, urinary tract infection, Parkinson’s disease, previous stroke history, comorbid cognitive impairment, and past delirium history. All medications prescribed to a patient during hospital admission were documented and are presented as the number of medications received when delirium occurred. Auditory and visual impairments, laboratory test results, malnutrition, urinary catheterization, physical restraints, and endotracheal intubation during hospitalization were also recorded.
Outcome measures included the length of hospital stay, death during hospitalization, institutionalization upon discharge, duration of delirium, and delirium severity. The days with DSM-5 delirium were counted to determine the duration of delirium. Delirium severity was measured according to the average K-DRS-98 total severity score and the highest K-DRS-98 total severity score (items 1–13) during delirium [
The CAM [
The Delirium Rating Scale-Revised-98 (DRS-R98) [
The Delirium Motor Subtype Scale (DMSS) [
At admission, the etiology of ischemic stroke was classified as large artery atherosclerosis (LAA), cardioembolism (CE), small vessel occlusion (SVO), or other, according to the Trial of Org 10172 in Acute Stroke Treatment (TOAST) criteria [
Demographic and clinical data are expressed as mean± standard deviation. Associations between continuous variables (e.g., age, length of hospital stay, duration of delirium, mean K-DRS-98 score) and delirium motor subtypes were analyzed using the Kruskal-Wallis test. Associations between categorical variables (e.g., sex, institutionalization, death during hospitalization) and delirium motor subtypes were analyzed using chi-square tests. The associations between motor subtype of delirium and outcomes, including duration of delirium, highest K-DRS-98 severity score, length of stay, NIHSS score at discharge, and mRS score at discharge, were adjusted for specific covariates that were significantly associated with the motor subtypes of delirium using a multiple linear regression analysis. All statistical analyses were conducted using SPSS software (ver. 22.0; IBM Corp., Armonk, NY, USA), and statistical significance was accepted at p<0.05.
A total of 1279 patients were admitted to the SU during the study period; Of these patients, 118 were excluded due to admission to the ICU, global aphasia, sensory aphasia, and/or coma, and 218 did not provide informed consent. Thus, 943 patients were ultimately included in the delirium cohort; the rate of incident delirium was 10.18% (96 of 943 patients).
Initially, the present study aimed to evaluate the outcomes of these 96 delirium patients by the motor subtype, but one of the patients was discharged with unresolved delirium and could not be contacted. Thus, 95 patients were included in the final analyses (
The results of the multiple linear regression analysis for the outcome variables are shown in
This study examined the relationship between the delirium motor subtypes and the clinical characteristics and outcomes in ischemic stroke patients. The incidence of delirium in the present study (10.18%) was in the low range of reported results (2.3–61%) [
Of the delirium patients, 35.8% had the hyperactive subtype, followed by the mixed subtype (31.6%), the hypoactive subtype (26.3%), and no subtype (6.3%). Previous studies of post-stroke delirium [
In studies [
The NIHSS and mRS scores on admission were the highest in the hypoactive subtype groups among all of the motor subtype groups. This suggests that the incidence of hypoactive delirium may be higher in patients with more severe stroke symptoms and poorer physical function. Several studies [
Meagher et al. [
The assessment of delirium is often difficult and many cases may be missed, especially in stroke patients, due to the high prevalence of language disorders, neglect, and mood disturbances that can be confused with delirium. Therefore, systematic assessments and longitudinal observations by medical personnel will be necessary to yield reliable data. In our study, assessments were conducted every day using screening methods with high sensitivity and specificity, and the final diagnosis was based on a daily observational chart provided by medical personnel.
The present study has several limitations that should be considered. First, we performed only a cross-sectional evaluation of the clinical characteristics and symptoms of patients with different motor subtypes of delirium. However, delirium is a complex neuropsychiatric syndrome in which a fluctuating course is a key characteristic in both the DSM and International Classification of Diseases (ICD) diagnostic systems [
In conclusion, the present results suggest that motor subtype of delirium is associated with different characteristics and outcomes in ischemic stroke patients. In particular, the patients with delirium that included elements of the hypoactive motor profile were associated with a greater severe stroke-related disability and poorer outcomes than those without it.
The authors have no potential conflicts of interest to disclose.
Conceptualization: Hee Won Yang, Jeong Lan Kim. Data curation: Miji Lee, Jong Wook Shin. Formal analysis: Hee Won Yang, Jeong Lan Kim. Funding acquisition: Jei Kim, Jeong Lan Kim. Investigation: Hee Won Yang, Jong Wook Shin, Hye Seon Jeong, Jei Kim, Jeong Lan Kim. Methodology: Hee Won Yang, Jei Kim, Jong Wook Shin, Jeong Lan Kim. Project administration: Hee Won Yang, Hye Seon Jeong, Jei Kim, Jeong Lan Kim. Resources: Jei Kim, Jeong Lan Kim. Software: Hee Won Yang, Jong Wook Shin. Supervision: Jei Kim, Jeong Lan Kim. Validation: Hee Won Yang, Jeong Lan Kim, Hye Seon Jeong. Visualization: Hee Won Yang, Jeong Lan Kim. Writing— original draft: Hee Won Yang, Jeong Lan Kim. Writing—review & editing: Jeong Lan Kim, Jei Kim, Hee Won Yang.
Flow diagram of the study.
Demographic and clinical characteristics of the 95 patients with delirium based on the DSM-5 criteria
Variable | Total (N=95) |
---|---|
Age (years), mean±SD | 77.58±7.26 |
Sex (male), N (%) | 55 (57.9) |
Hyperactive type, N (%) | 34 (35.8) |
Hypoactive type, N (%) | 25 (26.3) |
Mixed type, N (%) | 30 (31.6) |
No subtype, N (%) | 6 (6.3) |
Number of medications received, mean±SD | 5.81±3.13 |
Comorbid cognitive impairment, N (%) | 17 (17.9) |
NIHSS score at admission, mean±SD | 5.41±4.50 |
Mean K-DRS-98 severity score, mean±SD | 18.39±4.13 |
Duration of delirium (days), mean±SD | 7.10±6.36 |
SD: standard deviation, NIHSS: National Institutes of Health Stroke Scale, K-DRS-98: the Korean version of the Delirium Rating Scale-Revised-98
Clinical characteristics and motor subtypes of the 95 patients with delirium
Variable | Hyperactive (N=34) | Hypoactive (N=25) | Mixed (N=30) | No subtype (N=6) | p |
---|---|---|---|---|---|
Sex (male), N (%) | 22 (64.7) | 14 (56.0) | 18 (60.0) | 1 (16.7) | 0.16 |
Age (years), mean±SD | 78.76±5.50 | 76.76±8.78 | 77.36±7.39 | 75.33±9.29 | 0.90 |
BUN (mg/dL), mean±SD | 16.04±5.23 | 17.96±5.89 | 21.05±8.53 | 18.07±6.89 | 0.03 |
Number of medications received, mean±SD | 5.20±2.70 | 6.08±3.39 | 5.96±3.27 | 7.33±3.61 | 0.33 |
Comorbid cognitive impairment, N (%) | 5 (14.7) | 3 (12.0) | 7 (23.3) | 2 (33.3) | 0.21 |
History of delirium, N (%) | 4 (11.8) | 2 (8.0) | 6 (20.0) | 0 (0.0) | 0.87 |
Lesion, side | |||||
Left hemisphere, N (%) | 8 (23.5) | 7 (28.0) | 11 (36.7) | 3 (50.0) | |
Right hemisphere, N (%) | 18 (52.9) | 13 (52.0) | 13 (43.3) | 3 (50.0) | 0.13 |
Both hemisphere, N (%) | 8 (23.5) | 5 (20.0) | 6 (20.0) | 0 (0.0) | |
NIHSS score on admission, mean±SD | 3.97±3.42 | 6.72±4.75 | 6.53±5.10 | 2.50±1.87 | 0.02 |
mRS score on admission, mean±SD | 2.44±1.52 | 3.96±1.24 | 3.33±1.29 | 2.33±1.03 | <0.01 |
SD: standard deviation, BUN: blood urea nitrogen, NIHSS: National Institutes of Health Stroke Scale, mRS: modified Rankin Scale
Motor subtypes and outcomes in the 95 patients with delirium
Variable | Hyperactive (N=34) | Hypoactive (N=25) | Mixed (N=30) | No subtype (N=6) | P |
---|---|---|---|---|---|
Duration of delirium (days), mean±SD | 4.17±3.96 | 8.68±6.49 | 9.96±7.29 | 2.83±2.31 | <0.01 |
Mean K-DRS-98 severity, mean±SD | 17.83±4.17 | 18.43±3.91 | 19.27±4.94 | 17.00±2.60 | 0.57 |
Highest K-DRS-98 severity, mean±SD | 19.09±4.53 | 21.32±5.14 | 22.46±5.33 | 18.00±4.00 | 0.03 |
Length of stay (days), mean±SD | 15.14±14.71 | 36.88±27.71 | 21.90±19.10 | 13.83±16.83 | <0.01 |
Institutionalization, N (%) | 11 (32.4) | 16 (66.7) | 12 (41.4) | 1 (16.7) | 1.00 |
Died during hospitalization, N (%) | 0 (0.0) | 1 (4.0) | 1 (3.3) | 0 (0.0) | 0.70 |
NIHSS score at discharge, mean±SD | 3.17±4.53 | 6.36±5.42 | 3.66±3.31 | 1.83±2.56 | 0.03 |
mRS score at discharge, mean±SD | 2.00±1.67 | 3.44±1.55 | 3.00±1.62 | 1.66±1.36 | <0.01 |
SD: standard deviation, K-DRS-98: the Korean version of the Delirium Rating Scale-Revised-98, NIHSS: National Institutes of Health Stroke Scale, mRS: modified Rankin Scale
Predictors of outcome variables in the 95 patients with delirium (multiple linear regression analysis)
Duration of delirium |
Highest K-DRS-98 severity |
Length of stay |
NIHSS at discharge |
mRS at discharge |
||||||
---|---|---|---|---|---|---|---|---|---|---|
B | P | B | P | B | P | B | P | B | P | |
NIHSS at admission | -0.05 | 0.72 | -0.10 | 0.45 | -0.28 | 0.59 | 0.33 | <0.01 | 0.02 | 0.54 |
mRS at admission | 0.79 | 0.10 | -0.16 | 0.69 | 4.25 | 0.01 | 0.34 | 0.31 | 0.44 | <0.01 |
BUN | -0.03 | 0.28 | -0.03 | 0.21 | -0.08 | 0.40 | -0.02 | 0.25 | -0.01 | 0.15 |
Motor subtypes | ||||||||||
(Hypoactive, hyperactive) | 3.51 | 0.04 | 2.81 | 0.05 | 16.21 | <0.01 | 1.78 | 0.14 | 0.71 | 0.10 |
(Mixed, hyperactive) | 5.58 | 0.01 | 4.13 | 0.02 | 4.63 | 0.38 | -0.41 | 0.71 | 0.66 | 0.10 |
(No subtype, hyperactive) | -1.37 | 0.59 | -1.28 | 0.56 | -1.35 | 0.87 | -0.83 | 0.65 | -0.26 | 0.69 |
The motor subtype of delirium was represented as three dummy variables with the hyperactive subtype serving as the reference group. B: unstandardized coefficient, NIHSS: National Institutes of Health Stroke Scale, mRS: modified Rankin Scale, BUN: blood urea nitrogen, K-DRS-98: the Korean version of the Delirium Rating Scale-Revised-98