Comparing Symptoms of Delirium in Adults and Children SUSAN BECKWITT TURKEL, M.D. PAULA T. TRZEPACZ, M.D. C. JANE TAVARE´, M.S.
Delirium is presumed to be the same syndrome in all ages. Comparing pediatric and adult studies, the authors found many of the same symptoms reported, but often at significantly different rates. Sleep–wake disturbance, fluctuating symptoms, impaired attention, irritability, agitation, affective lability, and confusion were more often noted in children; impaired memory, depressed mood, speech disturbance, delusions, and paranoia, more often in adults; impaired alertness, apathy, anxiety, disorientation, and hallucination occurrence were similar. These may represent true differences in the presentation of delirium across the life-cycle, or may be attributable to inconsistent methodologies. Prospective studies are needed to resolve this question. (Psychosomatics 2006; 47:320–324)
D
elirium is a neuropsychiatric syndrome associated with pharmaceutical effects and medical and surgical conditions. Its recognition and accurate diagnosis are fundamental to psychosomatic medical practice. Delirium is typically characterized by disturbances of consciousness, attention, cognition, thought, language, memory, orientation, perception, sleep–wake cycle, behavior, mood, and affect.1 The DSM–IV criteria for the diagnosis of delirium were derived from studies in adults,2 and are also applicable in children and adolescents.3 Symptoms of delirium typically fluctuate over time, which may confound both accurate diagnosis and description of symptom prevalence. It has been proposed that certain “core” symptoms of delirium occur more consistently and may result from a perturbation of critical neural circuitry, irrespective of etiology.4 A wide variety of etiolo-
Received May 17, 2005; accepted October 4, 2005. From the Univ. of Southern California, Keck School of Medicine, Dept. of Psychiatry, Pathology, and Pediatrics; Lilly Research Laboratories, Neurosciences; Univ. of Mississippi School of Medicine; Dept. of Psychiatry; Tufts Univ. School of Medicine; Dept. of Psychiatry; Indiana Univ. School of Medicine, Dept. of Psychiatry. Address correspondence to Dr. Turkel, Children’s Hospital Los Angeles, 4650 Sunset Blvd., Los Angeles, CA 90027. e-mail:
[email protected] Copyright 䉷 2006 The Academy of Psychosomatic Medicine
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gies and mechanisms may alter brain functions in a final common pathway to produce characteristic symptoms of delirium.4,5 Better characterization of core symptoms of delirium might help elucidate its underlying neuropathogenesis.4,5 “Associated” symptoms may occur less consistently and may indicate effects on neural circuits more related to differences in etiology or individual differences in brain structure, function, or response to illness. Most studies of delirium have emphasized risk factors and outcomes, rather than the incidence or pattern of specific symptoms. Comparison of delirium symptoms among patients of different age-groups has not previously been done. In an effort to describe the presentation of delirium across the life-cycle and pursue clues to the fundamental phenomenology of delirium, we undertook a literature review and comparison of reported symptoms in adult and pediatric patients with delirium. METHOD Using the MEDLINE system of the Index Medicus to identify articles on delirium from 1966 through 2003, we obtained articles with specific descriptions of the frequency of individual symptoms associated with delirium in both Psychosomatics 47:4, July-August 2006
Turkel et al. adult and pediatric patients. For each report, we ascertained the diagnostic criteria, reported frequencies of delirium symptoms, demographic data, and number of cases. We made an assumption that clinical interviews and chart reviews to detect delirium symptoms were assessing symptoms with an acceptable degree of accuracy to ensure comparability across studies even though standardized evaluation methods were not used. We assumed the same terms were used to denote the same clinical symptoms. When different but synonymous terms were used, we combined them into a single term. Symptoms were grouped into six categories: daily course (alteration of sleep–wake cycle and fluctuating symptoms), language and thought disturbance (speech disturbance, delusions, and vigilant/ paranoid thinking), cognitive disturbance (alteration of alertness, attention, orientation, impaired memory, and confusion), perceptual disturbances (hallucinations and nonspecified perceptual disturbances), psychomotor alterations (agitation, apathy, or psychomotor retardation; or both, when not specifically noted in the study), and changes in mood and affect (anxious mood, depressed mood, irritability, and labile or abnormal affect). The rates of symptoms in each adult study were compared separately from the rates for the same symptom in pediatric patients. Then, for relevant adult studies combined, we determined the total number of adults with each symptom and calculated the overall adult rate, and then compared the rate noted in children and adolescents. Fisher’s exact chi-square test for homogeneity was used for analysis, with a cutoff of p⬍0.0001. RESULTS From among 2,455 articles found, 10 articles, with a total of 968 adult subjects, were identified that listed rates of symptoms associated with delirium and so were included in the study.6–15 Methods of identifying and assessing delirium patients varied considerably across studies. Even in recent articles, when DSM–III or DSM–III–R were cited, criteria were not consistently applied; different symptoms were reported in each study; most studies did not report all possible symptoms, nor did they use validated, standardized instruments. This variability in the study design complicated comparisons. All studies were cross-sectional. We identified four studies that directly or indirectly addressed the clinical features of delirium in children and adolescents.3,16–18 The first article was a psychological assessment that did not provide specific descriptions of observed symptoms of delirium.16 The next two pediatric Psychosomatics 47:4, July-August 2006
studies were descriptions of patients at risk for delirium, although the diagnosis was not specifically made, and only a few symptoms of delirium were described in each.17,18 These three pediatric studies could not be used for comparison. Only one pediatric study systematically described symptoms of delirium, describing 84 children and adolescents with delirium diagnosed by DSM–III–R criteria.3 Ages in the adult studies ranged from 30 to 100 years. The mean age was reported in 7 of 10 studies, and was over 60 years in all but one study, where the mean age was 52.8 (standard deviation [SD]: 18.2) years. The mean age in the pediatric study was 10.4 years, with a range of 1 to 18 years. Table 1 summarizes findings from the pediatric and adult studies. In the category of “daily course,” fluctuating symptoms and abnormalities of the sleep–wake cycle were recorded in about half of adult reports. Rates for fluctuating symptoms ranged from 40% to 100%, with a combined adult prevalence of 60%, significantly different from the rate of 100% noted in the pediatric cases (p⬍0.0001). Disturbance in sleep–wake cycle ranged in adult studies from 18% to 98%, with a combined rate of 53%, versus 98% for pediatric cases, again significantly different. In the category of cognitive disturbances, impaired attention and alertness might be considered as measuring an overlapping dimension, and were common in pediatric cases (100% and 95%, respectively). Impaired attention in adults ranged from 17% to 100%, although only four studies reported this diagnostic core symptom of delirium. The combined adult prevalence was 65%, significantly lower than the pediatric rate. Impaired alertness (or clouded consciousness) ranged in adults from 48% to 82% (combined, 75%), not significantly different from the pediatric rate. About half of adult studies reported impaired orientation (62%–100%; combined, 76%) and/or confusion (17%– 100%; combined, 72%). Impaired orientation in pediatric patients was similar in prevalence (77%), but confusion was significantly more common (96%). Impaired memory was noted only in three adult reports (64%–100%; combined, 84%), significantly higher than the rate of 52% in pediatric cases. Whether this represented impairment of short- or long-term memory was not designated. Although thought process was not mentioned specifically, the category of language and thought disturbances included speech disturbance, delusional thinking, and paranoia. The type of speech disturbance was not specified, but was noted in five adults studies, ranging from 2% to 68%; combined, 48%. Hypervigilance, or paranoid thoughts, ranged from 7% to 38% in adults; combined prevalence, http://psy.psychiatryonline.org
321
322
3
http://psy.psychiatryonline.org 62 100
100 17
29
22
23 46
43 55 35 24 24
Hallucinations
64 92
52
Impaired Memory
72
96
67
Psychomotor Changes
49 90 80 32 65 44
69 53 55 28 36
Agitation
60 58 59
53
68
61
60
61 63
52
52
0 53
Depressed Mood
48
14 68 47
100 60
73 53
27 20
0 68 19 36 19
Delusions
50
50
86
Irritable Mood
32
93 31
7
79 27 43
Abnormal or Labile Affect
27
31
7
0 38 17
Vigilant/Paranoid
26 Changes in Mood and Affect (% of Cases)
Speech Disturbance 0 2 62
40
45 55
100 100
41 49 98 87
98 18
Fluctuating Symptoms
Daily Course (% of Cases) Sleep–Wake Disturbance
Language and Thought Disturbance (% of cases)
78 52.8 (18.2) 81.4 (7.7) ⬎70 82 (8) 63 (10) 83.7 (5.2)
10.4 (5)
Mean (SD)
Age, Years
Anxious Mood
100 72
98 100
96 17 77
Confusion
44–78 75–100 65 – ⬎85
1–18 30 – ⬎90 50–80
Range
Apathy/Retardation
100 100 76 84 Psychomotor Alterations (% of Cases)
62 64 79
77 100 88
Impaired Orientation
84 60 100 50 58 235 47 48 15 315 40 968
Number of Cases
Bolded values show highly significant difference in adult rate compared with Turkel et al.’s19 pediatric study rate, p⬍0.0001, using Fisher’s exact chi-square test for homogeneity. Empty cells indicate that there were no relevant data given.
30 33
20 23 42 67
78
Perceptual Disturbance
III III III, III–R III–R III–R
IV II III III–R
DSM
Cognitive Disturbance (% of Cases)
2003 1971 1988 1990 1991 1992 1992 1993 1996 1999 1993
48 100 75 65 Perceptual Disturbance (% of Cases)
63
82
95
Impaired Alertness
Studies Reviewed Year
Impaired Attention
Studies Reviewed
Turkel and Tavare´ Morse and Litin6 Sirois7 Francis et al.8 Ross et al.9 Levkoff et al.11 Johnson et al.10 Rockwood12 Koolhoven et al.13 Sandburg et al.14 Cole et al.15 All adult studies combined
Author
TABLE 1.
Comparing Delirium in Adults and Children
Psychosomatics 47:4, July-August 2006
Turkel et al. 27%. Delusions were often described in adults (range: 19%–68%), overall occurring in about one-fourth of cases. Significantly different from adult combined rates, no pediatric cases of speech disturbance, paranoia, or delusions were noted. Hallucinations had similar rates in both adults (individual and combined studies) and children. Hallucinations were reported in 43% of pediatric patients, and ranged from 22% to 55% in seven adult studies; combined, 29%. Nonspecific perceptual disturbance was reported in 20% to 78% of adults patients; combined, 33%. The psychomotor presentation of delirium has been classified in the literature as agitated, apathetic, or mixed. Apathy (68%) and agitation (69%) occurred at similar rates in children. The rate of apathy in adults noted in three reports ranged from 53% to 60%; 59% combined, a rate similar to the pediatric-study rate. Agitation was noted in all but one of the adult studies, ranging from 28% to 90%; combined, 44%, which was significantly lower than the pediatric rate. Nonspecific psychomotor change was noted in two adult studies, with a 72% combined rate. Changes in mood or affect were not often noted in these delirium studies. Children and adults had similar rates of anxious mood (61%). Children were significantly more often described to have irritable mood (86%) or labile affect (79%), compared with adults (combined, 50% and 32%, respectively), whereas only adults were described as depressed (52% combined rate). DISCUSSION Despite the prevalence of delirium and its high associated morbidity and mortality, there is a dearth of research regarding its phenomenology in adults, and the situation for children is even worse. In our analysis of published studies, we found that the same delirium symptoms appear to occur in adults and children, supporting the clinical practice of making a diagnosis of delirium based on DSM criteria in patients of any age. We describe the prevalence rates of delirium symptoms as reported in 11 studies since 1966 that reported the frequency of specific symptoms, most but not all of which utilized DSM criteria for diagnosis. Unfortunately, these reflected a wide variety of methodologies that lacked standardization. Many adult studies failed to solicit the breadth of delirium symptoms. There was a dearth of research on pediatric delirium; only one pediatric study relevant for comparison was found. Also, the adult studies often included geriatric patients, in which there was no systematic exclusion of coPsychosomatics 47:4, July-August 2006
morbid dementia. Eight of 10 adult studies utilized DSM diagnostic criteria, 7 using DSM–III, the version that first explicitly included diagnostic inclusion and exclusion criteria for delirium as a diagnostic entity. Despite this heterogeneity, we felt it important to report and analyze these studies to gain at least a basic understanding of delirium phenomenology across age-groups and to heighten awareness of this needed research topic. We averaged the results across adult studies for which a symptom was reported and compared that to the pediatric study. Impaired alertness, apathy, anxiety, disorientation, and hallucinations were similar in children and adults. Impaired memory, depressed mood, speech disturbance, delusions, and paranoia occurred more often in adults. Sleep– wake cycle disturbance, fluctuating symptoms, impaired attention, irritability, agitation, affective lability, and confusion were more often reported in children. It is difficult to interpret the highly significant (p⬍0.0001) statistical differences in rates of certain symptoms in pediatric as compared with adult patients with delirium. They may represent true differences in the presentation of delirium in children and adolescents versus adults, or they may reflect observer bias or underreporting of symptoms by different authors because of the underuse of structured or standardized instruments. In a study of the sensitivity and specificity of the DSM–IV diagnostic criteria for delirium, inattention or clouding of consciousness was found to be most sensitive for the diagnosis of delirium.15 According to DSM–III and DSM–IV, the cardinal symptom required for the diagnosis of delirium is inattention, suggesting it should be present in 100% of cases, yet this was not the case for adults in our literature review. Thus, despite our initial intention, our analysis cannot address the issue of identifying core symptoms, such as inattention, because of methodological flaws in study designs. Nonetheless, on the basis of results in both adult and pediatric studies, hallucinations and delusions were much less common than other symptoms reported and perhaps are not part of the core symptoms of delirium. This low frequency is consistent with a prospective study of psychotic symptoms in delirium.20 The studies we analyzed were cross-sectional and did not use severity ratings of delirium in conjunction with prevalence of symptoms. The pattern and frequency of symptoms may vary within a delirium episode over its temporal course, with fewer symptoms during the early or subclinical phases or during the later, resolving phases, as compared with the most fulminant phase, when symptoms are numerous and prominent. Concomitant use of a stanhttp://psy.psychiatryonline.org
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Comparing Delirium in Adults and Children dardized delirium severity scale might help account for such differences related to phase of episode, especially when a longitudinal design is not convenient. Also, likely etiologies for the delirium were not collected in these studies. Most delirium cases are multifactorial, and how differing etiologies occurring at different time-points within an episode alter symptom expression is not captured in cross-sectional designs. Use of delirium rating scales in clinical studies of delirium may help standardize reporting of symptoms, and the Delirium Rating Scale (DRS), originally developed for adults, is applicable for pediatric patients.19 However, the DRS and other rating scales group some individual symptoms into one item (e.g., cognition), so the rates of each
specific symptom cannot easily be extracted from the rating scale data. A systematic collaborative study of symptom presentation of delirium diagnosed using consistent criteria in patients of all ages is needed in order to better understand the phenomenology of delirium and determine whether symptom patterns vary among age-groups. Only then, if differences exist, would it be possible to establish common, identifiable core symptoms irrespective of age, or to tell whether observed differences represent changes in brain cyto-architecture and neurochemistry with advancing age. This work was presented as a poster at the Academy of Psychosomatic Medicine Annual Meeting in San Diego, CA, in November 2003.
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