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Psychosomatics 49:300-308, July-August 2008
doi: 10.1176/appi.psy.49.4.300
© 2008 Academy of Psychosomatic Medicine
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* Delirium
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Motor Symptoms in 100 Patients With Delirium Versus Control Subjects: Comparison of Subtyping Methods

David J. Meagher, M.D., MRCPsych, Maria Moran, MRCPsych, Bangaru Raju, M.D., MRCPsych, Dympna Gibbons, MRCPsych, Sinead Donnelly, MRCPI, Jean Saunders, Ph.D., and Paula T. Trzepacz, M.D.

Received September 23, 2006; revised January 19, 2007; accepted January 29, 2007. From the Dept. of Adult Psychiatry, Midwestern Regional Hospital; Health Systems Research Unit, Univ. of Limerick, Limerick, Ireland; Milford Hospice Palliative Care Centre, Limerick, Ireland; Statistical Consulting Unit, University of Limerick, Limerick, Ireland; University of Mississippi Medical School, Jackson, MS; Tufts University School of Medicine, Boston, MA; Indiana University School of Medicine, Indianapolis, IN; and Lilly Research Laboratories, Indianapolis, IN. Send correspondence and reprint requests to Dr. David Meagher, Health Systems Research Unit, Univ. of Limerick, Limerick, Ireland. e-mail: david.meagher{at}ul.ie
© 2008 The Academy of Psychosomatic Medicine


  ABSTRACT

 
TOP
 ABSTRACT
INTRODUCTION
 METHOD
 RESULTS
 DISCUSSION
 REFERENCES
 
BACKGROUND: Different motor presentations of delirium may represent clinically meaningful subtypes. OBJECTIVE: Authors sought to evaluate delirium phenomena. METHOD: They used three non-validated delirium psychomotor subtype schemas, applied to a palliative-care population. Their unique items were merged to comprise a 30-item Delirium Motor Checklist (DMC) used to collect data, rate each schema, and determine subtype frequencies in 100 consecutive DSM–IV delirium patients and 52 medically-matched control subjects without delirium. The Delirium Rating Scale–Revised-98 (DRS–R98) assessed delirium severity, and subtype categorization using its two motor items was compared with the scale that used the psychomotor schema. RESULTS: In delirium, motor disturbance was present in 100% by DMC versus 92% by DRS–R98 motor items; the DMC motor items also significantly distinguished delirium from control subjects. Motor subtype classification (hyperactive, hypoactive, mixed, and none) varied among the four methods, with low concordance across all four methods and 76% concordance for pairwise comparisons. The DRS–R-98 identified the most hypoactive delirium cases. CONCLUSION: Motor disturbances are common in delirium, although whether they represent clinical subtypes is confounded by methodological issues. New motor subtyping methods are needed that are validated in other medical populations, use matched control subjects, and have higher sensitivity and specificity for pure motor features.

Key Words: Delirium • Motor Symptoms

  INTRODUCTION

 
TOP
 ABSTRACT
 INTRODUCTION
METHOD
 RESULTS
 DISCUSSION
 REFERENCES
 
Delirium is an acute disturbance of diffuse cognitive and higher cortical functions resulting from a wide range of etiologies.1,2 Compared with other neuropsychiatric disorders, delirium phenomenology, including the question of whether it has clinically meaningful subtypes, remains poorly understood. The possibility that clinically definable delirium subtypes might inform its neuropathogenesis, treatment, and outcome has been proposed.3 Most interest has focused on possible motor or psychomotor subtypes.4 Two presentations were recognized by the ancient Greeks and Romans, who described lethargus for inertia and sleepiness and phrenitis in patients with excitement and restlessness.5 Twentieth-century neurologists designated hypoactive delirium as acute confusional states or various encephalopathies and hyperactive as "acute agitated delirium." Lipowski5 introduced the concept of hypoactive and hyperactive delirium subtypes before adding a third, "mixed," category,6 recognizing patients with elements of both during an episode. Two other descriptive psychomotor schemas, by Liptzin and Levkoff7 and O’Keefe and Lavan,8 have been used. Others9,10 have used the descriptions of agitation and retardation from the Memorial Delirium Assessment Scale, the Delirium Rating Scale, the Delirium Rating Scale–Revised-98, or visual-analog scales, clinical observation, and agitation/sedation scale ratings (see Table 1) to define motor subtypes.


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TABLE 1. Studies of Motor Subtypes in Delirium



Studies using these various methods suggest that hyperactive, hypoactive, and mixed delirium subgroups may differ regarding their relationship to non-motor symptoms,10–12 etiology,10,13,14 pathophysiology,15 detection rates,16 delirium treatment experience,17–19 and duration of episodes and outcome.7,8,20–22 Poorer prognosis has been variously reported for hypoactive,23–25 hyperactive,22 and mixed subtypes,21 whereas still others report similar outcome regardless of subtype.26,27

These differences in incidence and clinical profile of motor subtypes may be attributable to assessment methods and populations studied. Descriptions of motor subtypes vary considerably and include a variety of behavioral, mood, language, and other symptoms that are not primarily motor, such that checklists should be more accurately termed "psychomotor." The value of these non-motor symptoms in subtyping delirium is unclear. Also, inconsistencies across studies raise doubts about the validity of motor subtypes, especially since core features of cognitive impairment and EEG-slowing appear comparable between hypoactive and hyperactive presentations.12,13

In this study, we assessed motor symptoms in delirium in a consecutive sample of cancer patients with delirium and in control subjects (without delirium) in the same clinical setting to address 1) the frequency of commonly assessed psychomotor symptoms in delirium patients, as compared with matched controls; and 2) how commonly-used subtyping methods compare with each other when applied to a single population with delirium.


  METHOD

 
TOP
 ABSTRACT
 INTRODUCTION
 METHOD
RESULTS
 DISCUSSION
 REFERENCES
 
Design and Subjects
We conducted a prospective cross-sectional descriptive study of psychomotor phenomenology in 100 consecutive cancer patients with DSM–IV-diagnosed delirium admitted to a palliative care center in Limerick, Ireland. This work was conducted as part of a larger study that included assessments of cognition, phenomenology, and etiology.

Subjects with delirium were identified by the attending medical team, who assessed each patient on daily ward rounds for altered mental state and screened suspected cases with the Confusion Assessment Method (CAM).28 The presence of DSM–IV delirium1 was then confirmed by a research physician, who assessed delirium symptoms over the preceding 24 hours by use of the Delirium Rating Scale–Revised-98.29 Ward nurses completed the Delirium Motor Checklist (DMC) independently of the research psychiatrist assessment for the same 24-hour period. Demographics, psychotropic drug exposure at the time of assessment, and notation on the possibility of underlying dementia (from case history or suggested by investigation) were also collected.

A group of non-delirium control subjects (N=52) who were receiving treatment in the same setting as the delirium cohort and with similar approximate age, medical diagnoses, and medication use, were assessed with the DMC to determine the frequency of motor symptoms for a 24-hour period.

Delirium phenomenology and severity were assessed with the Delirium Rating Scale–Revised-98 (DRS–R-98), which was designed for phenomenological assessment by use of anchored descriptive item ratings on Likert scales for its 16 items (13 that comprise the Severity scale plus 3 Diagnostic items).29 It has high interrater reliability, validity, sensitivity, and specificity for distinguishing delirium from among mixed neuropsychiatric populations that include dementia, depression, and schizophrenia.29 DRS–R-98 Severity scale scores range from 0 to 39, with higher scores indicating more severe delirium and a cutoff score of ≥15 consistent with a diagnosis of delirium. DRS–R-98 Items #7 and #8 rate levels of motor agitation and retardation, respectively.

Four methods of defining motor subtypes were applied to the delirium cohort: three psychomotor schemas and the DRS–R-98 motor items. The Lipowski5 description includes a list of hyperactive and hypoactive features without any anchoring descriptions and does not specify a cutoff for features to constitute subtypes such that presence of a single item can constitute evidence for a motoric subtype. The Liptzin and Levkoff7 schema involves descriptions taken from the Delirium Symptom Interview (DSI) and requires at least 3/20 hyperactive and/or 4/8 hypoactive features. The O’Keeffe and Lavan8 schema adapted items from the Brief Psychiatric Rating Scale (BPRS) and Cohen-Mansfield Agitation Inventory to define subtypes, and it utilizes the scoring method from the BPRS. Subtypes were defined as presence of any of four criteria for hyperactivity and or any of six criteria for hypoactivity

Features from the psychomotor subtyping schemas were combined to form the new 30-item Delirium Motor Checklist (DMC), without redundant items, for the purpose of simplifying data collection and capturing motor phenomena more efficiently for analyses. Some features were collapsed into a single item (e.g., swearing, singing, and laughing, from the Liptzin and Levkoff schema, were grouped together under "abnormal content of verbal output"). For the items that overlapped, a consensus description based on both methods was applied. The subtyping is therefore not an exact replication of the original schemas but is, nevertheless, extremely close.

Table 2 lists each DMC item with annotation for corresponding items of each of the three schemas. Each item was rated as present (1) or absent (0) during the previous 24 hours by the key nurse responsible for the patient at the time of assessment. Also, the 30 DMC items were categorized a priori into hyperactive (N=21) or hypoactive (N=9) groups, including subgroups of those that reflected "pure" motor-activity disturbance (Items #1 – #6 for hyperactivity and Items #1 and #2 for hypoactivity) or non-motor disturbance (Items #7 – #21 for hyperactivity and Items #3–#9 for hypoactivity). Information solicited from the DMC was then applied back to each of the subtyping schemas to populate them for each patient. A score of ≥1 on DRS–R-98 Items #7 and/or #8 indicated hypoactivity and/or hyperactivity, respectively. Mixed states required meeting both hyperactivity and hypoactivity criteria for each method.


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TABLE 2. Delirium Motor Checklist: Item Frequency of Psychomotor Features in Delirium Patients and Non-Delirium (Control) Patients



The procedures and rationale for the study were explained to all patients, but because patients had DSM–IV delirium at entry into the study it was presumed that most were not capable of giving informed written consent. Because of the noninvasive nature of the study, ethics committee approval was given to augment patient assent, with proxy consent from the next-of-kin (where possible) or a responsible caregiver for all participants, in accordance with the Helsinki Guidelines for Medical research involving human subjects.

Statistical Analyses
Statistical analyses were conducted with SPSS Version 14.1. Continuous variables for demographic and DRS–R-98 data are expressed as means and standard deviations (SD). The relationship between medication exposure and mean scores on DRS–R-98 motor items (non-normal) were examined by Mann-Whitney U tests. Mann-Whitney U tests were used to compare the frequency of motor items on the DMC between delirium subjects and controls. Fisher’s exact tests were used to compare frequency of individual items on the DMC and the frequency difference between delirium patients and non-delirium control subjects. Chi-square tests were used to compare medication use between delirium patients and non-delirium controls. The degree of concordance between schemas was expressed as the percentage of all delirium patients allocated to the same motor subtype category (hyperactive, hypoactive, mixed, or none). Significance was determined with a p value <0.05, except that Bonferroni correction for multiple comparisons was applied where appropriate.


  RESULTS

 
TOP
 ABSTRACT
 INTRODUCTION
 METHOD
 RESULTS
DISCUSSION
 REFERENCES
 
Subjects
The 100 delirium patients (50% men; mean age 70.1 [SD: 11.5] years) were assessed over a 2-year period between January 2002 and December 2003. These delirium patients had a mean DRS–R-98 Severity score of 16.1 (5.5); 17 patients had documented preexisting cognitive deficit. The non-delirium controls were 54% men, with a mean age of 66.1 (10.8) years, which was somewhat younger than the delirium group (p=0.04).

All delirium patients were taking medications, with a median of six medications per patient (range: 1–16). Of these, 91% were receiving at least one psychotropic or psychoactive agent: benzodiazepines (79%), antipsychotics (43%), antidepressants (31%), opiates (72%), corticosteroids (45%), and psychostimulants (6%). The only significant relationship between category of medication and motor profile was that patients receiving psychostimulants had higher scores on the DRS–R-98 Retardation item (p=0.03).

Medication exposure was similar in the non-delirium control group, with a median of six medications per subject (range: 2–12). The frequency of use of specific agents was not different between delirium patients and non-delirium controls (benzodiazepines, 71%; opiates, 60%; corticosteroids, 31%; and psychostimulants, 6%) except that there was less antidepressant use (15%) in controls (p=0.03) that was no longer significant after an appropriate Bonferroni correction and a trend (p=0.06) for less use of antipsychotics (27%) in control subjects.

Motor Symptom Profile
The frequency of psychomotor disturbances in delirium patients and non-delirium controls by DMC is shown in Table 2. Every delirium patient had evidence of at least some psychomotor disturbance, and 76 had evidence of both hyperactive and hypoactive features. However, when considering only "pure" DMC motor features, 92 had motor disturbance: 75 hyperactive, 51 hypoactive, and 34 both. Eighteen items on the DMC were more frequent in delirium than control patients at the p<0.05 level of significance, and after correction for multiple comparisons (at p<0.001), 10 items remained significant.

In contrast, motor disturbances were less frequent in non-delirium controls. Although 75% of control subjects had psychomotor disturbances rated with the DMC, only 33/52 had evidence of pure motor disturbance (15 hyperactivity, 19 hypoactivity, and only 1 mixed). Overall, DMC items were less common in non-delirium than delirium patients, with median total DMC score 3 versus 9, respectively (p<0.001), median total number of DMC hyperactivity items 0 versus 5 (p<0.001), and median total number of DMC hypoactivity items 1.5 versus 3 (p=0.001).

Although pure motor hyperactive symptoms were more common in delirium patients, many other symptoms lack psychiatric specificity for delirium (e.g., fear, irritability, euphoria, uncooperativeness, hallucinations). On the other hand, hypoactive features were found to be common in both delirium and non-delirium patients, with reduced speed of action and hypersomnolence noted in over one-third of control subjects. Items describing disturbances of speech did not occur significantly more often in delirium patients, as compared with non-delirium controls, nor did many affective (e.g., fear), behavioral (e.g., combativeness) or perceptual disturbances (e.g., hallucinations), after Bonferroni correction. DMC items that both significantly differentiated delirium from control patients (p<0.001) and occurred in ≥33% were restlessness (62%), distractibility (62%), tangentiality/irrelevant talk (52%), loss of control of activity (39%), increased activity levels (39%), irritability (38%), and involuntary movements (35%), for hyperactive items; and hypersomnolence (62%) and withdrawal/unawareness (42%) for hypoactive items.

Out of concern that the results from the 17 patients with preexisting cognitive impairment might have affected our findings, we repeated the above analyses for those patients without such evidence (N=83). These analyses did not alter findings with regard to comparison of medication exposure, nor for DMC items comparing delirium patients and non-delirium controls. Therefore, we continue to report on all 100 cases.

Comparison of Motor Subtype Methods
The frequency of motor subtypes in delirium patients according to the four methods is depicted in Figure 1 [A]. Hyperactive patients are easily identified by all methods. Liptzin and Levkoff7 use stricter criteria and identify the highest percentage of patients who have no subtype (19%), whereas the other methods are similar to each other. Conversely, the Lipowski6 criteria are the least strict, thereby identifying the most mixed cases (64%), whereas the DRS–R-98 and Liptzin and Levkoff7 methods identified the fewest mixed cases (28% each). The DRS–R-98 identified two to three times as many hypoactive patients as the other three (31%).


Figure 1
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FIGURE 1.  Frequency of Motor Subtypes, According to Four Subtyping Methods, in Delirium Patients (N=100) and According to Three Methods in Matched Subjects Without Delirium (N=52)


Table 3 depicts the degree of consensus among the methods, which was only 34% across all four simultaneously. Pairwise comparisons yielded concordance rates varying from over 75% of patients, when comparing the two least strict methods (Lipowski6 versus O’Keeffe and Lavan8) to 48% concordance between the two strictest methods (Liptzin and Levkoff7 versus the DRS–R-98).


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TABLE 3. Degree of Concordance (%) Among Four Methods of Defining Motor Subtypes When Applied to a Single Delirium Population (N=100)



Nonconcordance errors did not follow a simple pattern. This is highlighted by a comparison of patient allocation by the most discordant methods (Liptzin and Levkoff versus the DRS–R-98), where the 19 patients classed as No Subtype by Liptzin and Levkoff were classified by the DRS–R-98 method as No Subtype (N=2), hypoactive (N=10), mixed (N=1), and hyperactive (N=6). Conversely, the eight patients classed as No Subtype according to the DRS–R-98 method were classed by the Liptzin and Levkoff method as No Subtype (N=2), hypoactive (N=1), mixed (N=1), and hyperactive (N=4). This degree of variability indicates fundamental differences in subtype allocation between these methods.

Figure 1 [B] shows the frequency of motor subtypes when the schema were applied to non-delirium controls. As compared with the delirium group, a higher percentage of controls are classified as No Subtype by all three schemas, with Liptzin and Levkoff identifying the most (58%). A higher percentage of controls were categorized as hypoactive than were delirium patients by each schema, whereas far fewer controls were either hyperactive or mixed, using any schema. However, because the mixed subtype includes hypoactive features, combining prevalence for hypoactive and mixed subtypes finds numerically more patients in delirium than control groups, especially for the stricter Liptzin and Levkoff schema (45% versus 25%). The strictest schema, Liptzin and Levkoff, found far fewer controls (42%) meeting criteria for any motor subtype than the looser schema, where, for example, Lipowski’s method classified 75%.


  DISCUSSION

 
TOP
 ABSTRACT
 INTRODUCTION
 METHOD
 RESULTS
 DISCUSSION
REFERENCES
 
We describe a comprehensive and controlled study of the phenomenology of motor symptoms and subtypes in delirium. Delirium was diagnosed by DSM–IV criteria, and cases met the severity cutoff on the DRS–R-98, a well-validated scale. It is the first study to compare four methods simultaneously applied in the same delirium cohort. Also, we studied non-delirium control subjects in the same treatment setting to determine whether psychomotor symptoms described in commonly-used psychomotor schemas are in fact unique to delirium, given that previous work was uncontrolled, and schemas were unvalidated lists of clinically-defined symptoms. Most previous work combines motor symptoms with a variety of speech, cognitive, and behavioral features into subtype descriptions, determined a priori and without an external validator. We addressed such assumptions by condensing nonredundant features from three published psychomotor schemas into a single checklist, the DMC, which was rated independently from the DRS–R-98 and analyzed in comparison to controls. The relative frequencies for individual symptoms in delirium versus control groups who have comparable medical diagnoses, medication use, and treatment setting offers the opportunity to select features of the delirium state that might be more specific for the definition of motor subtypes, The selection of features that occur with significantly higher frequency and with motor phenomena with specificity to delirium should lend greater accuracy to a subtyping method.

We found that some psychomotor disturbances rated on the DMC occurred in all patients with delirium. When the analysis was restricted to DMC features that directly reflect motor disturbance (so-called "pure" motor features, as shown in bold in Table 2), the vast majority of delirium patients (92%) still had some evidence (i.e., at least one feature) of a motor disturbance (75% hyperactive, 51% hypoactive), as compared with controls (63%; with 29% hyperactive and 36% hypoactive). These data support the idea that motor disturbances are a characteristic feature of delirium, even though DSM–IV does not include motor alterations as a key delirium symptom. Mixed cases using the "pure" motor DMC items (at least one hypoactive and one hyperactive item) occurred in 34% of delirium versus only 2% of controls, suggesting that fluctuation of symptoms over a 24-hour period is more characteristic of delirium.

In order to understand better which features are more specific to delirium, we identified a subset of DMC items that were both frequent (≥33%) and occurred at significantly higher frequency in delirium patients than in non-delirium controls. These were 7 hyperactive and 2 hypoactive features out of 30 DMC items, suggesting that a far smaller number of symptoms may in fact be tenable for clinical assessment of motor subtypes than is generally done by use of schema. These may help in the search for a concise subjective rating system for motor subtypes.

The DMC items assessed different aspects of motor movement. Speed of action (when Bonferroni-corrected) did not differentiate either hyperactive or hypoactive delirium from controls, whereas amount of and control over movements differentiated among hyperactive items, with "restlessness" especially useful. Listlessness/apathy did not differentiate among hypoactive items, except at the uncorrected p<0.05 level, perhaps because it assesses more of a motivation domain. Features of speech, a motor expression of language, did not distinguish delirium patients from control subjects.

Our data suggest that pure motor symptoms (4 of 6 DMC hyperactive items) are more differentiating and meaningful than psychomotor symptoms in defining motor subtypes. However, hypoactive motor symptoms were less differentiating between groups, for several reasons. Hypoactivity is more challenging to measure, although the DRS–R-98 motor items, using concise motor ratings, found twice as many hypoactive-subtype cases than did the schema, suggesting that the measurement method may be a factor. This cancer population uses psychoactive polypharmacy, where sedative effects are present in both patients and controls. Interestingly, psychostimulants were the only medication category significantly related to any motor feature in delirium patients (higher DRS–R-98 Retardation scores), suggesting that their clinical use was to improve activity levels in this more hypoactive cancer population. Medication use by category did not distinguish the groups except that use of antidepressants and antipsychotics were somewhat lower in controls than delirium patients, with antipsychotics probably related to delirium treatment and antidepressants possibly contributing to delirium.

The comparisons of patient allocation into motor subtypes revealed substantial inconsistency across the four methods, with concordance rates between any two methods varying from one-half to two-thirds of cases. Only 34 patients were assigned to the same subtype by all four methods. Moreover, nonconcordance was not explained by simple differences in patient allocation, with patients classed as No Subtype by one method and classified as hypoactive, mixed, or hyperactive by another. We suspect that inadequate use of validated and standardized assessment methods contributes substantially to inconsistent findings in the published literature, confounding attempts to determine whether motor subtypes even truly exist, let alone assess their clinical implications. Greater consensus is needed regarding valid assessment tools and phenomenological definitions. One challenge is how to measure hypoactivity more reliably where certain non-motor symptoms, especially somnolence, present confounds.

Our analysis of motor subtypes among non-delirium control patients highlights the lack of specificity for delirium within current subtyping schemas, where 42%–75% of non-delirium controls met criteria for a motor subtype, depending on the schema applied, with the hypoactive subtype being most common in this palliative-care population. This is surprising and could be related to poor specificity and sensitivity of these schemas or to the challenge of detection of hypoactivity, in general, although some individual hypoactive symptoms on the DMC did occur significantly more often in delirium patients than controls. Also, controls had a far lower percentage of mixed cases than did the delirium group, and this subtype encompasses both hypoactive and hyperactive features. Whether the difficulty differentiating hypoactivity is unique to our patient population is not clear. Comparison with the literature for a variety of populations reveals much variability (6%–84% in Table 1) in hypoactive subtype frequency in delirium patients, although matched controls are not utilized. Higher percentages are noted in studies using motor items from standardized delirium rating scales (e.g., the MDAS and DRS) instead of symptom checklists in hospitalized cancer or AIDS patients or in postoperative geriatric populations. In our study, the DRS–R-98 motor items detected 2–3 times as many hypoactive cases as did the three psychomotor checklists. Therefore, both method for subtyping and characteristics of patient populations may be factors in determining rates of hypoactivity in delirium. Clearly, more studies are needed that use medically matched controls and sensitive, specific motor subtyping methods in a variety of homogeneous patient populations.

To address methodological issues for measurement of motor subtypes, we recommend trying to increase sensitivity and specificity of an instrument via its scoring and selection of features that reflect pure motor manifestations and features specific to delirium patients as compared with medically-matched controls. Furthermore, we recommend measuring delirium symptoms from other phenomenological domains, such as cognition, perception, speech, thought process, sleep, and mood lability, by use of separate, validated delirium-measurement tools. Features like uncooperativeness, fear, and irritability occur in many other psychiatric and medical conditions and are nonspecific. It may well require further study to decide which aspects of motor functions should be utilized to define clinically-observed motor activity or whether the simplicity of using rating scale motor items might suffice.

Our findings may not be generalizable to other delirium populations because of polypharmacy that can affect the symptom profile, although categorical medication analyses found our patient groups largely comparable. Our inclusion of 17 comorbid dementia cases is possibly confounding, although not as discerned by analyses. Previous work found delirium phenomena not appreciably affected by comorbid dementia because delirium overshadows it.30 Comorbidity with dementia, also a delirium risk factor, makes ours a real-world sample.

The fluctuating nature of delirium dictates that serial assessments are required in order to evaluate changing severity and phenomenology during an episode. Our sample’s range of DRS–R-98 severities probably captured peak and non-peak symptom levels, although this is not the same as longitudinal ratings to assess course of motor features and stability of subtypes during an episode of delirium. Lawlor et al.31 suggest that subtypes are not stable over time, but do not offer supporting data; others suggest that hypoactivity as a symptom is more enduring.25,32 The existence of mixed subtypes suggests that motor characteristics can fluctuate during a 24-hour period such that this probably also occurs over days.

This study highlights the lack of consistency in approaches to defining motor subtypes of delirium and calls into question the validity of existing literature on the prevalence and clinical consequences of motor subtypes in delirium. The use of the DRS–R-98 as an independent measure of pure motor activity is an important aspect of our work, but electronic motion analysis could provide a further objective measure of motor activity.33,37


  ACKNOWLEDGMENTS

 
This study was supported through departmental funds at Limerick Mental Health services. Unrelated to this research, Dr. Meagher has received research grant funding from Astra-Zeneca and has acted as an advisory consultant for Pfizer, Eli-Lilly, Bristol-Meyers, and Janssen Pharmaceuticals, and has received travel support from Smith-Kline Beecham, Eli-Lilly, Astra-Zeneca, Novartis, Wyeth, and Bristol-Meyers Pharmaceuticals, Ltd. Dr. Trzepacz is a full-time salaried employee of Eli Lilly and Company and a shareholder of Lilly. Lilly does not have a product with an indication for delirium. As of this time, Dr Trzepacz has not received royalties for the use of her copyrighted Delirium Rating Scale–Revised-98, nor does she accept payment for teaching or academic research collaborations (including NIH grant).


  REFERENCES

 
TOP
 ABSTRACT
 INTRODUCTION
 METHOD
 RESULTS
 DISCUSSION
 REFERENCES
 

  1. American Psychiatric Association: Diagnostic and Statistical Manual of Mental Disorders-Text Revision, 4th Edition, TR. Washington, DC, American Psychiatric Publishing, Inc, 1994
  2. World Health Organization: The ICD-10: Classification of Mental and Behavioral Disorders. Geneva, Switzerland, World Health Organization, 1993
  3. Trzepacz PT: The neuropathogenesis of delirium: a need to focus our research. Psychosomatics 1994; 35:374–391[Abstract/Free Full Text]
  4. Meagher DJ, Trzepacz PT: Motoric subtypes of delirium. Semin Clin Neuropsychiatry 2000; 5:75–85[Medline]
  5. Lipowski ZJ: Transient cognitive disorder in the elderly. Am J Psychiatry 1983; 140:1426–1436[Abstract/Free Full Text]
  6. Lipowski ZJ: Delirium in the elderly patient. N Engl J Med 1989; 320:578–582[Medline]
  7. Liptzin B, Levkoff SE: An empirical study of delirium subtypes. Br J Psychiatry 1992; 161:843–845[Abstract/Free Full Text]
  8. O’Keeffe ST, Lavan JN: Clinical significance of delirium subtypes in older people. Age Ageing 1999; 28:115–119[Abstract/Free Full Text]
  9. Platt MM, Breitbart W, Smith M, et al: Efficacy of neuroleptics for hypoactive delirium. J Neuropsychiatry Clin Neurosci 1994; 6:66[Free Full Text]
  10. Gupta AK, Saravay SM, Trzepacz PT, et al: Delirium motoric subtypes. Psychosomatics 2005; 46:158
  11. Sandberg O, Gustafson Y, Brannstrom B, et al: Clinical profile of delirium in older patients. J Am Geriatr Soc 1999; 47:1300–1306[Medline]
  12. Meagher DJ, O’Hanlon D, O’Mahony E, et al: Relationship between symptoms and motoric subtype of delirium. J Neuropsychiatry Clin Neurosci 2000; 12:51–56[Abstract/Free Full Text]
  13. Ross CA, Peyser CE, Shapiro I, et al: Delirium: phenomenologic and etiologic subtypes. Int Psychogeriatr 1991; 3:135–147[CrossRef][Medline]
  14. Meagher DJ, O’Hanlon D, O’Mahony E, et al: Relationship between etiology and phenomenologic profile in delirium. J Geriatr Psychiatry Neurol 1998; 11:146–149[Medline]
  15. Balan S, Leibowitz A, Zila SO, et al: The relation between the clinical subtypes of delirium and the urinary level of 6-SMT. J Neuropsychiatry Clin Neurosci 2003; 15:363–366[Abstract/Free Full Text]
  16. Inouye SK: The dilemma of delirium: clinical and research controversies regarding diagnosis and evaluation of delirium in hospitalized elderly medical patients. Am J Med 1994; 7:278–288
  17. Meagher DJ, O’Hanlon D, O’Mahony E, et al: The use of environmental strategies and psychotropic medications in the management of delirium. Br J Psychiatry 1996; 168:512–515[Abstract/Free Full Text]
  18. Breitbart W, Tremblay A, Gibson C: An open trial of olanzapine for the treatment of delirium in hospitalized cancer patients. Psychosomatics 2002; 43:175–182[Abstract/Free Full Text]
  19. Uchiyama M, Tanaka K, Isse K, et al: Efficacy of mianserin on symptoms of delirium in the aged: an open-trial study. Prog Neuro-Psychopharmacol Biol Psychiatry 1996; 20:651–656[CrossRef][Medline]
  20. Treloar AJ, MacDonald AJD: Outcome of delirium, part 1. Int J Geriatr Psychol 1997; 12:609–613[CrossRef]
  21. Kobayashi K, Takeuchi O, Suzuki M, et al: A retrospective study of delirium subtype. Jpn J Psychiatry Neurol 1992; 46:911–917[Medline]
  22. Marcantonio E, Ta T, Duthie E, et al: Delirium severity and psychomotor types: their relationship with outcomes after hip fracture repair. J Am Geriatr Soc 2002; 50:850–857[CrossRef][Medline]
  23. Olofsson SM, Weitzner MA, Valentine AD, et al: A retrospective study of the psychiatric management and outcome of delirium in the cancer patient. Support Care Cancer 1996; 4:351–357[CrossRef][Medline]
  24. Kelly KG, Zisselman M, Cutillo-Schmitter T, et al: Severity and course of delirium in medically hospitalized nursing facility residents. Am J Geriatr Psychiatry 2001; 9:72–77[CrossRef][Medline]
  25. Lam PT, Tse CY, Lee CH: Delirium in a palliative care unit. Prog Palliat Care 2003; 11:126–133[CrossRef]
  26. Camus V, Gonthier R, Dubos G, et al: Etiologic and outcome profiles in hypoactive and hyperactive subtypes of delirium. J Geriatr Psychiatry Neurol 2000; 13:38–42[Abstract/Free Full Text]
  27. Santana-Santos F, Wahlund LO, Varli F, et al: Incidence, clinical features, and subtypes of delirium in elderly patients treated for hip fractures. Dement Geriatr Cogn Disord 2005; 20:231–237[CrossRef][Medline]
  28. Inouye SK, van Dyck CH, Alessi CA, et al: Clarifying confusion: The Confusion Assessment Method, a new method for the detection of delirium. Ann Intern Med 1990; 113:941–948[Abstract/Free Full Text]
  29. Trzepacz PT, Mittal D, Torres R, et al: Validation of The Delirium Rating Scale-Revised-98 (DRS-R-98): comparison to The Delirium Rating Scale and Cognitive Test for Delirium. J Neuropsychiatry Clin Neurosci 2001; 13:229–242[Abstract/Free Full Text]
  30. Trzepacz PT, Mulsant BH, Dew MA, et al: Is delirium different when it occurs in dementia? a study using The Delirium Rating Scale. J Neuropsychiatry Clin Neurosci 1998; 10:199–204[Abstract/Free Full Text]
  31. Lawlor PG, Nekolaichuk C, Gagnon B, et al: Clinical utility, factor analysis, and further validation of The Memorial Delirium Assessment Scale in patients with advanced cancer. Cancer 2000; 88:2859–2867[CrossRef][Medline]
  32. Peterson JF, Truman B, Shintani A, et al: The prevalence of delirium subtypes in medical ICU patients. J Am Geriatr Soc 2003; 51:S174
  33. Honma H, Kohsaka M, Suzuki I, et al: Motor activity rhythm in dementia with delirium. Psychiatry Clin Neurosci 1998; 52:196–198[Medline]
  34. Koponen H, Hurri L, Stenback U, et al: Computed tomography findings in delirium. J Nerv Ment Dis 1989; 177:226–231[CrossRef][Medline]
  35. De Rooij S: Delirium subtype identification and the validation of The Delirium Rating Scale-Revised-98 (Dutch version) in hospitalised elderly patients. Int Psychogeriatr 2005;17(suppl 2):262
  36. Okamato Y, Matsuoka Y, Sasaki T, et al: Trazodone in the treatment of delirium. J Clin Psychopharmacol 1999; 19:280–282[CrossRef][Medline]
  37. Leonard M, Godfrey A, Silberhorn M, et al: Motion analysis in delirium: a novel method of clarifying motoric subtypes. Neurocase 2007; 13:272–277[CrossRef][Medline]




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