EARLY

DETECTION

OF AUTISM

843

of Psychology and Child Psychiatry, Institute of Psychiatry,Universityof London, DeCrespignyPark, Psychiatry, 142, 1450—1452. LondonSES8AF; JaneAllen, MD, Genera!Practi WiNG, L. & GOULD, J. (1979) Severe impairments of social interaction andassociated abnormalities in children:epidemiology tioner, WimbledonVillagePractice,35a High St, and classification. Journal of Autism and Developmental Wimbledon,London SWJ95BY;ChristopherGlllberg, VOLKMAR, F., STIER, D. & Co,ori, D. (1985) Age of recognition of pervasive developmental disorders. American Journal of

Disorders, 9, 11-29.

MD, Professor, Department of Child and Adolescent

Psychiatry, Child NeuropsychiatricClinic, University of Gothenburg, S-41345, Gothenburg, Sweden °SimonBaron-Cohen, BAOxon,PhD,MPhil,Senior Lecturer in DevelopmentalPsychology,Departments

An Empirical

Correspondence

Study of Delirium Subtypes

BENJAMIN LIPTZIN and SUE E. LEVKOFF

by systematic clinical research, and that is the Using a structured Instrument, 325 elderly patients admitted to a general hospital for an acute medical purpose of this study. problem were evaluated daly in order to detect Such empirical validation is particularly important symptoms of delirium. Patients were scored for ‘¿hyper since the diagnostic criteria which defme the syndrome active' or ‘¿hypoactlve' symptoms, and then the 125 of delirium have beenexplicitly defmed (American patients with DSM-Ill delirium were rated as ‘¿hyper active type' (15%), ‘¿hypoactlve type' (19%), ‘¿mIxedPsychiatric Association, 1980), revised (American PsychiatricAssociation, 1987),and arebeingrevised type' (52%), or ‘¿neither' (14%). There were no stat again (Frances eta!, 1989), to be consistent with the istically significant differences between the groups

tenth editionof the International Classificationof Diseasesof the World Health Organization (1992). None of thesesetsof criteria currently incorporates British Journal of Psychiatry (1992),161, 843—845 thesubtypesabove.In thispaper,weprovideempirical with respect to age, sex, place of residence, or presence

of dementia. These definitions of subtypes should be studied further.

data concerning the occurrence of different subtypes of delirium, and examinethe characteristicsof each. Delirium has beenrecognisedand described by doctors for over 2000 years. Lipowski (1990) points out that even early Greek and Roman writers distinguished Method two types of what we now think of as delirium. Two groups of patientsover the ageof 65 from a defined ‘¿Phrenitis' was regarded as an acute disorder, usually community (East Boston) and from a long-term care facility associated with fever, featuring cognitive and behavioural disturbances aswell asdisruption of sleep. (Hebrew Rehabilitation Center for the Aged, or HRCA) It wastypically marked by restlessand excitedbehaviour, who wereadmitted to Beth Israel Hospital for medical or in contrast to its opposite condition, ‘¿lethargus', surgicalcareover 18monthswerestudied.Patientsadmitted directly to an intensive-care unit were excluded. The which was characterisedby listlessness,sleepiness, participation rate was79.50/.of all eligiblepatients.In all, inertia, memory loss,and dullingof thesenses. 325 study participants were evaluated within 48 hours of Lipowski (1983) suggested that delirium be the hospital admissionand monitored daily throughout their term used to characterise both hyperactive and hospital stay for symptoms in each domain of DSM-III hypoactive states, rather than distinguishing delirium(i.e. cloudingof consciousness, disorientationl memoryimpairment,perceptualdisturbance,speechdis ‘¿delirium' from ‘¿acute confusion'. More recent literature cited by Lipowski (1990) distinguishes three turbance,psychomotorbehaviour,sleep/wakedisturbance, and fluctuatingbehaviour). subtypes of delirium —¿ the hyperactive—hyperalert, Since the study involved daily assessmentsof a large the hypoactive-hypoalert, and the mixed - but points numberof patientsovertheir entirehospitalstay,it was out that only one, unpublished, study presented data impractical to have a clinician conduct all the assessments. on the frequency of the respective subtypes, which An instrument(theDeliriumSymptomInterview,or DSI) found 55% of a small sample to be ‘¿active'. Lipowski wasdeveloped byaninterdisciplinary groupwhichdescribed suggested that clinical impressions of the frequency thebehavioursandresponses associated with a particular and characteristics of subtypes need to be validated symptom in explicit, operational terms, so that a research

844

LIPTZIN & LEVKOFF

assistant could perform the assessments.An extensive training manual was developedwhich provided specific definitions and instructions for a non-clinician on how to interpret and rate particular types of behaviour. This producedexcellentinter-raterreliabilitybetweentwo research assistants.The instrumentwasalsofield testedin 50elderly in-patients, and found to have good agreementwith the symptomratingsdoneby a trainedneurologistanda trained psychiatrist, both of whom were experiencedand expert

characteristics of eachgroup.Therewereno statistically significant differences between the groups. However, the

hyperactivegrouphada lengthof staycomparableto that of theneithergroup,andthelowestmortalityratein the hospital and at six-month follow-up

of any group.

Thefollowingcaseexamples illustrateeachsubtypefound in this study. Hyperactive

type. Mr A was a 78-year-old man from

the HRCA who wasadmitted for an electiveherniarepair.

in the care of the elderly (Albert et a!, 1992).

He had a history of hypertensiveheart diseaseand

Carers or relatives familiar with the patient's func tioning wereinterviewedto determinewhether symptoms of delirium observedon the patient's initial evaluation in thehospitalwereof recentonset,andthusdueto delirium and not a pre-existing dementia. The patient's medical

hypothyroidism treated with medication. He had no past historyof alcoholor sedativeuse.On day 4 after hissurgery under generalanaesthesia,he requiredtransfer to the intensive-care unit and was placed on a respirator. He began

to developsymptomsof deliriumonday5, andwasnoted

to be restless,inattentive, distractible, tangential, labile, andto haveloudandfastspeech,andvisualhallucinations. His symptoms beganto clearandhewasdischarged onday Patientswerediagnosedas delirioususingDSM—III 7. At six-month follow-up he had few residualsymptoms. criteria, sincethosewerethe onesavailablewhenthe study Hypoactive type. Mr B was a 93-year-old man from the beganand weresubsequentlyfound to bethemostinclusive HRCA who was admittedbecauseof a gastrointestinal (Liptzin eta!, 1991).Theoverallprospectivestudyof delirium haemorrhage. He was known to have a history of dementia, in elderlyin-patientshasbeendescribedpreviously(Levkoff of Alzheimer'sor multi-infarcttype. He hada historyof eta!, 1991a,b). Thedatafromthisstudyareuniquebecause chronicobstructivepulmonarydisease,hadbeenadmitted data on symptoms were collected using the DSI without severalmonths previously becauseof a seriousfall, was incontinent of urine, and febrile. He becameprogressively requiring that patients meet specific criteria for delirium. This allowed us to define the specific phenotypesaccording to moredisorientated,to the point of thinkinghe wasnot specificsymptompatterns.This studyalsohastheimportant really in a hospital and being unaware of his medical advantageof not excluding patients with dementia. condition.He was sleepyand lethargicduringthe day, Specific symptomson the DSI were defined as ‘¿hyperwould drift off during a conversation,but could be easily active'or ‘¿hypoactive'. The former includedhypervigilance, aroused.He wasinattentive and would stareinto spaceat restlessness,fast or loud speech, irritability, combativeness, times. He spoke little but, when asked, he expressedthe impatience,swearing,singing,laughing,uncooperativeness, belief that people were trying to harm him. His medical euphoria, anger, wandering,easystartling, fast motor condition stabilisedoverseveraldays,hebecamesomewhat responses,distractibility,tangentiality,nightmares,and morealert,attentiveandtalkative,andwasdischarged on day 6. At six-monthfollow-up his symptomshadimproved. persistent thoughts. ‘¿Hypoactive' symptoms included unawareness, decreasedalertness,sparseor slowspeech, Mired type.Mrs C wasa 93-year-oldwomanliving at lethargy,slowedmovements,staring,and apathy.Delirious home,withassistance. Shehada historyof wellcontrolled patients who had three or more different symptoms of hypertension,ischaemicheart disease,nephrectomy, and ‘¿hyperactivity' at any time of their hospital staywererated severalfalls. Before admissionshe had becomemore disorientated to place(thinkingshewasin adifferenttown) as ‘¿hyperactive'. Those who had four or more different symptomsof ‘¿hypoactivity' at any time of their hospital andto time(thinkingit wasmorningwhenit wasevening). She did not recogniseher nephew's wife one night. She stay were rated as ‘¿hypoactive'. These cut-off scores were chosento identify a pattern or clusterof symptomsrather developed auditoryhallucinations (hearingmendownstairs than an isolated symptom. Furthermore, these cut-off scores in her kitchen)and visualhallucinations(seeinga kitten differentiated between patients with DSM—IIIdelirium on her floor). She became hypervigilant and agitated, (86°!. of whom met oneor theothercut-off score)andthose often shouting at her carers. In the hospital the above without (77°!.of whom met neither cut-off). Those who symptomscontinued, along with restlessness,irritability, were rated as positive on both scores were considered agitation, and severelability. At the sametime, shewould ‘¿mixed'. Those who were rated as negative on both scores drift off at timesor haveslowor sparsespeech,would stare were considered ‘¿neither'. These four groups were then into space,or be lethargic. No specific medicalcausewas comparedin termsof age,sex,placeof residence,lengthof foundfor hercondition,andafter 113daysin thehospital hospitalstay,and mortality in thehospitalandat sixmonths. shewasdischargedto a nursinghome,whereherbehaviour continued over the next six months. records were also reviewed for documentation of dementia

by the patient's geriatrician from the two sites,which were both activelyinvolvedin researchon dementiain theelderly.

Results Of the 125patientswith DSM—IIIdelirium, 19(150/.)were rated asonly hyperactive,24 (19%) wereonly hypoactive, 65(520/.) had a mixed picture, and 17patients (l4%) had neither hyper- nor hypoactivity. Table 1 presents the

Discussion In the 125 patients with DSM—III delirium in this study, subtypes could be identified on the basis of

pattern of symptoms. The mixed type was most

SUBTYPES

845

OF DELIRIUM

Table 1 Number and characteristics of patients with DSM—lll delirium and hyperactive, hypoactive or mixed features HyperactiveHypoactiveMixedNeitherTotalNumber19246517125Mean years84.786.585.987.486.1% age:

men26.325.041.552.937.6% HRCA57.962.558.558.859.2% from dementia47.441.750.835.346.4Mean with days9.218.924.28.918.8In-hospital lengthof stay: dead012.54.65.95.6Six-month mortality: % mortality: % dead5.325.029.217.723.2

common. This is consistent with the notion that patients with DSM-III delirium tend to fluctuate, and that hypoactive symptomsare frequently seenalong with the hyperactive symptoms that were previously limited to ‘¿delirium' as opposed to ‘¿acute confusion'. It is possible that the lack of any statistically significant differences between the groups could be due to the small sample size in the subgroups. It is intriguing that the hyperactive group had a shorter length of stay and lower mortality rate than either the hypoactive or mixed groups. Whether this is

TaskForce/MacArthur Foundation. Theauthorsacknowledge the assistance of their collaborators in the overall conduct of the study,

including Paul Cleary, John W. Rowe, Catherine Reilly, Marilyn Albert, David Pilgrim, and Terrie Wetle. Ann Readingand Rachel Lee carried out the analysis of the data.

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*@njamin

ClassifIcation

Geneva: WHO.

Liptzin, MD, formerly Associate Pro

fessor of Psychiatry; Sue Levkoff, DSc,Assistant with multiple medical illnessesand medications. It Professor in Social Medicine, Harvard Medical would also be interesting to correlate the clinical School,Division on Aging, 643Huntington Avenue, subtypeswith findings from electroencephalography. Boston,MA 02115, USA Acknowledgements

*Correspondence:

Department

of Psychiatry,

Baystate

This work was supported by the Dana Foundation, the Common

MedicalCenter,140High Street,Springfield,MA 01199,

wealth Fund, and the American Psychiatric Association DSM—IV

USA

An empirical study of delirium subtypes. B Liptzin and S E Levkoff BJP 1992, 161:843-845. Access the most recent version at DOI: 10.1192/bjp.161.6.843

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