DRUG-INDUCED MOVEMENT DISORDERS IN INSTITUTIONALISED ADULTS WITH MENTAL RETARD ATlON : CLINICAL CHARACTERISTICS AND RISK FACTORS

Penninder Sachdev

Fifty-three institutionalised adults with mental retardation, the majority (73.5%) moderate to severe, were examined for drug-induced movement disorders. Using a global AIMS score of 2 or more, 16 (34%) of the 47 subjects who had been exposed to neuroleptics had tardive dyskinesia (TD). Three of these had developed the dyskinesia upon withdrawal of neuroleptics. The dyskinetic movements were mainly seen in the lingual, perioral and other facial muscles. Two (33%) out of 6 subjects with no history of exposure to neuroleptics also had similar dyskinetic movements. The total neuroleptic dose significantly, and age marginally, but not sex, brain damage or level of mental retardation, emerged as risk factors for TD. Two (3.7%) subjects had definite akathisia and 16 (30.8 Yo) significant extrapyramidal side effects. This study supports the findings of previous studies of considerable neurological adverse effects of neuroleptics in this patient group and cautions against their injudicious use. It provides further evidence for some putative risk factors for TD and is noteworthy for its lack of support for the contentious issue of brain damage as a risk factor.

Australian and New Zealand Journal of Psychiatry 1992; 26:242-248

The use of neuroleptic drugs in mentally retarded (MR) or developmentally disabled (DD) individuals is extremely common [I ] . Such use is reflected in the high rates of tardive dyskinesia (TD) in this popula- tion, as evidenced by a number of published reports in the past [2-61. The high prevalence has provided an opportunity to examine some risk factors for the development of TD in this group which may, to some extent, be generalisable to other populations. An ex- amination of the published literature on TD reveals

Neuropsychiatric Institute, The Prince Henry Hospital, Sydney, New South Wales 2036

Perminder Sachdev MD. PhD, FRANZCP

that a number of issues remain contentious: 1 . Age 14-61 and female sex [4-71 have not consistently emerged to be significant risk factors, although ad- vancing age is still the most common factor associated with TD in studies on the psychiatrically ill population [7]. 2. Although brain damage has been considered to be a risk factor for TD [7], the severity of mental handicap, in so far as it reflects putative brain damage. has been found to be a risk factor in some studies [3,5] but not in others [2,4]. Overt brain damage as a risk factor was examined in only one study [4], with nega- tive results. 3 . The difficulty of distinguishing dys- kinesia from stereotypic movements not uncommonly present in this population has been given consideration in oniy some studies [8]. Moreover, the prevalence of

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PERMINDER SACHDEV 243

Characteristic Value n Yo

Age: Mean (SD) (years) 44.7 (16.4)

Sex: Male Female

Level of mental retardation

Probable (unconfirmed) Mild Moderate Severe

Overt brain damage

Present Absent

Major psychiatric disorder

Current Past, but not current Never

37 (70.0) 16 (30.0)

2 (3.8) 12 (22.6) 19 (35.8) 20 (37.7)

15 (28.3) 38 (71.7)

10 (18.9) 15 (28.3) 28 (52.8)

Epilepsy

Yes 14 26.4

orofacial and other dyskinesias in some DD in- dividuals in the absence of known neuroleptic ex- posure has received attention in only two studies [5,8]. 4. The concomitant use of stimulants, anticonvulsants and antihistamines, all of which can produce involun- tary movements, has not usually been reported.

In this study, an attempt was made to address some of these issues in an institutional population of adult DD individuals.

Method

All inmates (N = 53) of the three wards for DD individuals of a large psychiatric hospital in New South Wales were examined in August 1989. Histori-

cal information was obtained from the charts, and records of medication were extensively reviewed. A detailed Inventory for Client and Agency Planning (ICAP) [9] had been completed on all subjects by the nursing staff within the last 12 months and this was used for information on behavioural problems and functional level. The categorisation of behavioural problems and the functional level was similar to that used by Intagliata and Rinck [ 11. Mental retardation was classified using the DSM-111-K [ 101 criteria. A staff nurse familiar with the patient completed a spe- cially prepared checklist of self-mutilative and stereotypic behaviours. Each behaviour was rated globally on a "0 absent, I mild, 2 moderate, 3 severe" scale on the basis of intensity and frequency as ob- served over the previous 3 months. A stereotypy was defined as a non-reflex, non-goal-directed motor ac- tivity that is repeated in exactly the same way, which may be quasipurposive, can be consciously controlled for varying periods of time and is affected by the level of involvement in interesting activities and interper- sonal interaction. A standardised neurological ex- amination [ I I ] was conducted on each subject and the following scales completed: Abnormal Involuntary Movements Scale (AIMS) [ I ? ] , Scale for Ex- trapyramidal Side Effects [ 131 and Akathisia Rating Scale [ 141. A 10-minute video-recording was made on each subject using a standard recording procedure (unpublished) developed in our laboratory for record- ing drug-induced movement disorders. These record- ings were later reviewed by a psychiatrist colleague blind to the background of the subject to assess reliability of the diagnosis. An inter-rater reliability of 0.78 (Cohen's k) was achieved on the presence or absence of TD. When gradation according to severity was compared, the range for individual AIMS items was 0.69 to 0.92.

A subject was classed as having overt brain damage if any of the following was present: 1. Cerebral palsy, 2. Epilepsy currently under treatment, 3. Muscle weakness attributable to brain injury, 4. Other neurological deficits, microcephaly or hydrocephalus, 5. Biochemical disorder responsible for the mental retardation, and 6. Clear evidence of dementia.

Data were analyzed using the SPSS/PC+ Statistical Package [ 151. All neuroleptic doses were converted to Chlorpromazine Equivalents (CPZE) using the equivalence data presented by Davis [16]. The total neuroleptic load per subject was calculated by arriving at a mean dose from the many doses available, noting

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244 DRUG-INDUCED MOVEMENT DISORDERS

the total duration of drug use and determining the percentage of time the subject was drug free. The values arrived at were approximate in a number of cases.

Results

Description of sample

Table 1 presents a summary of the major charac- teristics of the sample. The majority (73.5%) had moderate to severe retardation (IQ 4 0 ) . In two cases, the probable diagnosis of mental retardation could not be definitely established; one subject suffered from dementia and the other from chronic schizophrenia. The 10 subjects who were considered to have a psychiatric disorder currently suffered from: chronic schizophrenia 5. atypical psychosis 3, dementia 2.

Neuroieptic use

Thirty-two (60.4%) were currently on one or more neuroleptic drugs, and all but 6 ( 1 1.3%) had had neuroleptics at some stage of their stay in this institu- tion. The mean current neuroleptic dose for those on neuroleptics was 645.3 (SD 597.5) mg per day chlorpromazine equivalents (CPZE) (range 25 - 2350). Seven (13.2%) were on a dose greater than 1000 CPZE. In 8 cases, administration of the neuroleptic had been stopped in the last 3 months, and in 7 others it had been reduced in the same period. The mean duration of treatment with neuroleptics was 13.8 (SD 11.7) years, and 38 (38/47=80.9%) had been on neuroleptics continuously. The approximate total neuroleptic load was a mean 3.423 kg (SD 5.058). The neuroleptics drugs used were thioridazine, tri- f l uope raz ine , haloperidol , per icyazine and fluphenazine decanoate in the order of the frequency of their usage. Nineteen (35.8%) subjects were on one. 12 (22.6%) on two and 1 (1.9%) on three neuroleptic drugs currently. The details on the neuroleptic and other psychotropic drug use in this sample are being reported elsewhere 171.

Tardive dyskinesia

Using a global AIMS score of 2 or more as diagnos- tic of TD, 16 (34%) of the 47 subjects who had been exposed to neuroleptics had the disorder: 12 (25.5%) mild, 3 (6.4%) moderate, 1 (2.1 %) severe. Of these, 5

had had their neuroleptic medication terminated in the preceding 3 months, in 3 cases because it was con- sidered to be no longer indicated and in 2 because of the presence of TD. The former three had no TD at the time of cessation of medication and, therefore, could be said to have a withdrawal emergent dyskinesia. Two other subjects with TD had had their neuroleptic dose reduced in the preceding 3 months in response to observed dyskinetic movements. Thirteen (28%). therefore, had dyskinesia that met the Schooler and Kane [ 181 criteria for probable TD or persistent TD.

An examination of the topography of the dyskinetic movements suggested that it was not dissimilar to that in the psychiatrically ill with TD. The movements were predominantly seen in the lingual (89% sub- jects), lips and perioral region (44%) and other facial muscles (1 9%), and limb (3 1 %) and trunk ( 19%) dys- kinesias were present only in the severe cases. The TD was mild in 12 (75%) , moderately severe in 3 (19%) and severe in 1 (6%) subject. In only 2 (12.5%) was i t judged to produce any degree of incapacity.

Two of the six subjects, who had no record of having been treated with neuroleptic medications, had oro- lingual-facial dyskinesia which rated mild on the AIMS and was quite indistinguishable from TD. One of these subjects, aged 65 years, had dementia, probab- ly of vascular origin, superimposed on mild mental retardation. The other subject, 78 years old, had no psychiatric disorder.

Subjects with dyskinesia were compared with the non-dyskinetic group in three steps. The total dys- kinetic group (n =IS) was first compared with those with no such involuntary movements on the following variables, using the Mann-Whitney U Test: age, sex, level of mental retardation, presence of brain damage, duration of neuroleptic use, current neuroleptic use. total cumulative neuroleptic load, current an- ticholinergic and anticonvulsant drug use and ratings on Scale for Extrapyramidal Side Effects. Significant differences between the two groups were found on three variables, with the dyskinetic group being older (z=-2.48, p=0.01), having received neuroleptics for a longer period (z=-2.17, p=0.03) and a higher total neuroleptic dose (z=- 1.17, p=0.04). In the second comparison, the 6 subjects who had not been exposed to neuroleptics were excluded, and the 16 subjects with TD were compared with the 31 non-dyskinetic subjects on the same variables. The groups were again significantly different on total neuroleptic load (z=- 2.42, p=0.016) and duration of neuroleptic use (z=-

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PERMINDER SACHDEV 24s

Table 2 . Conipar-ison of mentally retarded siihjects with arid without dyskinesia

Characteristic

Age(years) Sex (MIF) Level of mental retardation Presence of brain damage Duration of neuroleptic use (years) Total cumulative neuroleptic dose (kg) Current anticholinergic medication Rating of extrapyramidal symptoms

TD group Non-dyskinetic Z e (N=13) group

(N=31)

49.5 (16.6) a 914

20.8

21.4 (15.2)a 7.18 (7.8)a

2.69 (3.1)a

b

5.0 (38.5%)

3.0 (23.1%)

41.6 (15.0)a

b 21/10 23.3

11.7 (7.6)a 2.16 (2.5)a

5.0 (16.1) 2.7 (3.9)a

8.0 (25.8%)

-1.40 -0.09 -0.68 -0.83 -1.97 -2 38 -0.22 -0.37

a Mean (SD) Excluding the 3 withdrawal TD subjects Mann-Whitney U test Mean rank Exposed to neuroleptics * Statistically significant

P (2-tailed)

0.160 0.920 0.490 0.41 0 0.048 0.017' 0.830 0.710

2.53, p=0.01), and marginally so on age (z=-1.92, p=0.05). In the third and the most important com- parison, the 3 subjects with withdrawal dyskinesia were also excluded, and the remaining 13 subjects with TD were compared with subjects without TD who had been exposed to neuroleptics. The results are presented in table 2. The total neuroleptic load and duration of neuroleptic use, but not age, were sig- nificantly different in the two groups. The correlation between total neuroleptic load and duration of neuroleptic use was 0.5 1.

No subject was on stimulant medication or on regular antihistamine drugs.

Multiple regression analyses were performed with the AIMS score as the dependent variable and the following variables entered in the analyses: age, sex, level of mental retardation, presence of brain damage, current neuroleptic dose, total neuroleptic load, and current anticholinergic drug administration. When the stepwise method of analysis was used. the total neuToleptic dose was entered at step 1 of the analysis (R = 226; B = .475; t = 3.29. p = .002). None of the other variables emerged as being significant. The con- clusion from the various analyses was that the total neuroleptic load was the most significant risk factor predicting the severity of TD. The duration of neuroleptic use was in itself a significant risk factor, but did not remain so once the total neuroleptic load had been taken into consideration owing to the moderately high correlation between the two vari- ables. The other variables were all weak predictors.

Akathisia ratings

As hyperactivity and pacing can be present in this population for a number of reasons, akathisia was diagnosed only if the subject complained of restless- ness, particularly referable to the legs, and showed evidence of increased lower limb movements while sitting. Two (3.7%) subjects had definite but mild akathisia. and another three had a questionable presence of akathisia. The two with akathisia were male, 41 and 45 years old, and both had mild oro-lin- gual dyskinesia in addition to their chronic akathisia. They had not had a change in neuroleptic dose in the previous three months. The movements were charac- terised by crossing-uncrossing of legs and flexion-ex- tension at hips.

Extrapyramidal side effects

Sixteen (30.8%) had a total score of 2 or more on the rating scale for extrapyramidal side effects (EPSE). (One patient, not on medication, had a definite parkin- sonian syndrome). The total EPSE score had a high (r=.61) and significant (p=0.01) correlation with the current neuroleptic dose and a significant negative correlation (r=-.52; p=0.01) with the current an- ticholinergic medication dose. There was a smaller but non-significant correlation with age (r=.29) and past anticholinergic treatment (r=-.27). Of the various EPSE, mild tremor and rigidity were the most com- mon, being present in 30% and 22% respectively.

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246 DRUG-INDUCED MOVEMENT DISORDERS

Table 3 . Nirmher of s ~ h j e ~ t s with stereotypies uiid self injurious behoviour-s ruted by tiur-ses

as preseiit in past 3 nioriths (N=.53)*

Behaviour

Stereotypies

Head nodding Head banging Bruxism Facial grimacing Non-communicative noises Hand movements Body rocking Jumping, hopping Spinning One or more stereotypies”

Number Total by severity nl + n2

Mild nl

3 2 9 4

6 8 3 4 3

22

Self-injurious behaviours

Hurling against walls Hand biting Self biting Eye poking Lip mutilation Scratching Breath holding Hyperventilation One or more self- injurious behaviours” 20

Moderate n2

0 3 1 3 1 10 7 11

9 15 7 15 4 7 1 5 0 3

21 22

1 7 7 11 7 14 3 11 0 5 6 15 0 1 1 3

13 27

Percent of total

5.7 5.7

18.9 20.7

28.3 28.3 13.2 9.4 5.7

41.5

13.2 20.7 26.4 20.7 9.4

28.3 1.9 5.7

50.9

No subjects were rated “severe” on these behaviours

** Numbers do not add up because of multiple stereotypies in some individuals

Stereotypies and self-injurious behaviours

The frequency and intensity of these behaviours as rated by the nurses is presented in table 3. While in most subjects the nature of these behaviours clearly differentiated them from drug-induced involuntary movements, occasional problems arose. Stereotypic facial grimacing was sometimes difficult to distin- guish from dyskinesia, although the “flowing” quality

and the usual involvement of lingual and perioral muscles in the latter, the ability to suppress stereotypic movements voluntarily, its quasipurposive nature, its occurrence at times of inactivity and boredom and disappearance while actively engaged did help dif- ferentiate the two kinds of movement. Akathisia was differentiated from stereotypic leg movements by the association of the former with subjective distress.

Discussion

The high prevalence of TD in this population is consistent with other similar reports that have ap- peared [2- 61. A number of issues with regard to this prevalence estimate, however, deserve special men- tion.

There were two (33%) subjects, out of a total of six, who had no record of having been given neuroleptic medication but had oro-bucco-lingual-facial (OBLF) dyskinetic movements indistinguishable from TD. It is possible, though extremely unlikely, that the medication records were in error, or the relevant por- tions had been lost. Both subjects had been present in this institution for over 30 years and most records were available. Both were old, and one had a recently diag- nosed dementia of vascular origin superimposed on the mental retardation. The base prevalence of the OBLF syndrome in the general population, in schizophrenic patients and in brain damaged or DD individuals has never been fully established although a number of reports attest to its presence [ S , 8,19221. The prevalence in normal, healthy elderly is reportedly low, of the order of 1-2% [23,24]. Higher rates have been reported in chronic psychiatric and neurological patients, but only two studies [ S $ ] have commented on the presence of orofacial dyskinesia in unmedicated DD subjects. In one of these [ 5 ] , two (29%) out of 7 never-medicated subjects had dyskinesia, and both suffered from severe retardation. In the other study [8], “fluid, random, mainly peri-oral movements of the face”, which, neurologically, might be described as “dyskinesia” (p 101) were present in 34% of those currently receiving neuroleptic medication, 20% of those who had previously received such medication, and 27% of those who had never received any neuroleptics.

The high frequency of occurrence of dyskinesia in DD individuals not exposed to neuroleptics raises the question of whether these drugs are indeed necessary or sufficient to cause the syndrome of TD. Owing to

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PERMINDER SACHDEV 247

the small numbers, especially in the unmedicated group, too much reliance cannot be placed on prevalence figures to decide whether neuroleptic drugs do cause dyskinesia. One must consider the characteristics of the patients. The TD subjects in our study were much younger than the two subjects with spontaneous dyskinesias, as was the case in the Yous- sef and Waddington [ 5 ] study. The duration of neuroleptic use and the total neuroleptic load were significant predictors of the development of dys- kinesia. Further, three subjects developed dyskinesia only upon withdrawal of the neuroleptics. It is fair to conclude from this that neuroleptics did play a major role in development of the dyskinesia. Whether they were sufficient causes, or merely brought forward the manifestation of a predisposition in this population, is difficult to argue on the basis of the data. The problem of distinguishing dyskinetic from a host of other ab- normal movements commonly present in DD in- dividuals has been highlighted previously [2]. In our expe r i ence , s ince the T D movements were predominantly of the OBLF type, they were easy to distinguish from other movements, and the reliability of diagnosis upon review of videotapes was high. It was more difficult to be certain about akathisia, espe- cially because testimony of the patients is usually necessary for this diagnosis. The nurses’ observations were helpful in this matter.

The drug status of the population at the time of the survey is likely to have significantly affected the results. The drug dose had been changed in 15 subjects in the three months prior to the examination. The main reason for this was the appointment of a visiting psychiatrist about 6 months before the study, who had undertaken to review the medication status of all the inmates. This review process had not been systematic, not all subjects had been reviewed and the psychiatrist was independent of the study. Three subjects received a diagnosis of withdrawal-emergent dyskinesia; as they were not followed up, their final outcome is unknown to us. Most other studies of TD in this population suffer from the same drawback of lack of systematic neuroleptic dose schedules, with perhaps the exception of one study [2] in which a neuroleptic withdrawal was carried out in all cases. This may partially explain the variance in the prevalence figures.

Increasing age emerged only as a weak risk factor for TD in our study, its significance disappearing when the withdrawal dyskinesia subjects were excluded from the analysis. Earlier reports have been both posi-

tive [2,4,5,25] and negative [6,7], although increasing age is one of the more consistent risk factors in the published literature. In our sample, the effect of age was not completely explained by an increased duration of neuroleptic treatment although the latter did con- tribute. Female sex, which has been considered a pos- sible risk factor [7], especially in the elderly, did not emerge as significant in our subjects. The findings with regard to sex in other studies involving the DD have been contentious [2,4-61.

An association between total neuroleptic load and TD has been reported in other studies of the DD [2,4] although a similar relationship has been difficult to establish in adult psychiatrically i l l patients [25]. The fact that drug history may be easier to reconstruct in chronically institutionalised individuals may perhaps be responsible for this discrepancy, but the possibility remains that the two groups are not strictly com- parable.

We did not find a significant association between TD and brain damage. The evidence with regard to this factor is conflicting in the literature [4,5,7,25]. Reasons for this are difficult to speculate, but one factor may be the different definitions of brain damage used in different studies. Youssef and Waddington [5] used severity of mental retardation and presence of epilepsy as indicators of brain damage while Rao et ul. [4] used a composite definition similar to the one used in this study. Similarly, our finding of no association between the level of mental retardation and the propensity to develop TD adds to the conflicting find- ings of other studies [2,4-61. Large epidemiological studies may help resolve some of these controversies.

This is, to our knowledge. the first report of chronic drug-induced akathisia in the DD population. The prevalence is much lower than the near 40% prevalence reported in chronically medicated schizophrenic patients [26,27], but the finding serves to highlight that akathisia is a significant side-effect in this population and that its manifestations are not distinct from that in the psychiatrically ill population.

The frequency of parkinsonian side-effects in our subjects was not surprising, considering the high doses of neuroleptics with which many of them were being treated. Predictably, the side-effects had an associa- tion with neuroleptic dose and the usage of an- ticholinergic medication. These side-effects were usually mild and did not greatly influence manage- ment.

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248 DRUG-INDUCED MOVEMENT DISORDERS

In conclusion, this study supports the finding that neuroleptic drug use in institutionalised DD in- dividuals leads to considerable side-effects. Total neuroleptic dose emerged as a putative risk factor for TD, but factors such as female sex, overt brain damage or severity of mental retardation did not. Increasing age was a marginal risk factor. Although there is some evidence that the DD may be predisposed to the development of spontaneous dyskinesias, neuroleptics do seem to play a prominent role in their manifestation. This finding does caution against the injudicious use of neuroleptics in this population. Considering that much of this drug use is for the control of behavioural disturbance [ 1, 171, a use which has no firm empirical basis [28], such caution is indeed necessary. If neuroleptics do need to be used, they should be ad- ministered for the shortest period necessary, and one must be particularly careful in the elderly.

Acknowledgements

Dr H Molony and Prof G Parker for valuable sup- port: S Cumming and D Hadzi-Pavlovic for statistical advice; R Lee for help in manuscript preparation: the staff of the study institution for help in data collection: the Chief Executive Officer of the hospital for permis- sion to publish; the Ramaciotti Foundations, the Rebecca Cooper Foundation and the Prince Henry Hospital Centenary Research Fund for financial assis- tance.

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