Case Examples

Case examples appear in Figure 1. The neuropsychological test data are presented in the form of Z scores, which have been calculated by deriving a Z score for individual tests in each domain based on the means and standard deviations of a normal control group of subjects (n = 74) of the same average age and parental social class as our patients. The formula is the raw score minus the control-group mean divided by the standard deviation (SD) of control group. The Z scores for each domain are the summed average of individual Z scores for that domain. Z scores reflect the performance of an individual relative to an average

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LANG EXEC VERBAL SPATIAL CONC7 SENS/ GLOBAL MEM MEM SPEED PERC

Figure 1 Comparison of two patients with schizophrenia on neuropsychology test battery.

LANG EXEC VERBAL SPATIAL CONC7 SENS/ GLOBAL MEM MEM SPEED PERC

Figure 1 Comparison of two patients with schizophrenia on neuropsychology test battery.

performance of 0 such that minus scores reflect below-average performances and positive scores reflect above-average performances. A standard deviation of -1.0 translates to a percentile rank of 16, and is comparable to an individual who is functioning at the 16th percentile compared to a normal reference group. That is, 84% of average individuals are functioning at a higher level. Tests used for each domain are listed in Table 1. Because the cases are from work done in the late 1980s and early 1990s, the WAIS-R, Wechsler Memory Scale-Revised, and WRAT-Revised are used. For the Verbal IQ, the Satz-Mogel abbreviated version (68) is also used. For additional details regarding the neuropsychological summary scales, see Ref. 12. Tests contributing to each scale are designated.

Case 1

MJ is a 28-year-old, single, left-handed Caucasian male who was an inpatient at Kings Park Psychiatric Center, a state hospital serving the Suffolk County area on Long Island, New York. This was his first psychiatric admission. He was tested after medication stabilization (20 mg haloperidol) approximately four weeks after admission. He had had psychotic symptoms for 18 months prior to admission, and his family had noted a change in behavior (social withdrawal) starting at age 25. As part of our first-episode longitudinal study, he received a

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u diagnosis of DSM-III-R schizophrenia, undifferentiated type, based on the Schedule for Schizophrenia and Affective Disorders-Lifetime (SADS-L) (69), two years after admission. He had had three years of college prior to admission and his total BPRS (70) (1-to-8 score on each item) score at admission was 33, indicating relatively mild symptom severity. His prorated verbal IQ was 110, with a WRAT-Reading IQ equivalent of 114. Review of his summary scale Z scores indicated that his performance was above average on measures of language/verbal ability and sensory-perceptual functioning. His worst performances were on measures of executive and memory functioning, ranging from -0.67 to -0.89 SDs below average, or at the 25th and 19th percentile, respectively. His Global scale—the average of the other six scales—was -0.29 SD below average, or at the 39th percentile. Given his overall premorbid intellectual functioning, his executive and memory functioning are well below expectation and signify a deterioration in cognitive function from premorbid levels.

Case 2

DK is a 44-year-old, left-handed, single male inpatient at Napa State Hospital who was recruited to be part of ongoing studies of neuropsy-chological function of chronically ill treatment-refractory patients. His age of first hospitalization was 23 years and he had been hospitalized for most of the past 21 years. DSM-III-R diagnosis confirmed by the Structured Clinical Interview for Diagnosis (71) was schizophrenia, paranoid type. He had graduated from college prior to becoming ill. His total BPRS score was 55 at the time of testing, indicating severe psychiatric illness that was chronic and unremitting. He took 750 mg of clozapine daily. His verbal IQ was 98 and his WRAT-Reading IQ equivalent was 99, both in the average range of intellectual functioning. Given his premorbid functioning, one would have expected a higher WRAT-Reading score. His summary Z scores ranged from -0.79 (21%) to -2.86 (0%) SDs below average, with the Global scale being -1.47 (7% ). Like MJ, his worst performances were on measures of verbal and spatial memory and executive functioning, but he also had very poor performances on measures of complex attention and perceptual-motor and pure motor speed (CONC/SP). It is difficult to assess how much effect the patient's medications had on his performance. Clozapine has strong anticholinergic properties; however, our group has found that it has a mixed effect on cognitive functioning, with improvement noted on measures of verbal fluency and perceptual-motor and pure motor

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u speed and worse performances on measures of spatial memory and executive functioning compared with typical neuroleptics (72).

Case Analysis

These two cases illustrate that patients with schizophrenia have deficits on measures of verbal and spatial memory, executive functioning, attention/concentration, and perceptual-motor speed. Although these two patients have different levels of illness severity, their pattern of dysfunction was similar. The treatment implications of this neuro-cognitive dysfunction are that patients are likely to have difficulty in the workforce and at home in areas of functioning that require sustained attention, memory skill, and rapid processing of information. It is important that family members and treating staff develop realistic expectations regarding a patient's true abilities and not attribute failure to laziness or lack of effort. Cognitive dysfunction in schizophrenia is an integral part of the illness and may improve only when effective cognitive rehabilitation and pharmacological strategies have been developed.

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