A peer-reviewed, evidence-based journal for clinicians in the field of neuroscience
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[ V O L U M E 1 2 , N U M B E R 3 – 4 , S U P P L E M E N T A , M A R C H – A P R I L 2 0 1 5 ] Innovations in CLINICAL NEUROSCIENCE 35S the characterization of mineralocorticoid-function. MR-related parameters appear to be predictive markers for clinical outcome of d epression treated with standard of care medication (e.g., mainly serotonin based therapies). 39 Therefore, easily available markers, which are related to MR function, can select patients likely to be refractory to standard of care. ACTIGRAPHIC MONITORING OF PHYSICAL ACTIVITY IN CLINICAL TRIALS IN SCHIZOPHRENIA (S. Walther) Physical activity in schizophrenia is linked to the psychopathology, as are obesity, medication use, and lifestyle choices. Daytime actigraphy, with the actigraph strapped to the non- dominant wrist, can provide a useful measure of physical activity. This is in contrast to the typical nocturnal use for sleep studies. Linking daytime actigraphy and neuroimaging has been informative on neural correlates of motor behavior. 55 Behavior and symptoms. Not surprisingly, hypokinesia and obesity in schizophrenic patients are linked. 56 The sedentary behaviors, which result in less than optimal exercise habits, are related to poor health-related quality of life. 57 Furthermore, hypokinesia is associated with negative syndrome: the Positive and Negative Syndrome Scale (PANSS) and even more so the PANSS avolition subscore correlate with reduced physical activity. 58,59 In fact, studies in chronic patients reported the strongest correlations between hypokinesia and negative symptoms. Overall movement patterns change as a function of clinical presentation, with irregular patterns associated with positive syndrome and disorganization, and reduced activity seen with negative syndrome. 60 Nosological subgroups. As has already been discussed, patients with schizophrenia overall tend to move less than do healthy controls. However, there is heterogeneity in activity level across nosological subgroups. 58,61,62 Patients who are catatonic have the lowest activity levels, in contrast to patients with cycloid psychosis and paranoia, who have the highest. 58,62,63 In addition, catatonic patients endorse longer periods of immobility (Figure 3). Medication effects. In general, the effect of antipsychotic medications on activity levels is complex. Cross- sectional studies yielded inconclusive results. In chronic patients no differences were noted in activity levels between risperidone and olanzapine treatment. 6 4 However, in more acute patients olanzapine and risperidone seemed to differ slightly. 65 Still, the major difference may stem from heterogeneity in patient groups: While in a large sample of mixed chronicity, the chlorpromazine equivalents were unrelated to physical activity 66 and higher antipsychotic doses in the first episode were linked to low activity levels (Walther et al, unpublished data). This suggests that first episode patients might be particularly vulnerable to antipsychotic dosage, with other factors but medication contributing to hypokinesia in chronic patients. However, to tease out the effects of antipsychotics on activity levels, longitudinal studies with actigraphy and standardized treatment are necessary, ideally taking chronicity into account. As with other motor signs, we would expect that depending on the baseline measures there will be patients in whom medication would ameliorate hypokinesia and others who would experience negative effects by antipsychotics. 67 Longitudinal course. When the activity levels of patients at the beginning of an acute psychotic episode are compared to those at the end of said episode, overall there appears to be no trend. High activity at baseline predicts high activity at end and low activity at baseline predicts low activity at end. However, patients with low activity levels at baseline present with high baseline PANSS negative scores, which will then decline over the course of treatment. On the other hand, patients with high activity levels at baseline tend to have low PANSS negative scores that remain stable over the course of the episode (Walther et al. unpublished data). Also between episodes, activity levels tend to remain stable, particularly in those patients who already have low activity levels and increased negative symptoms. When the longitudinal course between episodes is examined, a high activity level at the index episode predicts an increase in PANSS negative score in later episodes, accompanied by a decrease in activity level. In summary, physical activity as measured by actigraphy may indicate the severity and course of negative FIGURE 3. Actigraphic differences in nosologically different forms of schizophrenia