Diurnal variation of motor activity in adult ADHD patients analyzed with methods from graph theory.

Attention-deficit /hyperactivity disorder (ADHD) is a common neurodevelopmental syndrome characterized by age-inappropriate levels of motor activity, impulsivity and attention. The aim of the present study was to study diurnal variation of motor activity in adult ADHD patients, compared to healthy controls and clinical controls with mood and anxiety disorders. Wrist-worn actigraphs were used to record motor activity in a sample of 81 patients and 30 healthy controls. Time series from registrations in the morning and evening were analyzed using measures of variability, complexity and a newly developed method, the similarity algorithm, based on transforming time series into graphs. In healthy controls the evening registrations showed higher variability and lower complexity compared to morning registrations, however this was evident only in the female controls. In the two patient groups the same measures were not significantly different, with one exception, the graph measure bridges. This was the measure that most clearly separated morning and evening registrations and was significantly different both in healthy controls and in patients with a diagnosis of ADHD. These findings suggest that actigraph registrations, combined with mathematical methods based on graph theory, may be used to elucidate the mechanisms responsible for the diurnal regulation of motor activity.

Graph theory applied to the analysis of motor activity in patients with schizophrenia and depression.

Depression and schizophrenia are defined only by their clinical features, and diagnostic separation between them can be difficult. Disturbances in motor activity pattern are central features of both types of disorders. We introduce a new method to analyze time series, called the similarity graph algorithm. Time series of motor activity, obtained from actigraph registrations over 12 days in depressed and schizophrenic patients, were mapped into a graph and we then applied techniques from graph theory to characterize these time series, primarily looking for changes in complexity. The most marked finding was that depressed patients were found to be significantly different from both controls and schizophrenic patients, with evidence of less regularity of the time series, when analyzing the recordings with one hour intervals. These findings support the contention that there are important differences in control systems regulating motor behavior in patients with depression and schizophrenia. The similarity graph algorithm we have described can easily be applied to the study of other types of time series.

Nonlinear analysis of motor activity shows differences between schizophrenia and depression: a study using Fourier analysis and sample entropy.

The purpose of this study has been to describe motor activity data obtained by using wrist-worn actigraphs in patients with schizophrenia and major depression by the use of linear and non-linear methods of analysis. Different time frames were investigated, i.e., activity counts measured every minute for up to five hours and activity counts made hourly for up to two weeks. The results show that motor activity was lower in the schizophrenic patients and in patients with major depression, compared to controls. Using one minute intervals the depressed patients had a higher standard deviation (SD) compared to both the schizophrenic patients and the controls. The ratio between the root mean square successive differences (RMSSD) and SD was higher in the schizophrenic patients compared to controls. The Fourier analysis of the activity counts measured every minute showed that the relation between variance in the low and the high frequency range was lower in the schizophrenic patients compared to the controls. The sample entropy was higher in the schizophrenic patients compared to controls in the time series from the activity counts made every minute. The main conclusions of the study are that schizophrenic and depressive patients have distinctly different profiles of motor activity and that the results differ according to period length analysed.

Actigraphic registration of motor activity reveals a more structured behavioural pattern in schizophrenia than in major depression.

BACKGROUND: Disturbances in motor activity pattern are seen in both schizophrenia and depression. However, this activity has rarely been studied objectively. The purpose of the present study has been to study the complexity of motor activity patterns in these patients by using actigraphy. FINDINGS: Motor activity was recorded using wrist-worn actigraphs for periods of 2 weeks in patients with schizophrenia and major depression and compare them to healthy controls. Average motor activity was recorded and three non-parametric variables, interdaily stability (IS), intradaily variability (IV), and relative amplitude (RA) were calculated on the basis of these data. The motor activity was significantly lower both in patients with schizophrenia (153 +/- 61, mean +/- SD, p < 0.001) and depression (187 +/- 84, p < 0.001), compared to controls (286 +/- 80). The schizophrenic patients had higher IS and lower IV than the controls reflecting a more structured behavioural pattern. This pattern was particularly obvious in schizophrenic patients treated with clozapine and was not found in depressed patients. CONCLUSIONS: Motor activity was significantly reduced in both schizophrenic and depressed patients. However, schizophrenic patients differed from both depressed patients and controls, demonstrating motor activity patterns marked by less complexity and more structured behaviour. These findings may indicate that disturbances in motor activity reflect different pathophysiological mechanisms in schizophrenia compared to major depression.

Observational study of prevalence of long-term Raynaud-like phenomena and neurological side effects in testicular cancer survivors.

BACKGROUND: Sensory neuropathy (paresthesias), tinnitus, hearing impairment, and Raynaud phenomena are side effects of cisplatin-based chemotherapy used to treat testicular cancer patients. We assessed the long-term occurrence of these side effects among testicular cancer survivors according to the treatment they received. METHODS: A total of 1814 men who were treated for unilateral testicular cancer in Norway during 1980-1994 were invited to participate in a national multicenter follow-up survey conducted during 1998-2002. The men were allocated to six groups according to the treatment they had received. Self-reported symptoms were assessed by a mailed questionnaire that included the Scale for Chemotherapy-Induced Neurotoxicity. A total of 1409 participants who responded to the questionnaire and/or underwent audiometry were assessable in this study. Respondents to the questionnaire (n = 1402) scored the relevant symptoms according to how troubled they were by each (not at all, a little, quite a bit, or very much). Hearing impairment was objectively assessed by audiometry at 4000 Hz in 755 men (seven of whom did not respond to the questionnaire). Group comparisons of symptom assessments were performed with chi2 or Kruskal-Wallis tests. Associations between relevant factors and self-reported symptoms or hearing impairment measured by audiometry were assessed using proportional odds ordinal logistic regression models and linear regression models, respectively. All statistical tests were two-sided. RESULTS: The median follow-up for the 1409 assessable men was 10.7 years (range = 4-21 years). All chemotherapy groups had statistically significantly higher odds for increasing severity of all assessed symptoms and inferior audiometric results compared with men who did not receive chemotherapy. Among chemotherapy-treated men, 39% (95% confidence interval [CI] = 35% to 43%) reported Raynaud-like phenomena (defined as white or cold hands or fingers [or feet or toes] on cold exposure), 29% (95% CI = 25% to 33%) reported paresthesias in the hands or feet, 21% (95% CI = 18% to 25%) reported hearing impairment, and 22% (95% CI = 19% to 26%) reported tinnitus as major symptoms troubling them quite a bit or very much. Hearing impairment (odds ratio [OR] = 5.3, 95% CI = 3.0 to 9.2) and tinnitus (OR = 7.1, 95% CI = 4.1 to 12.4) were particularly common in the dose-intensive chemotherapy group compared with the no chemotherapy group. Men who were treated with radiotherapy had higher odds of self-reported paresthesias in feet compared with those not treated with radiotherapy (OR = 1.5, 95% CI = 1.01 to 2.1, P = .04). CONCLUSION: Long-term survivors of testicular cancer who were treated with cisplatin-based chemotherapy were more often troubled by dose-dependent neurological side effects and Raynaud-like phenomena compared with those who were not treated with chemotherapy.

Normal overall mortality rate in Addison's disease, but young patients are at risk of premature death.

CONTEXT: Primary adrenal insufficiency (Addison's disease) is a rare autoimmune disease. Until recently, life expectancy in Addison's disease patients was considered normal. OBJECTIVE: To determine the mortality rate in Addison's disease patients. DESIGN AND METHODS: i) Patients registered with Addison's disease in Norway during 1943-2005 were identified through search in hospital diagnosis registries. Scrutiny of the medical records provided diagnostic accuracy and age at diagnosis. ii) The patients who had died were identified from the National Directory of Residents. iii) Background mortality data were obtained from Statistics Norway, and standard mortality rate (SMR) calculated. iv) Death diagnoses were obtained from the Norwegian Death Cause Registry. RESULTS: Totally 811 patients with Addison's disease were identified, of whom 147 were deceased. Overall SMR was 1.15 (95% confidence intervals (CI) 0.96-1.35), similar in females (1.18 (0.92-1.44)) and males (1.10 (0.80-1.39)). Patients diagnosed before the age of 40 had significantly elevated SMR at 1.50 (95% CI 1.09-2.01), most pronounced in males (2.03 (1.19-2.86)). Acute adrenal failure was a major cause of death; infection and sudden death were more common than in the general population. The mean ages at death for females (75.7 years) and males (64.8 years) were 3.2 and 11.2 years less than the estimated life expectancy. CONCLUSION: Addison's disease is still a potentially lethal condition, with excess mortality in acute adrenal failure, infection, and sudden death in patients diagnosed at young age. Otherwise, the prognosis is excellent for patients with Addison's disease.