Proprioceptive reflexes in patients with reflex sympathetic dystrophy

Reflex sympathetic dystrophy (RSD) is a syndrome that frequently follows an injury and is characterized by sensory, autonomic and motor features of the affected extremities. One of the more common motor features of RSD is tonic dystonia, which is caused by impairment of inhibitory interneuronal spinal circuits. In this study the circuits that modulate the gain of proprioceptive reflexes of the shoulder musculature are quantitatively assessed in 19 RSD patients, 9 of whom presented with dystonia. The proprioceptive reflexes are quantified by applying two types of force disturbances: (1) disturbances with a fixed low frequency and a variable bandwidth and (2) disturbances with a small bandwidth around a prescribed centre frequency. Compared to controls, patients have lower reflex gains for velocity feedback in response to the disturbances around a prescribed centre frequency. Additionally, patients with dystonia lack the ability to generate negative reflex gains for position feedback, for these same disturbances. Proprioceptive reflexes to the disturbances with a fixed low frequency and variable bandwidth present no difference between patients and controls. Although dystonia in the RSD patients was limited to the distal musculature, the results suggest involvement of interneuronal circuits that mediate postsynaptic inhibition of the motoneurons of the proximal musculature.

The contribution of somatic symptoms to the diagnosis of depressive disorder in Parkinson's disease: a discriminant analytic approach

This study assessed the sensitivity of individual depressive symptoms and their relative contribution to the diagnosis of depressive disorder in patients with Parkinson's disease. The Structured Clinical Interview for DSM-IV Depression and the Hamilton and Montgomery-Asberg depression rating scales (Ham-D, MADRS) were administered to 149 consecutive nondemented patients. The contribution of the individual items of these scales to the diagnosis of "depressive disorder" was calculated by discriminant analysis. The discriminant models based on the Ham-D and MADRS scores were both highly significant. Nonsomatic core symptoms of depression had the highest correlation coefficient. Somatic items had mostly low correlation coefficients, with the exception of reduced appetite and early morning wakening (late insomnia). Nonsomatic symptoms of depression appear to be the most important for distinguishing between depressed and nondepressed patients with Parkinson's disease, along with reduced appetite and early morning awakening.

Where to record motor activity: an evaluation of commonly used sites of placement for activity monitors

The aim of this study was to evaluate the role of the site of attachment of activity monitors. We compared mean diurnal and nocturnal motor activity measures as well as the daily pattern of motor activity of dominant and non-dominant wrist recordings over 5 successive days of 10 healthy right-handed and 10 left-handed subjects. In a second study we evaluated the relationship between truncal motor activity and wrist motor activity. No differences emerged between the diurnal and nocturnal measures as well as the diurnal activity pattern of the dominant and the non-dominant wrist. Additionally, no differences were found in relation to handedness. Our results show that it is inaccurate to regard wrist motor activity measurements as representative of an invariable percentage of truncal motor activity; the relation between the measurements of these two recording sites varies across the daytime period. During the nocturnal period bilateral wrist motor activity occurred frequently in absence of truncal motor activity. The reverse situation, however, may occur sporadically. This finding most likely reflects that integrated generalized movements like postural shifts are measured at all recording sites, while the small movements that occur at the distal extremities are predominantly recorded by wrist-worn monitors. In conclusion, it is apparent that for both diurnal and nocturnal studies on the assessment of motor activity, either wrist can be chosen as the recording site. Across the diurnal period the relation between motor activity recorded at the wrist and waist is subject to considerable variability.(ABSTRACT TRUNCATED AT 250 WORDS)

Quantitative assessment of parkinsonian patients by continuous wrist activity monitoring

The aim of this study was to examine the quantitative relationship between activity monitor measures and clinical scores of patients with Parkinson disease (PD). Motor activity was recorded continuously for 5 to 6 days at home with a wrist-worn activity monitor in 69 PD patients and 59 healthy controls. Clinical scores of the patients, age, and sex were submitted to multiple regression analysis to examine the quantitative relationship with measures reflecting the activity level and the proportion of activity and immobility over time. The patients' age, sex, and scores representing hypokinesia and rigidity and resting tremor explained approximately 50% of the variance of the motor activity measures. All motor activity measures declined with age; the rate of decline was similar for the patients and controls. Sex emerged as a predictor of the motor activity measures in the patients only. Male patients with PD showed significantly lower values for all motor activity measures than female patients and controls. Our results show that activity monitoring can be used as an objective quantitative assessment in PD.