This chapter focuses on the participants who were required to produce a new bimanual coordination pattern with a 90° phase offset. During learning, participants are provided with visual relative motion information about their arm movements on a computer terminal, because it is generally agreed that visual information is an important source of information feedback in the control of movement in Parkinson's disease patients. The chapter demonstrates that Parkinson's patients can improve their performance on a new coordination pattern, in the presence of enhanced real-time visual information of limb motion, as shown by a decrease in relative-phase error. When enhanced visual information was eliminated, the Parkinson's patients relapsed to the preferred coordination patterns and performed very poorly on the circle task. In contrast to the changes observed across practice in relative phase, no dramatic shifts in amplitude and cycle duration were established.
Progressive supranuclear palsy (syndrome of Steele-Richardson-Olszewski) represents one of the neuro-degenerative diseases, difficult to distinguish from other forms of parkinsonism. Although uncommon, the syndrome should be included in the differential diagnosis of recurrent falls in the elderly, especially in cases of parkinsonism presenting with axial rigidity and associated with gaze paralysis and/or poor response to L-dopa-therapy. The diagnosis is mainly based on the clinical findings. At present, no effective therapy is known.
Bisschop, Anja, Ghislaine Gayan-Ramirez, Hélène Rollier, P. N. Richard Dekhuijzen, René Dom, Vera de Bock, and Marc Decramer. Effects of nandrolone decanoate on respiratory and peripheral muscles in male and female rats. J. Appl. Physiol. 82(4): 1112–1118, 1997.—Thirty male and 18 female adult rats received weekly an intramuscular injection of either saline (control; C), 1.5 mg/kg (low-dose; LD) nandrolone decanoate or 7.5 mg/kg (high-dose; HD) nandrolone decanoate during 5 wk. Compared with respective C, growth rate was stunted in male HD rats from 2 wk of treatment on, whereas it was enhanced in female LD and HD rats after 1 wk. Mass of all muscles studied varied proportionally to body weight, except for the gastrocnemius (males: 0.49 ± 0.04 vs. C: 0.52 ± 0.03%, not significant; females: 0.17 ± 0.01 vs. C: 0.15 ± 0.01%, P < 0.05). In vitro contractile and fatigue properties of the diaphragm remained unchanged, except for a decrease in twitch kinetics (time to peak tension: C, 21 ± 2; LD, 19 ± 1; HD, 19 ± 2 ms, P < 0.05; half-relaxation time: C, 26 ± 5, LD, 25 ± 5, HD, 23 ± 3 ms, P < 0.01). Histochemistry of the diaphragm and the gastrocnemius revealed a significant increase in type IIx/b dimensions. In the gastrocnemius, type I fiber dimensions also increased. A pair-fed study, including another 24 female rats, showed that the changes in oral food intake only partly accounted for the observed anabolic effects.
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