Hamish F. Ross

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OBJECTIVE To compare the incidence of dementia in PD with that of a control group without PD, and to assess the relationship between dementia and other features of PD. METHODS The authors recruited 83 patients with PD and 50 controls, all without dementia at initial assessment, and assessed them at regular intervals over a maximum period of 122 months.(More)
OBJECTIVE To compare the mortality rate in Parkinson's disease (PD) with a control group without PD, and to assess the relationship between mortality and features of PD. MATERIAL AND METHODS Ninety PD patients and 50 controls, mortality ascertained at 11 years follow-up. RESULTS The hazard ratio (HR) for mortality in PD patients compared with controls(More)
Evidence from animal studies suggests that beta-blockers can act within the central nervous system to increase cardiac vagal motoneuron activity. We have attempted to determine whether such an effect is evident in healthy humans, by examining the effects of lipophilic and hydrophilic agents on heart rate variability and cardiac vagal reflexes. A total of 20(More)
Forces and electromyograms were recorded from patients with Parkinson's disease during imposed joint movements. Muscles which were stretched by 3 to 5 Hz sinusoidally alternating movements often showed vigorous bursts of EMG activity whose timing established that it was a reflex response to the movement. The same movements provoke no stretch reflex response(More)
Subjects with active stretch reflexes responded to an imposed sinusoidal movement of the ankle joint with a reflex force whose amplitude and timing varied widely with changes in the frequency of movement. At some frequency between 6 and 8 Hz, the reflex force tended to offset the non-reflex component of resistance, and thus to reduce the total resistance to(More)
Forces and electromyograms were recorded during sinusoidal flexion-extension movements of normal and spastic ankle joints. Spastic subjects showed relatively stereotyped responses, with evidence of a vigorous spinal stretch reflex. The responses of normal limbs were variable; there was little reflex response to the first cycles, but as the movement(More)
1. A method is described for driving the interphalangeal joint of the thumb through repeated sinusoidal flexion-extension movements, while immobilizing other joints of the wrist and hand.2. The joint met the sinusoidal movement with a force that fluctuated in an approximately sinusoidal manner. This paper is concerned with the relationship between the(More)
1. The upper limbs of normal subjects were immobilized in a way that allowed measurement of forces and movements at the thumb interphalangeal joint without significant movement elsewhere in the limb. 2. When the subject attempted to maintain a steady flexing force at the joint against a rigid stop, the actual force showed the irregular 8-11 Hz fluctuations(More)
Cardiac autonomic control is of prognostic significance in cardiac disease, yet the control mechanisms of this system remain poorly defined. Animal data suggest that nitric oxide (NO) modulates cardiac autonomic control. We investigated the influence of NO on the baroreflex control of heart rate in healthy human subjects. In 26 healthy male volunteers (mean(More)