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Differential cardiovascular and noradrenaline responses to clonidine in patients with multiple system atrophy and pure autonomic failure
85 Differential cardiovascular and noradrenaline responses to cionidine in patients with multiple system atrophy and pure autonomic failure J.S. Kooner, S. Raimbach, R. Bannister, W.S. Peart and C.J. Mathias Medical unit, St. Mary's Hospital Medical School and Institute of Neurology, National Hospital for Nervous Diseases, Queen Square, London, U.K.
The site and functional significance of the autonomic lesion may differ in patients with multiple system atrophy (MSA) and pure autonomic failure (PAF). As clonidine lowers blood pressure, digital skin vascular resistance and plasma noradrenaline by reducing central sympathetic outflow, we have studied its effects on patients with MSA and PAF to determine if differential responses occur in the two groups. We studied 9 patients with MSA and 6 with PAF. Non-invasive measurements of blood pressure (BP) and heart rate (HR) (Sentron), digital (1st digit) skin blood flow (DSBF, laser Doppler flow, Periflux PF2b) and skin temperature were made before and after clonidine (2 # g / k g , i.v.). Blood samples were taken for measurements of plasma noradrenaline and adrenaline. Mean BP was higher in MSA compared to PAF. After clonidine, mean BP fell in MSA (125 + 5 to 108 + 6 mm Hg, P < 0.05), but rose in PAF (110 + 4 to 119 + 3 mm Hg, P < 0.05). There was a fall in H R after clonidine in MSA but not in PAF. Basal DSBF and temperature were lower in MSA compared to PAF. After clonidine, there was a rise in DSBF (0.74 4- 0.14 to 1.26 + 0.28 v, P < 0.05) and temperature (29.8 + 1.3 to 32.8 + 1.1°C, P < 0.05) in MSA. In PAF however, there was no fall in DSBF or skin temperature (1.2 + 0.3 to 1.0 4-0.3 v, 32.9 + 0.4 to 32.4 + 0.25 o C; both ns). Basal digital skin vascular resistance (DSVR) was higher in MSA compared to PAF. After clonidine, DSVR fell in MSA (208 + 46 to 108 + 25 mm H g / v , P < 0.05), but rose in PAF (128 + 10 to 165 + 29, mm H g / v , P < 0.05). Basal supine plasma noradrenaline was higher in MSA compared to PAF, and fell after clonidine in MSA (456 + 160 to 209 + 67 p g / m l , P < 0.05) but not in PAF (75 + 15 to 54 + 9 p g / m l , ns). Plasma adrenaline levels were at the lower limit of detection ( < 20 p g / m l ) in both groups. Clonidine lowered BP, DSVR and plasma noradrenaline in MSA which is consistent with a further reduction in central sympathetic activity in these patients. Mean basal BP, digital vascular resistance and plasma noradrenaline were lower in PAF compared to MSA, indicating lower basal sympathetic activity compared to MSA. After clonidine, there was a rise in blood pressure and digital skin vascular resistance, which is likely to be due to its peripheral a-adrenoceptor agonist effects. These responses may provide a means to further determine the site and functional significance of the lesion in different subgroups of autonomic failure.
Effects of short-term treatment with cabergoline in stable responder parkinsonian patients: relevance of postprandial hypotension A. Cavallini 1, G. Micieli 1, E. Martignoni 1, M.C. Jori 2, L. SibiUa 1, G. Nappi 1 I Regional Centre for Parkinson Disease, Mondino Foundation, University of Pavia, and 2 Medicine Department, Farmitalia Carlo Erba, Milano, Italy.
Parkinson's disease (PD) is known to frequently exhibit autonomic disturbances. Among them, orthostatic hypotension (OH) is often reported, mostly occurring during the first stages of therapies with dopaminergic drugs, but in some cases also described when the patients have not yet been treated. Moreover, marked decreases on systolic blood pressure (BP) after meals have been also recogniT.ed in a
The site and functional significance of the autonomic lesion may differ in patients with multiple system atrophy (MSA) and pure autonomic failure (PAF). As clonidine lowers blood pressure, digital skin vascular resistance and plasma noradrenaline by reducing central sympathetic outflow, we have studied its effects on patients with MSA and PAF to determine if differential responses occur in the two groups. We studied 9 patients with MSA and 6 with PAF. Non-invasive measurements of blood pressure (BP) and heart rate (HR) (Sentron), digital (1st digit) skin blood flow (DSBF, laser Doppler flow, Periflux PF2b) and skin temperature were made before and after clonidine (2 # g / k g , i.v.). Blood samples were taken for measurements of plasma noradrenaline and adrenaline. Mean BP was higher in MSA compared to PAF. After clonidine, mean BP fell in MSA (125 + 5 to 108 + 6 mm Hg, P < 0.05), but rose in PAF (110 + 4 to 119 + 3 mm Hg, P < 0.05). There was a fall in H R after clonidine in MSA but not in PAF. Basal DSBF and temperature were lower in MSA compared to PAF. After clonidine, there was a rise in DSBF (0.74 4- 0.14 to 1.26 + 0.28 v, P < 0.05) and temperature (29.8 + 1.3 to 32.8 + 1.1°C, P < 0.05) in MSA. In PAF however, there was no fall in DSBF or skin temperature (1.2 + 0.3 to 1.0 4-0.3 v, 32.9 + 0.4 to 32.4 + 0.25 o C; both ns). Basal digital skin vascular resistance (DSVR) was higher in MSA compared to PAF. After clonidine, DSVR fell in MSA (208 + 46 to 108 + 25 mm H g / v , P < 0.05), but rose in PAF (128 + 10 to 165 + 29, mm H g / v , P < 0.05). Basal supine plasma noradrenaline was higher in MSA compared to PAF, and fell after clonidine in MSA (456 + 160 to 209 + 67 p g / m l , P < 0.05) but not in PAF (75 + 15 to 54 + 9 p g / m l , ns). Plasma adrenaline levels were at the lower limit of detection ( < 20 p g / m l ) in both groups. Clonidine lowered BP, DSVR and plasma noradrenaline in MSA which is consistent with a further reduction in central sympathetic activity in these patients. Mean basal BP, digital vascular resistance and plasma noradrenaline were lower in PAF compared to MSA, indicating lower basal sympathetic activity compared to MSA. After clonidine, there was a rise in blood pressure and digital skin vascular resistance, which is likely to be due to its peripheral a-adrenoceptor agonist effects. These responses may provide a means to further determine the site and functional significance of the lesion in different subgroups of autonomic failure.
Effects of short-term treatment with cabergoline in stable responder parkinsonian patients: relevance of postprandial hypotension A. Cavallini 1, G. Micieli 1, E. Martignoni 1, M.C. Jori 2, L. SibiUa 1, G. Nappi 1 I Regional Centre for Parkinson Disease, Mondino Foundation, University of Pavia, and 2 Medicine Department, Farmitalia Carlo Erba, Milano, Italy.
Parkinson's disease (PD) is known to frequently exhibit autonomic disturbances. Among them, orthostatic hypotension (OH) is often reported, mostly occurring during the first stages of therapies with dopaminergic drugs, but in some cases also described when the patients have not yet been treated. Moreover, marked decreases on systolic blood pressure (BP) after meals have been also recogniT.ed in a