Postprandial hypotension in clinical geriatric patients and healthy elderly: prevalence related to patient selection and diagnostic criteria.

Contains fulltext : 89682.pdf (publisher's version ) (Open Access)The aims of this study were to find out whether Postprandial hypotension (PPH) occurs more frequently in patients admitted to a geriatric ward than in healthy elderly individuals, what the optimal interval between blood pressure measurements is in order to diagnose PPH and how often it is associated with symptoms.The result of this study indicates that PPH is present in a high number of frail elderly, but also in a few healthy older persons. Measuring blood pressure at least every 10 minutes for 60 minutes after breakfast will adequately diagnose PPH, defined as >20 mmHg systolic fall, in most patients. However with definition of PPH as >30 mmHg systolic fall, measuring blood pressure every 10 minutes will miss PPH in one of three patients. With the latter definition of PPH the presence of postprandial complaints is not associated with the existence of PPH

Hypoxic neuropathy versus diabetic neuropathy : an electrophysiological study in rats

In the experimental rat model of diabetes a slowing of nerve conduction velocity and a resistance to ischemic conduction failure have been found as an indication of polyneuropathy. The same electrophysiological abnormalities have been demonstrated in a model in which healthy rats are kept under hypoxic conditions (10% O2) for a 10-week period. Two factors are held responsible for the development of diabetic polyneuropathy: metabolic deterioration and hypoxia. However, until now the relative roles of metabolic deterioration and hypoxia in the development of polyneuropathy have not been settled. To test both explanations further with more sophisticated electrophysiological techniques, the H-reflex (motor and sensory NVC) and the stimulated SF-EMG (measures terminal nerve branch and neuromuscular transmission) were measured in 3 groups of 10 rats, a healthy control group, a diabetic group, and a hypoxic group, every 5 weeks, for 6 months. In the control rats an age-related increase in motor and sensory conduction velocity was found, whereas in the diabetic rats as well as in the hypoxic rats a marked decrease in sensory and a slight decrease in motor nerve conduction velocity was observed. The jitter measured in the stimulated SF-EMG was significantly increased in both the diabetic and the hypoxic group. The results of the present study support the possible role of hypoxia, in addition to metabolic factors, in the development of experimental diabetic neuropathy

Subtle involvement of the sympathetic nervous system in amyotrophic lateral sclerosis.

Item does not contain fulltextThe literature on the involvement of the autonomic nervous system (ANS) in amyotrophic lateral sclerosis (ALS) is conflicting. We therefore investigated several aspects of autonomic function, namely muscle sympathetic nerve activity (MSNA), blood pressure, cardiac function (electrocardiogram; ECG), and respiration in 16 patients with sporadic ALS and in 12 age-matched healthy volunteers, both at rest and during sympathoexcitatory stimulation. We measured MSNA by provoking venous pooling during short-lasting lower body negative pressure (LBNP) and during the cold pressor test (CPT). To assess the vagal (baroreflex) control of heart rate (HR), we measured spontaneous baroreflex sensitivity (BRS). To assess the involvement of the ANS beyond the cardiovascular system, we measured the sympathetic skin response (SSR). The stand-up test showed that none of the subjects had orthostatic intolerance. In comparison with the control group, the ALS patients had an increased HR and a decreased BRS at rest, and a reduced MSNA response to LBNP. The CPT response was normal and the total MSNA at rest did not differ significantly from that of controls. The latencies of the palmar and plantar SSR were prolonged, and in 3 ALS patients there was no plantar SSR. The results indicate that the sympathetic nervous system shows subtle abnormalities in ALS, predominantly sympathetic overactivity. They also point to the involvement of the preganglionic sympathetic column as the cause of the higher sympathetic activity and the absence of SSR. The higher sympathetic activity is postulated to be due to changes in modulation of the sympathetic system, whereas the absence of the SSR is probably caused by disruption of the reflex pathway

Evaluation of electrophysiological and clinical tests in an exploratory trial of Org 2766 in motor neuron disease

Twenty four patients with motor neuron disease (MND) participated in a double-blind, placebo-controlled trial with the ACTH 4-9 analog, Org 2766. Patients were examined three times during an 8 week treatment period, using a summated score for several manually and functionally tested muscles (sum score), myometry, jitter, fibre density (FD), macro motor unit potential (MUP), and supramaximal evoked muscle action potentials. No differences were found between Org 2766 and placebo treated patients. In an open 1 yr follow-up study, 5 out of 13 patients treated with Org 2766 died; the others showed continued progression of weakness. The methods used for assessment of muscle function were compared. The highest intertest reliability was obtained in the sum score and myometry. Mean differences that might be detectable were relatively small for the sum score and myometry, and large for FD and MUP. We concluded that clinical function testing and myometry are superior to electromyographic measurements for assessment of changes in MND patient