The course of autonomic neural function in chronic uraemic patients during haemodialysis treatment.

Autonomic function was followed in 19 patients with uraemia on chronic haemodialysis treatment over a period of 18 months. A smaller group of 12 patients were studied over 56 months. The battery of cardiovascular reflex tests included R-R interval variation test, deep breathing, Valsalva manoeuvre, heart rate, and blood pressure responses to standing and sustained handgrip. Two indices of autonomic function were measured: the autonomic score, and the confidence level on Bayesian analysis. There was great variability in the course of autonomic function over the period studied, with improvement occurring in some subjects and deterioration in others. In addition some patients did not develop any abnormality. Among those patients with uraemia and normal autonomic function at the start of the study, a deterioration occurred in 33-36% in the 18-month follow-up but in 62.5% in the 56-month follow-up. As a group there was no significant change in autonomic function during follow-up, although a clear trend to deterioration was found despite chronic haemodialysis treatment.

Uremic autonomic dysfunction evaluated by pattern recognition analysis.

A pattern recognition analysis of six cardiovascular reflex tests was performed with the aim to increase their diagnostic efficiency. A normal model was defined by SIMCA method using log-transformed values of 85 healthy subjects. The model was tested with data from 60 patients with chronic renal failure. Specificity resulted 94% and sensitivity 96%. 55% of the uremics were recognized affected by autonomic damage. The method allowed a better definition of autonomic function in those patients defined as "borderline" on conventional evaluation of the tests. Pattern recognition analysis of autonomic tests provides a global assessment of all the tests performed. Its use should be encouraged as a diagnostic tool.

Complex partial status epilepticus simulating an ischemic insult: case report.

A patient presenting complex partial status epilepticus (CPSE) had a clinical history and neurological picture on admission that mimicked a cerebrovascular insult. On admission she was confused and totally unresponsive to verbal stimuli. EEG showed high voltage paroxysmal activity on the left hemisphere, prominent on the temporoccipital leads and tending to spread to the opposite regions. Intravenous diazepam led to resolution of the clinical and EEG picture within 24 hours, only a medium voltage slow wave focus being present on the left temporal regions. CPSE should be considered whenever a prolonged impairment of consciousness is present. Only accurate EEG recordings permit correct diagnosis in doubtful cases.

Pattern recognition analysis of cardiovascular reflexes: its application in the diagnosis of autonomic neuropathy.

We describe pattern recognition analysis of six cardiovascular reflex tests and its application in the diagnosis of autonomic neuropathy. A discriminating model was performed by SIMCA method using the results of 85 healthy subjects. The prediction ability of the model was then verified with data from 95 patients at risk for autonomic neuropathy. Specificity resulted 93% and sensitivity 97%. The method increases the diagnostic efficiency of the tests, being particularly useful in patients with borderline autonomic involvement.

Wake and sleep cardiovascular reflex tests and GH profiles in diabetic patients.

Fourteen diabetic patients (13 males, 1 female, 7 IDDM and 7 NIDDM) were tested during wakefulness with a battery of tests examining parasympathetic and sympathetic control of the cardiovascular system. Subsequently sleep recordings including EEG, EOG, submental, left and right anterior tibialis EMGs, ECG, nasal airflow, thoracic and abdominal respirograms, nocturnal penile tumescence, were performed in each subject. The assessment of cardiovascular functions during sleep was based on the following parameters: Rbm, R-wake, apnea index, adequate penile tumescence during phase REM. Parasympathetic and sympathetic control of cardiovascular system were both impaired during wakefulness in only one patient, who also showed a low Rbm index indicative of ascertained autonomic neuropathy. Indices Rbm sufficiently low to be considered an evidence of probable autonomic neuropathy were found in 5 patients (3 IDDM and 2 NIDDM); all but one with normal cardiovascular tests during wakefulness. Five patients showed gross deficiency upon nocturnal penile tumescence monitoring. In comparison with a control group the patients showed a significantly lower overall Rbm index (p less than 0.001). IDDM patients showed an increased plasma GH response to insulin-induced hypoglycemia compared to NIDDM and normal subjects. Increased GH secretion was furthermore confirmed by GH values obtained in blood samples drawn during the first REM stage of the night in IDDM patients. The evaluation of the variables taken into consideration during sleep appears to be crucial for the assessment and prevention of autonomic neuropathies and neuroendocrine dysregulation in diabetic patients.

Autonomic nervous system dysfunction in chronic uraemics on haemodialysis.

A battery of cardiovascular reflex tests were performed in 35 patients with chronic renal failure on intermittent haemodialysis. An impairment of parasympathetic control was found isolated (14%) or combined with a damage of sympathetic control of cardiovascular system (26%). Moreover, maximum conduction velocity along sensory and motor fibres of posterior tibial nerve was measured in 21 patients. Autonomic dysfunction and somatic neuropathy did not appear strictly related.

Wakefulness and sleep autonomic dysfunction in diabetics.

Parasympathetic and sympathetic controls on cardiovascular systems were studied during wakefulness and sleep in 8 diabetic patients (3 IDDM and 5 NIDDM), in order to detect the presence of autonomic dysfunction. In particular, cardiovascular assessment during sleep allowed to detect minimal autonomic abnormalities in the absence of a documented pathology during wakefulness.

Nocturnal complex partial seizures precipitated by REM sleep. A case report.

A 16-year-old patient presenting with complex partial seizures occurring in the transition from a REM period to wakefulness is described. His baseline EEG showed generalized and symmetrical slow spike and wave complexes, on a normal background activity, activated by NREM sleep. Polygraphic and videotape recordings, carried out for several nights, showed that after nearly each REM period, he would wake up briefly, presenting eye blinking followed by a burst of generalized hypersynchronous theta to start his seizures. These were characterized by moaning and autoaggressive behaviour, the ictal EEG showing generalized slow spike and wave complexes in the midst of several movement artifacts. At the end of each fit he fell back to REM sleep. Carbamazepine treatment completely resolved his symptoms, with full normalization of EEG activity.

Amyotrophic lateral sclerosis: an epidemiological study in the Province of Messina, Italy, 1976-1985.

An epidemiological investigation of 41 subjects with amyotrophic lateral sclerosis observed in the Province of Messina during 1976-1985 was performed. The incidence was 0.61/100,000 and the prevalence 2.48/100,000 inhabitants. The illness was found to be prevalent in males. The atrophic type occurred in 17 subjects, the bulbar type in 23 cases and the pseudo-polyneuritic form in only one patient. The mean age on the onset was 57.29 +/- 10.55 years. The duration of the illness was significantly higher in patients with atrophic type (p less than 0.01). No significant difference between occupation and development of the disease was found. Among all patients 12.19% presented evidence of trauma, but traumatic events were equally present in a control group.

Occurrence of uraemic autonomic dysfunction in relation to age.

A battery of cardiovascular reflex tests were performed on 20 patients with chronic renal failure on intermittent haemodialysis, to assess occurrence of parasympathetic and sympathetic abnormalities. Using age-adjusted confidence limits, elderly uraemics showed more extensive parasympathetic and sympathetic dysfunction than middle-aged patients. The results suggest that the autonomic nervous system in the elderly is more susceptible to uraemic toxins than in the middle aged. This should lead to better preventive and therapeutic strategies for older uraemics.

Age-dependent occurrence of autonomic dysfunction in chronic uraemia.

A battery of cardiovascular reflex tests were performed in twenty patients with chronic renal failure on intermittent haemodialysis. Using age-adjusted confidence limits, old-aged uraemics showed more extensive parasympathetic and sympathetic dysfunction than middle-aged patients. The results suggest that autonomic nervous system in the elderly is more susceptible to uraemic toxins than in the middle age. This should lead to better preventive and therapeutic strategies in older uraemics.

Pentylenetetrazol-induced spike wave discharges in rats: a polygraphic study.

14 male Wistar rats were studied, before and after pentylenetetrazol (PTZ) 20 mg/kg i.p., since a petit mal-like electroclinical pattern, either spontaneous or PTZ-induced was recently described in a breeding station where this strain is raised. In particular, surface EEG, muscular, respiratory and cardiac activities were recorded in order to detect possible clinical-electroencephalographic correlations. Spontaneous epileptic phenomena were never observed. In all the animals PTZ-induced short, usually generalized and synchronous spike wave discharges often concomitant with rhythmic twitches of the vibrissae. Epileptic bursts were related to arousal level, disappearing during motor behavior and arousing stimuli. Moreover individual discharges could be interrupted by a sudden noise. Photosensitivity was not present. Muscular tone and autonomic functions were not affected. The features of PTZ-induced generalized nonconvulsive seizures in rats are compared to those of cat penicillin epilepsy and human petit mal.

Cardiovascular-reflex testing and single-fiber electromyography in botulism. A longitudinal study.

Four patients with botulism were studied on admission and at different times after intoxication, using a battery of cardiovascular autonomic tests. The results were compared with clinical status and single-fiber electromyographic findings. In the early stage of intoxication, the control of heart-rate and blood-pressure responsivity was markedly impaired, as was the neuromuscular transmission. At follow-up, results of sympathetic tests normalized earlier than those of parasympathetic tests. The recovery of autonomic function was slower than that of neuromuscular transmission in three patients. Monitoring autonomic derangement in botulism adds further information on the course of the disease and may identify patients at risk for cardiac or respiratory arrest. Further clinical investigation can help in determining more precisely the autonomic sites where the toxin acts.

Single fiber EMG and cardiovascular reflexes in botulism: a follow-up study.

A patient with botulism was studied at different times after intoxication using various autonomic tests of the cardiovascular reflexes, and by single fiber EMG (SFEMG). The control of heart rate and blood pressure appeared markedly impaired in the early stage of the disease as well as SFEMG. Autonomic function recovered more slowly as neuromuscular transmission. Monitoring autonomic derangement in botulism may give the opportunity to select patients at risk for cardiac or respiratory arrest.