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Biomedical subjects

L Murri

Publications and source records attributed to L Murri.

At least 145 records · Page 8Linked to original sources
PubMedDate not supplied

[Status epilepticus in chronically dialyzed patients treated with erythropoietin].

This paper describes the clinical features of two patients with chronic renal failure and uremic anaemia treated with recombinant human erythropoietin (9000 I.U. subcutaneously subdivided in 3 times weekly at the end of haemodialysis treatment) who developed seizures and status epilepticus. This treatment has unequivocal benefits but in some patients has been accompanied by elevated blood pressure leading to hypertensive encephalopathy with seizures. In fact, the correction of the anaemia results in a rise in packed cell volume with a consequent increase in blood viscosity, predisposing to increased vascular resistance and the development of hypertension.

Adult↗
PubMedDate not supplied

[Somatosensory evoked potentials after stimulation of the posterior tibial nerve in multiple sclerosis: comparative analysis with other modalities of evoked response and magnetic resonance].

Electrophysiological tests have proved to be a valuable method in assessing multiple sclerosis (MS) patients. In the last few years, scalp recorded short latency somatosensory evoked potentials to stimulation of nerves in the "lower extremity" have been more and more extensively employed. Some studies have aimed at comparing the sensitivity of MR imaging and multimodality evoked potentials, with somewhat conflicting results. In the present study posterior tibial nerve somatosensory evoked potentials (ptnSEPs) were performed in 29 MS patients with the aim to investigate the ability in revealing spinal cord conduction abnormalities and the sensitivity towards other evoked potentials and MR in MS. ptnSEPs showed a high percentage of abnormalities which did not significantly differ from that of visual evoked potentials; moreover in conjunction with median nerve SEPs can be used to localize thoracic or lumbar cord demielinating lesions, not evidenced on MR imaging. These results confirm that ptnSEPs, although non specific and crude in terms of precise localization, are a sensitive tool in detecting lesions, even subclinical, in MS patients. Moreover in anatomic regions like spinal cord where MR imaging is not very sensitive because the lower signal-to-noise ratio, they represent the only method available for demonstrating lesions.

Adult↗
PubMedDate not supplied

[Mechanisms of muscular fatigue].

According to Merton (1954), Bigland-Ritchie (1978), Edwards (1981) and De Luca (1984), two groups of mechanisms, central and peripheral, may be distinguished in physiopathology of fatigue process. Central mechanisms are related to subjective phenomena, like fatigue sensation or motivation, and to objective aspects as spatial and temporal motoneurones recruitment.

Electroencephalography↗
PubMedDate not supplied

[P300 and Parkinson disease. The role of cognitive changes].

Cognitive disturbances are frequently encountered in advancing Parkinson's disease (PD). Typically there are visuo-spatial disorders, memory impairment and bradyphrenia, defined as 'subcortical dementia' to distinguish it from the dementia that occurs in Alzheimer's disease, where the most prominent dysfunctions are agnosia, apraxia and aphasia. An electrophysiological test to study cognitive processing is the P300 (or P3) of the Event Related Potentials; in particular the latency of the P3 seems to correlate with cognitive decline. Thirty patients affected with idiopathic PD were investigated using a classic auditory "oddball" paradigm (rare tone--"target"--3000 Hz, frequent tone--"non target"--1000 Hz; the patients were instructed to recognize and keep a mental count of the number of rare tones). Electrophysiological findings were compared with those obtained in twenty normal subjects, age and sex matched with the patient's group. The parameters of P300 were correlated with patient's age, duration of the disease, motor and cognitive impairment levels and L-Dopa therapy. The P300 was loss in 16.6% (5 p.) and delayed in 33.3% (10 p.). Significative correlations were found only with age and cognitive impairment scores, but not with other variables analyzed. These results suggest that P300 could be a useful test to identify demented patients among those with PD, despite different motor disabilities.

Aged↗
PubMedDate not supplied

The evaluation of sellar region tumours with pattern visual evoked potentials.

Pattern visual evoked potentials (PVEPs) were performed on 20 patients with sellar tumours. The aim was to assess the validity of full-field PVEPs combined with a topographic recording in chiasmatic compression. They were abnormal in 95% of the patients, with variable patterns (absent or distorted responses). Our results show that PVEPs are very sensitive in revealing compression on visual pathways and that they correlate with the progression of the tumour. However, they are not reliable in detecting the chiasmatic or retrochiasmatic site of the lesion and relative visual field defect, because of the multidirectional extension of the tumour.

Adult↗
PubMedDate not supplied

Correlation between pain thresholds and polysynaptic components of blink reflex in essential arterial hypertension.

An interaction between pain modulation and arterial pressure control has been proposed on the basis of experimental data in man and animal. Eight hypertensive patients and eight normotensive volunteers were investigated by electrical stimulation of the first trigeminal branch and dental pulp, to evaluate nociceptive sensation and reflex responses. A significant threshold increase of pain sensation and R2, R3 polysynaptic components of the blink reflex, has been found in hypertensive patients.

Adult↗
PubMedDate not supplied

Pattern of plasma opioids in menstrually-related migraine and epilepsy.

Plasma estradiol (E2), progesterone (P), beta-endorphin (beta-EP) and beta-lipotropin (beta-LPH) were measured in the luteal phase of 8 patients affected by menstrually-related migraine (M) and in 3 cases of catamenial epilepsy (CE). Plasma P and E2 of the M patients were lower than in the CE group. Both beta-LPH and beta-EP showed a reduction in M patients near menses, while the opposite pattern was found in CE. These data demonstrate that premenstrual syndrome is sustained by different, neurobiological dysfunction even if endogenous opioids could be involved in both migraine and epilepsy.

Endorphins↗
PubMedDate not supplied

Neuroendocrine evaluation in catamenial epilepsy.

The hypothesis that catamenial epilepsy depends on abnormal rhythmic hormone activity in the hypothalamus-pituitary-gonadal axis has never been critically tested. No significant modifications in the secretory pattern of pituitary hormones, both basally and in response to stimulatory tests, were found in a group of catamenial epileptic women. On the contrary, our data showed a reduction of luteal phase progesterone secretion. These findings indicate that an imbalanced secretion of ovarian steroids plays a role in the catamenial exacerbation of epilepsy.

Adult↗
PubMedDate not supplied

Topographic variations in EEG asymmetry during sleep.

EEG signals were recorded in 11 normal subjects from F4-C4, F3-C3, P4-O2 and P3-O1 during both stage 2 and the REM stage of each NREM/REM cycle. The logarithm of the right/left ratio for the power in the range of the various frequency bands showed a prevalent right-side asymmetry only with the fronto-central derivations. This trend, observed for all frequency bands, remained stable over the various NREM/REM cycles with the exception of the last one. These data indirectly support the hypothesis that the right hemisphere is more heavily involved in dreaming than the left, and suggest a prevalent involvement of the anterior regions.

Adult↗