Biomedical subjects

M Inghilleri

Publications and source records attributed to M Inghilleri.

78 records · Page 5Linked to original sources

PubMed1983

[Perception of light modulation].

A simple method for testing visual sensitivity to flickering light sources is proposed. The method employs a triangular function generator, which modulates the luminance of a chromatic light source. Amplitude and frequency of the triangular pattern are adjusted until the subject perceives a periodic variation of luminance. In normal subjects the maximum sensitivity was found at a frequency modulation of 5-10 Hz. In multiple sclerosis patients the method proved to be more accurate than flicker fusion frequency in revealing subclinical damage of the visual pathway.

Flicker Fusion↗

PubMed1983

Reflex and cortical responses to dental stimuli.

Tooth pulp stimulation may evoke reflex responses in the orbicularis oculi, temporal, masseter and retronuchal muscles, which may to a varying degree contaminate the cortical evoked responses. The use of repetitive stimulation reduces the amplitude of the cortical responses but avoids the onset of the majority of the muscle reflexes. The appearance of a silent period in the temporal muscle is hard to avoid and it alters the signal recorded from S1 for the first 60-70 msec. In the center-posterior leads, more protected from the EMG signal of the temporal muscle, a first negative deflection is recorded at 43 msec in 60% of subjects.

Cerebral Cortex↗

PubMed1983

The limits of tooth pulp evoked potentials for pain quantitation.

Tooth pulp evoked potentials (TPEPs) and subjective evaluation of painful dental stimuli have been recorded in healthy volunteers. The amplitude of TPEPs late components and the subjective rating have been studied in different psychological states, by the expectancy of pain with a placebo and by providing foreknowledge of stimulus timing with self-stimulation. The placebo induced a significant depression of TPEPs and pain sensation. The amplitude of TPEPs evoked by self-delivered stimuli was reduced but the subjective report remained unchanged. These results demonstrate that TPEPs are not a stable correlate of the pain perceived or of the painful input.

Dental Pulp↗

PubMed1982

[Effect of high-frequency percutaneous stimulation on experimental pain].

Ten healthy volunteers were submitted to an experimental pain test performed by electrical stimulation of one tooth, before and after 20 min high-frequency (300 Hz) electrical stimulation, for the purpose of relieving pain, delivered to the lip or to three other somatotopically non related areas. The stimulation of the lip only showed a statistically significant analgesic action. The effect was remarkable (31% of total pain relief) and of the same order of magnitude at any intensity level of the tooth stimulation, the threshold being affected too. It is concluded that a central inhibitory mechanism, activated by large afferents input, should subserve this kind of analgetic procedure.

Adult↗

PubMedDate not supplied

Motor potentials evoked by paired cortical stimuli.

We recorded the motor evoked potentials (MEPs) from the abductor pollicis brevis muscle, after supramaximal electrical transcranial stimulation, and studied the effect of paired transcranial shocks with varying interstimulus time intervals, in 10 normal subjects, 4 patients with median nerve neuropathy and 2 patients with motoneurone disease. In relaxed muscles the amplitude of the MEP evoked by a single shock averaged 30% of the M wave. With intervals from 1 to 2.5 msec 2 shocks evoked one MEP far larger in size than the control MEP (70% of the M wave). With intervals of 10 msec and longer, the 2 shocks evoked 2 independent MEPs; the size of the MEP following the second shock (test) was inversely correlated with the size of the control MEP: the more the control MEP approached the size of the M wave, the smaller the test MEP. Single motor unit records showed that, in the normal subjects and patients with peripheral neuropathy, the same motor unit was activated either by the first or the second shock, whereas in the patients with motoneurone disease it fired twice. In active muscles, the control MEP averaged 70% of the M wave. With intervals of 10 msec and longer the test MEP was markedly suppressed; with 100 msec intervals it fully recovered. In relaxed muscles, by delivering a double shock at a 1.5 msec interval, thus evoking a large MEP, followed by a second double-shock, the test MEP was completely suppressed for a period of 20 msec; it began to recover at 50 msec intervals and fully recovered after 150 msec.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMedDate not supplied

Increased ocular pressure in two patients with narrow angle glaucoma treated with venlafaxine.

Venlafaxine blocks the specific monoamine transporters and is devoid of significant action on muscarinic cholinergic receptors. To our knowledge, no cases of glaucoma have been reported so far. Because pain perception involves both serotonergic and noradrenergic mechanisms, venlafaxine also may be useful in neuropathic pain therapy. We report on two patients with narrow angle glaucoma affected by chronic pain. When venlafaxine treatment was begun, their ocular pressure was steadily around 17-18 mmHg. Venlafaxine was chosen (daily dose 75 mg) because this drug is claimed not to bind on muscarinic cholinergic receptors. However, 4 days later the ocular pressure of the first patient increased to 22 mmHg, which led to suspension of the drug. The ocular pressure of the second patient was 18.5 mmHg after a week, 21 mmHg after 2 weeks, and 23 mmHg after 16 days. One week after suspension, ocular pressure of the patients was 17 and 18 mmHg, respectively. Possible explanations of this ocular effect are offered: pharmacokinetic interference on the drugs used in glaucoma treatment, in vivo action on the muscarinic receptor, indirect effect via dopaminergic receptors, or direct effect on the ocular sympathetic postganglionic neurones. In any case, from a clinical viewpoint, caution should be used when giving venlafaxine to patients with narrow-angle glaucoma, and ocular pressure must be monitored.

Aged↗