Biomedical subjects
Publications and source records attributed to A Lugaresi.
A 51-year-old man with type I Arnold-Chiari malformation presented with severe autonomic impairment. Polysomnography disclosed central and obstructive sleep apneas. During REM sleep apneas were accompanied by hypotension and led to convulsive nonepileptic attacks. Marked blood pressure oscillations and central apneas persisted after tracheostomy.
Eight consecutive patients with chronic inflammatory demyelinating polyneuropathy (CIDP) were investigated by visual evoked potential (VEP), brainstem auditory evoked response (BAER) and magnetic resonance imaging (MRI) to assess central nervous system (CNS) involvement. VEPs were abnormal in 6 patients and BAERs in 2. MRI showed changes suggestive of CNS demyelination in 2 cases. Our findings suggest the existence of a combined central and peripheral demyelinating syndrome and emphasize the possibility of a common pathogenetic mechanism for both.
Eleven patients with cranial dystonia were investigated for diurnal variations in disability by means of video recordings. Disability increased significantly from morning to evening. The increase was not related to changes in vigilance levels assessed by dynamic electroencephalogram. Cranial movement disorders display diurnal fluctuations that are probably related to endogenous circadian rhythms.
A 39 year old man with acute panautonomic and mild somatic neuropathy had severe postural hypotension 1 week after onset. Porphyric neuropathy was excluded. The final diagnosis was Guillain-Barré syndrome (GBS). After 2 months he began to recover progressively and after 9 months he presented asymptomatic postural hypotension. We consider the hypothesis of a spectrum of clinico-pathological entities at one end of which lies GBS with autonomic signs and at the other acute pure dysautonomia. The site of the autonomic lesion, might have been in post-ganglionic sympathetic fibers and vagus nerve.
A 67-year-old man presented four recurrent, alternating facial palsies, two right abducens palsies and eventually a right extrinsic third nerve palsy due to brain-stem infarction in a 37-year time-span. Neuroradiological examinations showed hydrocephalus and an elongated, tortuous, ectasic basilar artery. This patient presented in his lifetime the whole clinical spectrum of the dolichoectasic basilar artery complications.
The F response represents the recurrent discharge of a small percentage of the motoneuron pool activated antidromically by any single impulse delivered to the nerve. We studied F waves from median nerve stimulation in 22 controls, in 30 patients with spasticity after cerebrovascular accident (CVA), and in 4 patients with familial spastic paraplegia (FSP). The following parameters were analyzed: median nerve conduction velocity, median nerve M response amplitude (M), average amplitude of 16 F responses (F16); persistence of F response (Fp) defined as the percentage of measurable responses to 16 stimuli, average amplitude of F response expressed as percentage of maximal M amplitude: (F16/M%). Results showed that Fp, F16 and F16/M% values were significantly increased on the spastic side of CVA patients and in FSP. Our findings indicate that after upper motor neuron lesions (whatever etiology and course) a change in the frequency of recurrent discharge and/or in the total number of lower motor neurons capable of backfiring occurs. Therefore, F response reflects the hyperexcitability state of the lower motor neurons in spasticity.
In 3 patients, carbon monoxide poisoning was followed by a modification of habits and personality without definite mental deterioration, but with loss of initiative, which led the patients to lose all their previous interests and to spend most of their time in bed. CT scans showed bilateral calcification of globi pallidi in one patient and pallidal hypodensities in another.
We report a case of transdermal scopolamine-induced cycloplegia in a 15-year-old diabetic girl. Transdermal scopolamine disks are widely used and neurologists should be ready to discern their possible side-effects.
Physiological hypnic myoclonus (PHM) was quantified during wakefulness and sleep in 7 normal subjects. PHM was evident during relaxed wakefulness and increased during stage 1 and especially REM sleep. In some muscles, however, (e.g., soleus) it showed no increase during sleep. PHM resembled simple fasciculation potentials, or, when repeated or in clusters, the fragmentary myoclonus in NREM sleep. Both 'hypnic' and 'myoclonus' are terms inappropriate to the description of this physiological spontaneous motor activity.
Apathy, mood depression and extrapyramidal signs consisting of akinesia, amimia, gait apraxia, slight rigidity and tremor were induced in 10 patients by long-term treatment with flunarizine for trivial complaints. These symptoms suggest a mild antidopaminergic activity of flunarizine. Long-term administration of flunarizine should be avoided particularly in the elderly and in patients with extrapyramidal disorders.
A total lack of neuroendocrine and vegetative circadian rhythms was observed in a patient with a familial degeneration of the anterior and dorso-medial thalamic nuclei. Our findings support the role of the thalamus in regulating the periodicity of endocrine and vegetative functions.
Fasciculation potentials were quantitated during wakefulness (W) and the different sleep stages in 10 patients affected by motor neuron disease. Compared to W, no statistically significant variation was present in fasciculations during any sleep stage. Fasciculations remain unaffected by the decrease in central nervous system excitability which occurs during sleep.
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Rat heart ornithine decarboxylate activity from isoproterenol-treated rats was inactivated in vitro by reactive species of oxygen generated by the reaction xanthine/xanthine oxidase. Reduced glutathione, dithiothreitol and superoxide dismutase has a protective effect in homogenates and in partially purified ornithine decarboxylase exposed to the xanthine/xanthine oxidase reaction, while diethyldithiocarbamate, which is an inhibitor of superoxide dismutase, potentiated the damage induced by O2- on enzyme activity. Dithiothreitol at concentrations above 1.25 mM had an inhibitory effect upon supernatant ornithine decarboxylase activity, while at 2.5 mM it was most effective in the recovery of ornithine decarboxylase activity, after the purification of the enzyme by the ammonium sulphate precipitation procedure. The ornithine decarboxylase inactivated by the xanthine/xanthine oxidase reaction showed a higher value of Km and a reduction of Vmax with respect to control activity. The exposure of rats to 100% oxygen for 3 h reduced significantly the isoproterenol-induced heart ornithine decarboxylase activity. The injection with diethyldithiocarbamate 1 h before hyperoxic exposure further reduced heart ornithine decarboxylase activity.
The sympathetic skin response (SSR) represents the momentary change in skin potential reflexively evoked by a variety of arousal stimuli. Although sudomotor unmyelinated fibres are the final efferent pathway of SSR, little is known about the afferent and central components. SSR was recorded using different classes of stimuli in 20 controls, 15 peripheral neuropathy and 13 stroke patients. In controls SSR latencies changed significantly with different recording sites but not with different stimulation sites. Additionally, ischemic conduction block of the arm abolished SSR recorded at the hand after median nerve stimulation. In 1 patient with subacute ganglionitis and in 3 with demyelinating neuropathies the SSR could be elicited with deep inspiration but not by electric stimulation. These results suggest that myelinated fibres serve as afferents for SSR. In stroke patients SSR was absent bilaterally after stimulation of the paralyzed side but present after stimulation of the normal one. Therefore in humans the cortex seems to have a suprasegmental excitatory influence on SSR. The above findings imply that an unobtainable SSR by electric stimulation may be due not only to dysfunction of the autonomic efferent nerve fibers, but also to involvement of sensory afferents or suprasegmental structures.
A case of Chiari malformation type I with orthostatic hypotension and sleep apnea leading to convulsive attacks is presented.
Ten migraine patients underwent a tilt test both during migraine attack and headache-free interval, and the following parameters were assessed: plasma levels of norepinephrine (NE), and serum dopamine beta hydroxylase (D beta H), systolic and diastolic blood pressure and heart rate (SBP, DBP, HR). SBP during the tilt test showed a fall greater than 30 mmHg in 2 cases in the headache-free interval and in 4 cases during migraine attack. In migraine patients in headache-free interval, tilt test increased NE and D beta H as it did in the control group, while in migraine attack tilt test increased NE and D beta H less than in the control group. This impairment of the sympathetic nervous system during the migraine attack is discussed.