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Biomedical subjects

A Uncini

Publications and source records attributed to A Uncini.

At least 91 records · Page 5Linked to original sources

Methyl bromide myoclonus: an electrophysiological study.

We report a case of myoclonus from overnight exposure to methyl bromide. Myoclonus was either spontaneous or induced by somatosensory stimulation or voluntary movements, multifocal and sometimes generalized. Median SEP showed normal size P14-N20, but giant parietal P25, N33 and frontal P22-N30 waves. Back-averaging showed a biphasic EEG spike of maximal amplitude at the central region contralateral to the corresponding myoclonic jerk recorded from abductor pollicis brevis and preceding it by a short interval consistent with conduction in corticospinal pathways. Long latency reflexes from cutaneous and mixed nerve stimulation were enhanced. The above electrophysiological findings suggest that myoclonus following methyl bromide poisoning belongs to the cortical reflex myoclonus category.

Adolescent↗

Ring finger testing in carpal tunnel syndrome: a comparative study of diagnostic utility.

Because digit 4 (D4) has dual innervation, median and ulnar sensory latencies can be determined over identical distances. To determine if D4 testing is more sensitive than other commonly used techniques to diagnose carpal tunnel syndrome (CTS), we examined 42 hands with clinical evidence of carpal tunnel syndrome and 43 control hands. D4 latency was significantly longer than controls more often than digit 2 (D2) in patients with CTS. Comparing median to ulnar latencies from D4 was the most sensitive method to make the diagnosis of CTS. In mild CTS, a characteristic double peak potential was seen in recordings from the median nerve after stimulating D4. This potential provided immediate visual confirmation of the diagnosis of CTS. Comparing D4 latency along median and ulnar nerves is useful for detecting mild CTS and should be used whenever there are clinical signs and symptoms of CTS but electrodiagnostic studies are normal or borderline.

Adolescent↗

Recurrent myoglobinuria and HIV seropositivity: incidental or pathogenic association?

There have been few cases of polymyositis in patients with AIDS, and polymyositis is rarely a cause of myoglobinuria. We studied a 20-year-old homosexual man with recurrent myoglobinuria. He was asymptomatic between episodes. Each episode was accompanied by muscle pain, limb weakness, high serum levels of creatine kinase, and pigmenturia. Muscle biopsy showed active necrosis without inflammation or abnormalities of glycolytic or other energy-generating enzymes. Antibodies to HIV were present in serum. Clinical evidence of AIDS has not developed in 2 years. Recurrent myoglobinuria may be another consequence of HIV infection.

Adult↗

Orthostatic tremor: report of two cases and an electrophysiological study.

Two patients with legs tremor present on standing, but none on walking or sitting, are reported. Tremor was not exclusive or orthostatism and was also evoked by strong tonic contraction of leg muscles. Synchronous EMG bursts were recorded in antagonistic muscle groups at 8-10 Hz in the first patient and at 16 Hz in the second. EMG activity was synchronous in corresponding muscles of both legs. The occurrence of EMG activity was not influenced by stimulation of nerve afferent fibers. We suggest that this movement disorder may be an exaggeration of physiological tremor due to synchronization of motor units by spontaneous oscillations in central structures.

Aged↗

Physiologic and anatomic basis for contralateral R1 in blink reflex.

We studied the rate of appearance and mechanism of contralateral R1 responses in normal subjects. Contralateral R1 could be produced by facilitating maneuvers such as a gentle contraction of the orbicularis oculi and conditioning stimulus of the median nerve. In addition, changing the position of the stimulating anode to the midline evoked these responses that were abolished by blocking the contralateral supraorbital nerve, confirming its peripheral origin. We conclude that crossed trigeminofacial pathways probably exist in normal subjects, but in some instances contralateral peripheral trigeminal ophthalmic sensory fibers may be stimulated, giving rise to a contralateral R1 response.

Blinking↗

Tellurium-induced demyelination: an electrophysiological and morphological study.

Tellurium (Te) is a naturally occurring element with many industrial uses. Microinjection of 0.3 micrograms of potassium tellurite [K(2)TeO(3)] into the endoneurial space of rat tibial nerve causes a rapidly progressing focal conduction block as measured by the disappearance of the evoked compound muscle action potential (CMAP) of the intrinsic foot muscles following stimulation proximal to the injection site. Conduction block was fully established within 6 hours and persisted for approximately 7 days, followed by the appearance of low amplitude, long latency, temporally dispersed potentials. The proximal CMAPs increased in amplitude and decreased in latency and temporal dispersion until normalization by 28 days after injection. The distal CMAP showed a minimal decline in amplitude. Morphological observations showed splitting of myelin, especially in the paranodal regions, followed by accumulation of myelin debris in Schwann cells and macrophages. Although the exact mechanism remains unknown, this in vivo model provides a unique opportunity to study the electrophysiological and morphological correlates of an acutely evolving demyelinative process.

Animals↗

Associated central and peripheral demyelination: an electrophysiological study.

A case is reported in which retrobulbar neuritis preceded Guillain-Barré syndrome by 4 weeks. The visual evoked potential latencies were prolonged. After peripheral nervous system signs had cleared, median and peroneal somatosensory evoked potentials showed prolonged cervical N13, scalp N20 and L3-scalp conduction times.

Adult↗

Anomalous intrinsic hand muscle innervation in median and ulnar nerve lesions: an electrophysiological study.

A case with a median nerve lesion at the wrist without thenar atrophy and another with an ulnar nerve lesion at the elbow sparing the first dorsal interosseous are reported. Simultaneous multiple channel recording demonstrated in the first case a dual innervation of the abductor pollicis brevis by median and ulnar fibers via a Martin-Gruber anastomosis. In the second case, the cross over of the median fibers innervating the first dorsal interosseous was very proximal in the antecubital fossa. Stimulation at discrete points documented that the communicating fibers from the median joined the ulnar nerve 3 cm below the medial epicondyle.

Female↗

The sympathetic skin response: normal values, elucidation of afferent components and application limits.

The sympathetic skin response (SSR), recorded at the hand and foot, was elicited using different classes of stimuli in 20 normal controls and 10 patients with peripheral neuropathy. We found that SSR latencies changed significantly with different recording sites, but not with different stimulation sites. Additionally, after ischemic conduction block of the arm in 3 normal controls, the previously obtainable SSR recorded at the hand became unobtainable with median nerve stimulation. Also, in one patient with subacute ganglionitis and 3 patients with demyelinating neuropathies, the SSR could not be elicited by electrical stimulation, but it could with deep inspiration. These results suggest that large diameter myelinated fibers may serve as afferents for the SSR. Furthermore, these findings imply that an unobtainable SSR by electrical stimulation may be due not only to dysfunction of the autonomic efferent nerve fibers, but also to abnormalities of the sensory afferents of the reflex. Therefore, investigations of autonomic dysfunction utilizing the SSR must be interpreted with caution in patients with peripheral neuropathies.

Acoustic Stimulation↗

Strümpell's familial spastic paraplegia: an electrophysiological demonstration of selective central distal axonopathy.

Three patients with autosomal dominant Strümpell's familial spastic paraplegia (SFSP) were evaluated by means of somatosensory evoked potentials (SEPs) from upper and lower limb and determination of sural nerve conduction velocity. Findings of normal sural nerve conduction but reduced amplitude and poor definition of SEPs with normal latencies on peroneal nerve stimulation support a pattern of central nervous system degeneration characterized by a selective involvement of centrally directed axons within the gracile fasciculi.

Adult↗

Femoral neuropathy from iliac muscle hematoma complicating anticoagulant therapy: a surgical emergency. Report of a case.

A case of femoral neuropathy from iliac muscle hematoma occurring during heparin administration, successfully treated by early surgical decompression is reported. Following the evaluation of anatomy, possible pathogenesis and CT scanning findings, the role of early diagnosis is emphasized in the assessment of prognosis and for successful operative decompression.

Emergencies↗

Parkinsonism, basal ganglia calcification and epilepsy as late complications of postoperative hypoparathyroidism.

A patient with post-thyroidectomy hypoparathyroidism, basal ganglia calcification, parkinsonism and seizures is reported. The parkinsonism was resistant to levodopa therapy but was not significantly improved by the correction of hypoparathyroidism. Previously reported cases are discussed, as well as the relationship between hypoparathyroidism, calcification of basal ganglia, parkinsonism and epilepsy.

Basal Ganglia Diseases↗

Clinical study of proximal spinal muscular atrophy. Report on 89 cases.

A report on 89 cases of proximal Spinal Muscular Atrophy with observations on the clinical features, criteria of classification and modes of inheritance. The various forms into which SMA is divided probably represent a single disease that may begin at any age and may vary in severity, due, as a rule, to an autosomal recessive gene.

Adolescent↗

So-called neuralgic amyotrophy: clinical features and long term follow-up.

The clinical features of 61 patients with Neuralgic Amyotrophy are analysed with special reference to recovery time, recurrence and residual deficits in 42 of these patients. Although the etiology is still unknown, N.A. has a characteristic clinical picture with a fairly typical pattern of symptoms and signs. A correct diagnosis is important because in spite of the severity and extent of the initial symptoms the overall prognosis in good.

Adolescent↗