Search PubMed⌕ Search

Biomedical subjects

V M Synek

Publications and source records attributed to V M Synek.

At least 37 records · Page 2Linked to original sources
PubMed1986

Validity of median nerve somatosensory evoked potentials in the diagnosis of supraclavicular brachial plexus lesions.

Experience with median nerve SEPs in the diagnosis of brachial plexus lesions is analysed in 49 patients selected from a total material of 264 cases with brachial plexus problems tested by SEP techniques. Median nerve SEPs were always compared with the results of SEPs after stimulation of at least one other nerve relevant to the site of the lesion as suspected clinically and electromyographically. All patients presented with unilateral brachial plexus problems and all root lesions were verified by clinical presentation, EMG studies, myelogram or surgery. There were 19 brachial plexus injuries, 13 cases with cervical spondylopathic radiculopaties without myelopathy and 7 patients presented brachial plexopathy with systemic cancer. It was found that median nerve SEPs were always normal in injuries of upper trunk and root avulsions confined to one or two root levels. Median nerve SEPs were abnormal in multiple trunk lesions and multiple root avulsions. In patients with spondylopathic radiculopathies median nerve SEPs were normal apart from one case where involvement of multiple roots was present. Median nerve SEPs were useful in assessing patients presenting brachial plexus problems in the presence of systematic cancer apart from cases where lower trunk involvement was present. In general, median nerve SEPs are useful if they are combined with SEP testing of other nerves anatomically more closely related to the problem as outlined clinically and electromyographically.

Adolescent↗
PubMed1986

Somatosensory evoked potentials in syringomyelia.

The two types of upper limb somatosensory evoked potential abnormality observed in nine patients with syringomyelia were reduced amplitude or absent cervical potentials and an abnormal central conduction time. Although this pattern of abnormalities resembles that observed in other intrinsic spinal cord lesions, it differs from peripheral nerve diseases and cervical radiculopathy in which the central conduction time is normal.

Adolescent↗
PubMed1986

Diagnostic importance of somatosensory evoked potentials in the diagnosis of thoracic outlet syndrome.

Somatosensory evoked potentials (SEPs) after stimulation of median and ulnar nerves were analyzed retrospectively in a group of 14 patients presenting with rudimentary cervical ribs or ill-healed clavicular fractures, where clinically the possibility of thoracic outlet syndrome was raised. In 5 patients who presented with pain in the arm and hypoesthesia along the ulnar border of the forearm without weakness and wasting in the muscles supplied by the lower trunk of the brachial plexus, the SEPs after both median and ulnar nerve stimulation were normal. In the second group of 9 patients there was weakness and wasting of the lower trunk-supplied muscles. All these patients were treated surgically by excision of abnormal tissues; all of them improved subjectively, and most of them improved strength in the previously affected muscles. SEPs in this group recorded preoperatively showed normal findings after median nerve stimulation, while the potentials after stimulation of ulnar nerve were always abnormal from the affected arm, being delayed, attenuated or even absent at Erb's point, cervical spinal cord and contralateral scalp. The results of this study, which were based on 314 investigations performed in patients with different lesions of the brachial plexus, suggest that abnormal ulnar nerve SEPs in the presence of normal median nerve SEPs are supportive means in the diagnosis of thoracic outlet syndrome, where nervous structures have been endangered. This is in accordance with the most recent reports in the literature.

Evoked Potentials, Somatosensory↗
PubMed1985

Recovery from alpha coma after decompression sickness complicated by spinal cord lesions at cervical and midthoracic levels.

A modified alpha pattern activity occurred in the EEG of a 21-year-old man during recovery from a diving injury. It persisted for 10 days but finally the EEG became normal. There was clinical and neurophysiological evidence of additional separate lesions in the cervical and mid-thoracic spinal cord. The latter resulted in spastic paraplegia but the patient made an otherwise good recovery.

Adult↗
PubMed1985

Somatosensory evoked potentials following stimulation of the tibial, peroneal and sural nerves using four different montages.

Cortical and lumbar somatosensory evoked potentials (SEPs) were recorded following unilateral stimulation of the tibial, peroneal and sural nerves in 20 normal adults. The active cortical electrode (Cz) was referred to either a cephalic (mid-forehead, contralateral central scalp, linked ears) or a non-cephalic (contralateral shoulder) site. The configuration of the short-latency cortical SEP waveforms was nearly identical irrespective of the nerve stimulated or the location of the reference. Central conduction times (CCTs) were also calculated by subtracting the peak latency of the lumbar SEP from that of the primary cortical response following stimulation of the tibial and peroneal nerves. A stronger relationship was consistently observed between the absolute cortical latency and height than between CCT and height. The potential clinical applications of the results are discussed.

Adolescent↗
PubMed1985

Triplicate post-traumatic sciatic nerve palsy: evoked potentials in the diagnosis.

Three episodes of sciatic nerve palsy occurred after open reduction and internal fixation of a fracture-dislocation of the left hip and pelvis in a 20-year-old female injured in a motor cycle accident. There were also ipsilateral open fractures of the tibia and fibula and an open knee injury. When the palsy first developed the patient was in a hip spica plaster cast extending from the costal margin to encase the whole left lower limb. At the time of the second and third episodes of palsy she was in a left below-knee cast and it was not possible to fully assess the function of involved muscles clinically or electromyographically. Psychological factors due to prolonged disability and hospitalization were suspected as a possible cause of weakness. Therefore evoked potentials obtained by stimulation of the peroneal nerves were used to aid diagnosis. There was no response from lumbar and cerebral recording sites on stimulation of the peroneal nerve on the affected side. Diagnosis of a conduction block in the sciatic nerve was thus established. The patient recovered clinically and on repeated testing after motor recovery the cortical potential was attenuated and delayed by 15ms. Recurrent sciatic nerve palsy, occurring three times after hip trauma and with heterotopic bone formation and diagnostic application of evoked potential techniques, has not been previously reported.

Adult↗
PubMed1984

Theta pattern coma, a variant of alpha pattern coma.

Electroencephalograms with a dominant rhythmic areactive 5Hz theta activity are reported in two comatose patients with fatal outcome. This pattern was followed by isoelectric EEG and death in the first patient, who suffered multiple injuries including severe cerebral concussion and later tentorial herniation. The second patient died eight hours after the second EEG recording, both EEGs having shown a very rhythmic 5-6 Hz activity which was maximal anteriorly. He died two days after a severe cerebral hypoxic episode due to acute respiratory failure. Both patients were in their late sixties. It is suggested that the dominant areactive theta activity is a variant of malignant "alpha pattern coma".

Aged↗
PubMed1982

Somatosensory evoked potentials in patients with supraclavicular brachial plexus injuries.

In 12 patients with traumatic lesions of brachial plexus, we studied somatosensory evoked potentials by stimulation of median, radial, and ulnar nerves at the wrist and by recording at the arm, Erb point, cervical spinal cord, and contralateral cortex. Results after median nerve stimulation in patients with upper trunk lesions were normal. Patients with C5/6 root avulsion had either normal, delayed, or absent responses at the cervical cord and cortex, depending on the presence of complicating distal lesions. In patients with particular involvement of C7 root, results were normal after median and ulnar stimulation but were abnormal after radial nerve stimulation. In patients with multiple root avulsions and flail anesthetic arm, no potentials could be recorded from the cervical cord or contralateral cortex, regardless of which nerve was stimulated. For relevant information, it was important to stimulate nerves having roots near the anatomic site of the lesion as determined clinically and electromyographically.

Adolescent↗