Search PubMed⌕ Search

Biomedical subjects

U Zifko

Publications and source records attributed to U Zifko.

At least 19 recordsLinked to original sources
PubMed2000

Dose-dependent effects of inspiratory muscle training in neuromuscular disorders.

The goal of this study was to show whether a correlation exists between the intensity of specific respiratory muscle training and the improvement of strength and endurance in inspiratory musculature in patients with neuromuscular disorders (NMD). Sixteen patients with NMD (13 with Duchenne muscular dystrophy and 3 with spinal muscular atrophy) performed inspiratory muscle training (IMT) at home with a special training apparatus for 9 months. Maximal inspiratory mouth pressure (PI(MAX)) and 12s-maximum voluntary ventilation (12s-MVV) test served as parameters for inspiratory muscle strength and endurance, respectively. In patients whose inspiratory vital capacity (VC(in)) declined by less than 10% during the year before training began (n = 10), a significant positive correlation was found between the number of successfully completed strength and endurance exercises and the improvement of PI(MAX) (P < 0.05) and 12s-MVV (P < 0.05). In patients whose VC(in)-decline exceeded 10% (n = 6), indicating more progressive respiratory system involvement of the disease, no significant correlation between the improvement of PI(MAX) and 12s-MVV and the intensity of training was found. In patients with NMD, the effects of IMT-runs are dose-dependent, provided that the respiratory system involvement of the disease is only slowly progressive.

Adolescent↗
PubMed1999

Iliac artery aneurysm causing isolated superior gluteal nerve lesion.

Lesions of the superior gluteal nerve (SGN) lead to weakness of hip abduction, manifesting itself as a gait abnormality, with contralateral tilting of the pelvis with each step. Causes are numerous and may occur at different anatomical locations before the nerve enters the suprapiriform foramen, in the foramen itself, or after the nerve has exited the foramen. This case report describes an SGN lesion by a large iliac artery aneurysm in a patient presenting with a gait disorder.

Buttocks↗
PubMed1998

[Role of electrophysiology in diagnosis of polyneuropathies].

Most for polyneuropathies present in a uniform, distally accentuated, rather symmetrical pattern, although asymmetric or multifocal distributions occur. The main feature of diagnosis is the history of development and the neurological clinical examination. Neurophysiologic studies, mainly nerve conduction studies (motor and sensory), reflex studies and electromyography are very accurate, but unspecific tools in order to establish the diagnosis of polyneuropathies, define special electrophysiologic features and can also reveal undetected (subclinical) lesions. For clinical purposes most neuropathies can be divided according the nerve conduction studies in axonal, demyelinating and mixed types. In recent years additional electrophysiological features as conduction block have appeared and are still under discussion. The etiology of polyneuropathy has to be determined in each patient with scrutinity. Additionally to general diseases (e.g. diabetes), common toxins (e.g. alcohol), concurrent medication (e.g. some cytostatic drugs) also immunologic (e.g. vasculitis) and hereditary factors have to be considered. A nerve biopsy is only indicated after a thorough consideration of electrophysiology and ancilliary findings. This applies in particular to hereditary neuropathies, where genetic testing has become a highly reliable test replacing biopsy.

Diagnosis, Differential↗
PubMed1997

Repetitive phrenic nerve stimulation study in normal subjects.

In patients with myasthenia gravis (MG), it may be difficult to determine by clinical methods if respiratory insufficiency is due to a defect in neuromuscular transmission. We therefore studied the technique of repetitive electrical stimulation of the phrenic nerve in 6 healthy subjects. It was easily performed and quite reproducible. Responses at 3-Hz stimulation were recorded from surface electrodes of the ipsilateral hemidiaphragm, before and after exercise. We analyzed the percent decrement of the negative peak (NP) amplitude, area, and duration of the diaphragmatic compound muscle action potential (CMAP) between the first and the fifth or sixth potentials. The mean percentage change of the area was -2.2% (+/-4.3), and in all tests the change was <10.6%, yielding a normal range of <11%. The change in the NP amplitude was 12.1% (+/-8.3); in duration, the change was -8.7% (+/-9.6). Producing diaphragm fatigue did not change these results. The increase in amplitude and decrease in duration with little change in area, termed pseudofacilitation, may be due to shifts in the position of the diaphragm affecting volume conduction. The technique is a promising tool in the diagnosis of respiratory involvement from neuromuscular transmission disorders.

Action Potentials↗
PubMed1996

Transcortical and cervical magnetic stimulation with recording of the diaphragm.

Transcortical and cervical magnetic stimulation is a potential method of examining the central inspiratory pathway to phrenic motor neurons. The reliability and accuracy of this technique were studied. We performed magnetic stimulations of the cortex and cervical spinal cord with recording from both hemidiaphragms in 35 normal subjects using two different stimulation coils (90-mm circular coil and 70-mm figure-of-eight coil). Needle electrode recordings and ultrasound real-time documentation in 2 subjects excluded volume-conducted contaminations from adjacent chest wall and abdominal muscles. The effect of diaphragmatic facilitation (stimulation at the end of a deep breath) on latency, and amplitude were compared to the effect of hypothenar muscle facilitation. Normal ranges were established for: latency; central motor conduction time; amplitude; amplitude ratio between between peripheral and both cortical and cervical amplitude; and excitability threshold. The latencies were similar for both coils. The amplitudes were significantly higher, and excitability thresholds significantly lower for the 90-mm circular coil, indicating that this coil is preferable for transcortical diaphragmatic stimulations. The effect of facilitation was greater for hypothenar than diaphragmatic recordings. There was excellent right-left agreement for all measurements. Transcortical and cervical magnetic stimulation with recording from the diaphragm can be used routinely to diagnose and monitor patients with impaired central respiratory drive.

Action Potentials↗
PubMed1996

MRI in patients with general paresis.

Few cases of MRI in neurosyphilis have been reported. We examined the value of MRI in patients with general paresis; MRI was performed on four HIV-negative patients with parenchymatous neurosyphilis. It demonstrated frontal and temporal atrophy, subcortical gliosis and, in one patient, increased ferritin in the basal ganglia. The progression of the lesions on MRI correlated well with the neuropsychiatric disturbances. The MRI findings correlated with the well-known neuropathological findings. This combination of pathological findings in neurosyphilis has not been described before and we suggest that MRI is of prognostic value in patients with general paresis.

Adult↗
PubMed1996

Vinorelbine-induced neurotoxicity in patients with advanced breast cancer pretreated with paclitaxel--a phase II study.

Vinorelbine (VNB) shows high antitumoral activity in advanced breast cancer due to its high affinity for mitotic tubulin and differs from the other vinca alkaloids with regard to its low degree of neurotoxicity because of its low affinity for axonal tubulin. Preclinical data show the existence of different binding sites on tubulin for vinca alkaloids and paclitaxel (P), suggesting a lack of cross-resistance. Thus, VNB was chosen eligible for a phase II study to evaluate both the therapeutic efficacy and the toxicity of VNB in patients (pts) with advanced breast cancer failing first- or second-line chemotherapy with P. A total of 14 pts with advanced breast cancer pretreated with P were entered into the study. Therapy consisted of VNB at 30 mg/m2 diluted in 500 ml of normal saline given over 30 min after a minimal interval of 4 weeks since the last application of P. For the first four cycles, injections were repeated at 2-week intervals; thereafter they were repeated at 3-week intervals until evidence of progressive disease or severe toxicity developed. All but one pt was considered assessable for response and all pts were evaluable for toxicity. No objective response was observed; two pts showed no change in their disease. In four pts therapy had to be stopped because peripheral neurotoxicity increased from a pretherapeutic level after therapy with P from National Cancer Institute Common Toxicity Criteria (NCI-CTC) grade 1 (n = 3) and 2 (n = 1) to neurotoxicity grade 3 after 1, 2 (n = 2), and 3 cycles of therapy with VNB, respectively. In addition, constipation of grade 2 occurred in 10 pts. Hematologic toxicity was negligible. No other evaluable toxicity exceeded NCI-CTC grade 1. Both observations of this study, the complete resistance to VNB and the increase in peripheral neuropathy, let us assume the existence of a preclinically not anticipated but clinically relevant cross-resistance between these two spindle poisons and the presence of common functional targets. Therefore, P-pretreated pts should be excluded from consecutive VNB-containing therapies.

Adult↗
PubMed1996

Respiratory electrophysiological studies in Guillain-Barré syndrome.

Respiratory failure is a common and potentially life threatening complication in patients with Guillain-Barré syndrome. The incidence of phrenic nerve involvement and the predictive value of phrenic nerve conduction and diaphragmatic needle EMG were studied in 40 patients with Guillain-Barré syndrome within the first three days of admission to hospital. The negative peak onset latency of the diaphragmatic compound muscle action potential (CMAP), and its amplitude, duration, and area were abnormal in 83%. The need for ventilation was correlated with diaphragmatic CMAP amplitude (P = 0.005), and area (P = 0.001), but not with latency or duration. Abnormalities in diaphragmatic needle EMG were found in 45%, mainly a decreased number of motor unit potentials. The abnormalities correlated with the need for ventilation (P = 0.013). Of the 40% who required ventilation, all had either abnormal phrenic conduction, abnormal diaphragmatic needle EMG, or both. Eighty one per cent of the ventilated patients had abnormal forced vital capacity on the day of the electrophysiological examination. The results indicate that phrenic nerve conduction studies and diaphragmatic EMG are useful in detecting respiratory involvement in patients with Guillain-Barré syndrome and in identifying those at risk of respiratory failure.

Adolescent↗
PubMed1996

[Multifocal motor neuropathy with conduction block--a clinico-neuropathologic case report].

Descriptions on patients with multifocal motor neuropathy with conduction block (MMNCB), including histology, nerve fiber teasing and electron microscopy on nerve biopsy, are rare. We report a 64-year old female patient with progredient weakness of the upper extremities without sensory deficit. Electrophysiology shows conduction blocks up to 80% in several examined motor nerves. A biopsy of the sensory sural nerve reveals features of a mixed axonal and de- and remyelinating neuropathy. Thus sural nerve biopsy contributes here significantly to differential diagnosis and supports an immune mediated pathogenesis of MMNCB.

Amyotrophic Lateral Sclerosis↗
PubMed1996

The respiratory system.

Neurological disorders frequently contribute to respiratory failure in critically ill patients. They may be the primary reason for the initiation of mechanical ventilation, or may develop later as a secondary complication. Disorders of the central nervous system leading to respiratory failure include metabolic encephalopathies, acute stroke, lesions of the motor cortex and brain-stem respiratory centres, and their descending pathways. Guillan-Barré syndrome, critical illness polyneuropathy and acute quadriplegic myopathy are the more common neuromuscular causes of respiratory failure. Clinical observations and pulmonary function tests are important in monitoring respiratory function. Respiratory electrophysiological studies are useful in the investigation and monitoring of respiratory failure. Transcortical and cervical magnetic stimulation can assess the central respiratory drive, and may be useful in determining the prognosis in ventilated patients, with cervical cord dysfunction. It is also helpful in the assessment of failure to wean, which is often caused by a combination of central and peripheral nervous system disorders. Phrenic nerve conduction studies and needle electromyography of the diaphragm and chest wall muscles are useful to characterize neuropathies and myopathies affecting the diaphragm. Repetitive phrenic nerve stimulation can assess neuromuscular transmission defects. It is important to identify patients at risk of respiratory failure. They should be carefully monitored and mechanical ventilation should be initiated before the development of severe hypoxaemia.

Critical Care↗
PubMed1995

Diaphragmatic paresis in newborns due to phrenic nerve injury.

Phrenic nerve lesions as a result of birth trauma have been reported as a cause of acute respiratory distress infrequently. We report recent diagnostic and therapeutic experiences in four newborns with birth-traumatic phrenic nerve injury: one bilaterally, and three unilaterally, all right-sided. In each case, mechanical ventilation was required for at least 16 days. Ultrasound examination of the diaphragm and phrenic nerve conduction studies turned out to be the diagnostic methods of choice. Spontaneous recovery occurred in two children and two became asymptomatic after operative treatment. One improved after plication of diaphragm and one after autologous nerve transplantation.

Birth Injuries↗
PubMed1995

Phrenic neuropathy in chronic renal failure.

BACKGROUND: Peripheral neuropathy and alterations in diaphragmatic muscle function are frequently caused by uraemia. Phrenic nerve function in patients with end stage renal failure, however, has not been examined to date. METHODS: An electrophysiological study of the phrenic nerve was performed to determine its possible involvement in 32 nondiabetic patients with end stage renal disease undergoing chronic haemodialysis. RESULTS: Seventeen patients had electrophysiological signs of peripheral neuropathy in at least one of the investigated nerves and 14 of the 17 showed pathological phrenic nerve latencies. Delayed phrenic nerve latencies correlated clearly with pathological peroneal nerve conduction velocities. CONCLUSIONS: Phrenic neuropathy is a frequent complication of uraemia.

Adolescent↗
PubMed1995

Sciatic neuropathy.

Explore the source record for details and available documents.

Electromyography↗