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Biomedical subjects

E Chroni

Publications and source records attributed to E Chroni.

At least 19 recordsLinked to original sources
PubMed2001

Carpal tunnel syndrome and hand configuration.

The likelihood that hand configuration is related to the development of carpal tunnel syndrome (CTS) was examined in this study. Based on neurophysiological criteria, 50 female subjects with CTS and 50 healthy female controls were selected and their external hand dimensions were measured. Our results showed that the palm length and third digit length were significantly shorter and the palm width larger in the subjects with CTS compared with controls. Regression analysis demonstrated that the hand ratio [(palm + third digit length)/palm width] was significantly correlated with median nerve conduction measurements. The hand ratio may be a simple and useful predictive measurement in determining the tendency for CTS.

Adult↗
PubMed2001

Segmental myoclonus as the sole manifestation of a choroid plexus papilloma in the posterior fossa. Case report.

The authors describe the case of a 22-year-old woman with involuntary contractions of the sternocleidomastoid and trapezius muscles that resulted in turning movements of the head. The jerks displayed the clinical and neurophysiological characteristics of segmental myoclonus (SM) restricted to muscles supplied bilaterally by the first four cervical segments. Magnetic resonance imaging disclosed a tumor in the midline above the cisterna magna that was later histologically proven to be a choroid plexus papilloma. The patient's involuntary movements did not extend to other muscle groups or, in particular, to the palate, as one might have expected in the case of brainstem lesions. Myoclonus was the sole clinical manifestation of the tumor in this patient; other signs and symptoms invariably reported in other cases of posterior fossa papilloma, such as increased intracranial pressure or cranial nerve palsies, were absent. Release from suprasegmental control is suggested as a possible pathophysiological mechanism in this case of SM.

Adult↗
PubMed2000

Stiff-person like syndrome in a patient with multiple pituitary hormone deficiencies.

A patient with long-standing, occult pituitary insufficiency, who developed painful muscle stiffness and superimposed spasms, closely resembling stiff-person syndrome, was described. Complete resolution of neuromuscular symptoms with hormone replacement in this case, as well as in a previously reported one, led to the suggestion that a syndrome like stiff-person could represent a rare consequence of multiple pituitary hormone deficiencies.

Female↗
PubMed1997

Effect of carpal tunnel syndrome on median nerve proximal conduction estimated by F-waves.

Slowing of median nerve proximal motor conduction in patients with carpal tunnel syndrome (CTS) could be considered as an indicator of an additional proximal lesion (double crush syndrome). The effect of CTS on proximal conduction was assessed by comparing motor velocities calculated by F-waves obtained from muscles with the same root and nerve supply but different median branches, one emerging before the carpal tunnel (pronator quadratus muscle) and one passing through the tunnel (abductor pollicis brevis). Data were obtained from 26 patients with CTS and 21 age-matched healthy subjects. In the control group, the proximal (spinal cord and elbow) F-wave maximal velocity calculated when recording from abductor pollicis brevis (FCVmax-APB) was not different from the F-wave maximal velocity calculated when recording from pronator quadratus (FCVmax-PQ), while it was significantly different in the group of CTS patients, especially in patients with terminal motor latency greater than 4.5 ms (approximately 9% less, p = 0.001, Wilcoxon signed rank test). The study showed that median nerve proximal conduction velocity slowing in patients with CTS is restricted to the fibers that distally pass through the carpal tunnel and does not necessarily imply an additional proximal lesion. We suggest that comparison of FCVmax-APB and FCVmax-PQ could be useful when the question arises if a single (distal) or two (one distal, one proximal) lesions are responsible for a patient's symptoms.

Adolescent↗
PubMed1996

Motor nerve conduction velocities calculated by F tacheodispersion in patients with anterior horn diseases.

F tacheodispersion, a new neurophysiological technique based on F waves, was used to determine the motor nerve conduction velocities in 16 patients with motor neuron disease and 19 patients with sequelae following paralytic poliomyelitis. The findings were compared to two age-matched groups, each consisting of 20 healthy volunteers. In each subject the F wave maximal, minimal, mean conduction velocities and the difference between maximal and minimal velocities of the ulnar and peroneal nerves were calculated. M response distal latency, amplitude and conduction velocity were also measured. There was a statistical significant slowing of one or more of the F wave estimated velocities in the absence of M response abnormalities in 31.3% of nerves in motor neuron disease group and in 27.3% of nerves in the poliomyelitis group; between 6.3% and 37.5%, of the nerves studied showed a significant change in the difference between maximal and minimal conduction velocities. Our results favour the presence of changes of motor fibre conduction properties in some patients with anterior horn diseases.

Adult↗
PubMed1996

F-waves in clinical neurophysiology: a review, methodological issues and overall value in peripheral neuropathies.

This report comments on methodological issues related to the use of F-wave in clinical neurophysiology. An F-wave study aims to describe with relative accuracy the properties of the compound F-wave population which is the population of F-waves consecutively recorded from a muscle. This can only be achieved if an adequate number of F-waves is sampled. In order to avoid inaccuracies, correction of F-wave latency measurements for height or limb length and age is also required. Differences in the recording procedure could account for the variability in F-wave measurements. The usefulness of F-wave parameters other than latency is discussed. F-chronodispersion and F-tacheodispersion are more sensitive than conventional neurophysiological methods in detecting mild nerve lesions. F-persistence provides valuable information only if the findings are interpreted in correlation with the particular clinical setting. The suitability of the F-wave technique for routine studies is examined and a current view on the clinical applications is briefly recounted. There is an urgent need for the standardization of F-wave methodology.

Electromyography↗
PubMed1996

The importance of sample size for the estimation of F wave latency parameters in the peroneal nerve.

We studied the peroneal nerve F waves in 20 healthy subjects and 20 patients with neuropathy to assess the effect of sample size on the accuracy of measurements of the following F wave latency parameters: F wave minimum latency, mean latency, median latency and F chronodispersion. The values obtained from a large sample (65-110 F responses) were compared with the corresponding values from smaller samples of 10, 20 and 40 responses. The results indicated that equally accurate measurements for all parameters were provided by larger F wave samples in patients, compared with healthy subjects. Amongst the various parameters, FchR required the largest and FLmean the smallest sample, in order to achieve results of the same accuracy. A sample of 40 fulfilled the requirements for all F wave latency parameters of the peroneal nerve in almost all subjects, a finding which is in good agreement with that of a similar study for the ulnar nerve.

Adult↗
PubMed1995

Chronic relapsing axonal neuropathy: a first case report.

A relapsing and remitting axonal polyneuropathy developed in a woman at age 47. Serial electrophysiological studies showed that the amplitudes of compound muscle action potentials and sensory action potentials were reduced but conduction velocities were only mildly slowed. F wave latencies were normal and there was no evidence of conduction block. Two sural nerve biopsy specimens showed changes supportive of axonal neuropathy. Repeated responses to prednisolone alone and later prednisolone and azathioprine suggested that inflammatory, possibly autoimmune, processes were important in this case of chronic relapsing axonal neuropathy.

Action Potentials↗
PubMed1995

A comprehensive electrophysiological evaluation of phrenic nerve injury related to open-heart surgery.

A prospective electrophysiological study of phrenic nerve was performed in 59 subjects undergoing open-heart surgery. The nerve was stimulated percutaneously at the neck and the diaphragmatic response was recorded with surface electrodes placed over the 8th intercostal space. The latency, amplitude, duration and area of the evoked response were measured before and after the operation. Post-operatively no response was elicited in 2 patients bilaterally, in 5 from the left and in 2 from the right. Comparison of the post-operative with the pre-operative group values in the remaining subjects showed that the amplitude and area of the left phrenic were lower in the post-operative study, indicating that some of the nerve fibres were not conducting. There were no statistically significant differences between pre and post-operative values of latency or duration on the left or any of the parameters on the right. Our findings suggest that the amplitude and area of the diaphragmatic response are more sensitive than latency in detecting phrenic nerve paresis associated with open-heart surgery.

Aged↗
PubMed1995

Multiple sclerosis presenting as late functional deterioration after poliomyelitis.

We describe five patients with previous poliomyelitis who developed multiple sclerosis (two laboratory supported definite and three clinically definite). The initial symptoms of functional deterioration developed a mean of 30 years following poliomyelitis. Initial functional deterioration was due to progressive limb weakness or impaired mobility and in three cases this led to an initial diagnosis of post-polio muscular atrophy. The clinical diagnosis became apparent with the subsequent development of characteristic clinical features, including optic nerve, brainstem, cerebellum, and spinal cord involvement. The occurrence of multiple sclerosis in these patients emphasises that late functional deterioration may be apparently unrelated to previous poliomyelitis. Furthermore, characteristic clinical features may be masked by the severe pre-existing neuromuscular and orthopaedic impairment leading to diagnostic delay and confusion with the ill-defined clinical syndrome of progressive post-polio muscular atrophy.

Adult↗
PubMed1993

F tacheodispersion: quantitative analysis of motor fiber conduction velocities in patients with polyneuropathy.

The distribution of motor fiber conduction velocities (FCVs) of the ulnar and peroneal nerves in patients with polyneuropathy was estimated using F tacheodispersion, a technique based on F wave latencies. Twenty-three ulnar and 23 peroneal nerves were studied. Three groups of nerves were identified according to conventional, M response, and F wave measurements: those with all parameters normal (group 1), those with abnormal F wave parameters only (group 2), and those with all parameters abnormal (group 3). Application of F tacheodispersion to nerves in group 1 revealed a shift of the distribution of FCVs toward the lower normal values in 6 of 7 nerves. In group 2, a significant proportion of FCVs were below the lower normal limits despite normal maximum conduction velocity estimated by the M response. In group 3, all nerve fibers were abnormally slow. The results indicate that application of F tacheodispersion in clinical practice will increase sensitivity of nerve conduction studies and enable quantitative estimation of conduction in a motor nerve fiber population.

Adult↗
PubMed1993

F tacheodispersion.

F tacheodispersion is defined as the distribution of the conduction velocities of individual or small groups of nerve fibres estimated from significant numbers of consecutively recorded F waves. The ulnar and peroneal nerves in 18 healthy subjects were studied using this method and histograms of motor fibre conduction velocities for the control nerves were created. F tacheodispersion was applied in nine patients with neuropathies and radiculopathies selected on the basis that at least one nerve was 'normal' as measured by conventional techniques (M response, F wave minimum latency to height). In the patient group it was demonstrated that a significant proportion of motor nerve fibres had F tacheodispersion conduction velocities below normal limits despite normal conventional findings. It is concluded that F tacheodispersion should be considered in routine neurophysiological investigation when conventional methods had failed to reveal a suspected nerve lesion.

Action Potentials↗