Papers by Elisabeth Chroni
Journal of Dermatological Treatment, 2006
Neurochemical Research, 2008
The study aimed to directly measure in vivo superoxide radical (O 2 -) a direct indicator of oxid... more The study aimed to directly measure in vivo superoxide radical (O 2 -) a direct indicator of oxidative stress, in the brain of rats with experimentally induced obstructive jaundice by employing a new quantitative ultrasensitive fluorescent assay requiring minimum sample. O 2 anion is specific for dihydroethidine (DHE) and upon reaction gives a characteristic product, namely 2-OHethidium. Ten male rats underwent laparotomy and were divided into two groups: I, sham operated and II bile duct ligation. Ten days later, following injection with DHE (a O 2 trap), all animals were killed and samples from cerebral cortex, midbrain and cerebellum were removed for analysis. It was shown that compared to group I, in group II the O 2 was increased by 67% in the cerebral cortex and by 37% in the midbrain as a consequence of experimental obstructive jaundice, while its levels were unaffected in the cerebellum. The data in this experimental obstructive jaundice model imply a region-specific increase of O 2 -formation rate, being higher in cerebral cortex, less so in the midbrain and not at all in cerebellum.
Journal of Neuropathology and Experimental Neurology, 2006
The effect of experimental obstructive jaundice on the oxidative status of brain tissues in rats ... more The effect of experimental obstructive jaundice on the oxidative status of brain tissues in rats was examined. Twenty-four male Wistar rats were divided into 4 groups: Group I was the control, group II was the sham operated, and groups III and IV were bile duct ligated and killed on the 5th and the 10th day, respectively. Oxidative stress was assessed by measuring the thiol redox state (protein and nonprotein components) and lipid peroxidation level variations in samples from the cerebral cortex, midbrain, and cerebellar tissue in all animals. Results indicated the presence of oxidative stress in the jaundiced animals that was more pronounced on the 10th day as indicated by a decrease in reduced glutathione and protein thiol and an increase in protein disulphide and lipid peroxidation. A dramatic elevation of the level of total nonprotein mixed disulphide level was found specifically in the midbrain in the 10th day group. This suggests an accumulation of nonprotein disulfides other than oxidized glutathione, which remained unchanged, in this particular brain area. This study showed a correlation between experimental obstructive jaundice and the oxidative stress in the rats' brain, implying that a similar pathogenetic mechanism may play a key role in cholestatic liver disease, resulting in hepatic encephalopathy in humans.
Amino Acids, 2010
In a recently published article in ''Amino Acids'' it was shown that obstructive jaundice of 9 da... more In a recently published article in ''Amino Acids'' it was shown that obstructive jaundice of 9 days' duration in rats induces significant alterations of polyamines' metabolism in the brain, which might play an important pathogenetic role in cholestatic brain injury. The authors proposed that alterations of polyamines in cholestatic brain might induce neuronal toxicity through a mechanism that implicates the production of reactive oxygen species and oxidative stress, although this parameter was not evaluated in their study. This hypothesis is supported by our recent findings on brain oxidative status in rats with obstructive jaundice of 10 days' duration. Potential interrelations of the two studies' findings are discussed in this commentary.
Muscle & Nerve
Conrad B, AschofT JC, Fischler M : Der diagnostische Wert der F-Wellen-Latenz. J Neurol 210:151-1... more Conrad B, AschofT JC, Fischler M : Der diagnostische Wert der F-Wellen-Latenz. J Neurol 210:151-159, 1975. Fisher MA, Shahani BT, Young RR: Assessing segmental excitability after acute rostra1 lesions. I. The F Response. Neurology (Minneap), in press. Lachman T, Shahani BT, Young RR: Clinical uses of late responses in the evaluation of patients suspected of having a neumpathy. Unpublished manuscript. Lefebre-D'Amour M, Shahani BT, Young RR, Bird K T Importance of studying sural conduction and late responses in the evaluation of alcoholic subjects. Neurology (Minneap) 26:368, 1976.
Electromyography and clinical neurophysiology
F tacheodispersion, a new neurophysiological technique based on F waves, was used to determine th... more 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.
Journal of neurosciences in rural practice, 2014
Electroencephalography and Clinical Neurophysiology/Electromyography and Motor Control, 1995
Electroencephalography and Clinical Neurophysiology, 1995
Electroencephalography and clinical neurophysiology, 1996
This report comments on methodological issues related to the use of F-wave in clinical neurophysi... more 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 c...
Postgraduate medical journal, 1995
We describe five patients with previous poliomyelitis who developed multiple sclerosis (two labor... more 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 po...
Spine, 2004
This report aims, in the light of the recent literature, to describe the clinical features of bil... more This report aims, in the light of the recent literature, to describe the clinical features of bilateral thoracic outlet syndrome in a case of Klippel-Feil syndrome, the results of electrophysiologic evaluation, and the outcome after surgical intervention. Cervical ribs in the context of Klippel-Feil syndrome as the cause of bilateral thoracic outlet syndrome is discussed. In Klippel-Feil syndrome, congenital fusion of cervical vertebrae occurs and may also be associated with various anomalies, including musculoskeletal anomalies. The typical neurologic defects in this syndrome are caused by compression of the cervical cord and/or the corresponding roots. A 25-year-old woman had experienced, for 3 years, sensory symptoms, mainly numbness and pain, in both arms and episodic color changes of the hands that were aggravated by certain activities. Radiologic examination revealed Klippel-Feil syndrome type I, accompanied by bilateral cervical ribs. Electrophysiologic evaluation demonstrated impairment of nerve conduction, as indicated by F wave changes, after the arms were raised. The patient underwent successful decompression of the neurovascular structures at the thoracic aperture. It is often difficult to diagnose thoracic outlet syndrome by conventional neurophysiology. Dynamic changes in F waves appear to be a useful finding. In the absence of symptoms of myeloradiculopathy, thoracic outlet syndrome could be the sole manifestation of Klippel-Feil syndrome.
Neurology, 2005
The authors conducted a pilot, randomized, open label with blind assessment, controlled trial to ... more The authors conducted a pilot, randomized, open label with blind assessment, controlled trial to determine whether vitamin E supplementation has a neuroprotective effect in chemotherapy-induced peripheral nerve damage. Thirty-one patients with cancer treated with six courses of cumulative cisplatin, paclitaxel, or their combination regimens were randomly assigned in two groups and followed by neurologic examination and electrophysiologic study. Patients assigned in Group I (n = 16) received oral vitamin E at a daily dose of 600 mg/day during chemotherapy and 3 months after its cessation were compared to patients of Group II (n = 15), who received no supplementation and served as controls. The severity of neurotoxicity was summarized by means of a modified peripheral neuropathy score. The incidence of neurotoxicity differed between the two groups, occurring in 4/16 (25%) patients assigned in the vitamin E supplementation group and in 11/15 (73.3%) patients assigned in the control group (p = 0.019). Mean peripheral neuropathy scores were 3.4 +/- 6.3 for patients of Group I and 11.5 +/- 10.6 for patients of Group II (p = 0.026). The relative risk (RR) of developing neurotoxicity was significantly higher in case of control patients, RR = 0.34, 95% CI = 0.14 to 0.84. Vitamin E supplementation in cancer patients may have an important neuroprotective effect.
Neurology, 2001
To describe the peripheral neuropathy resulting from chronic and critical arterial leg ischemia. ... more To describe the peripheral neuropathy resulting from chronic and critical arterial leg ischemia. The authors evaluated 19 patients on entry to a gene therapy treatment trial for chronic and critical leg ischemia. Measurements included medical history, examination, neurologic symptom (NSS) and neurologic examination (NES) scores, motor and sensory nerve conduction studies, and quantitative sensory testing. The critically ischemic leg was compared with the less affected contralateral limb. All patients experienced pain from skin ulceration or vascular claudication, but many also had rest pain (58%), numbness (58%), burning (42%), and paresthesias (37%) in the ischemic foot that were consistent with peripheral nerve ischemia. Only three patients (16%) were free of neuropathic symptoms. The most common asymmetric neurologic signs included hypalgesia (74%), toe weakness (64%), hyperesthesia (63%), and pallanesthesia (53%) in the distal leg. NSS and NES were more abnormal in the critically ischemic leg, as were distal motor, total motor, and sensory examination subscores (p < 0.01 for each). Sural sensory potentials were reduced or absent, frequently on both sides. The symptomatic limb had reduced tibial motor amplitudes and increased thermal (cold) sensory thresholds (p < 0.01 for both) whereas the distal latencies, conduction velocities, and vibration thresholds were similar in the two legs. There is a predominantly sensory neuropathy associated with chronic and critical limb ischemia. Neuropathic symptoms are often obscured by the effects of ischemia on other tissues. The neurophysiologic changes suggest that the underlying pathophysiology is a distal axonopathy affecting nerve fibers of all sizes. Measures of blood flow in the leg correlate with neurologic symptom scores, examination scores, and electrophysiologic testing.
Muscle & Nerve, 2001
The likelihood that hand configuration is related to the development of carpal tunnel syndrome (C... more 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.
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Papers by Elisabeth Chroni