Dimitris Konstantinou

IgG and IgM concentration in the prolapsed human intervertebral disc and sciatica etiology.

Study Design A prospective study was conducted in patients who underwent surgeries for sciatica. The results were compared to those of control subjects. Objectives This study expanded knowledge about the pathogenesis of back pain and sciatica in disc herniation. Methods Nucleus pulposus, retrieved from 10 patients who underwent surgeries for sciatica caused by disc herniation and from 8 patients used as control subjects, was homogenized and together with serum and cerebrospinal fluid was examined for local production of IgG and IgM by rate nephelometry. Summary of the Background Data Experimental data have shown an inflammatory reaction in the nucleus pulposus of animal models. Results and Conclusions An increased ratio IgGNP/IgGs x 103 and IgMNP/IgMs x 103 was found in all patient samples, whereas only the IgMNP/IgMs x 103 ratio was significantly higher (P< 0.005) when compared with those of the control values. These findings may be secondary to an inflammatory reaction close to the nerve root and prolapsed nucleus pulposus. Therefore, they may contribute in some way to the inflammatory origin of sciatica.

Effect of N-acetylcysteine, allopurinol and vitamin E on jaundice-induced brain oxidative stress in rats.

We examined the possible protective effect of certain antioxidants (N-acetylcysteine, allopurinol and vitamin E) against the oxidative stress of brain tissue induced by experimental obstructive jaundice in rats. Thirty-six male Wistar rats were randomly divided into six groups; group I control, group II sham operated, group III bile duct ligated and groups IV, V, and VI in which the rats, after bile duct ligation, were given every day an intraperitoneal injection with N-acetylcysteine, allopurinol and Vit-E respectively. All rats were sacrificed on the tenth day by exsanguination and the oxidative state in samples from cortex, midbrain and cerebellum was assessed by measuring the thiol redox state and lipid peroxidation quantified by MDA measurements. The main finding was that all three antioxidants decrease lipid peroxidation in the three brain areas. Cysteine levels increased and protein thiol levels were reserved only in the group treated with N-acetylcysteine, whereas oxidized glutathione increased dramatically in the group treated with allopurinol, suggesting that each antioxidant agent had a certain influence profile on the different antioxidant defense systems. The observed effects of the antioxidants in this experimental model could also provide insight into some aspects of jaundice-induced hepatic encephalopathy in humans.

The predictive value of external continuous lumbar drainage, with cerebrospinal fluid outflow controlled by medium pressure valve, in normal pressure hydrocephalus

SummaryBackground. Although sporadic studies have described temporary external cerebrospinal fluid (CSF) lumbar drainage as a highly accurate test for predicting the outcome after ventricular shunting in normal pressure hydrocephalus (NPH) patients, a more recent study reports that the positive predictive value of external lumbar drainage (ELD) is high but the negative predictive value is deceptively low. Therefore, we conducted a prospective study in order to evaluate the predictive value of a continuous ELD, with CSF outflow controlled by medium pressure valve, in NPH patients.Method. Twenty-seven patients with presumed NPH were admitted to our department and CSF drainage was carried out by a temporary (ELD) with CSF outflow controlled by a medium pressure valve for five days. All patients received a ventriculoperitoneal shunt using a medium pressure valve based upon preoperative clinical and radiographic criteria of NPH, regardless of ELD outcome. Clinical evaluation of gait disturbances, urinary incontinence and mental status, and radiological evaluation with brain CT was performed prior to and after ELD test, as well as three months after shunting.Findings. Twenty-two patients were finally shunted and included in this study. In a three-month follow-up, using a previously validated score system, overall improvement after permanent shunting correlated well to improvement after ELD test (Spearman’s rho = 0.462, p = 0.03). When considering any degree of improvement as a positive response, ELD test yielded high positive predictive values for all individual parameters (gait disturbances 94%, 95% CI 71%–100%, urinary incontinence 100%, 95% CI 66%–100%, and mental status 100%, 95% CI 66%–100%) but negative predictive values were low (< 50%) except for cognitive impairment (85%, 95% CI 55%–98%).Conclusion. This study suggests that a positive ELD-valve system test should be considered a reliable criterion for preoperative selection of shunt-responsive NPH patients. In case of a negative ELD-valve system test, further investigation of the presumed NPH patients with additional tests should be performed.

Klippel-feil Syndrome Presenting with Bilateral Thoracic Outlet Syndrome

Study Design. 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. Objectives. Cervical ribs in the context of Klippel-Feil syndrome as the cause of bilateral thoracic outlet syndrome is discussed. Summary of Background Data. 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. Methods. 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. Results. 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. Conclusions. 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.

Time-related alterations of superoxide radical levels in diverse organs of bile duct-ligated rats

The time-related alterations of superoxide radical measured in vivo by employing an ultrasensitive fluorescent assay in the liver, intestine, kidney and brain of rats with experimentally induced obstructive jaundice was investigated. Eighteen rats were randomly divided into Group A, rats subjected to sham operation, and Group B, rats subjected to bile duct ligation (BDL). Three rats from each group were subsequently killed at different time points post-operatively (1, 5 and 10 days). As compared to sham-operated, BDL rats showed a gradual increase with time of superoxide radical in the intestine, liver, kidney and brain: for animals sacrificed on the 1st, 5th and 10th day the increase was 45%, 50% and 96% in the liver, 76%, 81% and 118% in the intestine, 64%, 71% and 110% in the kidney and 76%, 95% and 142% in the brain, respectively. This study provides direct evidence of an early appearance of oxidative stress in diverse organs, implying a uniform systemic response to biliary obstruction and emphasizing the need of early bile flow restoration.

Pattern reversal visual evoked potentials in minor head injury

Pattern reversal visual evoked potentials (PR-VEPs) have been recorded in 50 patients with minor head injury (MHI) on days 1 and 30 after trauma and the data compared to 20 normals. None of the patients had visual complaints. The aim was to investigate a possible visual pathway affection in MHI and test the usefulness of PR-VEPs as an objective noninvasive tool in the detection of a possible subclinical affection of the visual system in MHI. P100 latency and amplitude had no significant difference compared to normals. Comparison of patient data on days 1 and 30 after trauma showed a significant latency decrease and amplitude increase on day 30, compared to day 1. These alterations were not age dependent. Our data suggest affection of the human visual pathway in MHI. PR-VEP recording seems to be a useful, objective, noninvasive tool, helping to identify possible subclinical affections of the visual pathway in MHI.

Spinal bone mineral density changes following halo vest immobilization for cervical trauma

SummaryIn this prospective study we followed the bone mineral density (BMD) changes of the injured cervical spine immobilized with the halo vest. In order to define the natural history of cancellous vertebral bone loss and restoration, dual-energy densitometry was used on each of ten selected cervical spines in the lateral view (1) immediately after the application of the device, (2) at the end of the treatment and (3) 3 months after the removal of the halo vest. The halo vest produces local osteoporosis in the immobilized cervical spine with an overall reduction of BMD averaging 2.83% (P < 0.05). The response of the cervical spine to immobilization was only slightly different from patient to patient and between different vertebral bodies in each particular spine. The type and the level of injury of the cervical spine were not related to the changes of BMD, age or gender of the patient, whereas the local osteoporosis was mostly reversible in the follow-up evaluation of 5–6 months.

Kümmell's disease: is ischemic necrosis or vertebral "microcracking" the first step in the sequence?

Kümmell’s disease: Is ischemic necrosis or vertebral ‘‘microcracking’’ the first step in the sequence? [1] Li H, Liang CZ, Shen CC, Chen QX. Decreases in fluid shear stress due to microcracks: a possible primary pathogenesis of Kümmell’s disease. Med Hypotheses 2011;77(5):897–9. [2] Matzaroglou C, Georgiou CS, Assimakopoulos K, et al. Kümmell’s disease: a rare spine entity in a young adult. Hell J Nucl Med 2010;13(1):52–5. [3] Matzaroglou C, Georgiou CS, Assimakopoulos K, et al. Kümmell’s disease: pathophysiology, diagnosis, treatment and the role of nuclear medicine. Rationale according to our experience. Hell J Nucl Med 2011;14(3):291–9. [4] Glimcher MJ, Kenzora JE. The biology of osteonecrosis of the human femoral head and its clinical implications: 1. Tissue biology. Clin Orthop Relat Res 1979:284–309. [5] Swartz K, Fee D. Kümmell’s disease: a case report and literature review. Spine (Phila Pa 1976) 2008;33(5):E152–5. [6] McDonnell P, McHugh PE, O’Mahoney D. Vertebral osteoporosis and trabecular bone quality. Ann Biomed Eng 2007;35(2):170–89.

Occludin dislocation in brain capillary endothelium of rats with bile duct ligation induced cholestasis

The present study used a rat model with bile duct ligation to examine the effect of cholestasis, to the localization of occludin in brain capillary endothelium by means of electronic microscopy. The results demonstrated a dislocation of occludin away from the tight junction sites of brain endothelial cells. A significant increase of the occludin-interendothelial cleft distance was demonstrated in the midbrain and the cerebellum samples but not in the frontal cortex, compared to the control group samples. These findings imply a brain region selective derangement of occludin in response to liver disease.

Co‐occurrence of brain tumours and demyelination of the central nervous system: coincidence or interrelation?

The co-occurrence of a brain tumour and demyelinating disease of the central nervous system (CNS) constitutes a rare clinical entity. We herein report the incidence of meningioma and CNS non-specific demyelination in a patient with a 6-year history of operated brain tumour (meningioma). Our case bolsters the argument that in at least some cases, the occurrence of a brain tumour could predispose to CNS non-specific demyelination.