Selenium: a case for its essentiality in man

Selenium Metabolism in Patients on Continuous Ambulatory Peritoneal Dialysis

Background

Selenium is an essential trace element for living organisms. In many publications, researchers express concern about a possible Se deficiency in patients with end-stage chronic renal failure (ESCRF) undergoing continuous ambulatory peritoneal dialysis (CAPD). However, in a number of published articles, the data provide no evidence that patients under CAPD develop Se deficiency.

Objective

We investigated Se metabolism in ESCRF patients on CAPD.

Setting

The study was carried out at the Department of Propaedeutic Surgery, Athens University; the Laboratory for Material Analysis of the Nuclear Physics Institute; and the State General Hospital, Athens, Greece.

Patients and Methods

The study group included 24 patients on CAPD treatment, 14 ESCRF patients, and 17 healthy controls. We measured the Se and Fe content of serum, blood, and erythrocytes. We also measured hematocrit, serum total proteins and albumins, and Se in dialysate effluent.

Results

As compared with healthy subjects, the ESCRF and CAPD patients exhibited reduced serum concentrations of Se. However, considering the difference in hematocrit values, the total serum-transported Se per liter of blood was close to normal. Erythrocyte Se proved normal for both groups. The measured Se in the spent effluent indicates that patients under CAPD receive approximately 100 μg Se from their daily diet, as normal subjects do. The Se measurement data from the effluent indicate that 90% of the Se carried by the serum is bound to albumins and that only the remaining 10% is in the form of low molecular weight selenate, free to pass the peritoneal membrane. Of the 24 CAPD patients studied, 4 patients (all women) showed extremely low Se serum levels. Data suggest that those low levels are more likely due to the significantly lower serum albumin levels in the 4 patients than to an insufficient dietary intake.

Conclusions

Data from the present experimental work suggest that patients undergoing CAPD receive the necessary quantities of Se from their regular diet. The data contradict statements in the relevant literature that CAPD patients develop Se deficiency.

An unusual cause of flaccid paralysis and coma: baclofen overdose

Baclofen is a γ-aminobutyric acid (GABA) agonist that is commonly prescribed for the treatment of spasticity in children. The clinical indications for baclofen use in the pediatric population have increased in recent years. Prescribing baclofen mandates education regarding abrupt withdrawal and overdose because of the severe clinical reactions this can precipitate. This report highlights the case of a patient who presented with acute onset of coma and a flaccid paralysis after baclofen overdose. We reviewed the presentation, clinical course, diagnostic studies, and outcome of this patient. A review of prior literature regarding baclofen overdose is included. Baclofen overdose is heralded by dose-related alteration in consciousness and weakness, progressing to coma and a flaccid paralysis. Screening for baclofen overdose is accomplished through high-power liquid chromatography. Baclofen overdose is treated with supportive care and antiepileptic medications as indicated. There is usually full spontaneous recovery with elimination of the medication.

Long-term oral baclofen treatment in a child with cerebral palsy: electroencephalographic changes and clinical adverse effects

Baclofen is widely used to control spasticity in children with cerebral palsy. Several publications described clinical adverse effects of baclofen oral treatment, but the effect of baclofen on seizure potentiation is still controversial. We describe a 10-year-old female patient with cerebral palsy, epilepsy, and mental retardation who developed clinical adverse effects (confusion, agitated state, insomnia, diffuse hypotonia, and hyporeflexia) and electroencephalographic (EEG) changes (quasiperiodic, generalized burst of sharp waves that take up >50% of standard EEG) during long-term oral baclofen treatment, after gradually increasing the dosage but still within the therapeutic dose. Our case showed clearly that the EEG changes in our patient, with a history of epilepsy in good control, have been induced by the baclofen increase, and we describe the possible mechanisms that could explain proconvulsive effect of baclofen.

Limitations of Intrathecal Baclofen for Spastic Hemiparesis Following Stroke

Objective. Intrathecal baclofen (ITB) has become the first choice in the management of deleterious spasticity that does not respond to oral and intramuscular medications following spinal cord injury, traumatic brain injury, and cerebral palsy. The usefulness of ITB in severe spastic hemiparesis following stroke is studied. Methods. A total of 8 patients underwent clinical and video assessment following ITB bolus application (n = 5) and during continuous infusion via a temporary catheter system (n = 3). Results. The mean daily dosage alleviating spasticity on the hemiparetic side—without affecting the nonparetic side—was 119 μg/day (range 50 to 360 μg/day). However, 6 patients experienced functional deterioration as ITB weakened their paretic side such that the antigravity pattern they used for ambulation was suppressed. In 2 patients, spasticity-associated pain and spasms subsided and they underwent implantation of a long-term drug delivery system. Conclusions. ITB may reduce spasticity in a dose-dependent manner irrespective of its origin. Although not primarily antinociceptive in humans, ITB may alleviate pain if arising from increased muscle tone. A functional benefit may result if ITB can uncover “subclinical” motor control that had been suppressed by spasticity. However, when a patient uses antigravity patterns for ambulation in the absence of more complex motor control, ITB may cause the loss of residual walking ability, which becomes a major limitation for patients with hemiplegic stroke.

Development of scoliosis following intrathecally placed opioid pump for chronic low back pain

STUDY DESIGN

Case report.

OBJECTIVE

To report a case and review the literature on development of scoliosis following intrathecally placed opioid pump for chronic low back pain.

SUMMARY OF BACKGROUND DATA

Intrathecal opioid administration is a technique currently indicated for the management of chronic pain syndromes. Despite evidence of scoliosis occurring after baclofen pump insertion, there has been no evidence that development of scoliosis occurs following implantation of an intrathecally placed opioid pump for treatment of lower back pain (LBP).

METHODS

A retrospective review of patients with adult onset scoliosis was performed at our institution. One patient was identified as showing significant scoliotic progression following implantation of an intrathecally placed opioid pump. Radiographs were analyzed to evaluate the magnitude and configuration of her kyphoscoliosis following pump insertion.

RESULTS

A 50-year-old woman with intractable LBP underwent placement of a spinal cord stimulator (SCS) followed shortly by removal of the SCS and placement of an intrathecal opioid pump. Five years later, she presented with severe kyphoscoliosis involving a left thoracolumbar curve of 84 degrees and sagittal balance of 158 mm. Because of intractable pain and progressive deformity, she underwent multilevel osteotomies, instrumented fusion, and replacement of her Dilaudid pump. Postoperative radiographs demonstrated a residual 23 degrees thoracolumbar curve with restoration of her sagittal alignment. No major morbidity/mortality occurred with treatment.

CONCLUSION

Although there may not be a direct correlation between implantation of an intrathecal opioid pump with subsequent development of adult onset scoliosis, deformity must be considered a potential sequela in patients treated with such neuromodulation.

Surgical management of spasticity of cerebral origin in children

In children, spasticity is commonly seen in the context of cerebral palsy (CP), but also following head injury, cerebral infarct or other brain insults. CP is a wide term used to describe a constellation of symptoms that characterise the physical impairment of movement due to abnormal brain development. The management of spasticity is tailored according to the clinical picture of the child. Ambulatory mild spastic diplegics tend to reach the maximum of their disability in the first few years of life, and change little after the age of 5-7 years. Such patients who are between 3-5 years and who attempt to mobilise with walking frames are often good candidates for either dorsal rhizotomy or intrathecal baclofen (ITB) administration with the implantation of an indwelling pump. Non-ambulatory mild spastic diplegics and spastic quadriplegics have more profound spasticity, painful spasms, orthopaedic deformities, and difficulties with daily care and posture. ITB has become established as the first line of surgical treatment for these patients. In the last decade, there has been a definite trend away from ablative treatments and towards reversible stimulation and infusion systems. Current pumps have practical limitations but, in the next decade, it is anticipated that technological improvements will render the pumps more patient friendly.

Nonoperative management of spasticity in children

Central to the longitudinal management of childhood hypertonia are nonsurgical treatments. These include physical and occupational therapy, electrical stimulation, orthotics, botulium toxin, and drugs. This manuscripts reviews these treatment modalities as well as evaluation tools available to assess their impact on a child's hypertonia.

The influence of methionine, selenomethionine, and vitamin E on liver metabolic pathways and steatosis in high-cholesterol fed rabbits

Significant disorders of liver metabolic pathways enzymes after high-cholesterol diet could give information on liver steatosis development. This process could probably also be inhibited by some compounds, as examined in rabbits. Forty-two male rabbits were served a high-cholesterol diet (2 g%) (0.67 g/kg b.m./24 h) with addition of d,l-methionine (70 mg/kg b.m./24 h) or seleno-d,l-methionine (12.5 microg/kg b.m./24 h) or alpha-tocopherol (10 mg/kg b.m./24 h) for 3 months to compare the protection effect of used compounds on liver metabolism and steatosis. At the beginning and every month, blood was taken. After the experiment was completed, livers were dissected for histological examinations. The concentration of total cholesterol (t-CH), triacylglycerol (TG), and the activities of aldolase (ALD), sorbitol dehydrogenase (SDH), glutamate dehydrogenase (GLDH), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were determined. Plasma t-CH and TG concentrations were significantly higher in all experimental groups vs control group. Blood serum AST and ALT activities did not undergo change but there were observed not significant increase in the CH group vs control group. Activities of SDH, GLDH, and LDH increased in blood serum and decreased in the liver in all experimental groups. Activities of LDH and SDH increased in the liver in the CH+Met group vs CH group. ALD activity decreased in the liver only in the CH and CH+Se groups. This data support a lipotoxic model of cholesterol-mediated hepatic steatosis. Prolonged administration of high-cholesterol diet not only disturbs the structure of cell membranes, which is expressed by decreased activity of enzymes in the liver and the migration of those enzymes to plasma but as well leads to steatosis of the liver, which has been confirmed by histological examinations. The applied compounds appear to have a varying influence upon the activity of enzymes determined in serum and liver. Obtained results showed a beneficial influence of methionine and vitamin E supplementation on liver steatosis development.

Oral baclofen in children with cerebral palsy: a double-blind cross-over pilot study

AIM

To assess the effectiveness of oral baclofen in reducing spasticity and improving function in children with cerebral palsy.

METHODS

A double-blind, randomised cross-over pilot study of oral baclofen versus placebo. Assessment tools included the Goal Attainment Scale, Pediatric Evaluation of Disability Inventory, Modified Tardieu Scale and parent questionnaire.

RESULTS

Fifteen children with mean age 7.4 years (SD=2.7 years) and spastic or spastic/dystonic quadriplegia (Gross Motor Function Classification System Level IV or V) were enrolled. Children scored significantly better on the Goal Attainment Scale with baclofen compared with placebo (F(1,13)=4.5, P=0.05). There was no significant difference between baclofen and placebo for the Pediatric Evaluation of Disability Inventory or Modified Tardieu Scale. Parent questionnaire results are described.

CONCLUSION

This pilot study demonstrates that oral baclofen has an effect beyond placebo in improving goal-oriented tasks, such as transfers, in children with spastic quadriplegic cerebral palsy.

The use of baclofen in full-term neonates with hypertonia

The use of baclofen in neonates has been minimally reported. We report on two term neonates who were treated successfully for hypertonia with baclofen.

Respiratory Distress After Intrathecal Baclofen Withdrawal

We present the case of a 19-yr-old woman with a history of generalized dystonia who developed sudden onset of adductor spasms of the vocal cords and increased dystonia after the interruption or intrathecal baclofen therapy. Her symptoms resolved after intrathecal baclofen was restored. In patients with dystonia receiving intrathecal baclofen therapy, the onset of dyspnea associated with increased muscle tone should prompt the investigation of baclofen withdrawal.

Effect of baclofen on emesis and 24-hour esophageal pH in neurologically impaired children with gastroesophageal reflux disease

OBJECTIVES

Gastroesophageal reflux disease (GERD) is difficult to control with medical therapy in neurologically impaired children. The gamma-aminobutyric acid type B receptor agonist baclofen was recently reported to reduce reflux in adult patients with GERD by reducing the incidence of transient lower esophageal sphincter relaxations. The current study was undertaken to investigate the effects of baclofen on GERD in neurologically impaired children.

METHODS

Eight neurologically impaired children with GERD between 2 months and 16 years were studied. Baclofen (0.7 mg/kg/day) was administered orally or via nasogastric tube in three divided doses 30 minutes before meals for 7 days. The frequency of emesis on and off baclofen were recorded as a measure of clinical impact. Twenty-four-hour esophageal pH monitoring was conducted before and on the seventh day of the administration of baclofen.

RESULTS

The frequency of emesis was significantly decreased (P = 0.03). The total number of acid refluxes was significantly decreased both during the entire 24-hour period (P = 0.01) and during the postprandial period (P = 0.049). The number of acid refluxes longer than 5 minutes was significantly decreased during the 24-hour period (P = 0.02). The percentage total time of esophageal pH <4.0 and esophageal acid clearance time were not significantly different during the 24-hour period or during the postprandial period. No adverse effects were observed, except for a slight reduction in muscle tone in one subject.

CONCLUSIONS

In this 1-week trial, repetitive administration of baclofen reduced the frequency of emesis and the total number of acid refluxes in neurologically impaired children with GERD.

Orally Delivered Baclofen to Control Spastic Hypertonia in Acquired Brain Injury

To determine if oral/systemic delivery of baclofen can effectively decrease spastic hypertonia due to acquired brain injury (traumatic brain injury, stroke, anoxia, or encephalopathy). Tertiary care outpatient rehabilitation center directly attached to a university hospital. Patients were a convenience sample recruited consecutively who had been referred for treatment of their spastic hypertonia to our spasticity clinic over a 5-year period. The spastic hypertonia was due to an acquired brain injury by either traumatic brain injury (TBI), stroke, or anoxic brain injury. All patients were more than 6 months postinjury or illness. Retrospective review of patients before and after initiation of treatment with oral baclofen, per standardized clinical data sheets. Thirty-five patients (22 TBI patients) were started on oral baclofen and were reevaluated between 1 to 3 months after initiation of treatment. Data for motor tone (Ashworth scores), spasm scores (Penn spasm frequency score), and deep tendon reflex scores were collected on the affected upper extremity (UE) and lower extremity (LE) side(s). Normal extremities were not assessed. Differences over time were assessed via descriptive statistics and Wilcoxon signed-rank. After 1 to 3 months of treatment when subjects had reached their maximal tolerated dosage, the average LE Ashworth score in the affected lower extremities (LEs) decreased from 3.5 to 3.2 (P =.0003), the reflex score decreased from 2.5 to 2.2 (P =.0274), and there was no statistical difference in the spasm score (P >.05). When the 22 TBI patients are analyzed separately, the average LE Ashworth score decreased from 3.5 to 3.2 (P =.0044) and the reflex score decreased from 2.7 to 2.0 (P =.0003). There was no statistically significant change in UE tone, spasm frequency, or reflexes after 1 to 3 months of treatment (P >.05). The average dosage at follow-up was 57 mg/day of baclofen (range 15-120 mg/day). There was a 17% incidence of somnolence that limited the maximum daily dosage of the medication. The oral delivery of baclofen is capable of reducing LE spastic hypertonia resulting from acquired brain injury. The lack of effect upon the upper extremities may be due to receptor specificity issues. GABA-B receptors may be less involved in the modulation of UE spastic hypertonia.

Baclofen neurotoxicity in uremic patients: is continuous ambulatory peritoneal dialysis less effective than intermittent hemodialysis?

OBJECTIVES

To compare the efficacy between continuous ambulatory peritoneal dialysis (CAPD) and intermittent hemodialysis in the treatment of baclofen-associated neurotoxicity.

METHODS

Three uremic patients suffering baclofen-associated neurotoxicity were treated by CAPD at our hospital. We obtain 12 cases with detailed clinical course of baclofen-associated neurotoxicity treated by hemodialysis from a literature review using the Medline and Science Citation Index, six of these patients were treated by early hemodialysis which was defined as hemodialysis intervention within 48 h of the onset of clinical toxicity.

RESULTS

Our cases regain full consciousness within 2-3 days after the onset of neurotoxicity. Clinical characteristics of our cases including age, dialysis time, preexisting central nervous system (CNS) lesion, concomitant use of CNS depressant, total baclofen dose, onset of neurotoxicity, and duration of neurotoxicity are not significantly different from reported cases that treated by either early or routine hemodialysis.

CONCLUSIONS

Baclofen should be avoided in uremic patients. When consciousness disturbance occurs in uremic patients, baclofen-associated neurotoxicity should be included in the list of differential diagnosis. According to experiences of our patients, we conclude that neither early nor routine hemodialysis is more effective than CAPD in shortening the recovery time of baclofen-associated neurotoxicity.

Pharmacologic options for the management of multiple sclerosis symptoms

Multiple sclerosis (MS) is a disease with a wide-ranging impact on physical functioning. Although pharmacotherapy plays an indispensable role in the management of MS symptoms, optimal disease management requires a multidisciplinary approach that combines medication, rehabilitation, and patient education. Successful control of symptoms is critical to quality of life for MS patients. Immunomodulating drugs provide a means of controlling the underlying disease process, but they are not a cure. This places responsibility on health care providers to control a patient's MS-related symptoms to limit disability and delay impairment in the activities of daily living. Owing to the importance of symptom control, comprehensive patient evaluations should be performed at regular intervals to determine the extent of neurological damage and disease progression and to address changing patient needs. The goal of interventions should be not only to treat the primary and secondary symptoms of MS but also to provide access to the psychosocial support that will help MS patients and their families continue to cope as disease status changes.

Pain and spasticity after spinal cord injury: mechanisms and treatment

STUDY DESIGN

A comprehensive survey of literature on the proposed mechanisms and treatment of pain and spasticity after spinal cord injury (SCI) was completed.

OBJECTIVES

To define the current understanding of these entities and to review various treatment options.

SUMMARY OF BACKGROUND DATA

The neurophysiologic basis of spasticity after SCI is well established. The mechanism of neuropathic pain after SCI remains conjectural, although considerable new data, much of it from animal models, now add to our understanding of this condition.

METHODS

A comprehensive search and review of the published literature was undertaken.

RESULTS

Treatment options for spasticity are effective and include oral medication (baclofen, tizanidine), intrathecal baclofen, and rarely, surgical rhizotomy or myelotomy. Selected patients with post-SCI pain can respond to surgical myelotomy (DREZ lesions) or intrathecal agents (e.g., morphine + clonidine), but the majority continue to suffer.

CONCLUSIONS

Medical and surgical treatments for spasticity are established and highly successful. Management of post-SCI pain remains a clinical challenge, as there is no uniformly successful medical or surgical treatment.

Intrathecal baclofen in tetraplegia of spinal origin: efficacy for upper extremity hypertonia

STUDY DESIGN

Retrospective analysis.

OBJECTIVES

To evaluate the efficacy of intrathecal baclofen (ITB) for upper extremity spastic hypertonia in tetraplegia of spinal origin.

SETTING

University of Alabama at Birmingham hospital.

METHODS

The medical records of 14 individuals with tetraplegia of spinal origin who underwent intrathecal baclofen pump placement were reviewed. The effects of intrathecal baclofen on spasm frequency, deep tendon reflexes, and tone (Ashworth scale) were assessed for the upper and lower extremities for a 1-year follow-up period.

RESULTS

There were statistically significant declines in upper extremity spasm scores (1.8 points, P=0.012), reflex scores (1.4 points, P<0.0001) and Ashworth scores (0.6 points, P<0.0001) for the 1-year follow-up period. For the lower extremities, all decreases were significant (P<0.0001). There was also a statistically significant (P<0.0001) increase in intrathecal baclofen dosage requirements during the 1-year follow-up period to maintain the reductions in spasm frequency, reflexes and tone.

CONCLUSIONS

Intrathecal baclofen is a safe and effective intervention for treating upper extremity hypertonia of spinal origin. In addition, the level of intrathecal catheter placement is felt to be of importance.

Selenium, glutathione peroxidases, and some other antioxidant parameters in blood of patients with chronic renal failure

In the present study several parameters associated with oxidative stress were examined in the blood of 25 chronic renal failure (CRF) patients and the results were compared with 18 healthy subjects. Mean creatinine concentration in patients was 1,216 +/- 292 micromol/l. Selenium (Se) concentration in red cells, whole blood and in plasma of CRF patients (106 +/- 32.5, 59.0 +/- 16.7 and 42.4 +/- 13.8 ng/ml, respectively) was significantly (0.0001 < P 0.01) lower (by 20-42%) compared with the controls. Red cell and plasma glutathione peroxidase (GSH-Px) activities (16.6 +/- 3.4 U/g Hb and 93.7 +/- 32.9 U/l plasma) were lower by 12 and 53% (P < 0.05 and < 0.0001, respectively) in patients than in healthy subjects. GSH concentration in red cells of patients (2.81 +/- 0.45 mmol/l) was significantly (P < 0.001) higher (by 20%) than in control group. Malonyldialdehyde (MDA) concentration (expressed as thiobarbituric acid-reactive substances) in red cells of patients (725 +/- 155 nmol/g Hb) was significantly (P < 0.001) higher (by 28%) than in control group. No significant difference was observed in the activity of superoxide dismutase in pLasma between the two groups. In conclusion, our results confirm that the aLterations in Se levels in blood components and in GSH-Px activity in plasma show that the kidney plays an important role in Se homeostasis and in plasma GSH-Px synthesis.

Pharmacotherapy of spasticity: oral medications and intrathecal baclofen

Spasticity is a common problem in children with neurologic impairment, particularly in those with cerebral palsy. Clinicians commonly make use of oral medications to attempt to reduce spasticity and increase function. Little has been published in the literature concerning the use of these medications in children and their effects on both muscle tone and function. This article is a review of the sites of action, side effects, and efficacy of benzodiazepines, baclofen, dantrolene sodium, alpha2-adrenergic agonists, and gabapentin. A brief review of intrathecal baclofen is included as well.

Rehabilitation and Recovery After Stroke

Many poststroke complications are preventable. There are few data comparing the efficacy of specific, standard physiotherapeutic approaches with each other or with the incidence of spontaneous recovery. More intensive physiotherapeutic approaches may be of benefit, but the available data are inconclusive. Innovative physiotherapeutic approaches, such as robot training and forced-use therapy, are promising but require further study. Certain classes of drugs affecting central neurotransmitters (eg, alpha(2)-adrenergic receptor agonists, alpha(1)-adrenergic receptor antagonists, haloperidol, phenytoin, phenobarbital, and benzodiazepines) may interfere with recovery and should be avoided if possible until definitive data become available. Pharmacotherapy to improve poststroke recovery remains experimental.

Intrathecal baclofen for management of spastic cerebral palsy: multicenter trial

Intrathecal baclofen infusion has demonstrated effectiveness in decreasing spasticity of spinal origin. Oral antispasticity medication is minimally effective or not well tolerated in cerebral palsy. This study assessed the effectiveness of intrathecal baclofen in reducing spasticity in cerebral palsy. Candidates were screened by randomized, double-blind, intrathecal injections of baclofen and placebo. Responders were defined as those who experienced an average reduction of 1.0 in the lower extremities on the Ashworth Scale for spasticity. Responders received intrathecal baclofen via the SynchroMed System and were followed for up to 43 months. Fifty-one patients completed screening and 44 entered open-label trials. Lower-extremity spasticity decreased from an average baseline score of 3.64 to 1.90 at 39 months. A decrease in upper extremity spasticity was evidenced over the same study period. Forty-two patients reported adverse events. Most common reports were hypotonia, seizures (no new onset), somnolence, and nausea or vomiting. Fifty-nine percent of the patients experienced procedural or system-related events. Spasticity in patients with cerebral palsy can be treated effectively by continuous intrathecal baclofen. Adverse events, although common, were manageable.

Continuously infused intrathecal baclofen for spastic/dystonic hemiplegia: a preliminary report

The objective of this study was to determine whether the continuous intrathecal delivery of baclofen will control spastic hypertonia associated with long-standing hemiplegia from acquired brain injury. Six hemiparetic patients (average age, 50 (range, 42-66) yr) with more than 6 mo of disabling lower limb spastic hypertonia on one side caused by either a unilateral traumatic brain injury or a stroke were recruited in a consecutive manner. The setting was a tertiary care outpatient and inpatient rehabilitation center directly attached to a university hospital. Patients were screened via a randomized, double-blind, placebo-controlled, crossover design to receive either an intrathecally administered bolus injection of normal saline or 50 microg of baclofen. Data for Ashworth rigidity scores, spasm scores, and deep tendon reflex scores were collected on the affected upper limb and lower limb side. Those who dropped an average of two points on their affected lower limb side Ashworth scores were then offered computer-controlled pump implantation for continuous intrathecal administration of baclofen. Differences over time were assessed via descriptive statistics and Wilcoxon's signed-rank test. After 3 mo of treatment, the average lower limb Ashworth score on the affected side decreased from 3.7 +/- 1.0 to 1.9 +/- 0.6 standard deviation (SD) (P < 0.0001), the reflex score from 1.8 +/- 1.3 to 0.5 +/- 0.8 SD (P = 0.0208), and the spasm score from 1.3 +/- 1.2 to 0.8 +/- 1.3 SD (P > 0.05). The average upper limb Ashworth score on the affected side decreased from 3.4 +/- 0.9 to 2.1 +/- 0.9 SD (P = 0.0002), the reflex score from 2.3 +/- 0.5 to 1.7 +/- 0.5 SD (P > 0.050, and the spasm score from 0.8 +/- 1.3 to 0 +/- 0 SD (P > 0.05). The average intrathecally administered dose of baclofen that was required to attain these effects was 205.3 microg, which was continuously infused for 24 h. Continuous intrathecal infusion of baclofen is capable of maintaining a reduction in the dystonia on the hemiparetic side without significantly affecting motor strength on the normal side.

The effects of baclofen on calcium channel currents in dorsal sensory cells of the spinal cord in the lamprey

Dorsal sensory cells isolated from the spinal cord of the lamprey species Ichthyomyzon unicuspis and Lampetra fluviatilis were used for whole-cell patch-clamp studies of the effects of baclofen on calcium channel currents, evoked in conditions in which Na+, K+ currents were blocked, by depolarizing membranes from constant holding potentials of -100 or -80 mV to +30 mV. Ba ions were used as carriers of currents through calcium channels. These studies demonstrated that baclofen (0.5 mM) decreased the peak amplitude of the Ba2+ current by an average of 22.5 +/- 4.2% (n = 12) in dorsal sensory cells of the lamprey Ichthyomyzon unicuspis and by 28.4 +/- 3.3% in the dorsal sensory cells of Lampetra fluviatilis (n = 25). The conductivity of dorsal sensory cell membranes in the presence of baclofen (and GABA) did not change. The blocking action of baclofen persisted in the presence of bicuculline (100 microM) and was lifted by addition of delta-aminovaleric acid and 2-hydroxysaclofen to the perfusing solution. These results are interpreted as evidence for the presence of GABAB receptors in dorsal sensory cell membranes. The data were compared with published results, and the question of the functional significance of GABAB receptors in the dorsal sensory cells (primary afferent cells) of cyclostomata is discussed.

Gabapentin for relief of spasticity associated with multiple sclerosis

The use of a recently released anticonvulsant, gabapentin, in the treatment of spasticity in two patients with multiple sclerosis is reported. Gabapentin was chosen because of its GABA-ergic effect and because previously reported studies have shown that it is well tolerated compared with other GABA-mimetic medication. Satisfactory release of spasticity with significant improvement of functional outcome was noted in both cases. Both patients were first treated with gabapentin for one month at 300 mg per day and then, with no reported side-effects, at 400 mg per day. Before treatment, spasticity (graded with modified Ashworth Scale) in one patient was 3 for left lower and 2 for right lower limbs, and Expanded Disability Status Scale (EDSS) was 7; ambulation was limited to a few steps with a standard walker. After two weeks of treatment, spasticity was 2 and 1 for the left and right lower limbs, respectively. At three-month intervals, spasticity was +1 for left and 1 for right lower limbs, and EDSS was 6; the patient could ambulate 75 to 100 m with a standard walker. In the second patient, spasticity before treatment was 2 for both lower and left upper limbs. EDSS was 5.5, and ambulation was confined to 100 m with a cane. Spasticity improved to +1 in lower and 1 in left upper limbs after two weeks and to 1 and normal after three months. At three months, EDSS was 3 and the patient could ambulate for long distances without an assistive device. We suggest that gabapentin can be used effectively to decrease spasticity without significant side effects in patients with multiple sclerosis.

Effect of selenium on vanadium toxicity in different regions of rat brain

The protective effect of selenium on the neurotoxicity of vanadium in different brain regions of rats was investigated. The lipid peroxidation was significantly accentuated after intraperitoneal (i.p.) administration of vanadium (1.5 mg kg-1 b.wt) for a period of 12 consecutive days to rats. The increase in lipid peroxidation was inhibited by selenium treatment (0.02 mg kg-1 b.wt., i.p.) for 12 consecutive days. Vanadium exposure produced a decrease in nonprotein sulfhydryl group. Selenium treatment prevented the depression in nonprotein sulfhydryl group in all the brain regions of the vanadium exposed rats. The concentration of ascorbic acid was decreased after co-administration of selenium and vanadium. These results suggest that selenium protects neuronal cells against neurotoxic effects of vanadium by maintaining the availability of antioxidant nonprotein sulfhydryl groups. The decrease in ascorbic acid levels may have been due to its consumption in forming complexes with vanadium.

High-performance liquid chromatography of selenoamino acids and organo selenium compounds. Speciation by inductively coupled plasma mass spectrometry

As part of an ongoing study to identify selenium compounds with cancer chemopreventive activity, extracts of selenium-enriched samples were analyzed by HPLC-inductively coupled plasma (ICP)-MS. Ion-exchange, ion pair and derivatization methods for reversed-phase HPLC were considered and advantages and disadvantages for each compared. Anion exchange allows separation of selenite and selenate, but otherwise provides poor separation. Pre-column derivatization and reversed-phase chromatography provides separation of compounds with terminal amine functionalities, but many other species elute in the void volume. The ion pair method gave optimal separation and was compatible with standard ICP-MS operating conditions.

Baclofen toxicity in patients with severely impaired renal function

OBJECTIVE

To report the toxic effects of baclofen in patients with severely impaired renal function.

DATA SOURCES

From 1991 to 1995, nine patients with severely impaired renal function (2 not receiving dialysis, 1 undergoing continuous ambulatory peritoneal dialysis [CAPD], and 6 receiving maintenance hemodialysis), who exhibited clinical toxicity after baclofen therapy at our hospital were included for analysis. Another seven cases from the literature obtained by computerized (MEDLINE) and manual (Index Medicus) search methods published between 1980 and 1995 were also reviewed.

INTERVENTION

Among our nine patients, the six undergoing chronic hemodialysis and one not undergoing dialysis received early (< 48 h) hemodialysis after toxic symptoms developed. The patient undergoing CAPD received late hemodialysis (> 72 h), and the other patient who had not undergone dialysis received only supportive care.

RESULTS

A review of these 16 cases revealed that most patients received only small doses and very short-term baclofen therapy. Altered consciousness was the major presenting feature. Severe acute complications, such as seizures and respiratory depression, were relatively uncommon among patients with severely impaired renal function. However, abdominal pain, which has previously rarely been reported, was noted in five of our nine patients. Most patients showed clinical improvement after hemodialysis. An analysis of these nine patients revealed that those who received early hemodialysis had a shorter recovery time than the patient who received only supportive care (2.71 +/- 0.42, respectively, vs. 9 d; p < 0.01). A lag of several hours between the end of the hemodialysis session and an improvement in the level of consciousness was noted.

DISCUSSION

As most patients with severely impaired renal function developed toxic symptoms soon after initiating a low-dose baclofen regimen, the accumulated dosage was small and severe complications were less common. Abdominal pain may have occurred as a result of the gamma-aminobutyric acid-mediated cholinergic effect exerted by baclofen. The delay in conscious recovery after hemodialysis may be due to a delay in the clearance of baclofen from the central nervous system.

CONCLUSIONS

Patients with severely impaired renal function generally develop baclofen intoxication soon after the initiation of low-dose therapy. Thus, the administration of baclofen, regardless of the dosage, in these patients is not appropriate. Abdominal pain, in addition to altered consciousness, is a common presenting feature in patients with renal failure who have baclofen intoxication. Hemodialysis is effective in alleviating the clinical symptoms and shortening the recovery time for such patients.

Prospective assessment of continuous intrathecal infusion of baclofen for spasticity caused by acquired brain injury: a preliminary report

Twelve consecutive patients with severe spasticity and hypertonia following acquired brain injury were treated with continuous intrathecal infusion of baclofen via an implanted, programmable infusion pump-catheter system for a minimum of 3 months. In every case intrathecal baclofen therapy resulted in a statistically significant reduction in upper- and lower-extremity tone, spasm frequency, and reflexes, contributing to improved functional abilities. There were no untoward side effects or complications associated with treatment. This preliminary assessment indicates that intrathecal administration of baclofen is effective in treating the disabling spasticity caused by acquired brain injury in selected patients.

The protective role of selenium on the toxicity of cisplatin-contained chemotherapy regimen in cancer patients

The effect of selenium (Se) in reducing the toxicity of cisplatin in cancer patients was studied. Forty-one patients were randomized into group A (20 patients with Se administration in first cycle of chemotherapy as study cases and without Se in second cycle of chemotherapy as control) and group B (21 patients without Se in first cycle of chemotherapy and with Se in second cycle of chemotherapy). The 4000 micrograms per day of Se as Seleno-Kappacarrageenan were administered from 4 before to 4 d after chemotherapy for study cases. The serum Se increased from 70.4 +/- 22.86 to 157.04 +/- 60.23 ng/mL (P < 0.001) in patients received Se. The cisplatin dosage was iv administration in 60-80 mg/m2 on the first day. The results showed that the peripheral WBC counts on day 14 after initiation of chemotherapy in study cases was significantly higher than the controls (3.35 +/- 2.01 vs 2.31 +/- 1.38 [x10(9)L])/L, p < 0.05). On the other hand, the consumption of GCSF for the cases was significantly less than the controls (110.1 +/- 82.2 vs 723.6 +/- 192.6 IU, p < 0.05). The volumes of blood transfusion for the study group were also significantly less than the controls (0 vs 62 +/- 38 mL, p < 0.05). The nephrotoxicity of cisplatin was measured by urine enzymes (NAG, GGT, AAP, LAP, and ALP) were determined prior to and at 2, 24, 48, and 72 h after initiation of chemotherapy. The urine enzymes NAG, GGT, AAP, and ALP after chemotherapy for cases were significantly lower than the controls. No toxicity of Seleno-Kappacarrageenan was noted. The above results suggest that the Se can be used as an agent for reducing the nephrotoxicity and bone marrow suppression induced by cisplatin.

Botulinum toxin type A for the treatment of arm and hand spasticity in stroke patients

BACKGROUND

Focal spasticity can be a major drawback in the rehabilitation of stroke patients. Previous studies suggest a beneficial effect for botulinum toxin A (BTX-A) for relief of spasticity.

OBJECTIVE

To evaluate the safety and efficacy of BTX-A in the treatment of spasticity in a homogeneous group of stroke patients.

METHODS

In this phase III open label trial 19 stroke patients stable for at least six months were enrolled (mean age 53.1 (SD 3.27) years; range 26-72). There were 16 males and 4 females.

ASSESSMENTS

Clinical (Ashworth spasticity rating scale, scores for joint mobility, pain and frequency of spasms, Frenchay arm test (FAT)) and subjective (semi-quantitative rating scale filled out by the patient). Only hand and finger flexors were injected. The maximum dosage was 150 U BOTOX (25 U/muscle), the mean dosage was 92.1 +/- 31.6 U BOTOX.

RESULTS

Ashworth rating scale and joint mobility scores improved from a median value of 2 at baseline to a median value of 1 one month after treatment, FAT scores also improved from a median value of 0 at baseline to a median value of 1 one month after treatment (Kruskall-Wallis test p < 0.01). Two-thirds of the patients rated their functional improvement as none or mild.

CONCLUSIONS

Our study confirmed that BTX-A has an anti-spastic effect but its functional impact needs further evaluation.

Chronic intrathecal delivery of baclofen by a programmable pump for the treatment of severe spasticity

The aim of this study was to determine the efficacy, safety, and cost-effectiveness of intrathecal baclofen delivered by a programmable pump for the chronic treatment of severe spasticity. Sixty-six patients with severe spasticity of spinal cord origin that was refractory to oral baclofen or who experienced intolerable side effects with this form of the drug were screened. The first nine participated in a double-blinded, randomized, placebo (normal saline)-controlled trial to determine response to a bolus dose of intrathecal baclofen. Subsequent patients were enrolled in an open-label treatment protocol without a placebo trial. All passed the screening, and the pump was implanted in 59 patients. Spasticity scores and medical costs before and after surgery were analyzed. In all patients, the mean Ashworth score for rigidity decreased from 4.3 preoperatively to 1.4 (p < 0.0005) with use of intrathecal baclofen. The spasm frequency score decreased from a mean of 3.6 to 0.5 (p < 0.0005). Activities of daily living, sleep, and skin integrity improved, and pain was eradicated in some. Constipation occurred in six patients. A reduction in dosage was necessitated by muscular hypotonia in three ambulatory patients, areflexic bladder and urinary retention in three others, and nausea, dizziness, and drowsiness in one. Catheter-related problems occurred 19 times in 15 patients. One pump was explanted because of infection in the pump pocket, and one was removed after it eroded through the skin. There were no pump failures. The use of intrathecal baclofen resulted in a decrease in the average length of subsequent hospitalizations. It is concluded that intrathecal baclofen delivered by an implanted programmable pump is a safe, effective, and cost-efficient method for treatment of severe intractable spinal spasticity.

Evaluation of selenium exposure in copper refinery workers

Concentrations of selenium in plasma and urine and activity of glutathione peroxidase in erythrocytes were determined in workers exposed to selenium and in a control group. Plasma selenium concentrations were significantly lower in exposed workers compared to the controls. Erythrocyte glutathione peroxidase activity in selenium workers was significantly higher than in the control subjects. Urine selenium concentrations were not statistically different between the two groups. There was a significant positive correlation between plasma selenium concentrations and urine selenium concentrations in workers exposed to selenium. A weak significant positive correlation was found between plasma selenium concentrations and erythrocyte glutathione peroxidase activity in exposed workers. Our results suggest that the lower plasma selenium concentrations in selenium workers may be attributed to an increase of urinary selenium excretion.

Effect of selenium on 1,2-dimethylhydrazine-induced intestinal cancer in rats

PURPOSE

This study was designed to determine the cancer prevention and therapeutic effects of selenium on rats treated with 1,2-dimethylhydrazine (DMH).

METHODS

One hundred sixty Spraque-Dawley male rats were divided into seven groups and received 20 mg/kg/week DMH, subcutaneously for 20 weeks. Two different dosages of selenium (8 and 4 ppm) were administered to the rats through drinking water during DMH treatment (B and C groups) or one month before and during DMH treatment (D and E groups). The rats of Groups A (control group), B, C, D, and E were killed immediately after the last DMH injection. The incidence of intestinal cancer in each group was compared. Eight ppm selenium was also administered to rats after DMH treatment (Group F), and survival times were observed and compared with Group G (treated with DMH only).

RESULTS

Rats of Groups B and D received 8 ppm selenium and had a significantly decreased incidence of intestinal cancer (from 65.8 percent (Group A) to 33.3 percent (Group B) and 27.8 percent (Group D); P = 0.0225 and 0.0038). Rats receiving 4 ppm selenium had a relatively decreased incidence of intestinal cancer (from 65.8 percent (Group A) to 44.4 percent (Group C) and 47.1 percent (Group E) but P > 0.05). Survival time of Groups F and G showed no difference.

CONCLUSIONS

Eight ppm selenium provided via drinking water has a significant intestinal cancer prevention effect in the presence of a high dose of DMH (20 mg/kg x 20 weeks), and the cancer therapeutic effect of selenium is doubtful in this animal model.

The necessity of selenium substitution in total parenteral nutrition and artificial alimentation

For the trace element selenium, in contrast to zinc, iron, copper, chromium, manganese and iodine, there is still no clear official recommendation with regard to routine substitution in artificial nutrition. An overview of the manifestations of selenium deficiency in humans during the period 1979-1995 shows that nutritive deficiencies are exclusively TPN-induced or the result of severe malnutrition. The pathology of TPN-induced selenium deficiency and the analytic assessment of selenium status are described. Patients undergoing long-term parenteral nutrition or suffering from an increased loss of intestinal secretions have to be characterized as being especially at risk for clinical selenium deficiency. The relationship of the serum selenium kinetics in pediatric and adult patients to the depletion of body compartments during the course of short-term and prolonged TPN is discussed. Because of the importance of the selenoproteins, the regularly occurring depletion during selenium-free TPN and the borderline supply of selenium in Germany the routine substitution of selenium in TPN is strongly recommended. The pharmaceutical industry should be encouraged to develop a trace element solution that includes selenium, so that the nutritive requirement of patients on TPN can be satisfied. Adequate intravenous dosage recommendations are based on maintenance of glutathione peroxidase homeostasis. The routine supplementation dosage may not meet the selenium requirements of intensive care patients under conditions of increased metabolic demands on their anti-oxidative system.

Hemodialysis with regenerated cellulosic membranes does not reduce plasma selenium levels in chronic uremic patients

Selenium (Se) is considered an essential and very important trace element for humans. Se blood levels are frequently low in end-stage renal disease (ESRD) patients, but very little has been established concerning the mechanisms that could modify Se status in uremia, including a supposed dialysis-mediated Se depletion. In order to verify whether hemodialysis (HD) can induce a loss of Se, thereby leading or contributing to a low plasma Se concentration, we investigated the effect of HD procedure with the most commonly used regenerated cellulosic membrane (Cuprophan) on plasma Se levels in 20 uremic patients on HD for 62.5 +/- 49.4 months. Plasma Se levels were also determined in 15 chronic renal failure (CRF) nondialyzed patients and in 28 age-matched healthy controls. Se concentration was determined by atomic absorption spectrophotometry. Plasma Se levels of both HD patients (61.3 +/- 8.5 micrograms/L) and CRF nondialyzed patients (56.4 +/- 10.1 micrograms/L) were significantly lower than in normal subjects (78.3 +/- 9.7 micrograms/L, p < 0.001). In CRF nondialyzed patients, a significant (p < 0.05) negative correlation was found between the plasma Se concentration versus serum creatinine values. Within the HD group, plasma Se levels significantly increased after the HD procedure (72.8 +/- 17.2 micrograms/L, p < 0.02) together with hematocrit and total plasma protein values (p < 0.05 and p < 0.001, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of gamma-aminobutyric acid on baclofen intestinal absorption

Since previous studies suggested that baclofen absorption in the rat middle intestine was inhibited by beta-alanine and therefore mediated, at least in part, by the beta-aminoacid carrier, we focused our new studies on the analysis of the possible inhibition of the drug by a gamma-aminoacid model compound, gamma-aminobutyric acid (GABA). A rat jejunum in situ study was undertaken in order to evaluate the effect of GABA on baclofen absorption and to establish the inhibition model. Assays using isotonic perfusion solutions of 0.5 mM baclofen with starting GABA concentrations ranging from 0 to 100 mM are reported. The results show that the absorption rate pseudoconstants of the drug decrease at the GABA concentration increases, with a limiting value of 0.65 h-1 (+/- 0.01). A partial competitive inhibition or complete competitive inhibition in the presence of a passive component could define the interaction phenomena between the two substances. Kinetic absorption parameters for GABA in the presence and absence of baclofen (Ki = 5.67 +/- 1.54, Km = 3.87 +/- 0.63) suggest the existence of more than one intestinal carrier system for baclofen or GABA.

Chronic spinal cord injury

Spinal cord injuries predispose patients to numerous complications. The care of such patients requires attention to multiple bodily systems, sensitivity to the effects of interventions on function and lifestyle, and a special vigilance because of the tendency of spinal cord injuries to mask problems. Improved clinical care, however, has increased the life expectancy of people with spinal cord injuries and therefore the prevalence of such injuries. The Americans with Disabilities Act should make people with spinal injuries more visible, as they participate in and contribute to society in greater numbers. Maintenance of health brings greater opportunities for self-care and mobility through rehabilitation and may allow people with spinal cord injuries to take advantage of future opportunities for neurologic improvement or cure.