Influence of temperature changes on multiple sclerosis: critical review of mechanisms and research potential

Excitability and the safety margin in human axons during hyperthermia

Abstract  Hyperthermia challenges the nervous system's ability to transmit action potentials faithfully. Neuromuscular diseases, particularly those involving demyelination have an impaired safety margin for action potential generation and propagation, and symptoms are commonly accentuated by increases in temperature. The aim of this study was to examine the mechanisms responsible for reduced excitability during hyperthermia. Additionally, we sought to determine if motor and sensory axons differ in their propensity for conduction block during hyperthermia. Recordings of axonal excitability were performed at normal temperatures and during focal hyperthermia for motor and sensory axons in six healthy subjects. There were clear changes in excitability during hyperthermia, with reduced superexcitability following an action potential, faster accommodation to long-lasting depolarization and reduced accommodation to hyperpolarization. A verified model of human motor and sensory axons was used to clarify the effects of hyperthermia. The hyperthermia-induced changes in excitability could be accounted for by increasing the modelled temperature by 6°C (and adjusting the maximum conductances and activation kinetics according to their Q10 values; producing a 2 mV hyperpolarization of resting membrane potential), further hyperpolarizing the voltage dependence of Ih (motor, 11 mV; sensory, 7 mV) and adding a small depolarizing current at the internode (motor, 20 pA; sensory, 30 pA). The modelling suggested that slow K(+) channels play a significant role in reducing axonal excitability during hyperthermia. The further hyperpolarization of the activation of Ih would limit its ability to counter the hyperpolarization produced by activity, thereby allowing conduction block to occur during hyperthermia.

Effect of passive whole body heating on central conduction and cortical excitability in multiple sclerosis patients and healthy controls

Heat stress is associated with increased fatigue perception and decrements in function for individuals with multiple sclerosis (MS). Similarly, healthy individuals experience decrements in exercise performance during hyperthermia. Alterations in central nervous system (CNS) function during hyperthermia include reduced voluntary activation of muscle and increased effort perception. The purpose of this investigation was to test the hypothesis that passive heat exposure in MS patients will produce increased subjective fatigue and impairments in physiological measures of central conduction and cortical excitability compared with healthy individuals. Eleven healthy individuals and 11 MS patients completed a series of transcranial magnetic stimulation studies to examine central conduction and cortical excitability under thermoneutral and heat-stressed (HS) conditions at rest and after a fatiguing thumb abduction task. Passive heat stress resulted in significantly greater fatigue perception and impairments in force production in MS patients. Central motor conduction time was significantly shorter during HS in controls; however, in MS patients normal increases in conduction velocity with increased temperature were not observed centrally. MS patients also exhibited decreased cortical excitability during HS, evidenced by significant increases in resting motor threshold, decreased MEP amplitude, and decreased recruitment curve slope. Both groups exhibited postexercise depression of MEP amplitude, but the magnitude of these decrements was amplified in MS patients during HS. Taken together, these results suggest that CNS pathology in MS patients played a substantial role in reducing cortical excitability during HS.

Apply Awaji-shima Consensus Conference Criteria Before Diagnosing Amyotrophic Lateral Sclerosis

Objectives:

ALS may be diagnosed although affection of other organs suggests another pathogenetic back-ground.

Case report:

In a 72yo non-smoking male progressive gait disturbance with recurrent falls since 2y was initially attributed to axonal polyneuropathy. Additionally, he had arterial hypertension, diabetes, hyperlipidemia, hyperuricemia, hyper-CK-emia, hepatopathy, atrial fibrillation, recurrent heart-failure, pulmonary hypertension, mitral insufficiency, and restrictive cardiomyopathy. Possible causes of polyneuropathy were diabetes, long-standing alcoholism, folate-deficiency, or hereditary disease. Later the patient was re-diagnosed as ALS despite absence of upper motor-neuron or bulbar signs, the presence of multiple risk factors for polyneuropathy, of stocking-type sensory disturbances, and of cardiac abnormalities, which could explain dyspnea. Misdiagnosing polyneuropathy as ALS stigmatized the patient and prevented him from further diagnostic work-up for cardiac disease and adequate treatment for heart-failure. Though the diagnosis of ALS was withdrawn, he was put on comfort care and opiates were given when dyspnea acutely deteriorated to death without further cardiac or pulmonary investigations or specific cardiac treatment.

Conclusions:

ALS should be diagnosed only if the Awaji-shima criteria are fulfilled and if all differential diagnoses were profoundly excluded. Respiratory insufficiency should not be attributed to bulbar involvement in ALS as long as cardiac, pulmonary, or myopathic causes were excluded.

Anesthetic technique in a patient with multiple sclerosis scheduled for laparoscopic nephrectomy for a renal tumor: a case report

Perioperative stress and anesthesia are risk factors for exacerbation of Multiple Sclerosis (MS) attacks. Infection, emotional labiality and hyperpyrexia are also known to increase the risk of postoperative MS attacks. Appropriate preoperative evaluation, administration of a good premedication, control of fever, selection of the anesthetic agents and effective postoperative pain control can prevent problems after prolonged major surgery in patients with MS diagnosed. This report presents the anesthetic technique in a patient who was a known case of MS for past nine years and presented with renal tumor to undergo laparoscopic nephrectomy under general anesthesia.

Fatigue and heat sensitivity in patients with multiple sclerosis

OBJECTIVES

Fatigue is one of the most common and troubling symptoms of multiple sclerosis (MS), and heat is often reported as a trigger. Although it is assumed that this heat sensitivity is specific for MS, the evidence for disease specificity is limited. We studied the relationship between fatigue, heat sensitivity, and environmental temperature, and its specificity for MS.

MATERIALS AND METHODS

We compared 88 MS patients with 76 patients with ulcerative colitis (UC), another chronic auto-immune disease. As most important outcome measures, heat sensitivity, physical fatigue, mental fatigue, environmental temperature, and ambient UV-light levels were determined.

RESULTS

More patients with MS reported heat sensitivity for fatigue, compared to patients with UC (53.4% vs 35.5%, respectively, P = 0.016). However, heat-sensitive patients were equally fatigued as heat-insensitive patients. Climatological data, including day temperature and amount of ambient UV light, were not related to fatigue in both heat-sensitive and heat-insensitive patients with MS.

CONCLUSIONS

Our findings support the assumption that heat sensitivity regarding fatigue has an MS-specific component. Although patients with MS experience a relationship between environmental temperature and fatigue, objective assessment by climatological data could not confirm this.

Mind-body medicine for multiple sclerosis: a systematic review

Background. Mind-body therapies are used to manage physical and psychological symptoms in many chronic health conditions. Objective. To assess the published evidence for using mind-body techniques for symptom management of multiple sclerosis. Methods. MEDLINE, PsycINFO, and Cochrane Clinical Trials Register were searched from inception to March 24, 2012. Eleven mind-body studies were reviewed (meditation, yoga, biofeedback, hypnosis, relaxation, and imagery). Results. Four high quality trials (yoga, mindfulness, relaxation, and biofeedback) were found helpful for a variety of MS symptoms. Conclusions. The evidence for mind-body medicine in MS is limited, yet mind-body therapies are relatively safe and may provide a nonpharmacological benefit for MS symptoms.

Mobile phones and multiple sclerosis--a nationwide cohort study in Denmark

We investigated the risk of, prognosis of and symptoms of multiple sclerosis (MS) among all Danish residents who owned a mobile phone subscription before 1996. Using the Danish Multiple Sclerosis Registry and Civil Registration System, study subjects were followed up for MS through 2004. Poisson models were used to calculate incidence rate ratios (IRR, age range: 18–64 years) and mortality rate ratios (MRR, age range: 18+) and to compare presenting symptoms among subscribers and all non-subscribers. A total of 405 971 subscription holders accrued four million years of follow up, with men accounting for 86% of the observation time. Among subscription holding men, the IRR of MS was close to unity, overall as well as 13+ years after first subscription (IRR 1.02, 95% CI: 0.48–2.16). Among women, the IRR was 3.43 (95% CI: 0.86–13.72) 13+ years after first subscription, however, based on only two cases. Presenting symptoms of MS differed between subscribers and non-subscribers (p = 0.03), with slightly increased risk of diplopia in both genders (IRR: 1.38, 95% CI: 1.02–1.86), an increased risk of fatigue among women (IRR: 3.02, 95% CI: 1.45–6.28), and of optic neuritis among men (IRR: 1.38, 95% CI: 1.03–1.86). Overall the MRR was close to one (MRR: 0.91, 95%CI 0.70–1.19) among MS-patients with a subscription and although we observed some increased MRR estimates among women, these were based on small numbers. In conclusion, we found little evidence for a pronounced association between mobile phone use and risk of MS or mortality rate among MS patients. Symptoms of MS differed between subscribers and nonsubscribers for symptoms previously suggested to be associated with mobile phone use. This deserves further attention, as does the increased long-term risk of MS among female subscribers, although small numbers and lack of consistency between genders prevent causal interpretation.

Keeping cool: use of air conditioning by australians with multiple sclerosis

Despite the known difficulties many people with MS have with high ambient temperatures, there are no reported studies of air conditioning use and MS. This study systematically examined air conditioner use by Australians with MS. A short survey was sent to all participants in the Australian MS Longitudinal Study cohort with a response rate of 76% (n = 2,385). Questions included hours of air-conditioner use, areas cooled, type and age of equipment, and the personal effects of overheating. Air conditioners were used by 81.9% of respondents, with an additional 9.6% who could not afford an air conditioner. Regional and seasonal variation in air conditioning use was reported, with a national annual mean of 1,557 hours running time. 90.7% reported negative effects from overheating including increased fatigue, an increase in other MS symptoms, reduced household and social activities, and reduced work capacity. Households that include people with MS spend between 4 and 12 times more on keeping cool than average Australian households.

A proposed staging system for amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis is a neurodegenerative disorder characterized by progressive loss of upper and lower motor neurons, with a median survival of 2-3 years. Although various phenotypic and research diagnostic classification systems exist and several prognostic models have been generated, there is no staging system. Staging criteria for amyotrophic lateral sclerosis would help to provide a universal and objective measure of disease progression with benefits for patient care, resource allocation, research classifications and clinical trial design. We therefore sought to define easily identified clinical milestones that could be shown to occur at specific points in the disease course, reflect disease progression and impact prognosis and treatment. A tertiary referral centre clinical database was analysed, consisting of 1471 patients with amyotrophic lateral sclerosis seen between 1993 and 2007. Milestones were defined as symptom onset (functional involvement by weakness, wasting, spasticity, dysarthria or dysphagia of one central nervous system region defined as bulbar, upper limb, lower limb or diaphragmatic), diagnosis, functional involvement of a second region, functional involvement of a third region, needing gastrostomy and non-invasive ventilation. Milestone timings were standardized as proportions of time elapsed through the disease course using information from patients who had died by dividing time to a milestone by disease duration. Milestones occurred at predictable proportions of the disease course. Diagnosis occurred at 35% through the disease course, involvement of a second region at 38%, a third region at 61%, need for gastrostomy at 77% and need for non-invasive ventilation at 80%. We therefore propose a simple staging system for amyotrophic lateral sclerosis. Stage 1: symptom onset (involvement of first region); Stage 2A: diagnosis; Stage 2B: involvement of second region; Stage 3: involvement of third region; Stage 4A: need for gastrostomy; and Stage 4B: need for non-invasive ventilation. Validation of this staging system will require further studies in other populations, in population registers and in other clinic databases. The standardized times to milestones may well vary between different studies and populations, although the stages themselves and their meanings are likely to remain unchanged.

Exercise in multiple sclerosis -- an integral component of disease management

Multiple sclerosis (MS) is the most common chronic inflammatory disorder of the central nervous system (CNS) in young adults. The disease causes a wide range of symptoms depending on the localization and characteristics of the CNS pathology. In addition to drug-based immunomodulatory treatment, both drug-based and non-drug approaches are established as complementary strategies to alleviate existing symptoms and to prevent secondary diseases. In particular, physical therapy like exercise and physiotherapy can be customized to the individual patient's needs and has the potential to improve the individual outcome. However, high quality systematic data on physical therapy in MS are rare. This article summarizes the current knowledge on the influence of physical activity and exercise on disease-related symptoms and physical restrictions in MS patients. Other treatment strategies such as drug treatments or cognitive training were deliberately excluded for the purposes of this article.

The critical limiting temperature and selective brain cooling: neuroprotection during exercise?

There is wide consensus that long duration exercise in the heat is impaired compared with cooler conditions. A common observation when examining exercise tolerance in the heat in laboratory studies is the critical limiting core temperature (CLT) and the apparent attenuation in central nervous system (CNS) drive leading to premature fatigue. Selective brain cooling (SBC) purportedly confers neuroprotection during exercise heat stress by attenuating the increase in brain temperature. As the CLT is dependent on heating to invoke a reduction in efferent drive, it is thus not compatible with SBC which supposedly attenuates the rise in brain temperature. Therefore, the CLT and SBC hypotheses cannot be complimentary if the goal is to confer neuroprotection from thermal insult as it is counter-intuitive to selectively cool the brain if the purpose of rising brain temperature is to down-regulate skeletal muscle recruitment. This presents a circular model for which there is no apparent end to the ultimate physiological outcome; a 'hot brain' selectively cooled in order to reduce the CNS drive to skeletal muscle. This review will examine the postulates of the CLT and SBC with their relationship to the avoidance of a 'hot brain' which together argue for a theoretical position against neuroprotection as the key physiological strategy in exercise-induced hyperthermia.

The effects of heat stress on cognition in persons with multiple sclerosis

Background: Heat sensitivity and cognitive deficits are typical manifestations of multiple sclerosis (MS). Although cognitive deficits are quite well characterized, practically no data exist on the effects of heat on cognitive performances in MS.

Objective: To assess the effects of short-term heat stress on cognitive functioning in subjects with MS.

Methods: A total of 23 heat-sensitive MS and 19 healthy control (HC) subjects participated. Moderate heat exposure took place in a Finnish sauna. Cognitive functioning was measured with tests of sustained attention and processing speed, the Paced Auditory Serial Addition Test (PASAT 3” and 2”) and the computerized visual vigilance test, before, during and after heat exposure.

Results: During the heat exposure, the core body temperature of the MS group rose significantly more ( p = 0.002) than that of the HC group. The heat stress worsened the performance of the MS group in the PASAT 3” ( p = 0.025) but not in the other cognitive measures. The performance in the PASAT 3” was reversed almost to the baseline level only 1- h after the heat exposure.

Conclusions: A significant increase in core body temperature during heat stress is associated with a mild and reversible worsening of the PASAT 3” performance, while visual vigilance performance seems to remain almost unaffected.

The influence of warm versus cold climate on the effect of physiotherapy in multiple sclerosis

OBJECTIVE

To compare the effect of inpatient physiotherapy in a warm versus cold climate in short- and long-term perspectives.

METHODS

Sixty multiple sclerosis (MS) patients with gait problems, without heat intolerance, were included in a randomized cross-over study of 4-week inpatient physiotherapy in warm (Spain) and cold (Norway) climate. The primary outcome, 6-min walk test (6MWT), and secondary physical performance and self-reported measures were scored at screening, baseline, after treatment and at 3 and 6 months of follow-up. Treatment effects were analysed by mixed models.

RESULTS

After treatment, the mean walking distance had increased by 70 m in Spain and 49 m in Norway (P = 0.060). Improvement in favour of warm climate was demonstrated at 6 months of follow-up, 43 m (Spain) compared to 20 m (Norway) (P = 0.048). The patients reported less exertion after walking (6MWT) in favour of treatment in Spain at all time points (P < 0.05). No significant differences in change were detected for the other physical performance measures. Most self-reported measures showed more improvement after treatment in Spain, but these improvements were not sustained at follow-up.

CONCLUSION

The results indicate that MS patients without heat intolerance have additional benefits from physiotherapy in a warm climate.

Sensitivity to heat in MS patients: a factor strongly influencing symptomology--an explorative survey

BACKGROUND

Many individuals diagnosed with Multiple Sclerosis (MS) are sensitive to increased body temperature, which has been recognized as correlating with the symptom of fatigue. The need to explore this association has been highlighted. The aim of this study was to investigate the occurrence of heat sensitivity and its relations to disease course, disability, common MS-related symptoms and ongoing immunosuppressive treatments among individuals 65 years of age or younger diagnosed with MS.

METHODS

A cross-sectional designed survey was undertaken. A questionnaire was sent to MS-patients with an Expanded Disability Status Score (EDSS) in the interval of 0-6.5 and who were between 20 and 65 years of age, living in an eastern region of Sweden (n = 334). Besides occurrence of heat sensitivity (Yes/No) and corresponding questions, the Fatigue Severity Scale (FSS), the MS-related symptom checklist and the Perceived Deficit Questionnaire (PDQ) were included. Data were analysed in relation to data level using Chi-square, Mann Whitney U-test, and Student's t-test. Pearson's and Spearman's correlations were calculated. In the logistic regression analyses (enter) dichotomized MS-symptoms were used as dependent variables, and EDSS, disease-course, time since onset, heat-sensitivity, age and sex (female/male) were independent variables. In the linear regression analyses, enter, mean FSS and summarized PDQ were entered as dependent variables and EDSS, disease-course, time since onset, heat sensitivity, age and sex (female/male) were independent variables.

RESULTS

Of the responding patients (n = 256), 58% reported heat sensitivity. The regression analyses revealed heat sensitivity as a significant factor relating not only to fatigue (p < 0.001), but also to several other common MS symptoms such as pain (p < 0.001), concentration difficulties (p < 0.001), and urination urgency (p = 0.009).

CONCLUSIONS

Heat sensitivity in MS patients is a key symptom that is highly correlated with disabling symptoms such as fatigue, pain, concentration difficulty and urination urgency.

Quality control of vital capacity as a primary outcome measure during phase III therapeutic clinical trial in amyotrophic lateral sclerosis

Currently, ALS clinical trials require large sample size and the participation of many clinical evaluators to perform the outcome measure. High variability due to testers, instruments, or patients performance errors may result in systematic bias or random error leading to erroneous or uninterpretable results. Consequently, a quality control system that aims to produce high quality data in terms of reproducibility and accuracy to ensure reliability of the primary outcome measure is essential. In this paper we report our experience in preparing and executing a prospective quality control system that was implemented in conjunction with a large multicenter, multinational randomized placebo-controlled phase III clinical trial in ALS. We have shown that a prospective quality control system is highly effective to ensure inter- and intra-rater reliability of vital capacity as a primary outcome measure during the entire trial.

Thermoregulation in multiple sclerosis

Multiple sclerosis (MS) is a progressive neurological disorder that disrupts axonal myelin in the central nervous system. Demyelination produces alterations in saltatory conduction, slowed conduction velocity, and a predisposition to conduction block. An estimated 60-80% of MS patients experience temporary worsening of clinical signs and neurological symptoms with heat exposure. Additionally, MS may produce impaired neural control of autonomic and endocrine functions. This review focuses on five main themes regarding the current understanding of thermoregulatory dysfunction in MS: 1) heat sensitivity; 2) central regulation of body temperature; 3) thermoregulatory effector responses; 4) heat-induced fatigue; and 5) countermeasures to improve or maintain function during thermal stress. Heat sensitivity in MS is related to the detrimental effects of increased temperature on action potential propagation in demyelinated axons, resulting in conduction slowing and/or block, which can be quantitatively characterized using precise measurements of ocular movements. MS lesions can also occur in areas of the brain responsible for the control and regulation of body temperature and thermoregulatory effector responses, resulting in impaired neural control of sudomotor pathways or neural-induced changes in eccrine sweat glands, as evidenced by observations of reduced sweating responses in MS patients. Fatigue during thermal stress is common in MS and results in decreased motor function and increased symptomatology likely due to impairments in central conduction. Although not comprehensive, some evidence exists concerning treatments (cooling, precooling, and pharmacological) for the MS patient to preserve function and decrease symptom worsening during heat stress.

Effects of hyperthermia on the peripheral nervous system: a review

The present paper overviews the current knowledge about effects of hyperthermia at temperatures used in clinical oncology on the peripheral nervous system. From the experimental studies it may be concluded that the heat sensitivity of the nerve is determined by the sensitivity of the nerve vasculature. These studies show that in order to avoid induction of severe neuropathy, application of heat to the peripheral nerves should not be in excess of doses of 30 min at 44 degrees C or equivalent. Using modern equipment for application of loco-regional hyperthermia the incidence of even mild neurological complications is very low. In hyperthermic isolated limb perfusion (HILP) neurotoxicity is an often-mentioned side effect, this is in spite of the fact that in all studies a relatively mild hyperthermic temperature is used that, based on the experimental studies, should be well tolerated by the nerves and other normal tissues in the limbs. It seems that the neurotoxicity observed after HILP results from thermal enhancement of drug toxicity, very probably combined with effects of a high tourniquet pressure that is used to isolate the blood flow in the leg. Whole body hyperthermia (WBH), using anesthesia and appropriate monitoring to avoid cardiovascular stress is at present considered a safe procedure. Still in the recent past cases of neuropathy after treatment have been described. When chemotherapy, and notably cisplatin, is administered before or during hyperthermia there are several clinical and experimental observations that indicate a limited tolerance of the peripheral nervous tissue in such case. Also previous radiotherapy may limit the tolerance of nerves to hyperthermia, notably when radiation is applied with a large field size. Experimental studies show that combined treatment with radiation and heat leads to enhancement of effects of radiation (enhancement ratio approximately 1.5 at 60 min at 44 degrees C). A clear contraindication for the application of hyperthermia in patients is the presence of a neurodegenerative disease, such as multiple sclerosis. Vigilance is also required in the treatment of diabetic patients with hyperthermia, this based on experimental animal studies, but so far no clear clinical data are available.

Factors perceived as being related to accidental falls by persons with multiple sclerosis

PURPOSE

This study explores and describes factors that persons with multiple sclerosis (MS) perceive as being related to accidental falls.

METHOD

A qualitative content analysis with primarily deductive approach was conducted using the International Classification of Functioning, Disability and Health. Twelve persons with MS, and identified as fallers, were interviewed.

RESULTS

Factors perceived to cause accidental falls that had not previously been targeted in MS populations in relation to falls were identified as divided attention, reduced muscular endurance, fatigue and heat sensitivity. Previously reported risk factors such as changed gait pattern, limited walking ability, impaired proprioception, vision and spasticity were supported. Activities involving walking, recreation and leisure, maintaining and changing body position, lifting or carrying, taking care of the home, washing the body, moving around, preparing meals and housekeeping were limited and considered to be risk activities. Supportive persons and assistive device reduced falls, and unsuitable physical environments and climate conditions induced falls. Several preventative strategies were described as partially compensating for the impairments, limitations and restrictions.

CONCLUSIONS

Investigating accidental falls using the perspective of the patient gave important information about variables not earlier targeted in MS research.

Sweating impairment in patients with multiple sclerosis

OBJECTIVES

To measure sweating in patients with multiple sclerosis (MS).

MATERIALS AND METHODS

Sweating was measured by an evaporimeter after a heating stimulus in 29 MS patients and in 15 healthy control subjects.

RESULTS

The MS patients sweated markedly less than the controls. After 10 min of heating the sweating was significantly lower in the forehead (P = 0.034), feet (right, P = 0.033; left, P = 0.037) and legs (right, P = 0.043; left, P = 0.029) of the MS patients than in those of the controls. After 15 min of heating the difference was statistically significant only in the feet (right, P = 0.043; left, P = 0.029). The Expanded Disability Status Scale score correlated inversely with sweating at 15 min of heating in the left hand (r = 0.42, P < 0.05), and in the left (r = 0.36, P < 0.05) and right foot (r = 0.37, P < 0.05).

CONCLUSIONS

MS is associated with an impairment in thermoregulatory sweating which seems to be related to the disease severity.

[Multiple sclerosis and exercise : effects of physical activity on the immune system]

Multiple sclerosis is a chronic inflammatory CNS disease which accounts for functional impairment and lasting disability in young adults. Current studies demonstrate that physical activity in patients with MS counteracts depression and fatigue and may improve quality of life. Interventional studies have described a reduction of the functional impairment in MS patients. This report presents information on the effects of physical activity on the immune system and the release of neurotrophic factors, and highlights current data on a potential immunomodulatory effect of exercise in multiple sclerosis.

Clinical phenotypes and natural progression for motor neuron disease: analysis from an Australian database

From 1997 to 2003 we prospectively followed a cohort of ALS/MND patients. Patients were allocated to predetermined clinical phenotypes using the principles established in the modified El Escorial criteria. The date and region of symptom onset were carefully determined and their progression was scored using the Appel ALS rating scale. The four distinct clinical phenotypes: Global, Flail Arm, Flail Leg and Primary Lateral Sclerosis (PLS) demonstrated significantly different rates of progression and survival times. The Global ALS/MND phenotype can present with initial symptoms in any region and rapidly progresses to involve all segments, with symptoms due to a mixture of combined corticospinal tract and anterior horn cell dysfunction. The Global phenotype has the shortest survival and most rapid rate of disease progression. There was a significant difference in survival between Global bulbar onset and cervical onset disease but no significant difference in the rate of disease progression between the three Global subgroups as determined by the Appel/ALS rating scale. Flail patients had much slower rates of progression and significantly longer survival compared to the Global phenotype. Patients with Primary Lateral Sclerosis as expected progressed the slowest and survived the longest compared to the other clinical phenotypes. The utility of developing a method of assigning clinical phenotypes with similar survival and disease progression rates is discussed in relation to therapeutic trial design, practice benchmarking and clinico-pathological correlations.

Heat reactions in multiple sclerosis: an overlooked paradigm in the study of comparative fatigue

Multiple sclerosis (MS) is a demyelinating and debilitating disease characterised by a range of symptoms such as motor dysfunction and muscle weakness. A significant MS symptom is heat sensitivity so that exposure to heat will increase body temperature and consequently the appearance of neurological signs. Although some people with MS can undertake exercise, it is thought to be limited by the sensitivity to heat and the subsequent rise in body temperature which occurs. It has been found that central fatigue is a determining factor in muscle activation and performance in normal healthy subjects. However, it is unknown whether thermal strain also induces central fatigue in MS even though muscular fatigue in MS is due mainly to central rather than peripheral factors. This review focuses on the similarities in the manifestation of central fatigue in both MS and healthy subjects with reference to thermal strain and heat reactions.

Multiple sclerosis

Multiple sclerosis is the most common disabling neurologic disease affecting young adults and adolescents in the United States. The first objective of this article is to familiarize nonspecialists with the cardinal features of multiple sclerosis and our current understanding of its etiology, epidemiology, and natural history. The second objective is to explain the approach to diagnosis. The third is to clarify current evidence-based treatment strategies and their roles in disease modification. The overall goal is to facilitate the timely evaluation and confirmation of diagnosis and enhance effective management through collaboration among primary physicians, neurologists, and other care providers who are confronted with these formidably challenging patients.

Multiple sclerosis and reproductive risks in women

During the previous decades, women with Multiple Sclerosis (MS) were discouraged from having children, as pregnancy was deemed dangerous for pregnancy outcome and a contributing factor for exacerbation of MS. Current knowledge shows that women with MS are no more likely to have pregnancy or delivery complications compared to healthy women. Immunomodulatory therapies should be avoided during pregnancy and while breastfeeding. However, despite that it is still not recommended during pregnancy, Glatiramer acetate has fewer risks than the other MS drugs with respect to pregnancy outcome. IVIg treatment appears to be safe in unblinded studies and may be used after the first trimester to prevent the exacerbation of postpartum relapses. Gestation is a period of decreased risk for a relapse, whereas relapses are more common in the first six months after childbirth, compared to the pre-pregnancy period. Breastfeeding and epidural anaesthesia are not associated with increased incidence of post-partum relapses.

Mind-body interventions: applications in neurology

OBJECTIVE

Half of the adults in the United States use complementary and alternative medicine with mind-body therapy being the most commonly used form. Neurology patients often turn to their physicians for insight into the effectiveness of the therapies and resources to integrate them into their care. The objective of this article is to give a clinical overview of mind-body interventions and their applications in neurology.

METHODS

Medline and PsychInfo were searched on mind-body therapies and neurologic disease search terms for clinical trials and reviews and published evidence was graded.

RESULTS

Meditation, relaxation, and breathing techniques, yoga, tai chi, and qigong, hypnosis, and biofeedback are described. Mind-body therapy application to general pain, back and neck pain, carpal tunnel syndrome, headaches, fibromyalgia, multiple sclerosis, epilepsy, muscular dysfunction, stroke, aging, Parkinson disease, stroke, and attention deficit-hyperactivity disorder are reviewed.

CONCLUSIONS

There are several conditions where the evidence for mind-body therapies is quite strong such as migraine headache. Mind-body therapies for other neurology applications have limited evidence due mostly to small clinical trials and inadequate control groups.

Cooling via one hand improves physical performance in heat-sensitive individuals with multiple sclerosis: a preliminary study

Background

Many individuals afflicted with multiple sclerosis (MS) experience a transient worsening of symptoms when body temperature increases due to ambient conditions or physical activity. Resulting symptom exacerbations can limit performance. We hypothesized that extraction of heat from the body through the subcutaneous retia venosa that underlie the palmar surfaces of the hands would reduce exercise-related heat stress and thereby increase the physical performance capacity of heat-sensitive individuals with MS.

Methods

Ten ambulatory MS patients completed one or more randomized paired trials of walking on a treadmill in a temperate environment with and without cooling. Stop criteria were symptom exacerbation and subjective fatigue. The cooling treatment entailed inserting one hand into a rigid chamber through an elastic sleeve that formed an airtight seal around the wrist. A small vacuum pump created a -40 mm Hg subatmospheric pressure enviinside the chamber where the palmar surface of the hand rested on a metal surface maintained at 18–22°C. During the treatment trials, the device was suspended from above the treadmill on a bungee cord so the subjects could comfortably keep a hand in the device without having to bear its weight while walking on the treadmill.

Results

When the trials were grouped by treatment only, cooling treatment increased exercise durations by 33% (43.6 ± 17.1 min with treatment vs. 32.8 ± 10.9 min. without treatment, mean ± SD, p < 5.0·10^-6, paired t-test, n = 26). When the average values were calculated for the subjects who performed multiple trials before the treatment group results were compared, cooling treatment increased exercise duration by 35% (42.8 ± 16.4 min with treatment vs. 31.7 ± 9.8 min. without treatment, mean ± SD, p < 0.003, paired t-test, n = 10).

Conclusion

These preliminary results suggest that utilization of the heat transfer capacity of the non-hairy skin surfaces can enable temperature-sensitive individuals with MS to extend participation in day-to-day physical activities despite thermally stressful conditions. However, systematic longitudinal studies in larger cohorts of MS patients with specific deficits and levels of disability conducted under a variety of test conditions are needed to confirm these preliminary findings.

Metals in motor neuron diseases

Degenerative processes within the nervous system are common features in disease entities such as dementia of Alzheimer type (DAT), Parkinson disease (PD), and amyotrophic lateral sclerosis (ALS). ALS is a neurodegenerative disease with unknown etiology; widespread muscle wasting and respiratory failure lead to death within a few years. Denervation can be detected with electromyography and axonal deterioration monitored by motor unit number estimates. Several suggestions about the cause of ALS have emerged but no solid theory has yet precipitated. Lead or mercury exposure has been suggested. Exposure data alone cannot support this connection. Alterations in metal kinetics may underlie the deterioration of motor function observed in patients with ALS. In this review the role of metals in motor neuron disease is discussed. Both classic studies on exposure and recent understanding of metal binding proteins are considered. Aspects of peak exposure and excretion are merged toward an understanding of metal dynamics in ALS. An overview of chemical and electrophysiological investigations is given in the context of neurodegeneration.

Outcomes of an aquatic exercise program including aerobic capacity, lactate threshold, and fatigue in two individuals with multiple sclerosis

BACKGROUND AND PURPOSE

Fatigue in individuals with multiple sclerosis (MS) may be exacerbated by poor cardiovascular fitness. Although aqua aerobic exercise is often recommended, little research has been conducted on the efficacy of aqua aerobic exercise in improving cardiovascular fitness in patients with MS. The purpose of this case report is to describe changes in cardiovascular fitness and fatigue for 2 people with MS following an aqua aerobics class.

CASE DESCRIPTIONS

The participants were 2 females, both with MS for over 10 years and mild disability. Participant A (40 years old and EDSS = 2.5/10) reported fatigue, numbness in her hands and feet, and occasional blurred vision. Participant B (51 years old and EDSS = 3.0/10) reported the same problems as Participant A plus stiffness in her right lower extremity. The participants performed aqua aerobics at an intensity equivalent to their lactate threshold twice a week for 8 weeks. Lactate threshold is the exercise intensity just prior to the accumulation of blood lactate during graded exercise.

OUTCOMES

A graded exercise test (with measurements of gas exchange) and a test of fatigue were administered before and after the intervention. Initially, both participants had poor cardiovascular fitness as demonstrated by their low peak oxygen consumption (VO2peak) and low lactate threshold (LT). After the intervention, both participants achieved a higher peak workload (their VO2peak increased) and they could sustain a higher submaximal workload without accumulation of acid substances causing fatigue (their LT increased). Changes in fatigue following the intervention were equivocal with Participant A reporting decreased fatigue and Participant B reporting no change.

SUMMARY

This report describes the use of exercise testing to guide clinical decision making for dosing of an aqua aerobic fitness intervention and illustrates positive effects of the intervention on cardiovascular fitness in 2 people with MS.

[Multiple sclerosis. An update with practical guidelines for ophthalmologists]

Multiple sclerosis (MS) is the most frequent chronic inflammatory disease of the central nervous system. Mostly young adults present with a variety of different symptoms due to the multiple localisations of the inflammatory lesions. Up to one-third of MS patients experience symptoms of optic neuritis as the initial symptom. That is the reason why the ophthalmologist often is the first physician contacted by patients later on diagnosed with MS. Today, it is known that there is already a significant irreversible axonal loss in MS patients progressing from the beginning of the disease. Therefore early, diagnosis and application of available therapeutic options are necessary for the patient's benefit. The therapeutic aim in early immunomodulatory treatment is to decrease the number of relapses and to slow down the development of clinical disability. This interdisciplinary overview presents guidelines for the clinical routine: how to assess the individual risk of each patient and how to treat the patient in accordance with current pathogenic, diagnostic and therapeutic knowledge.

Audit of outcomes in motor neuron disease (MND) patients treated with riluzole

A review of riluzole in MND by NICE concluded that riluzole was modestly effective. NICE however suggested that further studies were needed to gain further insights into its clinical effectiveness. As these studies have not been carried out we audited outcomes in our use of riluzole. Median survival of 148 MND patients receiving riluzole was 3.07 years (2.25 years for 327 patients not given riluzole), hazard ratio 1.66, 95% confidence interval (CI) 1.32-2.12; 3.61 years in 103 limb onset patients given riluzole (2.62 years for 124 limb onset patients not given riluzole), hazard ratio 1.50, 95% CI 1.09-2.05; 2.19 years in 43 bulbar onset patients receiving riluzole (1.84 years for 103 bulbar onset patients not given riluzole), hazard ratio 1.34, 95% CI 0.89-2.07 and 3.80 years in 87 patients with a PEG given riluzole (2.21 years for 261 patients with a PEG not given riluzole), hazard ratio 1.86, 95% CI 1.44-2.39. These findings are comparable with the results of similar analyses from other groups. The uncertainties they raise emphasize the importance of adequate randomized studies being completed prior to licensing of new drugs. They further illustrate the desirability of controlled introduction of new drugs into clinical practice when RCTs have only suggested a modest level of efficacy.

Limited Impact of the Summer Heat Wave in France (2003) on Hospital Admissions and Relapses for Multiple Sclerosis

Patients with multiple sclerosis (MS) often report worsening of symptoms with increased environmental temperature. The aim of this paper was to determine whether or not the heat wave of the summer of 2003 in France was responsible for an increase in hospital admissions and relapses in MS patients. MS patients who were hospitalized between January 1,2000 and December 31,2003 were identified, and we established which patients were suffering relapses. Hospitalization and relapse seasonality were examined and analyzed according to ambient temperature variations. We did not observe a greater number of hospital admissions and relapses during the summer of 2003 compared to the previous 3 years. Results showed that MS hospitalizations display a significant trough in the winter season, especially in December, but no significant peak season or month was observed. There was no statistically significant correlation between mean ambient temperature and the number of admissions and relapses. The adverse symptoms associated with high temperatures that are usually observed in MS patients may require rapid rises in ambient temperate or in internal body temperature.

Fatigue as the main presenting symptom of chronic inflammatory demyelinating polyradiculoneuropathy: a study of 11 cases

Fatigue has been shown to be more frequent than previously thought in immune-mediated polyneuropathies. However, fatigue has not been reported as the main cause of referral in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) patients. Between January 2001 and December 2003, we investigated 11 patients referred for fatigue, for which we established a final diagnosis of CIDP. All patients had at least two clinical examinations including assessment of the fatigue severity scale (FSS) and one electrophysiological and laboratory work up. Additionally, 10 of the 11 patients had a nerve biopsy. There were 11 male patients. Mean age at onset was 53 +/- 11 years. Main cause of referral was fatigue in all patients. Additional symptoms included cramps (one case), distal paresthesias (six cases), limb pain (seven cases) and vasomotor disturbances (one case). Cerebrospinal fluid (CSF) analysis displayed a moderate increase in protein content in four patients. Electrophysiological analysis showed abnormalities in all patients. Among 11 patients, one fulfilled the American Academy of Neurology electrodiagnostic criteria for CIDP and three fulfilled the inflammatory neuropathy cause and treatment group or the Nicolas et al. criteria. In the eight remaining patients, a nerve biopsy confirmed the diagnosis of CIDP. Ten patients were treated, among which seven showed a significant improvement based on the FSS scale. This study shows that fatigue is a possible cause of referral for patients with CIDP and, like previous reports, emphasizes the lack of sensitivity of widely accepted electrophysiological criteria of CIDP. Long-term follow up of these patients is warranted to determine the prognosis of these minimal forms of CIDP and establish the best therapeutic strategy in such cases.

Multiple Sclerosis–Related Fatigue

Fatigue is a significant factor in the lives of many MS patients and the most commonly reported symptom in many studies. Fatigue is an important symptom to consider because it affects patients' social lives, occupations, and activities of daily living. Efforts to predict fatigue have been mixed, but it appears to be related to overall quality of life and mood. From a pathophysiologic perspective, fatigue in MS is multifactorial and complex,involving dysregulation of the immune system, changes in the nervous system related to the disease process, neuroendocrine and neurotransmitter changes, and other factors such as physical deconditioning, sleep disturbance, pain, and medication side effects. Various attempts to assess fatigue have been made, and many measures are now available for use in clinical practice and research. In clinical practice, these measures help guide treatment considerations. Recent research has provided valuable strategies to ameliorate fatigue in MS, and although many patients continue to experience fatigue despite interventions, many receive substantial relief.Nonpharmacologic approaches-considered the first step in treatment-include exercise programs, cooling, dietary considerations, and energy conservation strategies. For patients who continue to experience significant fatigue, several medications (although not specifically approved for use in the reduction of MS-related fatigue) have proved effective in this regard.The first-line agents include amantadine for mild fatigue and modafinil for more severe cases. Second-line agents include pemoline and antidepressant medications. Other pharmacologic agents have also shown some promise.

Pilocarpine-induced sweat gland function in individuals with multiple sclerosis

This investigation tested the hypothesis that cholinergic sweat function of individuals with multiple sclerosis (MS) (MS-Con; n = 10) is diminished relative to matched healthy control subjects (Con; n = 10). In addition, cholinergic sweat function was determined before and after 15 wk of aerobic training in a subgroup of individuals with MS (MS-Ex; n = 7). Cholinergic sweating responses were assessed via pilocarpine iontophoresis on ventral forearm skin. A collection disk placed over the stimulated area collected sweat for 15 min. Sweat rate (SR) was calculated by dividing sweat collector volume by collection area and time. Iodine-treated paper was applied to the stimulated area to measure number of activated sweat glands (ASG). Sweat gland output (SGO) was calculated by dividing SR by density of glands under the collector. Sweat gland function was determined in MS-Ex to test the hypothesis that exercise training would increase sweating responses. No differences in ASG were observed between MS-Con and Con. SR and SGO in MS-Con [0.18 mg·cm−2·min−1(SD 0.08); 1.74 μg·gland−1·min−1(SD 0.79), respectively] were significantly lower ( P ≤ 0.05) than in Con [0.27 mg·cm−2·min−1(SD 0.10); 2.43 μg·gland−1·min−1(SD 0.69)]. Aerobic exercise training significantly ( P ≤ 0.05) increased peak aerobic capacity in MS-Ex [1.86 (SD 0.75) vs. 2.10 (SD 0.67) l/min] with no changes in ASG, SR, and SGO. Sweat gland function in individuals with MS is impaired relative to healthy controls. Fifteen weeks of aerobic training did not increase stimulated sweating responses in individuals with MS. Diminished peripheral sweating responses may be a consequence of impairments in autonomic control of sudomotor function.

Environmental Influences in Experimental Autoimmune Encephalomyelitis

Environmental factors, in particular infectious agents, are thought to have a major influence on the development and course of MS. Some of these influences are also reflected in the animal model, EAE. In this chapter, the role of infectious agents in the development and course of autoimmunity in EAE is discussed. Other environmental agents including trauma, solar radiation exposure, temperature, stress, toxins, are discussed in terms of their relevance to MS and EAE.

Quantification of Uhthoff's phenomenon in multiple sclerosis: a magnetic stimulation study

OBJECTIVE

To quantify temperature induced changes (=Uhthoff phenomenon) in central motor conduction and their relation to clinical motor deficits in 20 multiple sclerosis (MS) patients.

METHODS

Self-assessment of vulnerability to temperature and clinical examination were performed. We used motor evoked potentials to measure central motor conduction time (CMCT) and applied the triple stimulation technique (TST) to assess conduction failure. The TST allows an accurate quantification of the proportion of conducting central motor neurons, expressed by the TST amplitude ratio (TST-AR).

RESULTS

Temperature induced changes of TST-AR were significantly more marked in patients with prolonged CMCT (P=0.037). There was a significant linear correlation between changes of TST-AR and walking velocity (P=0.0002). Relationships were found between pronounced subjective vulnerability to temperature and (i) abnormal CMCT (P=0.02), (ii) temperature induced changes in TST-AR (P=0.04) and (iii) temperature induced changes in walking velocity (P=0.04). CMCT remained virtually unchanged by temperature modification.

CONCLUSIONS

Uhthoff phenomena in the motor system are due to varying degrees of conduction block and associated with prolonged CMCT. In contrast to conduction block, CMCT is not importantly affected by temperature.

SIGNIFICANCE

This is the first study quantifying the Uhthoff phenomenon in the pyramidal tract of MS patients. The results suggest that patients with central conduction slowing are particularly vulnerable to develop temperature-dependent central motor conduction blocks.

Influence des variations de la température sur la symptomatologie clinique dans la sclérose en plaques : étude épidémiologique

The effects of the modifications of temperature are well known in patients affected by multiple sclerosis (MS). They are variable and can influence daily living. This sensibility can be used in the management of the disabilities.

METHOD

An epidemiological study was realized on a cohort of 191 patients suffering from MS referred to the MS clinic of Rennes (France). All the patients were questioned about the influence of heat and cold on their clinical symptoms (fatigue spasticity, walking disorders, vision, em leader ). Correlations with the main clinical characteristics were studied.

POPULATION

One hundred ninety-one patients, 129 women and 62 men with an average age of 47.6 +/- 10 years were interviewed. Average score EDSS was of 5.2 +/- 1.5. The mean duration of MS was 13.5 +/- 10 years.

RESULTS

One hundred forty-seven patients (77%) reported a sensibility to the temperature. Heat deteriorated function in 104 cases and 82 patients improved with cold. Paradoxically 20 patients reported to be deteriorated with cold and 19 improved with heat. Fatigue and walking were the most sensitive to temperature fluctuations. No particular clinical profile could be established. Fifty percent of the patients used this sensibility with therapeutic aim in everyday life.

DISCUSSION

The clear influence of temperature fluctuations on the clinical symptom was confirmed in this study. However, there is a great variability from one patient to another. Different hypotheses have been evoked to explain this phenomenon. The most likely is an influence on the nervous specific conductivity. In routine practice cold physiotherapy will be proposed on case by case basis and still has an interesting place in the rehabilitation management.

Medicare Hospice Referral Criteria for Patients with Amyotrophic Lateral Sclerosis: A Need for Improvement

We conducted a retrospective review of 97 consecutive patients with amyotrophic lateral sclerosis (ALS) who were accepted into hospice care from a tertiary ALS center. Five patients met Medicare criteria at time of hospice enrollment. The mean number of hospice days was 85 (range, 1-534). All but 2 patients met hospice criteria proposed by the Columbia University ALS group. The present Medicare hospice criteria should be changed to reflect the reality of patients dying of ALS.

High-dose immunosuppressive therapy and autologous peripheral blood stem cell transplantation for severe multiple sclerosis

There were 26 patients enrolled in a pilot study of high-dose immunosuppressive therapy (HDIT) for severe multiple sclerosis (MS). Median baseline expanded disability status scale (EDSS) was 7.0 (range, 5.0-8.0). HDIT consisted of total body irradiation, cyclophosphamide, and antithymocyte globulin (ATG) and was followed by transplantation of autologous, granulocyte colony-stimulating factor (G-CSF)-mobilized CD34-selected stem cells. Regimen-related toxicities were mild. Because of bladder dysfunction, there were 8 infectious events of the lower urinary tract. One patient died from Epstein-Barr virus (EBV)-related posttransplantation lymphoproliferative disorder (PTLD) associated with a change from horse-derived to rabbit-derived ATG in the HDIT regimen. An engraftment syndrome characterized by noninfectious fever with or without rash developed in 13 of the first 18 patients and was associated in some cases with transient worsening of neurologic symptoms. There were 2 significant adverse neurologic events that occurred, including a flare of MS during mobilization and an episode of irreversible neurologic deterioration after HDIT associated with fever. With a median follow-up of 24 (range, 3-36) months, the Kaplan-Meier estimate of progression (>/= 1.0 point EDSS) at 3 years was 27%. Of 12 patients who had oligoclonal bands in the cerebrospinal fluid at baseline, 9 had persistence after HDIT. After HDIT, 4 patients developed new enhancing lesions on magnetic resonance imaging of the brain. The estimate of survival at 3 years was 91%. Important clinical issues in the use of HDIT and stem cell transplantation for MS were identified; however, modifications of the initial approaches appear to reduce treatment risks. This was a heterogeneous high-risk group, and a phase 3 study is planned to fully assess efficacy.

[Therapy of day time fatigue in patients with multiple sclerosis]

Fatigue is the most common symptom of multiple sclerosis. 75%-90% of patients with multiple sclerosis report having fatigue, and 50%-60% describe it as the worst symptom of their disease. Fatigue is significantly associated with reduced quality of life and is also a major reason for unemployment, especially for patients with otherwise minor disability. The mechanisms underlying abnormal levels of fatigue in multiple sclerosis are poorly understood. To date, drug treatment has been only partially successful in alleviating fatigue, and effects vary widely from patient to patient. Amantadine and modafinil showed to be effective in the treatment of fatigue in some studies. Non-pharmacological management of fatigue in multiple sclerosis includes inpatient rehabilitation and endurance training. There is also evidence, that pulsing electromagnetic fields may improve fatigue associated with multiple sclerosis. This paper summarizes the recent literature on pathophysiology, diagnosis and therapy of the most common symptom of multiple sclerosis.