Exercise as it relates to Disease/Motor Neuron Disease and exercise

What is Motor Neuron Disease? Motor Neuron Disease (MND) is a group of diseases affecting the nervous system, characterized by a degenerative loss of functioning.Leigh, P, Ray-Chaudhuri, K (1994) ‘Motor neuron disease’, Journal of Neurology, Neurosurgery and Psychiatry; 57; 886-896 As the name suggests, the disease targets the motor neurons which are specialised units of cells that consist of a nerve cell (neuron) which is in direct communication with a muscle.Brown, S, Wayne, M, Eason, J. ‘Exercise Physiology: Basis of human movement in health and disease’, 2006. Lippincott, Williams & Wilkins, Baltimore, USA. pp. 271 These motor neurons control the voluntary muscular activities that function in our everyday lives such as speaking, swallowing, breathing, walking and other general movements.Leigh, P, Abrahams, S, Al-Chalabi, A, Ampong, M, Goldstein, L, Johnson, J, Lyall, R, Moxham, J, Mustfa, N, Rio, A, Shaw, C, Willey, E (2003) ‘The management of motor neuron disease’, Journal of Neurology, Neurosurgery and Psychiatry; 74; 32-47 To date, the cause of MND is unknown, and with no cure, so treatment plans are largely focused on trying to improve the quality of life for those suffering.Talbot, K (2002) ‘Motor Neuron Disease’, Postgraduate Medical Journal; 78; 513-519 Due to the progressive and debilitating nature of the disease, patients are expected to have only 2 or 3 years to live from the time of diagnosis, where eventual death is due to respiratory muscle failure.Orrell, R (2010) ‘Motor Neuron Disease: systematic reviews of treatment for ALS and SMA’, British Medical Bulletin; 93; 124-159 MND consists of different subtypes however they all involve either the upper motor neurons, lower motor neurons or both. The type involving both is defined as Amyotrophic Lateral Sclerosis (ALS), and will be referred to synonymously with MND (MND/ALS). Prevalence and Incidence The average age that MND is experienced is 58 years old, or more commonly during middle to late life. The inclusion of exercise interventions is all the more important for MND sufferers. Due to this being regarded as time in life when exercise habits decrease anyway due to the normal ageing process, with known negative effects on the body.William, M, Stephen, G. ‘Exercise and mental health’, 1987. Hemisphere Publishing Corporation, USA pp. 7 The incidence of MND is relatively rare with only 2/100,000 affected. Although these numbers seem statistically quite low, the seriousness of MND is still highly relevant. Due to the debilitating nature and its rapid progression, MND is a significant issue affecting society with ethical and legal debates centered around end of life decisions and physician assisted suicides. Symptoms of MND Symptom Description Spasticity Due to upper motor neuron damage causing muscle tightness, seen as: stiffness, spasms, pain and decreased mobility Bethoux, F, Boulis, N, Hussain, M, Machado, A, McClelland, S, Mychkovsky, L, Pioro, E, Stough, D, Sutliff, M, Willis, M (2013) ‘Use of intrathecal Baclofen for treatment of severe spasticity in selected patients with Motor Neuron Disease’, Neurorehabilitation and Neural Repair; 27(9); 828-833 Muscle Atrophy Muscle wasting due to inactivity of large muscle groups affected Musaro, A (2013) ‘Understanding ALS: new therapeutic approaches’, FEBS journal; 280(17); 4315-4322 Weakness Usually asymmetrical weakness, meaning it's experienced in both limbs, may have difficulty turning a key in doors or car ignition, unscrewing bottle tops or holding a pen Fatigue Due to the decreased activation of muscle fibers of the motor units controlling the prominent large muscle groups Sharma, K, Kent-Brown, J, Majumdar, S (1995) ‘Physiology of fatigue in amyotrophic lateral sclerosis’, Neurology; 45; 733-740 Slurred speech Initially may stumble or stutter words then progressing to when speech becomes incomprehensible Dysphagia Difficulty swallowing, firstly solid foods become a challenge then progresses to struggling to swallow liquids such as water and saliva Respiratory failure Due to the associated respiratory muscle weakness and atrophy Explaining the Issue As previously described, MND/ALS is such a debilitating disease that even normal, simple, everyday tasks become a struggle to complete. As it progresses, the disease reaches a point where even the activities that are vital for life (such as breathing), become overwhelmingly difficult and lead to death. Although MND/ALS is of a physical target, whereby the decline in motor neuron functioning leads to dysfunctions in physical activities (such as walking), the cascading psychological effects of this should not be ignored.Corbo, M, Molinari, E, Pagnini, F, Simmons, Z (2012) ‘Amyotrophic Lateral Sclerosis: time for research on psychological intervention’. Amyotrophic Lateral Sclerosis; 13(5); 416-417 Therefore improving quality of life should encompass not only the progressive decline in muscular functions, but also addressing the mental health issues that stem from this. Proposed treatments for both of these issues is implementing exercise due to research already linking the benefits of it in addressing psychological issues and the obvious benefits it has on the physical body.Lopes de Almeida, J, Silvestre, R, Pinto, A, Carvalho, M (2012) ‘Exercise and Amyotrophic Lateral Sclerosis’, Neurological Sciences; 33(1); 9-15 However the role of exercise in the treatment of MND/ALS is still a debatable topic as conflicting studies have indicated beneficial responses to exercise (especially in other neuromuscular diseases), whilst others have indicated that exercise should be limited for the purposes of preserving remaining muscle integrity and function. As there is not yet a definitive answer as to whether exercise has a positive or negative relationship with MND/ALS, there will be an exploration into the positives due to the known benefits of exercise being all encompassing.Krivickas, L (2003) ‘Exercise in neuromuscular disease’, Journal of Clinical Neuromuscular Disease; 5(1); 29-39 Exercise Recommendations Although more research needs to be done in uncovering the specific responses MND/ALS sufferers have to exercise, other studies have demonstrated that exercise is largely beneficial to the majority of neuromuscular diseases, including MND/ALS. These studies presented important exercises for neuromuscular disease patients that assisted in managing symptoms and importantly improved their quality of life. These exercises were outlined as flexibility/balance, strength and aerobic training. Exercise type Description Flexibility/Balance Reduce the occurrence of contractures (spasticity). There is a high prevalence of contractures/spasticity in the shoulders, knees and ankles of neuromuscular disease patients who are confined to a seated position (such as a wheelchair) for the majority of the day. For MND/ALS patients this is common also as motor neuron deterioration leads to an inability to walk and the reliance on a wheelchair. Reduce spasticity therefore decreasing motor dysfunctions such as falls. Especially in MND/ALS patients as their spasticity has shown to decrease with regular flexibility training.Katz, R (1988) ‘Management of spasticity’, American Journal of Physical Medicine and Rehabilitation; 67; 108-116 Aerobic Similar aerobic responses to the average healthy individual.Sanjak, M, Paulson, D, Sufit, R, Reddan, W, Beaulieu, D, Erickson, L, Shug, A, Brooks B (1987) ‘Physiologic and metabolic response to progressive and prolonged exercise in amyotrophic lateral sclerosis’, Neurology; 37; 1217-1220 This is one of the few positives relating to the physiological functioning of MND/ALS sufferers, as it shows the disease is not limiting this type of activity and their underlying cardiopulmonary function. Simple exercises are sufficient such as walking on the treadmill and riding the stationary bike as long as they are performed at a moderate, submaximal level and the patient feels stable and free of severe pain.Drory, V, Goltsman, E, Reznik, J, Mosek, A, Korczyn, A (2001) ‘The value of muscle exercise in patients with amyotrophic lateral sclerosis’, Journal of Neurological Science; 191; 133-137 Simple exercises will be beneficial not only for maintaining a normal aerobic capacity, but also to slow the deterioration on the ALS functional rating scale and slow the progression of respiratory failure. Strength Maintaining muscular strength and postponing muscle loss. Muscle atrophy Is one of the main symptoms of ALS leading to obvious decreases in strength, stability and mobility.Majmudar, S, Wu, J, Paganoni, S (2014) ‘Rehabilitation in amyotrophic lateral sclerosis: Why it matters’, Muscle and Nerve; 50(1); 4-13 Administered as soon as the disease is diagnosed to maintain the function of the affected muscles. Isometric or dynamic exercises are recommended. Not high resistance, eccentric exercises as these have been shown to cause muscle damage.Aniziska, Y, Sternberg, A (2013) ‘Exercise in neuromuscular disease’, Muscle and Nerve; 48(1); 3-20 Targets/improvements are increased motor unit activation and synchronization, fiber hypertrophy, increased protein synthesis and increased capillary density. Other benefits can be attributed to exercise in general terms, where these benefits may be associated with many different kinds and not one particular type of exercise (like what is mentioned above). These benefits also relate to the symptoms of MND/ALS and the improvement of these via exercising. Sufferers often present with fatigue, due to the inability to activate large muscle groups. By implementing regular exercise, it could help to diminish this inability and increase the functioning of the neuromuscular system, reducing fatigue (with a similar response to healthy individuals). The presence of pain is another common symptom, especially in the later stages of MND/ALS, and is caused mainly by muscle spasms. This is another common symptom that regular exercise can help to control.Newrick, P, Langton-Hewer, R (1985) ‘Pain in motor neuron disease’, Journal of Neurology, Neurosurgery and Psychiatry; 48; 838-840 Even though exercise is evident in helping manage the physical issues of MND/ALS sufferers, the psychological issues associated with this debilitating disease still remain. It is these cascading mental health issues and their possible treatment with exercise that has been a huge topic of research in the past few decades.William, M, Stephen, G. ‘Exercise and mental health’, 1987. Hemisphere Publishing Corporation, USA pp. xiii (preface) It has been shown that the inclusion of exercise has positively benefited a wide spectrum of mental health issues, and proven to benefit people with depression especially.Burbach, F (1997) ‘The efficacy of physical activity interventions within mental health services: Anxiety and depressive disorders’, Journal of Mental Health; 6(6); 543-566 Furthering support, is the National Institute for Clinical Excellence 2004 guidelines, recommending regular exercise at a moderate intensity as an effective treatment option for depression.National Institute for Clinical Excellence. ‘Depression: Management of depression in primary and secondary care (quick reference guide)’, 2004, pp.7 The support for exercise in treating these psychological dysfunctions is overwhelming, and should be a major consideration as an all-encompassing treatment strategy for MND/ALS. The benefits of exercise in improving sufferers quality of life, beyond simply managing physical symptoms, is why this is a recommended inclusion in any program. Further Reading/Information Sources ‘Living better for longer’ information page at the MND Australia website: https://www.mndaust.asn.au/Get-informed/I-have-MND/Living-better.aspx ‘Scientists discovering possible cause of MND- blue/green algae’ news article: http://www.abc.net.au/news/2013-09-26/scientists-discover-potential-cause-of-motor-neurone-disease/4981598 References