# Exercise as it relates to Disease/The Role of Exercise in Managing Charcot Marie Tooth Disease

Charcot Marie Tooth (CMT) disease is a broad term describing any inherited peripheral nerve disorder. CMT can be broken down into different categories based on the pattern of inheritance, the gene(s) responsible and whether the nerve axons or the myelin surrounding them is affected. It is the most common disorder affecting peripheral nerves and is estimated to affect 1 in 2,500 people. As CMT occurs when the axons or myelin of nerves are damaged, the body’s ability to relay information between the brain and other parts of the body is negatively affected. The lower limbs, especially the feet are usually the first place affected by CMT.

## Effects of CMT

The symptoms present can vary significantly between patients. However, some common symptoms include:
      * Sensory loss (e.g.- temperature, vibration, proprioception)
      * Impaired balance
      * Muscle weakness (especially in the distal portion of the limb)
      * Muscle atrophy (reduction in muscle size)
      * Abnormal gait
      * Cavus foot (high arched foot)
      * Fatigue
      * Hypo- or areflexia (diminished or absent reflexes)
      * Neuropathic pain

## Treatment Options

Currently there is no cure for CMT, so treatment is based on managing symptoms and improving quality of life. Some common treatment strategies include:
      * Physiotherapy
      * Orthotics and leg braces
      * Surgery
      * Pain relief medication
      * Exercise

## What Can Exercise Do?

Many of the symptoms mentioned earlier can be eased by exercise, especially in the early stages of the disease. Exercise can improve patient quality of life in the following ways:
      * Resistance exercise can improve muscular strength in CMT patients, allowing them to perform activities of daily living more efficiently.
      * Interval training in CMT patients has been shown to improve cardio-respiratory fitness, dynamic strength and walking speed (both on flat ground and stairs).
      * Continuous aerobic training increases cardiovascular fitness and day to day functioning of people suffering from neuromuscular diseases.

## Exercise Recommendations

| Resistance Training | Interval Training | Aerobic Training |
| Frequency: 3 times a week Knee flexion/extension (using ankle weights): Start weight: 40% max isometric strength Start volume: 3 sets, 4 reps Increase reps to 10 before increasing resistance Elbow flexion/extension (using wrist weights): Start weight: 20% max isometric strength Start volume: 3 sets, 4 reps Increase reps to 10 before increasing resistance | Frequency: 3 times a week Duration: 45 mins Intensity: 4 mins at 40% VO$_{2max}$, 1 min at 80% VO$_{2max}$ Repeat cycle for duration of exercise Exercise was performed on an exercise bike | Frequency: 3-4 times a week Duration: 20-30 mins Intensity: 70-85% of Heart Rate Reserve (HRR) Exercise was performed on a treadmill |

## Considerations for Exercise Prescription

As balance is negatively affected by CMT, activities that require continuously moving the feet off the ground such as running and jumping may be dangerous. Alternatives to these activities include:
      * Exercise bike
      * Rowing machine
      * Swimming
      * Water aerobics

## Further reading

Charcot Marie Tooth Fact Sheet
National CMT Resource Center

## References

* 1 2 3 4 5 Johnson NE et al., Quality-of-life in Charcot–Marie–Tooth disease: The patient’s perspective, Neuromuscul Disord (2014), http://dx.doi.org/10.1016/j.nmd.2014.06.433
* 1 2 3 4 5 6 Pountney, D. (2009) Identifying and managing Charcot-Marie-Tooth disease. British Journal of Neuroscience Nursing, 5(6), pp.270--273.
* 1 2 3 Szigeti, K. and Lupski, J. (2009). Charcot--Marie--Tooth disease. European Journal of Human Genetics, 17(6), pp.703--710.
* ↑ Boentert, M., Dziewas, R., Heidbreder, A., Happe, S., Kleffner, I., Evers, S. and Young, P. (2010). Fatigue, reduced sleep quality and restless legs syndrome in Charcot-Marie-Tooth disease: a web-based survey. Journal of neurology, 257(4), pp.646--652.
* 1 2 Chetlin, R., Gutmann, L., Tarnopolsky, M., Ullrich, I. and Yeater, R. (2004). Resistance training exercise and creatine in patients with Charcot--Marie--Tooth disease. Muscle & nerve, 30(1), pp.69--76.
* 1 2 Ribiere, C., Bernardin, M., Sacconi, S., Delmont, E., Fournier-Mehouas, M., Rauscent, H., Benchortane, M., Staccini, P., Lant\'eri-Minet, M. and Desnuelle, C. (2012). Pain assessment in Charcot-Marie-Tooth (CMT) disease. Annals of physical and rehabilitation medicine, 55(3), pp.160--173.
* ↑ Chetlin, R., Gutmann, L., Tarnopolsky, M., Ullrich, I. and Yeater, R. (2004). Resistance training effectiveness in patients with Charcot-Marie-Tooth disease: recommendations for exercise prescription. Archives of physical medicine and rehabilitation, 85(8), pp.1217--1223.
* 1 2 El Mhandi, L., Millet, G., Calmels, P., Richard, A., Oullion, R., Gautheron, V. and Feasson, L. (2008). Benefits of interval-training on fatigue and functional capacities in Charcot--Marie--Tooth disease. Muscle \& nerve, 37(5), pp.601--610.
* 1 2 Taivassalo, T., De Stefano, N., Chen, J., Karpati, G., Arnold, D. and Argov, Z. (1999). Short-term aerobic training response in chronic myopathies. Muscle \& nerve, 22(9), pp.1239--1243.
* ↑ Chetlin., R. (2011) Exercise and activity training for patients with CMT: application of the exercise is medicine model. National CMT Resource Centre. http://help4cmt.com/downloads/CMTExerciseandActivity.pdf