Does Charcot Marie Tooth Affect The Brain & What About The Heart?

Charcot Marie Tooth disease is an inherited motor and sensory neuropathy that affects the peripheral nerves. First, let’s see what are peripheral nerves and this will help you understand whether it affects the brain and heart or not.

Peripheral nerves belong to the peripheral nervous system and these nerves lie outside the brain and spinal cord and connect the central nervous system to the peripheral nervous system. Cranial nerves, peripheral nerves, spinal nerves, and their roots and neuromuscular junctions all belong to the peripheral nervous system. There are three types of peripheral nerves: the sensory nerves which carry information regarding sensation to the brain, motor nerves which carry nerve signal from the brain to the muscles for muscle movements and autonomic nerves which innervate the involuntary muscles present in the heart and glands and smooth muscle cells. Any injury to the peripheral nerve can cause muscle weakness, loss of sensation, abnormal sensation and autonomic dysfunction. The severity depends on the degree of peripheral nerve damage. ^{(1) (2) (3)}

Does Charcot Marie Tooth Affect The Brain?

In Charcot Marie Tooth the peripheral nerves are damaged due to mutations in different genes that give instructions to make proteins that are involved with the function of the peripheral nerves in the feet, leg, hands, and arms. The exact abnormality the Charcot Marie Tooth gene mutation cause in these proteins is clearly not known. The most probable theory is a fault in these proteins impair the nerve conduction through axons or affect the cells that produce myelin in the nerve cells. This affects the nerve conduction of the peripheral nerves leading nerve degeneration. The nerves that are longer and nerves that transmit signals to appendages are affected more as the axons are longer in these nerves. Therefore, nerves in the extremities are affected more than other parts of the body. ⁽⁴⁾

The brain is not involved in Charcot Marie Tooth, the central nervous system is not affected by Charcot Marie Tooth therefore, there is no problem in the brain function. The problem is with the peripheral nerves. The brain sends accurate signals to the peripheral nerves but because of their dysfunction the peripheral nerves cannot transmit these signals properly to the muscles, therefore, the muscles are not working properly and becomes weak. Similarly, the sensory signals are not carried accurately to the brain so, some people will feel a sensory loss and whereas some sensory signals will be interpreted by the brain abnormally, therefore, some people feel abnormal sensations too.

Does Charcot Marie Tooth Affect The Heart?

The heart involvement in Charcot Marie Tooth is not heard a lot and remains controversial. There are some case reports of Charcot Marie Tooth patients having heart arrhythmias, conduction disturbances and dilated cardiac myopathy. The exact mechanism of how peripheral nerves cause problems in the heart is unknown as the heart muscles have their own conduction system, however, the heart is innervated by the autonomic nervous system and it is also part of the peripheral nervous system. The exact mechanism is of heart involvement is not known and research studies are conducted to find more about this involvement. ⁽⁵⁾

Conclusion

Peripheral nerves belong to the peripheral nervous system and it connects the peripheries (muscles and sensory glands) to the central nervous system and transmits the signals from and to the brain from the peripheries. Charcot Marie Tooth occurs due to a gene mutation that affects the peripheral nerves. The central nervous system nerves are not affected by Charcot Marie Tooth. Therefore, the brain functions are not affected however, the brain signal is not properly transferred to the peripheries and vice versa. The heart involvement in Charcot Marie Tooth is not heard a lot and remains controversial. There are some case reports of Charcot Marie Tooth patients having heart arrhythmias, conduction disturbances and dilated cardiac myopathy. The exact mechanism of how peripheral nerves cause problems in the heart is unknown.

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Does Charcot Marie Tooth Affect The Brain & What About The Heart?