What is Morton Neuralgia?
Morton neuralgia, also known as Morton metatarsalgia, is a progressive disease of the nerves that run from the bottom of the foot to each toe. In this disease, the affected persons complain of numbness at rest and pain when the foot is moved for a longer period of time or when the foot rolls.
The causes
Roughly speaking, the cause of its development is excessive strain or compression of the metatarsus. People who already suffer from a foot malposition are particularly susceptible. For example, patients with splayfoot symptoms or hallux valgus have a significantly higher risk of developing Morton’s neuralgia.
However, the underlying pathomechanism needs to be considered in a more differentiated way. For example, the excessive pressure of a foot malposition leads to the nerve also being slightly compressed or rubbing against the foot bone from time to time. As a reaction to this, a thicker layer of connective tissue forms around the nerve, which is intended to protect the nerve.
But the nerve itself also begins to become thicker. However, the space in which the nerve can expand is limited, so that the nerve is subsequently compressed further and further as it tries to expand. In addition to compression, other causes can also lead to the nerve wanting to expand due to damage.
Every nerve is surrounded by tiny blood vessels to supply it with oxygen and energy. If this blood flow is disturbed, such as in the case of peripheral arterial occlusive disease (PAD), the nerve also reacts by increasing its thickness. However, the most common form of nerve damage in Germany is due to excessive compression of the nerve between the metatarsals.
These are the symptoms of Morton Neuralgia
- Severe foot pain when walking for a long time
- Pain becomes stronger the more extreme the foot is rolled off
- The pain radiates from the midfoot to the toes
- Simultaneous numbness in the foot
- Compression of the forefoot also triggers the pain
The pain is not present right from the beginning of the disease, but only occurs when the nerve has already gained a considerable increase in thickness. Most patients describe the character of the pain as sharp and stabbing. The pain can be provoked by rolling extremely hard, which causes a compression of the thickened nerve between the metatarsals, or by compressing the forefoot from the sides with one hand, which also causes a compression of the nerve between the bones.
Numbness in the foot is caused because the nerves not only transport the perception of pain, but also information about pressure on the balls of the toes, the position of the foot in space and the tactile sensation of the feet. However, if the nerve is damaged, the transport of this information from the foot to the brain no longer functions correctly and the feeling develops that the foot is numb or not fully in place. On the other hand, damage to the nerve can also lead to nerve impulses being generated even though there is no reason for this. These are then felt by the brain as tingling sensations.
