The charcot-marie-tooth disease (also hereditary motor-sensitive neuropathy type 2) is a rare genetic disease of the peripheral nervous system. It causes nerve impulses from the brain to no longer reach the corresponding muscles. The consequence is a degradation of the musculature.
Synonyms and terms:
First symptoms can already appear in childhood. Muscle weakness starts in the hands and feet and then spreads to the body. The mobility of the affected person decreases more and more. Sensory disturbances, pain and muscle spasms may also occur. A cure of the disease is not possible until today. In germany, about 30.000 people affected by the disease.
symptoms of charcot-marie-tooth disease
The feet are often affected by charcot-marie-tooth disease. Increasing gait disturbance is often an early symptom. Clinically the lower leg muscles show typical changes. Due to the loss of musculature, the legs become thinner. The atrophy (muscle atrophy) of the muscles near the foot on the lower leg leads to a relatively typical picture. There are so-called. Stork legs, since the muscles near the knees are normally pronounced. Muscle loss on the lower legs often occurs symmetrically on both sides.
The typical pattern of involvement of the lower leg and foot muscles is as follows:
- The small sog. Intrinsic (localized in the foot) foot muscles
- The fibula-side muscles, i.e. the peroneal muscle group
- The anterior shin muscle (musculus tibialis anterior)
- The toe extensor (musculus extensor digitorum longus)
- In the further course the remaining lower leg muscles
In addition to the intrinsic foot muscles, the sensitive and autonomic nerves are increasingly affected, especially in the early stages of the disease. Further expression of hip dysplasia, scoliosis and an affection of the hands are often combined. In the hands, involvement of the small hand muscles is typical.
Clinical picture before surgery: the shape of the foot has changed significantly in the course of charcot-marie-tooth disease. © joint clinic
A gait analysis can show the progression of the symptoms
In addition to the clinical appearance of the lower legs and calves, the increasing weakening and paralysis of the legs can also lead to strain problems. This results in compensatory muscle activities at a very early stage.
As long as the toe extensors are sufficiently powerful, these muscles can partially take over the lifting of the foot. The orthopedist can systematically assess this support in the course of gait analysis and objectively verify the change as it progresses. This is very important, especially before planned operations, but also for monitoring the course of the disease and for objective testing of its progression.
Malalignment of the calcaneus
In the context of charcot-marie-tooth disease, there is also an insecurity to stand. This depends on the malposition of the heel. The heel is tilted inward (varus position) due to the normal function of the calf and the internal flexor and posterior tibial tendons when the external and anterior tendons are weakened. This tilt leads increasingly to twisting of the foot. The standing base area is reduced by the load on the outer edge of the foot. This reduces mobility in the upper ankle joint. the reason for this is the changed traction conditions, but also a bony impingement at the front ankle joint due to the changed foot shape. The changes can be explained by the damage of the motor nerves.
Involvement of sensory, autonomic and autonomic nerves
In addition, the sensory and autonomic nerves are also involved. The sensory parts of the nerves provide sensations such as pain, temperature, pressure or touch, vibration and positional sensation.
The vegetative nerves are also disturbed. All nerves regulating blood circulation, i.e. vascular control, are affected, as are the parts of the nerves supplying the sebaceous glands of the skin. Since all can be affected to varying degrees in charcot-marie-tooth disease, damage and limitations can occur in all of these areas. We often observe symptoms such as pressure sores or skin damage.
Which foot deformity is classic in charcot-marie-tooth disease??
Due to the typical sequence of muscle weakening, a hollow foot (pes excavatus) most frequently develops. Particularly typical is the so-called. Internal or medial bunions. It also affects the ankle joint and the hindfoot due to its particular load on the forefoot.
Clinical picture of a bunion in an adolescent with a CMT disease: here, the left foot, which has not been operated on, was mirrored in comparison to the corrected right foot. The altered traction conditions on the left foot show the elevation of the arch of the foot and the supination, i.e., the inward rotation of the foot in front of the ankle joint. Clinically, the hindfoot axis does not show a strong tilt. © joint clinic
In the early phase of the disease, the peroneus brevis muscle on the outside of the foot, i.e. the short fibula muscle, is affected. This muscle is an antagonist of the posterior tibial muscle. Thus, the weakness of the externally attached muscle results in a malposition with increased inward traction of the foot. This positional adjustment takes place in the joint in front of the upper ankle joint, i.e. in the chopart joint. Seen from above, the foot is positioned more inward (supination position).
With this weakening, there is also an imbalance between the two calf muscles M. Peroneus longus and brevis. Therefore, the weakening of the externally attached short fibula muscle (M. Peroneus brevis) the strength of the long fibula muscle (M. Peroneus longus), which attaches from the outside under the foot at the bottom, on the inside of the midfoot. This imbalance leads to increased subsidence of the first metatarsal bone. The outer edge of the foot is no longer guided due to the lack of muscle guidance and loses control (steep position of the 1. ray).
Foot pressure measurement of a patient with hollow foot due to paralysis in charcot-marie-tooth’s disease. © joint clinic
The change in muscle activity can also be observed in pedobarometry (foot pressure measurement). This measurement on a treadmill equipped with sensitive, calibrated pressure sensors enables the determination of pressures during walking on the treadmill. The red areas are zones of high pressure. The results shown here are the mean plots of both feet of a patient with charcot-marie-tooth disease with paralysis-related hollow foot formation.
On the right, the paralysis is present at an earlier stage. Here, due to the overtension of the long fibula muscle, we still find a clear lowering of the 1. ray with overpressure under the 1. Inner metatarsal.
In addition, a foot elevation is present due to the residual function of the remaining muscles. This can be recognized by the load on the heel (red area). On the left, the damage is already much more pronounced. The foot is already tilted outward during walking due to the muscle imbalance. There is no load on the heel during touchdown and rollover. Here, the front foot is already overloaded on the outside. Despite a clearly hollow foot, there is also a load on the middle of the foot. This is possible because of the tilt outwards. The pedobarometry also allows a comparative measurement during the course of the disease.
In addition, the function of the important foot lifter (anterior tibial muscle/M. tibialis anterior) at an early stage. Therefore, the big toe lifter and the long fibula muscle predominate.
Due to the failure of the small foot muscles and the extensor tendons of the toes, claw toes are very often formed as a sign of the muscle imbalance between the short toe flexors and extensors in relation to the long toe flexors and extensors.
These imbalances in different muscle parts and at different places of the foot lead via the changed movement to typical malpositions, which are then present depending on the stage of the disease.
Examination of the hanging leg: these toe malpositions are caused by the permanent strain on the muscles. © joint clinic
Course of the CMT disease
The course of the CMT disease is very individual and must be assessed prior to therapy. The course of the disease depends on the following factors:
- Onset of disease
- speed of formation
- Extent of paralysis
- Load on the foot
- Characteristics of the compensatory mechanisms
A series of examinations are useful for assessing the course of the disease. The more muscles fail in a short period of time and the shorter the period of strong imbalances, the smaller the malpositions will be in principle. The better the compensatory mechanisms function, the less the disease affects the neighboring regions, i.e. the hindfoot and the ankle joint. The change in the position of the leg axis is also dependent on this.
A malalignment of the foot but also a knee malalignment can cause each other due to the heavy loading. Therefore, a consideration of malpositions of the foot is only meaningful if the entire leg is included in the assessment. © joint clinic
Knowledge about the origin of the deformity and about the progression of the disease are essential for any consultation. For each therapy decision we collect a large number of parameters. These are intended to achieve the best possible assessment of the progression and thus enable a highly individualized treatment regimen. The assessment is carried out on an interdisciplinary basis between neurologists, orthopedists, foot surgeons, and in some cases knee surgeons and physiotherapists.
X-ray image of a bunion with marked axes of the bones. It is easy to see that there is no bone in contact with the ground in the middle of the arch of the foot. So there is a hollow arch. This position is represented by the upper axis line. A bend in this axis line results from a plantar flexion of the 1. beam (steep position). The heel bone also stands steeply to the ground. The toes do not show any malposition when standing. © joint clinic
Deformities of the hindfoot
charcot-marie-tooth disease affects not only the foot and toes, but also the hindfoot. The effects on the hindfoot due to the altered muscle pulls can be compensated well in part. In some cases, the resulting malalignment – often in combination with injuries to the ligaments – causes extensive damage to the ankle joint. The malposition then also affects the entire leg. This is how x-leg axes can develop. The malalignment of the foot often also results in an altered rotation of the lower leg. These effects can be very different for each individual. They depend very much on the individual pattern of affection. The principles are similar for all patients with CMT disorders, but never the same.
X-rays of a patient with a medial bunion with malalignment of the hindfoot (top right). A varus tilt of the calcaneus is visible, affecting the position of the ankle joint in the ankle joint fork between the tibia and fibula (2). Picture from left). Here, the talus tilts outwards. The malposition of the heel causes an arthrosis on the inside in the upper ankle joint. no joint space is visible anymore. © joint clinic
What is the cause of charcot-marie-tooth disease??
Charcot-marie-tooth is a hereditary disease in which a gene mutation of chromosome 17 causes nerve damage. The impulse-transmitting axons with their insulating myelin layer are affected. During the course of the disease, there is a disturbance in the conduction of excitation. The impulses no longer reach the muscles completely, causing them to atrophy (shrink). the more the disease progresses, the less impulses are transmitted. Although this process begins in childhood, the symptoms do not manifest themselves in many affected individuals until the third decade of life.
The myelin sheath serves as an insulating layer of the nerve cell. Action potentials are only built up between the individual myelin layers, at the so-called ranvier’s lacing ring. The action potentials thus jump from lacing ring to lacing ring, which considerably shortens the transmission speed. © joint clinic
Diagnosis of CMT disease
the diagram shows the axes of motion at the foot and ankle joint as red solid axes. The transverse axis is that of the upper ankle joint. the axis running from the front inside to the back outside is that of the lower ankle joint. the position of the tendons in neutral position of the foot is shown in turquoise. Depending on the position of the tendons in relation to the axes of movement, the muscles have different functions on the foot and thus on the movement that results when the muscles are active. The changes lead in the long term to malpositions of the foot. © joint clinic
The slowly developing foot deformity is the reason for the presentation in our consultation hours. In charcot-marie-tooth, increasing disturbances of the nerves develop. The muscles controlled by the nerves are therefore no longer adequately supplied. Since there are normally supplied and diminished addressed muscles, a muscle imbalance results. This affects the muscles in the foot itself, but also the extrinsic muscles. These muscles originate in the lower leg and attach to the foot with the tendons.
Depending on the position of the affected tendons in relation to the rotational axes of the foot and the extent of the weakening, there is a change in the direction of movement when the muscles are activated. This can be thought of as similar to a kite or a paraglider. the altered traction in the flying objects corresponds to an increasing change in the foot position in charcot-marie-tooth disease.
Which changes help in the diagnosis?
- Changes in the musculature, especially in the lower leg
- Evidence of altered sensations of the skin
- Decreased sensation of vibration and touch
- Decreased sensation of pain and temperature
- Decreased sense of position
- Early failure of the so-called achilles tendon reflex
- Changes measured by the neurologist in needle electromyography
- Altered nerve conduction velocity with typical patterns in the measurement
- Gene alterations with duplication of DNA on the short arm of chromosome 17
Treatment of charcot-marie-tooth
In charcot-marie-tooth disease, a very individual assessment of the situation is necessary. Since the results of the examination depend on many parameters, this is often not possible with a single contact. Even the most experienced practitioner can’t decide this ad hoc. In most cases, numerous follow-up controls and examinations are necessary. This requires a lot of patience from both sides. In order to mitigate the far-reaching effects of the disease, surgical measures are part of the treatment.
Goals of the therapy
The treatment is intended to prevent severe malalignment and extensive consequential damage in neighboring regions. In order to avoid the need for corrective stiffening interventions (arthrodesis), early surgical correction of the deforming muscle imbalances is essential.
For the planning, already existing malpositions must be assessed. Since the deformity is present in all spatial planes and the tensile relationships of all muscles change depending on the foot position, this assessment is particularly important. Furthermore, the examination of the static, but also the dynamic function during walking is useful.
Gait analysis with video-assisted documentation can be very helpful here. This measure not only allows the progress to be monitored after an operation, but can also be used to assess function and compensation during walking before an operation. Possible balancing movements at the knee joint are also worth considering.
Tendon transfer surgery
These operations change the tensile effect of the affected muscle by displacing a tendon insertion in the context of a tendon transfer. Since each muscle becomes active in a defined phase during walking, different transfers of tendons are performed depending on the desired effect. These have different effects and can thus prevent significant malpositions and deformations at an early stage.
Especially in young patients, such interventions achieve extremely good results after a retraining phase. Tendon displacement surgery should be planned according to neurological, physiotherapeutic and foot surgery assessment. In addition to analyzing the deformity, the muscle status and nerve function are essential.
The tendon transfer is primarily intended to prevent the progression of the disease. This ensures that no correction by means of stiffening will be necessary later on. However, this is not always successful, even with early intervention.
However, the measures very often allow a much more normal life to be led. However, as the disease progresses steadily, there is always a risk that the results achieved by surgery will gradually be undone.
Possible complete and half tendon transfers
principle of a tendon transfer operation on the foot and lower leg. © joint clinic
Depending on the residual function of the muscles, there are a number of possibilities to change the tensile conditions of the foot by means of a tendon transfer. The direction in which the tendons are pulled depends on the bony position of the foot and the remaining axes of movement of the foot. Depending on the location of the tendon insertions before and after such an operation, there are various changes that can be assessed on the basis of a precise preoperative analysis.
Tendon transfers are named after the muscle used and the muscle to be strengthened. A transfer of the M. Flexor digitorum longus on peroneus brevis is a displacement of one of the flexor muscles of the small toes from the inside on the weakened short fibula muscle to the outside. The effect improves a weakened control of the outer edge of the foot.
Soft tissue balancing through steindler release of the plantar fascia
Another frequently necessary intervention – especially in young patients with an increasing hollow foot – is the so-called steindler release. The doctor cuts the plantar fascia on the inside of the foot to reduce the straightening effect of the arch of the foot. Regardless of the cause, this is often a very important measure in the context of correcting a hollow foot.
Furthermore, early balancing of the posterior tibial muscle (M. tibialis posterior) and the short fibula muscles (M. Peroneus brevis) is useful in order to delay or avoid bony surgery. The later the soft tissue balance is performed, the more often a correction of the deformity must be performed at the same time. The primary goal in the case of a hollow foot is to prevent the increasing deformity.
This is how regular control and assessment of the situation in a hollow foot is necessary. A particularly important assessment for the specialist is the examination of the cause of each form of high arch. In the case of charcot-marie-tooth disease, this can be secured by. Nevertheless, there are also other unclear diseases that cause a hollow foot.
In the case of early visible changes, soft tissue surgery alone often achieves a very good improvement and can prevent the progression of the deformity. Forefoot surgery alone with soft tissue correction is also a helpful early measure. The more the often advancing malalignment of the hindfoot plays a role, the more complex corrections must be supplemented.
Surgery for severe foot deformities
Severe deformities or foot deformities that have developed over the years require further corrective surgery, which can be performed on the calcaneus or the tarsus. Depending on the extent of the problem, this can only be achieved by stiffening and correcting the foot.
An operation without stiffening by displacement, twisting or shortening of the calcaneus is sometimes useful to change the position and the misalignment of the foot.
A correction of the position at the highest point of the malalignment at the root of the foot can also be a sensible measure. This operation, in which a foot wedge is removed, is very efficient, particularly in the case of malpositioning of the little toes. In this procedure, a foot wedge is removed from the tarsal area and the bones are then fixed again. This correction is, among many other possibilities, a very effective measure, if an earlier treatment does not prevent the malalignment. Depending on the location of the malalignment, the position of the wedge removal can also be at the 1. metatarsal bone in the course of a sog. Tubby osteotomy or on the calcaneus in the context of a calcaneus osteotomy or dwyer osteotomy may be advisable. The choice of the intervention can sometimes only be made during the operation itself.
Therapeutic principle for malalignment of the longitudinal arch of the foot
the removal of a foot wedge at the highest point of the hollow foot offers a good possibility of correction. Above you can see the planning of the intervention on the lateral standing foot. © joint clinic
Correction of the malposition from above can also be carried out in different ways: 1. Additive, i.e. inserting surgery by fitting a bone chip into the osteotomy (bone cutting). 2. Subtractive, i.e. removing realignment by removing a bone wedge. In some cases, the methods are combined, so that the chip removed from the outer side is inserted on the inner side. © joint clinic
In view of the arthrosis of the ankle joint, which often results from the long-term malposition of the hollow foot, further operations may be useful. Straightening of oblique positions is always in the foreground with these methods. If symptomatic arthrosis is present, crooked axes are always a reason for correction. These often allow a causal therapy and a temporary improvement of the ankle joint arthrosis. Unfortunately, once arthroses have developed, they can no longer be cured. However, they often progress more slowly after such measures.
Such operations are particularly useful in the case of incipient arthrosis with malpositioning, so that no stiffening (arthrodesis) or ankle joint prosthesis becomes necessary in the course of time. Unfortunately, especially at the foot and ankle, this chance is often carelessly missed, because often no other therapy option is known except stiffening.
Possibilities in case of already existing arthrosis due to malalignment
The treatment of the internal arthrosis of the ankle joint in the case of a hollow foot was carried out by straightening and thus horizontal positioning of the talus (talus bone). Depending on the cause of the deformity, a number of supplementary position-correcting measures may be considered. Ligament replacement surgery, tendon relocation or even bone removal are often useful. Cartilage surgery is often supplemented. It makes sense to carry out these therapies as early as possible, also in the case of charcot-marie-tooth. © joint clinic
Correction when joint support is no longer possible
after many years without a position correction, arthrosis and malpositioning often occur. This can no longer be treated with joint-preserving therapy. Such a severe malalignment in the context of charcot-marie-tooth disease severely limits the quality of life. Such malpositions require good planning, vascular clarification and a neurological opinion prior to surgery. © gelenk-klinik
the final stage of charcot-marie-tooth disease and any severe deformity can only be treated by straightening and stiffening. Further correction of the position gives the patient mobility without an orthopedic shoe. A straighter foot can greatly improve the quality of life at this end stage, especially in very young patients. A prosthetic fitting with simultaneous paralysis is often not possible. © joint clinic
Procedure for the two operations
The primary treatment is the severe malalignment of the ankle joint and thus the malalignment of the hindfoot.
The x-ray image shows an ankle joint, above from the front and below from the side. On the left you can see the malposition before the position correction. The red line shows the position of the cannon bone. Since the charcot-marie-tooth disease was not treated for years, the operation is more complicated than it would have been with an earlier intervention. In the right picture, an intramedullary nail was inserted to hold the position until the bone heals in the context of an arthrodesis (stiffening). the fibula was removed (see above right). © joint clinic
In the 2. The malposition of the tarsus was then corrected by a wedge resection from the tarsus. The resulting straight position of the foot when standing and walking is particularly important here. The straightening and thus the overall better loading of the still existing joint in the foot are important objectives.
In the same patient, there was also a massive deformity in the rest of the foot. Correction of the ankle joint and hindfoot alone may allow a satisfactory gait, but otherwise does not improve the overall situation. Therefore, the twisted and fan-aligned metatarsals (top right) needed to be straightened. For this purpose a transverse wedge was removed from the tarsus and the forefoot was corrected against the hindfoot. Fixation was carried out with the staples or stables visible in the image. These compress the bones at the correction site for the necessary 8 weeks. The correction was performed in two operations, since the soft tissues of the foot would have been damaged with a very high risk in a single operation. Since patients with CMT disease suffer from impaired sensitivity, the risks of soft tissue damage are additionally increased. © gelenk-klinik
Physiotherapy and exercises for charcot-marie-tooth
Recommendations::
- Neurophysiological physiotherapy concepts (u. A. PNF = proprioceptive neuromuscular facilitation)
- Water gymnastics
- Moderate strength training
- Aerobic endurance training/cardiovascular training
- Fall prevention
- Balance training
- Stretching and joint mobilization
Avoidance:
- Physical inactivity
- Supramaximal/loads/training
training should be done in consultation with a doctor and therapist to avoid harmful stress peaks. © joint clinic.De
Physiotherapy is one of the most important symptomatic treatments for charcot-marie-tooth disease. Neurophysiological therapy concepts are used to awaken the potential of muscles and to initiate movement. The exercises are designed to train the compensatory musculature as well as the trunk and muscles close to the trunk. Exercises to prevent falls help those affected to cope more easily and safely with everyday life. Stretching and mobilization techniques help prevent contractures (stiffness) of the joints.
The type of training that produces the best results for patients with degenerative neuromuscular diseases has not yet been conclusively determined. However, some recommendations can be derived:
Patients with neuromuscular diseases are generally less physically active. condition and strength decrease continuously. This disease-related inactivity can be countered by aerobic endurance training (z. B. walking, hiking and cycling) and moderate strength training. Supramaximal training, i.e. training that exceeds the maximum strength of the muscle, should be avoided by patients with CMT. Otherwise, overuse can occur in the muscles, causing damage and a decrease in strength.
In order to avoid excessive demands, the training should therefore be based on the respective dynamics of the disease. An individual exercise plan in consultation with the doctor and therapist is essential.
Frequently asked questions about charcot-marie-tooth to dr. Thomas schneider from the gelenk-klinik
Does lecithin help with charcot-marie-tooth?
Lecithin is an important component of our diet. It is found, for example, in soybeans or eggs. As a component of our nerve cells, lecithin plays a significant role in the transmission of excitation stimuli. In rodent experiments, lecithin administration has been shown to improve the insulating function of myelin sheaths, which is lost as CMT disease progresses. Future studies should investigate whether lecithin as a food supplement can also lead to improved transmission of nerve impulses in people with charcot-marie-tooth.
Does heredity play a role in CMT disease??
Yes, charcot-marie-tooth is a hereditary disease that is passed on from one or both parents to the child. The cause is an anomaly of chromosome 17. The parents do not necessarily have to have the disease themselves, but can be carriers of the disease trait. It is also possible that a spontaneous mutation of chromosome 17 occurs. Then neither parent is a carrier and the child still gets sick.
Is charcot-marie-tooth an autoimmune disease?
No, charcot-marie-tooth is not an autoimmune disease in which the immune system attacks the body’s own tissues. CMT is a neurogenetic disease. A genetic mutation of chromosome 17 is responsible for damage to the insulating layer of nerve cells.
What experience do the doctors at the joint clinic have with CMT disease??
The joint clinic in freiburg is one of the first certified centers for foot and ankle surgery (ZFS) in baden-wurttemberg. As such, we are subject to constant quality control. Our experts have a high level of surgical experience in foot and ankle surgery. Regular visits to our specialist clinic ensure the quality of our diagnostic and therapeutic measures. In addition, the gelenk-klinik is the first certified endoprosthetics center (EPC) in baden-wurttemberg. We treat about 20.000 patients. Of these, 200 receive an endoprosthesis. Our specialists for foot and ankle surgery, dr. Thomas schneider and dr. Martin rinio, achieve proven successful surgical results without quality problems.
Is charcot-marie-tooth curable?
There is currently no causal therapy for charcot-marie-tooth disease. So it is not curable. Only the symptoms can be treated.