PD Dr Klaus Exner, MD, Dr h.c., is a renowned expert in the field of plastic and aesthetic surgery, with an impressive career spanning more than forty years. In addition to his extensive expertise in hand surgery and microsurgery, he has made a name for himself in the international medical community through numerous awards and accolades.
His expertise spans various areas of aesthetic and plastic surgery, including aesthetic surgery of the face and body, breast surgery in the form of reconstructions, reductions and augmentations, as well as tumor surgery, particularly of skin, soft tissue and breast tumors. He also performs body contouring procedures and offers treatments such as facelifts, eyelid surgery and rhinoplasty. Furthermore, he specializes in the treatment of congenital malformations such as cleft lip and palate and breast asymmetry.
As one of the leading experts in his field, Dr Exner is recognized worldwide and has made a significant contribution to the development of advanced medical care through his many years of practice, research and teaching, as well as through numerous innovations. His scientific publications and his involvement in the development of new surgical techniques have helped to raise standards in aesthetic and plastic surgery.
Dr Exner practises at two state-of-the-art clinics in Frankfurt am Main and in Oberursel in the Hochtaunus region, offering his patients personalized treatment of the highest standard, tailored to their individual needs. He attaches great importance to building a relationship of trust with his patients and to understanding their wishes and expectations precisely. His expertise covers a wide range of aesthetic and plastic procedures, in which he achieves natural and aesthetically pleasing results through innovative techniques such as lipo-filling.
Furthermore, Dr Exner is actively involved in research and the further development of surgical methods, so that he can always offer his patients the most modern and effective treatment options. Through his humanitarian work in poorer regions of the world, particularly through his missions in developing countries such as Myanmar and Ukraine, Dr Exner has not only demonstrated his medical expertise but has also made a significant contribution to improving medical care in these regions. His outstanding contribution to the entire field of aesthetic and
plastic surgery is evidenced by numerous awards and honors, as well as by his scientific and humanitarian work around the world. Facial paralysis is also one of the areas of specialization of this experienced specialist.
The editorial team of the Leading Medicine Guide spoke to Dr Exner about facial nerve palsy.
Facial nerve palsy, also known as facial paralysis, is a neurological disorder caused by damage to the facial nerve, which controls the muscles of the face. The effects can range from mild weakness to complete paralysis, which can impair both the aesthetic appearance and the functional ability of the face. A deeper understanding of facial nerve palsy is crucial for the diagnosis and treatment of this condition, as well as for supporting those affected during their recovery process.
Acquired facial nerve palsy is a sudden weakness or paralysis of the facial muscles caused by damage to the facial nerve.
This form of palsy can have various causes, including infections, trauma, inflammatory conditions, tumors or idiopathic cases where the exact cause is unknown. “Facial palsy is primarily caused by surgery on the cranial nerves. In most cases, it is surgery for acoustic neuroma or other brain tumors that can trigger this form of paralysis. This is because the acoustic nerve runs at a critical point directly adjacent to the facial nerve. And the auditory nerve has the unfortunate tendency, in rare cases, to form a lump – a benign neurinoma. However, if the auditory nerve is damaged, those affected experience symptoms such as bouts of dizziness, reduced hearing ability or tinnitus. To prevent the neurinoma from growing further and building up pressure, it is usually removed surgically. In the past, damage to the facial nerve was very common during this procedure, but this is less likely today as monitoring during the operation is significantly better. During the operation, electrodes are attached to the facial muscles, and nerve recordings on the monitor then show if the surgeon is getting too close to the facial nerve or putting too much strain on it. Unlike in the past, the entire operation is gentler because much of the tissue can be removed using ultrasound. Nevertheless, there are still a number of consequences following these neurinoma operations. The facial nerve branches off into a frontal branch, which runs from the temple up to the forehead and moves the facial muscles of the forehead. Then there are important branches to the eyelid, specifically to the eyelid-closing muscle. And this is where a major problem arises for patients with facial nerve palsy, namely when they can no longer close their eye. Consequently, the eye can dry out, the cornea can scar, and this can even lead to blindness. ‘Ultimately, the facial nerve controls all facial expressions, such as the movement of the nostrils or the protrusion of the lips,’ says Dr Exner regarding the effects of facial nerve palsy.
An acoustic neuroma, also known as a vestibular schwannoma, is a benign tumor that develops from the Schwann cells of the vestibular nerve (nervus vestibularis). This nerve is part of the eighth cranial nerve, which is responsible for hearing and balance. Acoustic neuromas usually grow slowly and often cause symptoms such as hearing loss, tinnitus (ringing in the ears) and balance disorders. As the tumor can affect the brainstem and other important structures within the cranial cavity, early diagnosis and treatment are important. Treatment options include regular monitoring, surgical removal and radiotherapy, depending on the size and location of the tumor as well as the patient’s general state of health.
The course of facial nerve palsy caused by an acoustic neuroma depends on various factors, including the size and location of the tumor and the extent of compression of the facial nerve. In some cases, the facial nerve palsy may progress as the tumor continues to grow and exerts more pressure on the nerve. In other cases, facial paralysis may remain stable or even improve once the tumor is treated and the pressure on the nerve is reduced. Treatment for an acoustic neuroma with associated facial nerve palsy may include various options, such as monitoring the tumor, radiotherapy, or surgical removal of the tumor. The choice of treatment depends on the size and location of the tumor, the extent of the facial nerve palsy, the patient’s general health and other individual factors. In some cases, physiotherapy may be recommended to improve facial function and support recovery following treatment of the tumor.
Congenital facial nerve palsy occurs when the facial nerve is already damaged at birth.
This form of facial nerve palsy can have various causes, including genetic factors, infections during pregnancy or birth trauma. Typical symptoms include asymmetrical facial expressions, difficulty closing the eye on the affected side and restricted muscle movement in the face. In such cases, physiotherapy, surgical intervention, or a combination of both therapies may be considered. Möbius syndrome is a rare congenital condition caused by the absence or underdevelopment of the sixth and seventh cranial nerves, leading to facial paralysis. “In this condition, the entire facial nerve does not function at all. It becomes noticeable in children because they are initially unable to drink or smile. They cannot close their eyelids properly and often squint. The condition can be further exacerbated by the development of clubfoot and muscular dystrophy. The masseter nerve from the masticatory muscles was assigned a major role because small muscle grafts could be attached to it. To do this, a piece of muscle containing nerves and blood vessels is taken from another part of the body, for example from the inner thigh, and connected via microsurgery to the blood vessels of the facial muscle and to the masseter nerve. “This then enables a child to mimic a smile, tense their face and also speak more clearly,” explains Dr Exner.
The exact prevalence of Möbius syndrome in Germany is not precisely known due to its rarity and possible under-diagnosis. However, it is estimated that approximately 1 in 50,000 to 1 in 500,000 newborns are affected by this syndrome.
The treatment of acquired facial nerve palsy depends on the underlying cause and the severity of the symptoms.
In some cases, the paralysis may resolve spontaneously and completely, while in others, treatment is required to alleviate symptoms and improve facial function. “Infections caused by viruses such as the herpes simplex virus or the varicella-zoster virus, as well as autoimmune diseases such as Lyme disease (transmitted by ticks) or sarcoidosis, can inflame the facial nerves and lead to paralysis. Traumatic injuries to the face, such as lacerations, skull fractures or tumors that compress the facial nerve, are further possible causes. The facial nerve runs through the facial canal in the area of the middle ear. And in the event of severe inflammation or suppuration in this area, the nerve can be compressed so severely within this bony canal that it suffers serious damage or fails. And then there are recurrent cases of nerve failure following vaccinations, which are usually temporary, for example after the early summer TBE (tick-borne encephalitis) vaccination, which protects against the virus transmitted by ticks. However, it is not uncommon for children to limp for a while, which usually resolves itself. That said, I have certainly had a number of patients (undoubtedly also due to the increase in vaccinations in recent years) who have developed facial nerve palsy following a vaccination. And there are now significantly more patients affected by the herpes zoster virus than was the case before COVID. In so-called idiopathic cases, on the other hand, patients wake up in the morning and suddenly find they can no longer move one side of their face. “We don’t know exactly where this comes from, but we suspect undiagnosed infections such as the aforementioned herpes virus, which can also trigger shingles, a condition in which the nerve pathways are severely affected,” explains Dr Exner, adding a few more points on diagnosis and initial treatment:
“Facial nerve palsy is essentially a visual diagnosis. Imaging techniques such as magnetic resonance imaging (MRI) are frequently used to look for possible causes such as tumors or injuries, while electrophysiological tests such as electromyography (EMG) can assess the nerve’s function and help determine whether there are still nerve impulses present, which may become apparent after a few weeks or months. In the past, patients were kept waiting too long, and in doing so, very valuable time was lost. This is because the 23 muscles responsible for facial movements atrophy if they have no nerve supply. The connection between the nerve and the muscle is then severed, and the muscle can no longer contract. Today, during this phase, a so-called ‘babysitter nerve’ can be implanted, which sends the necessary impulses to bridge the period during which it is not yet known whether the facial nerve will regenerate. The masseteric nerve, which is associated with the chewing muscle, is used for this purpose. This is sometimes sufficient, and sometimes further nerve grafts are used to restore facial expressions that are as symmetrical as possible.”
Microsurgical techniques for the treatment of facial nerve palsy offer precise and targeted approaches to improve or restore the impaired function of the facial nerve.
As regards the treatment options as a whole, Dr Exner explains: “A distinction is made between static and dynamic methods. Static methods (for example, small gold pieces in the eyelid to facilitate closing) are always only stopgap solutions, whereas dynamic methods are always the preferred option, particularly with regard to restoring facial expressions. In cases of congenital facial nerve palsy, the only option is microsurgical muscle transplantation. For this, the technique established by Sir Harold Gillies in 1937 is used to reroute the temporalis muscle (chewing muscle in the temple region) to the eye, so that this muscle can be used to close the eyelid again. Furthermore, there is the technique described by McLaughlin in 1956, whereby tendon strips are harvested from the thigh and connected to the masticatory muscles to mimic a smile and lift the face again. This technique is generally used in patients over the age of 50 or 60. Botox can be used for minor asymmetries and is injected on the side where the nerve is still healthy. This restores symmetry by reducing nerve activity on the healthy side and creating an adjustment.
The use of Botox for facial nerve palsy requires careful assessment and planning by an experienced doctor with specialist knowledge in treating this condition. The dosage and placement of the injections should be tailored to the individual, based on the patient’s specific needs and symptoms, to achieve optimal results and minimize potential side effects. Although Botox can be an effective option for treating certain symptoms of facial nerve palsy, it is important to note that there is no cure for this condition. The use of Botox aims to alleviate symptoms and improve the quality of life for those affected, but should be considered as part of a comprehensive treatment plan, which may also include physiotherapy, surgical procedures and other therapies.
Microsurgical treatment options
“Microsurgical procedures involve transplanting muscles along with blood vessels, but also offer the option of connecting the masseter nerve to the facial nerve and linking it to the facial nerve branches, i.e. the nerve fibers. Nerve grafts can also be performed using the so-called cross-face technique. In this procedure, nerves are taken from a healthy site, usually the lower leg, and can be placed, for example, beneath the upper lip (on the affected side). After a period of time, the Hoffmann-Tinel sign (a clinical sign used to diagnose nerve injuries and irritations) is then used to check whether the patient feels a tingling sensation at the site, which indicates whether the nerve has already grown in. This is important because when a nerve is transplanted, the nerve’s inner core – the axon – is initially non-functional. However, through the nerve sheath that has been sutured in place, the axon regrows at a rate of 1–2 mm per day. And then, by tapping, one can determine whether the nerve has reached the other side. That is the right time to connect a muscle with vascular anastomoses to the nerve in order to restore facial function. “The transplanted muscle should, of course, be a very fine muscle so that it is not so visible on the face. We are talking here about high-tech microsurgery,” explains Dr Exner.
The Hoffmann-Tinel sign, also known simply as the Tinel sign, is a clinical sign used to diagnose nerve injuries and irritation. It is performed by gently tapping or pressing over a nerve to determine whether this triggers a tingling or unpleasant sensation along the nerve. It is a helpful diagnostic tool for identifying nerve problems and localizing the area of nerve damage or compression.
Compared to non-surgical treatment methods, microsurgical procedures aim directly to treat the cause of facial nerve palsy, rather than merely alleviating the symptoms. They offer the possibility of a permanent restoration of facial function and can be particularly beneficial in cases of advanced facial nerve palsy. However, microsurgical procedures require careful planning and execution, as well as a longer post-operative rehabilitation process. It is important that these procedures are performed by experienced and specialized surgeons to achieve optimal results and minimize potential complications.
“I personally often recommend that my patients seek additional information from colleagues at other centers, which is usually welcomed. The patient can then choose where to go in the end. Especially when it comes to young patients, they simply need sound advice from several experienced centers to achieve the best possible treatment with the best possible outcome. They also need psychological support. Patients who still have some residual function of the facial nerve can also do exercises in front of the mirror to train the nerve. Advice on cosmetics and speech therapy is also important at this stage,” recommends Dr Exner at the end of our conversation.
Thank you very much, Dr Exner, for these informative insights into facial nerve palsy!
