TLNS after acoustic neuroma surgery
After an acoustic neuroma is removed, the problem people describe is rarely pain. It is that the floor stops feeling solid. Walking drifts to one side, darkness and closed eyes make everything worse, and standing with the feet together becomes impossible. This is ataxia — loss of balance and coordination. Below: why it happens, why the first month after surgery matters more than any later period, and what a translingual neurostimulation (TLNS) course changes.
Why balance breaks after the operation
An acoustic neuroma — in current medical language a vestibular schwannoma — grows from the sheath of the vestibulocochlear nerve in the cerebellopontine angle, right next to the facial nerve, the trigeminal nerve and the cerebellum. It is the most common tumour of that region: up to 80% of all cerebellopontine angle tumours and 8–10% of all primary brain tumours in adults.
Tumours larger than 3 cm are classed as large and giant. They account for roughly 10–15% of cases, and they are the ones most often followed by dizziness, unsteadiness, ataxia, swallowing difficulty and facial weakness. The surgeon removes the tumour, but the nerve that carried balance information from that side does not come back. The brain has to rebuild its sense of body position from what remains: vision, joint and muscle sense, and the intact labyrinth on the other side. That process is called vestibular compensation, and it goes better the earlier it starts.
Why the first month decides so much
In 2016–2017 a study was carried out at the Polenov Russian Research Institute of Neurosurgery — a branch of the Almazov National Medical Research Centre — with our centre taking part. It included 64 patients operated on for large and giant vestibular schwannomas who still had ataxia after surgery. Everyone received a course of 10 translingual stimulation sessions of 20 minutes each.
Patients were split by how soon rehabilitation began. Group one: 54 people who started within the first month after surgery, on days 4–34. Group two: 10 people who started later, between 3 months and 2 years.
In group one, standing ataxia fell from 2.5 to 1.2 points, gait ataxia from 2.4 to 1.3, and the Karnofsky performance score rose from 66.9 to 74.4. All three changes were statistically significant, p<0.001. Group two improved as well, but far less: on the Karnofsky score there was no significant change at all. No adverse effects were recorded.
The authors' conclusion is direct: the method belongs in the rehabilitation programme during the first month after tumour removal. It still works later, but the return is markedly smaller.
The publication
Kondratyeva E. A., Kondratyev S. A., Smirnov P. V., Bugorskiy E. V., Alekseeva T. M., Tastanbekov M. M., Ivanova N. E., Danilov Yu. P., Ulitin A. Yu., Shlyakhto E. V. Translingual stimulation in patients with ataxia after the resection of large and giant vestibular schwannomas // Russian Neurosurgical Journal named after professor A. L. Polenov. — 2018. — Vol. X, No. 2. — P. 42–46.
The study was run under a clinical approbation protocol and in line with Good Clinical Practice. Evgenii Bugorskii, MD, is chief physician of the RehaLine rehabilitation centre; Yuri Danilov, PhD, is one of the originators of the method and for many years led the Tactile Communication and Neurorehabilitation Laboratory at the University of Wisconsin–Madison.
What a course looks like
Ten sessions of 20 minutes, one per day. An electrode array sits on the front surface of the tongue and delivers weak electrical pulses; patients usually compare the sensation to sparkling water. It does not hurt.
The session is done standing on an unstable foam cushion, with a blackout mask over the eyes and quiet music playing — both are there to remove the visual crutch and force the brain to rely on its own internal signals. The feet are brought together, because that stance demands the most from the balance systems. When ataxia is severe, the first sessions are done seated and the feet are brought together gradually; in the study 15 of the 64 patients began that way.
Stimulation is not a stand-alone procedure you lie under. It works only together with the exercise performed during it. That is why TLNS is always delivered as a course, paired with training.
When the method is not suitable
- implanted cardiac pacemaker or any other electrical stimulator;
- seizure disorder, epilepsy;
- reduced level of consciousness;
- signs of systemic inflammation or sepsis;
- damaged tongue or oral mucosa, acute inflammation in the mouth;
- pregnancy.
The final decision is made by a physician after examination and review of the neurosurgical discharge summary.
What we do not claim
TLNS does not regrow the resected nerve and does not restore hearing on the operated side. It helps the brain reorganise faster and lean on the channels it still has — which is why the effect is measured in ataxia scores and walking ability, not in nerve status. The study above is not a double-blind randomised trial: it compares two groups by timing of rehabilitation within a clinical approbation protocol. We prefer to say that plainly.
What to do next
If surgery is behind you or scheduled, write to us. We will look at the discharge summary and tell you whether a course is indicated and when it should start. More about the method itself is on the translingual neurostimulation page; balance and gait problems of other origin are covered on the ataxia page.