Funding/financial disclosures. The authors have no conflicts of interest relevant to the content of this letter. No funding was received for the preparation of this letter.

Innov Clin Neurosci. 2023;20(10–12):8.

Dear Editor:

We read with interest the article by Cavallaro et al1 reporting on an adult female patient with right-sided facial nerve palsy that occurred following resection of a homolateral acoustic neuroma. Due to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic, the patient had to be rehabilitated using a remote approach via WhatsApp. The patient received telerehabilitation using mirror therapy, motor imagery, and cognitive sensory motor training (CSMT). After 10 months of treatment, the House-Brackman score had only improved from IV to III.1 The study is excellent but has limitations that should be discussed.

The main limitation of the study is that a causal relationship between the applied rehabilitation program and the outcome after 10 months of therapy was not substantiated by the information provided in the report. How can the authors rule out that the result at 10 months was simply the natural course of the disease? What evidence was there that rehabilitation was actually the cause of improvement? In order to document a beneficial effect of telerehabilitation, a prospective, multicenter, controlled trial is required.

A second limitation is that a causal relationship between surgery and facial nerve palsy could not be demonstrated. How many hours or days after the surgery did the facial nerve palsy appear? Have alternative causes of facial nerve palsy been adequately ruled out? The patient presented at the hospital two weeks after surgery at the earliest.1

A third limitation is that no cerebral imaging was reported.1 Peripheral facial nerve palsy can also be due to a lesion of the facial nucleus; this should be ruled out first.

A fourth limitation is that SARS-CoV-2 was not ruled out as the cause of facial nerve palsy. Since facial nerve palsy has emerged during the pandemic, and SARS-CoV-2 can cause isolated facial nerve palsy,2 it is imperative to know whether the polymerase chain reaction (PCR) for SARS-CoV-2 was positive at the time of onset of the palsy.

A fifth limitation is that the pathophysiology of facial nerve palsy, when due to surgery, was not discussed. Was it pressure, cut, or ischemia? Were there any complications during the operation? Since the outcome and treatment of facial nerve palsy depends on the underlying pathophysiology, it is important to completely understand it.

A sixth limitation of the study is that the course of palsy was not documented by nerve conduction studies (NCSs) or transcranial magnetic stimulation (TMS). A comparison of the NCSs at baseline and at 10 months might be useful to assess whether clinical improvement correlated with electrophysiological changes at 10 months.

It is unclear why the patient received steroids, when the cause of the facial nerve palsy was attributed to a nerve lesion during the operation.1 There is no evidence that steroids have a beneficial effect on secondary facial nerve palsy. Steroids have been shown to be useful only when classified as idiopathic.3

We disagree that 75 percent of facial nerve palsies are idiopathic (Bell’s palsy).1 In a recent retrospective study of 1,989 patients, only 38 percent were diagnosed with Bell’s palsy.4

Overall, the interesting study has limitations that put the results and their interpretation into perspective. Addressing these issues would strengthen the authors’ conclusion and could improve the status of the report. Whether telerehabilitation actually represents a valid strategy for neurocognitive rehabilitation in iatrogenic facial nerve palsy needs to be confirmed by prospective, multicenter, controlled studies.


  1. Cavallaro F, Portaro S, Pintaudi T, et al. Remote cognitive therapeutic exercise in facial nerve palsy rehabilitation: pandemic tips and tricks. Innov Clin Neurosci. 2023;20(1–3):10–12.
  2. Lima MA, Silva MTT, Soares CN, et al. Peripheral facial nerve palsy associated with COVID-19. J Neurovirol. 2020;26(6):941–944.
  3. Madhok VB, Gagyor I, Daly F, et al. Corticosteroids for Bell’s palsy (idiopathic facial paralysis). Cochrane Database Syst Rev. 2016;7(7):CD001942.
  4. Hohman MH, Hadlock TA. Etiology, diagnosis, and management of facial palsy: 2,000 patients at a facial nerve center. Laryngoscope. 2014;124(7):E283–E293.

With regards,

Josef Finsterer, MD, PhD, and Fulvio A. Scorza, MD

Dr. Finsterer is with Neurology & Neurophysiology Center in Vienna, Austria. Dr. Scorza is with Disciplina de Neurociência, Universidade Federal de São Paulo/Escola Paulista de Medicina (UNIFESP/EPM) in São Paulo, Brazil.