The whistle-smile reflex: a missed sign

O reflexo do assobio-sorriso: um sinal esquecido

Abstract

In this paper, we present a historical review of the whistle-smile reflex, a semiological sign missed in the literature and clinical practice.

Keywords
Parkinson Disease; Physical Examination

Resumo

Apresentamos neste artigo uma revisão histórica do reflexo do assovio-sorriso, um sinal semiológico esquecido na literatura e na prática clínica.

Palavras-chave
Doença de Parkinson; Exame Físico

INTRODUCTION

In 1943, Frederic Hanes described the whistle-smile reflex, also known as Hanes sign: when asked to whistle, a healthy person does so and then smiles after the unusual physician's request. Otherwise, a patient with parkinsonism performs the whistle but does not smile after whistling due to the facial bradykinetic movement¹ (▸^{Video 1} and ▸Figure 1).

Video 1

The whistle-smile reflex. The patient and the healthy person gave us written consent to use their images. https://www.arquivosdeneuropsiquiatria.org/wp-content/uploads/2022/08/ANP-2022.0120-Video.mov Online content including video sequences viewable at: https://www.thieme-connect.com/products/ejournals/html/10.1055/s-0042-1758396.

Figure 1
Non-Parkinson disease patient's smiles after whistling (A-B). Parkinson disease patient shows no reaction after doing the same (C–D).

Dr. Hanes was a neurologist and professor of medicine at Duke University. During his many years in Durham, North Carolina, he explored the presence of hypomimia as a semiological tool for the diagnosis of Parkinson disease (PD); finding, during his evaluations, what he considers a helpful and reliable sign.

Lack of facial expression is a well-known feature of parkinsonian syndrome and an essential clue to diagnosing PD. Although James Parkinson did not mention hypomimia in his seminal work “An Essay on the Shaking Palsy”², it was recognized as an important semiological finding in a patient with PD in early works by authors such as Charcot, Gowers, and Wilson.³ The facial movement impairment may be not only voluntary but also spontaneous and emotional. The involvement of emotional expressions can be noticed with spontaneous smiling, reflected in reduced frequency and opening degree of the mouth.⁴

The whistle-smile reflex, alongside the Rolex sign⁵ and the floating door sign,⁶ lost its role in assessing a parkinsonian patient throughout the years. Although it is an interesting possibility to use the whistle-smile reflex in clinical practice, this reflex has not been revised in detail over the years, and we still do not have established its sensitivity and specificity. Therefore, it deserves to be remembered, not only for its historical importance but for its possible semiological value in clinical practice, and further studies are needed for it to become a routine tool in the assessment of a parkinsonian patient.

• Support
  Carlos R. M. Rieder receives support from Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) – Brazil (scholarship of research productivity). The other authors declare that there are no additional disclosures to report.

References

• ¹
  Hanes FM. Two Clinically Useful Signs: 1. The Whistle-Smile Reflex in the Parkinsonian Syndrome 2. The ‘Nephritic Stare” in Chronic Nephritis. JAMA 1943;121(14):1152–1153
• ²
  Parkinson J. An essay on the shaking palsy. 1817. J Neuropsychiatry Clin Neurosci 2002;14(02):223–236, discussion 222. Doi: 10.1176/jnp.14.2.223
  » https://doi.org/10.1176/jnp.14.2.223
• ³
  Maycas-Cepeda T, López-Ruiz P, Feliz-Feliz C, et al. Hypomimia in Parkinson's Disease: What Is It Telling Us? Front Neurol 2021; 11:603582
• ⁴
  Bologna M, Fabbrini G, Marsili L, Defazio G, Thompson PD, Berardelli A. Facial bradykinesia. J Neurol Neurosurg Psychiatry 2013;84(06):681–685
• ⁵
  Teive HA, Sá DS. The Rolex sign: first manifestation of Parkinson's disease: case report. Arq Neuropsiquiatr 2000;58(3A):724–725
• ⁶
  Kulkarni O, Lafaver K, Tarsy D. The "floating door sign" in Parkinson's disease. Parkinsonism Relat Disord 2013;19(09):825–826

Publication Dates

• Publication in this collection
  09 Jan 2023
• Date of issue
  2022

History

• Received
  03 June 2022
• Accepted
  24 July 2022