Testing cranial nerve VII: It is all in the wording

Area of Science:

• Neurology
• Clinical Examination Techniques

Background:

• Clinical neurological examinations frequently involve testing cranial nerve VII (facial nerve).
• A common instruction is to
• wrinkle the forehead
• to assess the M. frontalis.
• Observed phenomenon: patients often
• frown
• (innervating corrugator supercilii) instead of wrinkling their forehead.

Purpose of the Study:

• To prospectively evaluate the prevalence and characteristics of false frowning during forehead wrinkling tests.
• To determine if this phenomenon is influenced by patient demographics or clinical factors.

Main Methods:

• A semi-structured questionnaire was used to gather observations from clinical colleagues.
• 113 unselected patients were prospectively examined for the phenomenon.
• Data collected included patient demographics, chief complaint, and clinical setting.

Main Results:

• The majority of clinical colleagues confirmed the observation of false frowning.
• 54.9% of the 113 examined patients exhibited false frowning.
• The phenomenon was largely independent of gender, age, chief complaint, and clinical setting.
• Patients who initially frowned correctly wrinkled their forehead when instructed to raise their eyebrows.

Conclusions:

• False frowning during the forehead wrinkling test is a highly prevalent artifact in clinical neurological examinations.
• Precise and clear wording of instructions is critical for accurate assessment of cranial nerve VII function.
• This finding underscores the importance of standardized examination techniques to avoid misinterpretation.