Facial pain in patients with hemifacial spasm: A prospective cohort study.

OBJECTIVE

To determine the prevalence and clinical characteristics of facial pain in patients with primary hemifacial spasm (HFS), identify factors associated with its occurrence, and evaluate its longitudinal course following botulinum toxin type A (BoNT-A) treatment.

DESIGN

Prospective cohort study with 4 months of follow-up.

SETTING

Tertiary public referral center.

SUBJECTS: Eighty-seven adults with primary HFS receiving BoNT-A treatment. Median age was 66 years, 71.3% were women, and median disease duration was 13 years (IQR 8-20).

METHODS

Participants underwent standardized assessment using a semi-structured questionnaire, Visual Analog Scale, McGill Pain Questionnaire, facial pain diary, Hospital Anxiety and Depression Scale, and Hemifacial Spasm Grading Questionnaire. Clinical characteristics and factors associated with facial pain were analyzed, and pain outcomes were assessed longitudinally following BoNT-A treatment.

RESULTS

Facial pain was present in 40.2% of patients, predominantly involving the periorbital region (77.1%) and occurring ipsilateral to the spasm (85.7%). Median pain frequency was 5 days/month (IQR 3-15), intensity 6/10 (IQR 5-8), and duration 5 hours (IQR 1-20). In multivariable analysis, facial pain was independently associated with female sex (OR 3.47, 95% CI 1.00-11.97; p = 0.049) and greater subjective disease burden, measured by the HFS Global Subjective score (OR 1.01, 95% CI 1.00-1.03; p = 0.034), but not with objective motor severity. Although 88.2% of patients reported subjective improvement after BoNT-A, objective pain measures remained unchanged during follow-up.

CONCLUSIONS

Facial pain is a frequent non-motor manifestation of HFS, affecting approximately 40% of patients. Its association with greater subjective disease burden, but not objective motor severity, suggests that pain represents a clinically relevant dimension of HFS not captured by motor assessment alone. Routine assessment of facial pain should therefore be incorporated into the comprehensive clinical evaluation of patients with HFS.