Nina Bylund: Bell’s Palsy - Sequelae, Quality of Life and PET/MRI

Abstract

Bell’s palsy, idiopathic peripheral facial palsy, is the most common cause of peripheral facial palsy. The main aetiological theory for Bell’s palsy is nerve inflammation and oedema within the narrow bone canal, leading to nerve injury, possibly triggered by herpes virus reactivation. Seventy per cent of patients recover spontaneously, and prednisolone treatment increases recovery rates. Synkinesis is a main sequela in patients with non-recovery.

This thesis aimed to study sequelae and quality of life in patients with Bell’s palsy and explore the benefit of FDG-PET/MRI in acute peripheral facial palsy.

In 829 patients randomized to prednisolone and/or valaciclovir, or placebo, we investigated if prednisolone reduced the severity of sequelae, and if valaciclovir had any additive effect. Synkinesis incidence, severity, and possible early predictors for synkinesis were analysed.

A longitudinal study evaluated patient-graded facial and psychosocial function in acute and follow-up stages in Bell’s palsy, using the Facial Clinimetric Evalution (FaCE) scale and Facial Disability Index (FDI). Correlations between FaCE/FDI and physician-graded facial function were analysed. Gender difference in patient-reported psychosocial function was evaluated.

Ten patients with acute peripheral facial palsy underwent FDG-PET/MRI, with the aim of visualising facial nerve inflammation.

Prednisolone was found to reduce mild and moderate facial dysfunction, but no statistically significant difference between treatment groups was found for severe sequelae.

Synkinesis incidence was 21%, with 6.6% of patients having moderate to severe synkinesis. The 1-month Sunnybrook score had a high predictive value for the risk of synkinesis at 12 months.

In the acute phase, low correlations between FaCE/FDI and Sunnybrook scores were seen, whereas moderate to high correlations were found at follow-up visits. Moderate correlations were also seen between social/well-being function and Sunnybrook scores. Women rated their social/well-being function lower than men.

Only one patient, who had herpes zoster, showed focal FDG uptake on PET/MRI. 

In summary, this thesis demonstrated that prednisolone is effective in reducing mild and moderate sequelae in Bell’s palsy. No statistically significant additive effect of valaciclovir was found. Synkinesis incidence was 21%. The 1-month Sunnybrook score estimates the risk for synkinesis. The FaCE and FDI instruments are well suited for Bell’s palsy and are recommended when evaluating patients with sequelae. FDG-PET/MRI is not a sensitive method in acute peripheral facial palsy.