Ultrasound Imaging and Guidance for Bell's Palsy: EURO-MUSCULUS/USPRM Approach.

Bell's palsy, or idiopathic peripheral facial nerve palsy, is characterized by the sudden onset of facial muscle paralysis resulting from damage to the facial nerve fibers. The diagnosis is typically established through clinical evaluation, although in cases with atypical features, imaging modalities like magnetic resonance imaging or computed tomography are indicated to rule out underlying lesions or temporal bone abnormalities compressing the facial nerve. High-resolution ultrasound has emerged as a promising modality for evaluating peripheral neuropathies, including cranial nerve disorders. Recent studies have highlighted its potential in measuring facial nerve diameter, detecting nerve edema, and predicting clinical prognosis in Bell's palsy. Beyond its diagnostic role, ultrasound also facilitates precise perineural corticosteroid injections, offering an alternative to systemic corticosteroid therapy, which is commonly associated with adverse effects such as hyperglycemia and hypertension. ultrasound also plays a crucial role in guiding botulinum toxin injections, which are used to manage synkinesis and facial asymmetry in chronic Bell's palsy cases.This review discusses the role of ultrasound in the diagnosis and management of Bell's palsy, emphasizing its advantages in visualizing facial nerve edema and guiding perineural corticosteroid and intramuscular botulinum toxin injections.