What's the next step in evaluating progressive facial asymmetry with normal MRI findings of the brain, skull, face, orbits, and neck?

Next Steps for Progressive Facial Asymmetry with Normal MRI

Perform a comprehensive neurological neck examination focusing on cranial nerves V, VII, IX, X, XI, and XII, combined with systematic mucosal surface inspection and neck palpation to identify underlying pathology that imaging may have missed. 1

Clinical Examination Protocol

Cranial Nerve Assessment

The neurological examination must systematically evaluate specific cranial nerves that commonly cause facial asymmetry:

• CN VII (Facial nerve): Test facial movement symmetry and strength bilaterally, looking for weakness or paralysis of facial expression muscles 2, 1
• CN V (Trigeminal nerve): Evaluate facial sensation across all three divisions and assess for mastication muscle weakness 2, 1
• CN XI (Accessory nerve): Test shoulder elevation and assess sternocleidomastoid and trapezius muscle strength 2, 1
• CN XII (Hypoglossal nerve): Assess tongue mobility and evaluate for weakness or paralysis 1
• CN IX and X: Evaluate palate elevation, gag reflex, and vocal fold movement 2, 1

Mucosal and Structural Examination

A comprehensive mucosal examination is critical because imaging is not a substitute for direct visualization:

• Oral cavity and oropharynx: Perform visual and digital examination to exclude mucosal neoplasms 2, 1
• Nasopharynx and hypopharynx: Use mirror or endoscope to visualize eustachian tube orifices and superior/posterior walls 1
• Nasal cavity: Examine septum, floor, and turbinates 1
• Otoscopy: Check for unilateral serous otitis media, which may suggest nasopharyngeal malignancy 1

Neck Palpation

Systematic palpation must assess:

• Lymph node chains: Palpate all cervical lymph node chains for adenopathy 1
• Neck masses: Assess firmness, size, fixation to underlying structures, and precise anatomical location 1
• Salivary glands: Palpate parotid and submandibular glands for masses 1
• Thyroid gland: Assess for masses or nodules 1
• Bimanual palpation: Detect deep masses in floor of mouth and entire neck 1

Imaging Considerations if Initial MRI Was Inadequate

Verify Contrast Administration

If the initial MRI was performed without contrast, repeat imaging with contrast is essential:

• MRI orbit, face, and neck WITH contrast (rating 9) performed in conjunction with MRI head WITH contrast (rating 8) provides the best opportunity to identify and characterize lesions along cranial nerve pathways 2
• Pre- and post-contrast imaging is strongly preferred, as omitting contrast may necessitate callback for additional imaging 2, 3

Verify Thin-Cut High-Resolution Sequences

Standard MRI protocols may miss subtle cranial nerve pathology without specialized sequences:

• Thin-cut heavily T2-weighted sequences and contrast-enhanced MRA focused on the posterior skull base are essential for visualizing cranial nerves within the jugular foramen 2
• These sequences visualize CN IX in 90-100% of patients and can detect neurovascular compression 2

Progressive Conditions Requiring Clinical Correlation

Hemifacial Microsomia

If facial asymmetry is progressive and involves mandibular hypoplasia:

• Facial asymmetry in hemifacial microsomia is progressive, with angular measurements increasing significantly from deciduous to permanent dentition 4
• Early surgical correction of mandibular asymmetry is important to improve growth potential and reduce secondary deformity 4

Parry-Romberg Syndrome (Progressive Hemifacial Atrophy)

If progressive soft tissue atrophy is present:

• This self-limited condition causes progressive subcutaneous tissue volume loss on one side of the face 5
• Surgical intervention should be delayed until disease quiescence (minimum 1-year quiescent interval) 6

Congenital Muscular Torticollis

If neck muscle contracture is present:

• Facial asymmetry is progressive if the contracted sternocleidomastoid muscle is not released, particularly before age 3 years 7
• Early correction should be considered to prevent progression of facial asymmetry 7

Critical Pitfalls to Avoid

• Multiple cranial nerve involvement is common due to close anatomic proximity at the skull base and brainstem; mass lesions frequently affect multiple cranial nerves simultaneously 1
• Normal contrast enhancement of the facial nerve can occur within the facial canal (labyrinthine, geniculate ganglion, tympanic, and mastoid segments), but pathological enhancement occurs outside the facial canal, extends to CN VIII, or shows intense enhancement in labyrinthine/mastoid segments 8
• Imaging without adequate contrast or thin-cut sequences may miss subtle pathology requiring repeat imaging with proper technique 2, 3