What is a good head and neck exam for a patient status post (after) resection of a cerebellopontine angle tumor?

Head and Neck Examination for Post-Cerebellopontine Angle Tumor Resection

A comprehensive cranial nerve examination is mandatory for patients status post cerebellopontine angle (CPA) tumor resection, with particular focus on cranial nerves V, VII, VIII, IX, X, XI, and XII, as these nerves are at highest risk for injury during CPA surgery. 1, 2

Essential Cranial Nerve Assessment

Facial Nerve (CN VII) Evaluation

• Assess forehead wrinkling, eyebrow elevation, and eye closure to distinguish complete peripheral facial nerve injury from partial dysfunction 2
• Grade facial function using the House-Brackmann scale (Grade I = normal function; Grade VI = complete paralysis), as this is the standard outcome measure following CPA surgery 3
• Examine for synkinesis or mass movement indicating aberrant nerve regeneration 2
• Check for hyperacusis by asking about sensitivity to loud sounds, which localizes injury to the facial nerve proximal to the stapedius branch 2
• Assess lacrimation using Schirmer test if available, as decreased tearing indicates injury proximal to the greater petrosal nerve 2

Vestibulocochlear Nerve (CN VIII) Evaluation

• Perform Weber and Rinne tests to assess for sensorineural versus conductive hearing loss 1
• Document subjective hearing changes including tinnitus, as hearing preservation rates vary from 5-50% depending on tumor size and surgical approach 4
• Assess for vertigo and balance disturbances through gait examination and Romberg testing 1
• Formal audiometry should be obtained postoperatively to quantify hearing thresholds and speech discrimination scores 3

Trigeminal Nerve (CN V) Examination

• Test facial sensation in all three divisions (V1-ophthalmic, V2-maxillary, V3-mandibular) using light touch and pinprick 5, 2
• Assess corneal reflex bilaterally, as this may be diminished with CN V or VII dysfunction 5
• Palpate masseter and temporalis muscles during jaw clenching to assess motor function of V3 5
• Check jaw deviation with mouth opening, as weakness causes deviation toward the affected side 5

Lower Cranial Nerves (CN IX, X, XI, XII)

• Examine palate elevation by having the patient say "ah" and observing for uvular deviation away from the weak side 5, 2
• Assess gag reflex bilaterally to evaluate glossopharyngeal and vagus nerve function 5
• Evaluate vocal cord mobility through flexible laryngoscopy if hoarseness is present, as vocal fold paralysis indicates vagal injury 5
• Test shoulder elevation and head turning against resistance to assess spinal accessory nerve (CN XI) function 5
• Examine tongue protrusion for deviation toward the side of hypoglossal nerve injury 2
• Combined CN VII and CN XII palsy with ipsilateral tongue deviation indicates skull base pathology and requires urgent MRI of head, orbit, face, and neck with contrast 2

Surgical Site and Wound Assessment

Incision and Soft Tissue Examination

• Inspect the retromastoid or translabyrinthine incision for signs of infection, dehiscence, or CSF leak 6, 7
• Palpate for fluid collections or pseudomeningocele formation along the surgical site 7
• Assess for temporal muscle atrophy which may occur after retrosigmoid approaches 7

Signs of Complications

• Check for clear rhinorrhea or otorrhea indicating CSF leak, which requires urgent neurosurgical consultation 1
• Examine for signs of meningitis including neck stiffness, photophobia, and altered mental status 1
• Assess for cerebellar signs including ataxia, dysmetria, and nystagmus, which may indicate cerebellar injury or edema 1, 6

Ophthalmologic Assessment

Eye Protection and Function

• Evaluate eye closure completeness as lagophthalmos from facial nerve injury risks corneal exposure keratopathy 2
• Examine for corneal abrasions using fluorescein staining if available 2
• Assess extraocular movements in all directions to evaluate CN III, IV, and VI function 5
• Check for diplopia which may indicate abducens nerve (CN VI) injury from brainstem compression or surgical manipulation 5, 2
• Examine pupils for size, symmetry, and reactivity 5

Oropharyngeal and Laryngeal Examination

Direct Visualization

• Perform flexible nasopharyngoscopy to visualize the nasopharynx, oropharynx, hypopharynx, and larynx if adequate PPE is available 5
• Examine vocal fold mobility bilaterally as vagal injury can cause unilateral vocal fold paralysis 5
• Assess for pooling of secretions in the pyriform sinuses indicating dysphagia 5
• Evaluate soft palate symmetry and movement during phonation 5

Neck Examination

Lymph Node and Mass Assessment

• Palpate all cervical lymph node levels (I-VI) bilaterally to assess for firmness, size, fixation, and tenderness 5
• Perform bimanual palpation of the floor of mouth and entire neck 5
• Examine parotid and submandibular glands for masses or asymmetry 5
• Palpate thyroid gland for nodules or enlargement 5

Critical Pitfalls to Avoid

• Missing subtle facial nerve dysfunction by not examining forehead movement separately from lower face, as this distinguishes peripheral from central lesions 2
• Failing to document baseline cranial nerve function immediately postoperatively, as delayed deficits may indicate hematoma or edema requiring urgent imaging 1
• Overlooking multiple cranial nerve involvement which suggests pontine or brainstem pathology requiring immediate MRI with contrast 2
• Delaying ophthalmology referral for patients with incomplete eye closure, as corneal protection must be initiated immediately 2
• Not performing laryngoscopy in patients with hoarseness or dysphagia, as vocal fold paralysis requires specific management 5

Postoperative Imaging Correlation

• MRI within 72 hours postoperatively is recommended to assess for residual tumor and surgical complications 1
• Serial MRI surveillance is essential for all CPA tumors to monitor for recurrence 1
• Audiological testing should be performed postoperatively and at regular intervals to document hearing outcomes 1, 3