What is the diagnosis and treatment for a patient presenting with tinnitus, visual disturbances, a sensation of rocking on a boat, tightness on the right side of the body, retracted right eyelid, right shoulder elevation, scapular winging, and left eye inflammation?

Differential Diagnosis and Management Approach

Most Likely Diagnosis: Myasthenia Gravis

Based on the constellation of symptoms—particularly the combination of retracted right eyelid, visual disturbances, variable tinnitus, and asymmetric body tightness with scapular winging—myasthenia gravis is the primary diagnosis to rule out, as this autoimmune disorder characteristically presents with variable, fatigable weakness affecting ocular, bulbar, and limb muscles. 1

Key Diagnostic Features Supporting Myasthenia Gravis

• Retracted right eyelid is a classic finding in myasthenia gravis, often occurring alongside or instead of ptosis, particularly when associated with thyroid eye disease (TED), which has increased comorbidity with myasthenia 1
• Variable visual disturbances with fatigable strabismus and diplopia occur in 50% of myasthenia patients as the initial presenting symptom 1
• Asymmetric body tightness and elevated right shoulder suggest unilateral muscle weakness or compensatory posturing, consistent with the variable incomitant weakness pattern seen in myasthenia 1
• Scapular winging indicates weakness of the serratus anterior or trapezius muscles, which can occur when myasthenia progresses beyond purely ocular involvement 1

Critical Immediate Actions

Perform an ice pack test immediately: apply ice over the closed eyes for 2 minutes for eyelid abnormalities and 5 minutes for eye movement abnormalities—a reduction of 2mm in lid position or improvement in alignment is 95% specific for myasthenia gravis. 1

Additional bedside testing should include:

• Rest test without ice pack to assess for improvement after periods of rest 1
• Cogan lid-twitch sign assessment during prolonged upgaze 1
• Detailed sensorimotor examination documenting how strabismus and diplopia change with fatigue or repetition of examination 1
• Slow saccade evaluation, which is characteristic of myasthenia 1

Laboratory Confirmation

Order the following serologic tests immediately:

• Antiacetylcholine receptor antibody (AChR-Ab) testing—positive in 80% of generalized myasthenia and 50% of ocular myasthenia 1
• Muscle-specific kinase (anti-MuSKAb) testing—positive in one-third of seronegative patients 1
• Lipoprotein-related protein 4 (LRP4) antibodies—associated with both generalized and ocular myasthenia 1
• Thyroid function tests and thyroid antibodies—given increased risk of myasthenia with autoimmune thyroid disease 1

Imaging Requirements

Obtain chest CT immediately to evaluate for thymoma, which is present in a significant proportion of myasthenia patients and requires surgical removal. 1

Order MRI brain and orbits with contrast to evaluate for alternative diagnoses and assess optic nerve involvement, particularly given the visual disturbances and to rule out neurosarcoidosis or other inflammatory conditions. 2

Alternative Diagnoses to Consider

Thyroid Eye Disease (TED)

The retracted right eyelid is a hallmark finding of TED, which has 8:1 female predominance and peaks in the fourth to fifth decade 1

Key distinguishing features:

• Eyelid retraction occurs in TED and can coexist with myasthenia gravis 1
• Restrictive myopathy affecting primarily the inferior rectus, then medial rectus, causing diplopia and compensatory head posture 1
• Exophthalmos should be measured with exophthalmometry 1
• Elevated intraocular pressure may be present 1

If TED is confirmed, refer immediately to an orbital specialist if there is vision-threatening disease, moderate-to-severe exophthalmos, or significant orbital pain. 1

Neurosarcoidosis

Given the combination of tinnitus, visual disturbances, and potential cranial neuropathies, neurosarcoidosis must be considered 2

Diagnostic approach:

• MRI brain and orbits looking for optic nerve sheath enhancement and pachymeningeal enhancement 2
• Chest imaging to identify pulmonary lymphadenopathy 2
• Audiologic evaluation to document hearing loss pattern 2

Skew Deviation vs. Superior Oblique Palsy

The "rocking on boat sensation" suggests vestibular dysfunction, and skew deviation can present with vertical diplopia and visual disturbances 1

Perform the upright-supine test: measure vertical misalignment in upright and supine positions—a reduction of >50% in the supine position suggests skew deviation (sensitivity 80%, specificity 100% in chronic cases). 1

Critical distinction:

• Skew deviation requires urgent brain and brainstem MRI to rule out stroke, demyelination, or mass lesion 1
• Associated ocular torsion pattern: in skew, the hypertropic eye shows fundus incyclotorsion and hypotropic eye shows excyclotorsion 1

Ménière's Disease

The "rocking on boat sensation" with right-sided tinnitus could represent vestibular dysfunction 1

However, Ménière's disease typically presents with:

• Episodic vertigo lasting 20 minutes to 12 hours (not continuous rocking sensation) 1
• Fluctuating hearing loss, tinnitus, and aural fullness occurring together 1
• True rotational vertigo, not vague dizziness 1

This diagnosis is less likely given the absence of classic episodic vertigo and the presence of multiple non-vestibular findings (eyelid retraction, scapular winging). 1

Tinnitus Evaluation

The unilateral right-sided tinnitus requires comprehensive audiologic examination and imaging evaluation, as unilateral tinnitus has higher risk of underlying pathology. 3, 4, 5

Immediate Tinnitus Workup

• Determine if pulsatile or non-pulsatile—pulsatile tinnitus suggests vascular etiology requiring urgent vascular imaging 3, 4, 5
• Comprehensive audiologic examination including pure tone audiometry, speech audiometry, and acoustic reflex testing 3
• Otoscopic examination to check for retrotympanic masses or vascular abnormalities 3

Imaging for Unilateral Tinnitus

If tinnitus is non-pulsatile: order MRI internal auditory canals with contrast to rule out vestibular schwannoma or other retrocochlear pathology. 3, 5

If tinnitus is pulsatile: order CT angiography (CTA) of head and neck with contrast as first-line study to evaluate for vascular abnormalities including sigmoid sinus diverticulum, jugular bulb dehiscence, or arteriovenous malformations. 4, 5

Treatment Algorithm

If Myasthenia Gravis is Confirmed:

1. Refer immediately to neurology for initiation of anticholinesterase therapy (pyridostigmine) and consideration of immunosuppressive treatment 1
2. Coordinate with neurology and thoracic surgery regarding thymectomy, which is indicated for thymoma and may substantially reduce symptoms in specific age-based and immune-based patient populations 1
3. Monitor for progression to generalized myasthenia—50-80% of patients with ocular myasthenia develop generalized disease within a few years, which can lead to life-threatening respiratory failure 1
4. Avoid medications that worsen myasthenia including aminoglycosides, fluoroquinolones, beta-blockers, and neuromuscular blocking agents 1

If TED is Confirmed:

1. Refer to orbital specialist for management of vision-threatening complications 1
2. Smoking cessation counseling is critical, as smoking significantly worsens TED severity 1
3. Coordinate with endocrinology for thyroid function optimization 1
4. Consider surgical intervention for restrictive myopathy once the disease is stable for 6 months 1

If Neurosarcoidosis is Confirmed:

Initiate high-dose corticosteroids (methylprednisolone 1000 mg IV daily for 5 days) followed by maintenance immunosuppression with mycophenolate mofetil or infliximab. 2

Critical Pitfalls to Avoid

• Do not dismiss variable symptoms as functional—the hallmark of myasthenia is fluctuation with fatigue, and symptoms that change throughout the day strongly support this diagnosis 1
• Do not delay thymoma evaluation—chest imaging must be obtained urgently as thymectomy is indicated for thymoma and can prevent progression 1
• Do not miss life-threatening causes of pulsatile tinnitus—if tinnitus is pulsatile, arterial dissection and dural arteriovenous fistula must be ruled out urgently as they can cause catastrophic hemorrhage or stroke 4, 5
• Do not attribute all findings to a single diagnosis—myasthenia gravis and thyroid eye disease frequently coexist, and both require specific treatment 1
• Do not perform Tensilon testing without appropriate monitoring—this test can cause bradycardia, bronchospasm, and syncope, and requires atropine availability 1