Bobble-Head Doll Syndrome with Bilateral Proptosis and Strabismus
The most likely diagnosis is a third ventricular cyst or suprasellar mass causing bobble-head doll syndrome, with concurrent thyroid eye disease (TED) producing the bilateral proptosis and restrictive strabismus. 1, 2
Most Likely Diagnosis
Bobble-head doll syndrome (BHDS) is a rare pediatric movement disorder characterized by involuntary 2–3 Hz head movements (bobbing or lateral "no-no" rotations) caused by third ventricular cysts, suprasellar cysts, aqueductal obstruction, or tectal tumors. 1, 3, 4 The syndrome typically presents in the first decade of life with macrocephaly, ataxia, developmental delay, optic disc pallor or atrophy, hyperreflexia, tremor, visual disturbance, headache, and vomiting. 1, 5
The bilateral proptosis and strabismus strongly suggest thyroid eye disease as a concurrent or causative diagnosis, since proptosis with restrictive strabismus is the hallmark presentation of TED, reflecting extraocular muscle enlargement and fibrosis. 2, 6 The inferior rectus muscle is most frequently involved, producing upward gaze limitation and vertical strabismus. 2
Compensatory head posture (tilt or turn) develops in TED to preserve binocular single vision and avoid diplopia by positioning the eyes where muscle restriction is minimal. 2 This head posture may be misinterpreted as or coexist with the bobbing movements of BHDS.
Initial Work-Up
Neuroimaging (Priority #1)
Obtain contrast-enhanced MRI of the brain and orbits immediately to evaluate for third ventricular cysts, suprasellar masses, aqueductal obstruction, hydrocephalus, and to document extraocular muscle enlargement with tendon-sparing pattern characteristic of TED. 6, 1, 3, 4 MRI provides superior soft-tissue characterization for cystic lesions, masses, inflammatory conditions, and optic nerve pathology. 7
CT orbits with contrast is complementary when assessing bony anatomy, orbital apex crowding, or when MRI is contraindicated. 7 CT demonstrates tendon-sparing enlargement of the extraocular muscles—most commonly the inferior and medial recti—and documents proptosis, thereby confirming thyroid eye disease. 6
Ophthalmology Consultation (Priority #2)
Immediate ophthalmology consultation is mandatory to assess for compressive optic neuropathy through visual acuity, color vision testing, visual fields, pupillary examination (looking for relative afferent pupillary defect), and fundoscopy to evaluate for papilledema or optic atrophy. 6, 7, 8 Optical coherence tomography and automated threshold visual fields provide ancillary screening for optic nerve compression. 6
Perform exophthalmometry to measure globe protrusion, quantifying asymmetry and establishing a baseline for monitoring disease progression. 6, 8
Forced-duction testing is essential to differentiate restrictive from paralytic strabismus; thyroid eye disease shows marked restriction on passive movement. 2, 6 This helps distinguish inflammatory restriction from fibrotic muscle contracture. 6
Examine for corneal exposure keratopathy using fluorescein staining, particularly if the patient has altered mental status or sedation. 7 Measure intraocular pressure in all patients with proptosis, as orbital congestion can cause secondary glaucoma. 7
Laboratory Evaluation
Order thyroid function tests (TSH, free T4) together with thyroid-associated antibodies (TSI, anti-TPO) to confirm or exclude TED. 6 Patients with TED may have hyperthyroid, hypothyroid, or euthyroid status; normal thyroid function tests do not exclude the diagnosis. 6
Screen for myasthenia gravis, as its incidence is increased in TED patients, and both conditions can cause diplopia and ptosis. 6, 8
Immediate Management
Neurological Stabilization
Urgent neurosurgical consultation is required for BHDS, as treatment is surgical. 1, 3, 4 Endoscopic third ventriculostomy or ventriculoperitoneal shunt placement is the definitive treatment, with immediate resolution of head bobbing in most cases. 1, 3, 4, 5 The reduction of CSF pressure is the best therapeutic option in bobble-head doll syndrome. 3
Ocular Surface Protection
Aggressive ocular surface lubrication with preservative-free artificial tears during the day and ointment at night is essential to prevent exposure keratopathy in patients with proptosis and lid retraction. 6, 7 Punctal plugs can be useful. 8
Broad-spectrum topical antibiotics (quinolone preparations such as moxifloxacin or levofloxacin four times daily) are recommended when corneal fluorescein staining or frank ulceration is present. 7
Thyroid Eye Disease Management
Achieving a euthyroid state in collaboration with endocrinology is the first step in managing active TED. 2 Smoking cessation is non-negotiable, as smoking significantly worsens orbitopathy progression and reduces treatment response. 6
For severe proptosis or compressive optic neuropathy in thyroid eye disease, orbital decompression, high-dose pulse IV methylprednisolone, or orbital radiation should be considered urgently. 7, 2
Teprotumumab reduces proptosis and clinical activity score in active TED, improves diplopia, and reduces the need for strabismus surgery. 7, 8 However, it is relatively contraindicated in patients with inflammatory bowel disease and absolutely contraindicated in pregnancy. 8
Surgical Sequencing (If Both Conditions Confirmed)
Neurosurgical intervention for BHDS must be performed first to relieve hydrocephalus and remove the causative lesion. 1, 3, 4
If orbital decompression is required for TED, it must be performed before any strabismus surgery, as decompression markedly alters ocular alignment, rendering prior strabismus surgery ineffective. 2
Strabismus surgery is performed second, after 4–6 months of disease stability and once the inflammatory phase has subsided. 2 Recession of the restricted muscles is the primary technique; muscle resection is generally avoided in restrictive disease. 2
Eyelid surgery is deferred until after strabismus repair. 2
Key Pitfalls to Avoid
Never attribute head movements solely to stereotypies or behavioral causes without neuroimaging, as this delays diagnosis of life-threatening hydrocephalus. 5 The movements in BHDS were initially thought to be stereotypies in one case, delaying appropriate treatment. 5
Failing to protect the cornea in patients with proptosis leads to irreversible corneal scarring and vision loss. 7
Delaying ophthalmology consultation can result in permanent blindness due to compressive optic neuropathy. 7
Never perform strabismus surgery before orbital decompression in patients with significant proptosis; doing so leads to unpredictable alignment changes and wasted procedures. 2
Do not operate on strabismus during the active inflammatory phase of TED; wait for clinical quiescence and stable measurements for at least 4–6 months. 2