Cranial nerve and eye muscle palsies

Chapter 83 Cranial nerve and eye muscle palsies

Congenital IIIrd nerve palsy: classification


A. Congenital cranial dysinnervation disorder (CCDD) (see Chapter 82). This is the commonest cause of bilateral congenital IIIrd nerve palsy. Inherited genetic mutations lead to primary maldevelopment of either the IIIrd (CFEOM1) or the IIIrd and IVth cranial nerve nuclei (CFEOM2). Clinical features include bilateral ptosis and symmetrically reduced elevation and adduction. High resolution MRI shows cranial nerve hypoplasia.1

B. Rarely, sporadic bilateral infranuclear congenital IIIrd nerve palsy has been described usually in association with extensive neurodevelopmental anomalies.

Unilateral congenital IIIrd nerve palsy

A. Clinical features suggesting pre- or perinatal peripheral IIIrd nerve damage, viz. variable IIIrd nerve innervated muscle involvement and signs of misdirection regeneration. The palsy may be isolated or associated with additional perinatal neurologic damage (Fig. 83.1).2

B. With features suggesting a primary nuclear maldevelopment, viz. bilateral partial ptosis and contralateral superior rectus palsy. A hypoplastic peripheral IIIrd nerve may be seen on MR imaging and specific genetic mutations known to be associated with CCDD identified.

C. Unilateral congenital IIIrd nerve palsy has also been reported in:

D. Variants:

Acquired IIIrd nerve palsy

Most cases are unilateral and likely to occur in a clinical context that helps establish the etiology.2


Intracranial and intraorbital tumors can present with signs including a IIIrd nerve palsy, usually progressively worsening (Fig. 83.3). External compression, direct involvement of the nerve (e.g. by schwannoma), infiltration, or malignant meningitis may be responsible. Compression can be anywhere along the course of the nerve (e.g. brainstem glioma or parasellar tumor). Raised intracranial pressure may be a contributory or primary cause.

Additional neuro-ophthalmic signs should be sought to help localize the pathology: neuro-imaging is mandatory.1

Rare causes

Jun 4, 2016 | Posted by in OPHTHALMOLOGY | Comments Off on Cranial nerve and eye muscle palsies

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