Nuclear Third Nerve Palsy

Anatomical Basis

• The third nerve (oculomotor) nucleus lies near the midline of the midbrain and has a complex organization consisting of four paired subnuclei and one unpaired subnucleus 1, 3
• The unpaired central caudal nucleus innervates both ipsilateral and contralateral levator palpebrae superioris muscles 1, 4

Associated Neurological Signs

• Lesions involving the superior cerebellar peduncle may cause ipsilateral cerebellar ataxia 1, 5
• Lesions involving the red nucleus may cause ipsilateral flapping hand tremor and ataxia 1, 3
• Lesions involving the cerebral peduncle may cause ipsilateral hemiplegia or hemiparesis 1, 4

Diagnostic Approach

• A detailed medical and ocular history should focus on onset, progression, and associated neurological symptoms 1, 4
• Comprehensive eye examination with particular attention to sensorimotor examination 1, 6
• Pupillary responses should be examined 1, 6
• Neuroimaging (MRI with gadolinium) is essential to confirm the diagnosis and identify the midbrain lesion 6

Management

• Reconstruction of ocular alignment is a key treatment outcome 1, 5
• Improvement of binocular vision is a key treatment outcome 1, 5
• Reduction of diplopia is a key treatment outcome 1, 5
• Reduction of compensatory head positioning is a key treatment outcome 1, 5