[1] The inability of an eye to turn outward, results in a convergent strabismus or esotropia of which the primary symptom is diplopia (commonly known as double vision) in which the two images appear side-by-side.

Vallee et al.[6] report that benign and rapidly recovering isolated VIth nerve palsy can occur in childhood, sometimes precipitated by ear, nose and throat infections.

Collier, however, was "unable to accept this explanation", his view being that since the sixth nerve emerges straight forward from the brain stem, whereas other cranial nerves emerge obliquely or transversely, it is more liable to the mechanical effects of backward brain stem displacement by intracranial space occupying lesions.

[8] Foville's syndrome can also arise as a result of brainstem lesions which affect Vth, VIth and VIIth cranial nerves.

This condition results in a VIth nerve palsy with an associated reduction in hearing ipsilaterally, plus facial pain and paralysis, and photophobia.

The nerve runs in the sinus body adjacent to the internal carotid artery and oculo-sympathetic fibres responsible for pupil control, thus, lesions here might be associated with pupillary dysfunctions such as Horner's syndrome.

In children, differential diagnosis is more difficult because of the problems inherent in getting infants to cooperate with a full eye movement investigation.

Mobius syndrome - a rare congenital disorder in which both VIth and VIIth nerves are bilaterally affected giving rise to a typically 'expressionless' face.

Duane syndrome - A condition in which both abduction and adduction are affected arising as a result of partial innervation of the lateral rectus by branches from the IIIrd oculomotor cranial nerve.

Cross fixation which develops in the presence of infantile esotropia or nystagmus blockage syndrome and results in habitual weakness of lateral recti.

The resultant palsy is identified through loss of lateral gaze after application of the orthosis and is the most common cranial nerve injury associated with this device.

[citation needed] A Cochrane Review on interventions for eye movement disorders due to acquired brain injury,[10] last updated June 2017, identified one study of botulinum toxin for acute sixth nerve palsy.

If adequate recovery has not occurred after the 6-month period (during which observation, prism management, occlusion, or botulinum toxin may be considered), surgical treatment is often recommended.

[citation needed] If the residual esotropia is small, or if the patient is unfit or unwilling to have surgery, prisms can be incorporated into their glasses to provide more permanent symptom relief.

[12][13][14] An alternative approach is to operate on both the lateral and medial recti of the affected eye, with the aim of stabilising it at the midline, thus giving single vision straight ahead but potentially diplopia on both far left and right gaze.

However, where the inhibitional palsy of the contralateral lateral rectus has not developed, there will still be gross incomitance, with the disparity between the eye positions being markedly greater in the field of action of the affected muscle.