Parinaud syndrome

= caused by lesions of the upper part of the midbrain

Signs:

– loss of vertical gaze + conjugate down gaze in resting position – the “setting-sun sign”

– nystagmus on attempted convergence

– pseudo-Argyll Robertson pupils – loss of light reflex but intact accommodation reflex

Causes:

– pinealoma

– any lesions causing compression in this area – trauma, neoplasms, hydrocephalus

– ischaemia – thromboembolic / vasculitis

– multiple sclerosis