TABLE 1. Comparison of controversies/key diagnostic criteria for microvascular ocular motor nerve palsies (as derived from Pane et al.29) with current evidence.

	Current clinical practice: all of the following (Pane et al., 2006)32	Evidence from literature review	Reference
History
Age	40 or over	93% occur in people over 50 years.	11
		63% acute isolated 6th nerve palsy in patients aged 2–82 years (mean 48 years) had non-microvascular cause compared with 16.5% in patients aged >50 years.	4, 16, 25, 43
Risk factors	One or more vasculopathic risk factors (e.g. hypertension, diabetes, smoking)	Risk factors are hypertension, diabetes, left ventricular hypertrophy, hypercholesterolemia, smoking.	12, 13, 14, 15
		60% of patients with non-microvascular palsies also had vascular risk factors	4, 16
All nerves	Sudden onset of diplopia	75% 3rd nerve palsies progressed over 1–3 days with some progression for up to 15 days.	12
	Diplopia remains stable until spontaneous improvement	54% 6th nerve palsies showed subsequent progression.	19
	No persisting pain	60% microvascular palsies are associated with pain.	12
		77% 3rd nerve palsy and 54% 6th nerve palsy have pain.	17
		Diabetic 3rd nerve palsy, 77% had headache and 49% had periocular pain.	15
	No numbness or pins and needles	–	–
	No other systemic neurological symptoms	–	–
Third nerve only	Sudden onset of unilateral ptosis
Examination
Third nerve	Complete ptosis, no movement on attempted elevation, depression or adduction	25% complete and 75% partial weakness	12
		45% complete paralysis, 48% partial weakness of all muscles, and 7% had weakness of specific extraocular muscles.	18
		Entirely normal pupil (same size as other side, constricts briskly to light)	75% have a normal pupil as opposed to 5–14% of compressive third nerve palsies.	12, 18
		26% diabetic 3rd nerve palsies had minor pupil dilatations (1– 2 mm).	15
		38% diabetic 3rd nerve palsies had minor pupil dilatation (≤1 mm).	21
Fourth nerve	Vertical or oblique deviation in the primary position on cover test Motility testing: hypertropia in the primary position that increases on gaze toward the side of the lower eye and on tilting of the head to the side of the higher eye	Degree of horizontal deviation is useful for making a determination between microvascular anddecompensation of congenital 4th nerve palsy.
Sixth nerve	Esotropia in primary position on observation and cover test Motility testing: unilateral restriction of abduction with slow abduction saccades	At 1 week 6% were complete and 94% were partial.	19
All nerves	Diplopia, motility (and ptosis, 3rd nerve palsy only) begins to resolve within 3 months	90.9% 3rd nerve palsies recovered completely within 12 months; 81.8% resolved within 3 months.	2
		60% 4th nerve palsies recovered completely within 12 months.	2
		86% 6th nerve palsy had complete recovery after 6 years. Recovery is usually complete by 3 months.	13
Investigations
	MRI brain (plus MRA or CTA brain third nerve palsy only) if the palsy has not started to resolve by 3 months after onset or new neurologic symptoms or signs develop at any stage	MRI brain in patients over 50 years with isolated ocular motor palsies identified other causes (neoplasms, infarcts, aneurysms, demyelination, pituitary apoplexy) in 43/268 (16.5%). Tamhankar et al. found (4.7%) with 4th and 6th nerve palsy had other causes.16 once giant cell arteritis was excluded (infarction, lymphoma, and meningioma).	4, 16, 25
Treatment
	Treat risk factors (smoking, cholesterol, blood pressure, improve diabetic control): this could prevent a heart attack or stroke in the future	14% of patients with microvascular sixth nerve palsy died; 7% from cardiac causes in follow-up period (range 2–13 years).	11
	Commence long term low dose aspirin (unless contraindicated) to decrease future vascular risk	Retrospective case-control study of 100 patients with microvascular nerve palsy associated with diabetes and/or hypertension found 34% were using aspirin compared with 30.1% of diabetic/hypertensive patients without a microvascular nerve palsy. Patients with microvascular cranial nerve palsy have a significantly lower rate of strokes and transient ischaemic attacks compared to the control group (6% versus. 23.9%) possibly due to earlier use of aspirin.	23
	Botulinum toxin injections to the ipsilateral medial rectus 3 months post 6th nerve palsy	Four RCTs on the therapeutic use of botulinum toxin in strabismus (due to any cause) have shown varying responses. Complication rates for use of Botox or Dysport ranged from 24% to 55.54%.	44