The College of Optometrists

for bv exam wot r supra nuclear disorders?! have never came across them at uni, not included n ny of my previous notes!!

are these essential reading for pqe??

this is important and yep you need to know. Basically, supra nuclear disorders are problems caused from areas of the brain rather than the oculomotor nerves and their nuclei and neurones.

If one of the oculomotor nerves go up the creak - then the muscle it serves packs up and the px gets a squint with the affected eye turning away from the bad muscle. This is true all the up to the oculomotor nuclei which are in the brain stem. These nuclei oraganise which nerves fire for which eye movement. There are two horizontal motor centres that are linked and one vertical nucleus. These nuclei get their instructions from the brain its self. So, for example you want to look right, then the brain instructs the horizontal nuclie to turn the eyes correctly to view a right gaze. This orig instruction from the brain is supra nuclear. Probs here are often from stroke, parkinsons and other neuro degenerations, it can also be from hydro celphalus.

THey cause wierd, and rare, problems - like the typical vertical upgaze weakness sometimes sen in parkinsons; like the weakness to move the eyes in certain positions (usually horizontally) called gaze palsies. These are mainly inability to move the eyes to fixate in one gaze - but the others may be okay. The saccades may be exagerated like in nystagmus, or inability to fixate steadily etc.. These problems come from weaknesses of the nerve pathways too the nuclear areas. Px overcome them by head pointing.

So if both eyes are straight but can gaze or hold a spot - think supra nuclear, if you get a ino think intra nuclear, if you get an incom squint think nuclear or the oculomotor nerve.

good luck - palf

last para - slip of th key board-

So if both eyes are straight but can NOT gaze or hold a spot - think supra nuclear, if you get a ino think intra nuclear, if you get an incom squint think nuclear or the oculomotor nerve.

-thats better!!

As Palfi says, supranuclear disorders are caused by lesions in motor pathways occurring before the cranial nerve nuclei. These are often caused by very serious pathology, such as MS and brain tumours. As such, if not detected and managed appropriately, you may place your patients' health and even their lives in jeopardy.

From the first day after you qualify, and for the rest of your working life, you must be able to competently deal with a patient harbouring such a disorder, presenting at any time. Ignorance of these conditions is not acceptable.

The PQE's require you to be safe to practice - so in answer to your question, yes.

n.b. University notes are a starting point, not a limitation.

just to add to Michael -

these things are rare - often sudden onset,

and often (and surprisingly cause less worry in th epx than you'd imagine).

But you have to be determined to manage properly, and usually this means direct referal to casualty if its new + sudden.

I ssent one last yr direct to radiology (from the opticians) - he had a sudden problem in looking to the right, (ie: right looking gaze palsy) , he had no trouble looking anywhere else. He also had a right incongruent superior quadrantanopia (these 'gaze'people often also have a field defect). No pupil defect. Vision 6/6 bilat. Sadly, he died 6 months later from inoperable brain tumour. See what I mean?

A slow one i can think of, was a teenager who mystified his doctor and me also. He had 6/6- bilat that varied sometimes, he also developed a fast central nystagmus now and again. While most neuro tests were normal - it was found that his intra craniel pressures could go high and in the end he was fitted with a by-pass which relieved his sub-acute hydrocephalus and his visual problems. So never be shy to refer, you can always refer for a second opinion at eye clinic.

If supranuclear control is lacking a total gaze palsy (i.e. inability to move both eyes together in a certain direction), limitation of gaze excursion, deviation with coarse nystagmus or internuclear ophthalmoplegia can result.

Frontal lobe lesions prevent conjugate movements to the opposite side on demand but normal movements on pursuit. Irritative lesions cause the eyes to deviate to the opposite side acutely. Destructive lesions result in ocular deviation to the same side but inability to turn to the opposite side.

Occipital lesions cause impairment of the pursuit movement to the same side and a homonymous field defect to the opposite side.

Brain stem pathology is associated with multiple cranial nerve palsies and contralateral hemiplaegia.

Oculogyric crises are spasms of upward gaze typical of post-encephalitic states, Parkinson’s disease and Phenothiazine toxicity.

Downward deviations occur in patients with hydrocephalus (setting sun), coma, thalamic pathology and transiently in newborns.

Vertical gaze paresis is classical for dorsal midbrain lesions, such as pinealomas (Parinaud’s), gliomas, AV malformations, MS and 3rd ventricle tumours.