NEURO- Clinical Examination

• Visual Acuity • Colour Vision • Visual Fields • Normal Eye and

Cupped disc The swollen optic disc

• Papilloedema • Papillitis • Malignant hypertension • Ischaemic • Diabetic optic neuropathy • CRVO • Intraocular 25 y.o. female Reduced VA Pain with eye movement Colour desaturation RAPD 65 y.o. male Reduced VA Painless loss of vision Essential hypertension Smoker The pale optic disc

• Congenital • Secondary to • raised ICP • vascular retinal disease • • compression • trauma • Papilloedema

Blurred optic • Disc swelling secondary to raised disc margin ICP Haemorrhages • Headache – Worse in the morning – Valsalva manouver Small optic • Nausea and projectile vomiting CWS cup • Horizontal (VI palsy) • Causes – Space occupying lesion Disc pallor – Intracranial hypertension • Idiopathic • Drugs • Endocrine – Severe hypertension Vessel attenuation Pupils

• First Order – to Pretectal Nucleus in B/S (at level of Superior colliculus) • Second Order – Pretectal nucleus to E/W nucleus (bilateral innervation!) • Third Order – E/W nucleus to • Fourth Order – Ciliary Ganglion to Sphincter pupillae (via short ciliary nerves)

• Constricted (mioisis) • Dilated () – Sympathetic – Parasympathetic (pupillodilator) (pupilloconstrictor) denervation denervation – Drugs – Lesion of the third CN • – Drugs • Morphine • Atropine • Cocaine

Horner’s

• Oculosympathetic paresis

– – – Ipsilateral anhidrosis – Does not dilate with cocaine 4% Sympathetic Pathway

• First Order – Posterior Hypothalamus to Ciliospinal centre of Budge (C8-T2) (Uncrossed in Brainstem) • Second Order – Ciliospinal centre of Budge to Superior Cervical Ganaglion • Third Order – Superior Cervical Ganglion to dilator pupillae muscle. (Close to

ICA and joins V1 intracranially) Internal Carotid Dissection

Herpes Zoster

CVA Otitis Media Tumour Tolosa-Hunt Sy.

Pancoast bronchogenic carcinoma Causes of Horner’s pupil • Central – B/S lesions (tumours, vascular and MS) Syringomyelia, Lat. Med. Syn., S.C. ca. • Preganglionic – Pancoast tumour, Carotid & Aortic aneurysms, Neck lesions/trauma. • Postganglionic – Cluster headaches, Nasopharyngeal tumours, Otitis media, Cavernous sinus mass and ICA disease. • Miscellaneous – Congenital (brachial plexus injury) Idiopathic. Afferent & efferent defects

• Argyll-Robertson • Miotonic pupil (Adie’s pupil syndrome) – Small, irreg – Dilated – Does not react to light – Poor response to light and convergence. – Reacts to • Constricts with weak Pilocarpine – Causes • Holmes-Adie syndrome • syphilis – Reduced tendon reflexes • diabetes (Knee, ankle) - Orthostatic hypotension Ocular motility abnormalities

• Third nerve palsy • – Double vision – Double vision – Eye turned down & out – Eye turned in – Ptosis – Dilated pupil & headache • Compressive lesion Cranial Nerve Palsies Looking straight ahead Posterior communicating artery aneurysm

Chiasma

Posterior cerebral artery III CN Internuclear Ophthalmoplegia

• Defective adduction of the ipsilateral eye • of the contralateral (abducting) eye • NORMAL CONVERGENCE • Causes – Young patients • Bilateral • Demyelination – Older patients • Unilateral • Vascular, tumours Myasthenia Gravis

• Fatigability • Double vision • Lid twitch • Ptosis • Normal reflexes & sensation INVESTIGATIONS MG

• Anti ACh receptor Ab’s ACh • Electromyography • Tensilon test – Edrophonium blocks acetyl-cholinesterase – Beware of cholinergic cardiac effects. Use with Atropine 0.6mg Anti AChR Ab’s AChR • Thoracic CT and MRI to rule out thymoma

Localising the lesion

• Monocular visual field defects indicate lesions anterior to the optic chiasm • Bitemporal defects are the hallmark of chiasmal lesions • Binocular homonymous hemianopia result from lesions in the contralateral postchiasmal region • Binocular quadrantanopias reflect optic tract lesions