Week 4 - Multiple nerve palsies Flashcards
What are multiple cranial nerve palsies? (MCNP)
• Can occur due to variety of causes, such as syndromes or systemic diseases; extra/intra cranial pathologies
• Most common syndromes of eye associated MCNP; Cavernous sinus syndrome, superior orbital fissure syndrome, Tolosa-hunt syndrome, and orbital apex syndrome
What are the most common causes of Multiple cranial nerve palsy?
• Tumours make up 30% of aetiology
• By frequency order; infarctions, trauma, infection, Guillain- Barré syndrome, Miller. Fisher syndrome, idiopathic cavernous sinusitis, surgery, MS, demyelinating encephalomyelitis, and diabetes mellitus
what is the cavernous sinus?
The cavernous sinus (CS) is a venous plexus located between the periosteal and durallayers of the meninx and at the central Bos, on both sides of the pituitary gland.
What are some cavernous sinus syndrome signs?
• Ophthalmoplegia
• Ptosis
• Facial sensory loss
• Proptosis
• Horners syndrome due to Multiple nerve palsy of CN 3, 4 and 6
• CSS does NOT involve optic nerve
What is the aetiology of cavernous sinus syndrome?
• Neoplastic causes (head and neck tumours, primary tumours such as lymphoma)
• Trauma
• Vascular (aneurysms, thrombosis)
• Congenital
• infectious
• Inflammatory or granulomatous pathologies, including Tulsa hunt syndrome
What is the superior orbital fissure?
• Superior orbital fissure lies back of orbit between lesser and greater wing of sphenoid bone
• Contains SOV and IOV, superior and inferior branches of CN 3, 4 and 6,
• V1 and its branches including lacrimal, frontal, supraorbital, supratrochlear and nasociliary nerves
What is superior orbital fissure syndrome?
• SOFS is a symptom complex caused by compression of structures which exist in SOF just anterior to the orbital apex.
• The main difference of SOFS from OAS is no optic nerve involvement in SOFS
What is superior orbital fissure syndrome’s aetiology?
• Most common cause is trauma, including orbital fractures
• Tumours including lymphoma and sarcomas
• Infectious diseases including syphillis, meningitis, sinusitis, herpes zoster, ischaemia,
• Vasculitic or inflammatory diseases including THS, sarcoidosis, systemic lupus or temporal arteries and vascular events
Which is the most damaged and least damaged nerve in Superior orbital fissure syndrome?
• CNVI is most commonly damaged because of its location within the central SOF and close to the greater wing
• CN IV is the least commonly involved CN because of its protection by the common tendinous ring
What are the clinical features of Superior orbital fissure syndrome? (Affects nerves)
• Ophthalmoplegia due to damage to CN III, IV and VI
• Proptosis due to decreased tension in the EOMs with loss of innervation
• Ptosis due to CN Ill injury and loss of sympathetic input
• Fixed dilated pupil due to loss of parasympathetic innervation of the pupil by the CN 3
What are the clinical features of Superior orbital fissure syndrome? (Affects Eyes)
• Lacrimal hyposecretion, and eyelid or forehead anaesthesia and % decreased corneal sensation due to damage to CN V
• The proptosis, eyelid swelling, and chemosis indicate significant orbital masses
What is Tolosa-Hunt syndrome? (THS)
• Painful ophthalmoplegia in the fifth decade with unknown aetiology located in SOF and anterior CSs.
• cause of pain is granulomatous inflammation due to infiltration of walls of SOF or CS by lymphocytes and macrophages.
• If the pain reduces with steroid treatment within 72 hours it is diagnostic
What is the orbital apex?
• The orbital apex (OA) is the most posterior part of the pyramidalshaped orbit at the craniofacial junction.
• OA includes tendinous ring where rectus EOMs originate; also entry of neuro-vascular structures transmitted from intracranial compartment into orbit through bony apertures (optic canal, SOF and inferior orbital fissure)
What is the orbital apex syndrome and its causes?
• OAS is involvement of CNs II, III, IV and VI
• Vision loss (if (NIl involvement is present), optic neuropathy and ophthalmoplegia.
• Tumours :
• inflammatory: orbital inflammation,, sarcoidosis, systemic lupus, giant cell arteritis, thyroid disease,
• iatrogenic causes (following sinonasal surgery),
• orbital apex fracture, vascular events like carotid aneurysm or trauma
What is Garcin syndrome, pathogenesis and prognosis?
• Ipsilateral step-by-step deterioration of all 12 brain cranial nerves
• Cause is usually a sarcoma or carcinoma of the skull base.
• Pathogenesis: Slow localized growth of these tumors, rather than by their histology and primary localisation.
• Prognosis: Unfavourable. The findings on computed and magnetic resonance tomography are important for an early diagnosis. Two cases of Garcin syndrome are reported, one of which was probably due to a tonsillar carcinoma, while the other was caused by a mucinous adenocarcinoma of the nasopharynx.
