10. Neurological Conditions/syndromes Flashcards
(28 cards)
Outline Wernicke’s encephalopathy
Thiamine (vit B1) def (decreased intake/absorption)=
- Acute neurological triad of ophthalmoparesis:
1) confusion
2) wide based gait ataxia
3) ophthalmoplegia (nystagmus, conjugate gaze, bilateral lateral rectus palsies)
Additional = decrease consciousness, memory disturbance, peripheral neuropathy, hypotension, hypothermia, ptosis
- due to haemorrhage in the midbrain
Mx = high dose IV/Im thiamine over 1w, then oral until no risk
Comp = Korsakoff syndrome (hypothalamic damage and cerebral atropy due to repeated thiamine def) - short-term mem loss with disorientation to time
Outline the Olfactory Nerve (CN I) and its palsy
Function = olfaction (SS)
Journey = olfactory N –> cribiform foramine –> olfactory bulb –> olfactory tract –> forebrain
Test = smelling salts
PALSY =
- Ae = ethmoid bone fracture, Alzheimer disease
- S+S = anosmia
Outline the Optic Nerve (CN II) and its palsy
Function = vision (SS)
Journey = retina –> optic N –> optic canal –> optic chiasm –> optic tracts –> visual cortex (occipital lobe)
Test = one eye at a time, visual tests, testing pupils
PALSY =
- Ae =
- Ischemic optic neuropathy (microvascular disease)
- Inflam: MS, sarcoidosis, viral infections (measles, mumps)
- Trauma
- Tumors (optic nerve glioma)
- Impaired nutrition: vitamin B def
- Drugs: sildenafil, amiodarone, ethambutol
- S+S = complete transection (ipsilateral blindness + loss of direct pupillary light reflex), increased intracranial pressure (papilledema), compression (optic atrophy)
Outline the Oculomotor Nerve (CN III) and its palsy
Function = most extra-ocular muscles, levator palpebrae superioris (M), sphincter pupillae, ciliary muscle (A)
Journey = midbrain –> oculomotor N –> Cavernous sinus –> superior orbital fissure –> Muscles surrounding the eye
Test = inspection of eyelid and pupils
PALSY
- Ae = ischaemia (HTN, DM), posterior communicating artery aneurysm, RICP tentorial herniation
- S+S = paralytic squint, ptosis, horizontal diplopia dilated pupil or sparing of the pupil
***external compression sees parasympathetic autonomic function lost first as they are on the outside
Outline the Trochlear Nerve (CN IV) and its palsy
Function = superior oblique muscle of the eye (M)
Journey = dorsal aspect of midbrain –> cavernous sinus –> Superior orbital fissure –> superior oblique
Test = eye movements
PALSY =
- Ae = microvascular damage (diabetes, hypertension, arteriosclerosis), cavernous sinus thrombosis, trauma
- S+S = diplopia, inability to depress and adduct simultaneously
Outline the Trigeminal Nerve (CN V) and its palsy
Function = main sensory nerve of the face (GS), nerve of mastication (M)
Journey = pons –> Trigeminal ganglion 1) Ophthalmic (S): superior orbital fissure –> Sensation to cornea/conjunctiva, 2) Maxillary (S): foramen rotundum –> cheek, 3) Mandibular: foramen ovale –> mandible
Test = sensation to face, muscles of mastication, corneal reflex
PALSY =
- Ae = tumour, vascular compression, oral surgery, inflam of N, cavernous sinus thrombosis
- S+S =
- V1: absent corneal reflex (afferent limb), anesthesia of the forehead
- V2: anaesthesia of the midface
- V3: anaesthesia of the chin, lower lip, and anterior two-thirds of the tongue; muscles of mastication are paralyzed
- Tensor tympani branch: hearing impairment
Outline the Abducens Nerve (CN VI) and its palsy
Function = lateral rectus (M)
Journey = lower pons –> cavernous sinus –> superior orbital fissure –> Lateral rectus
Test = eye movements
PALSY
- Ae = trauma (superior orbital fissure), cavernous sinus thrombosis, SOL causing downward pressure, DM neuropathy
- S+S = horizontal diplopia, esotropia, Inability to abduct eye (will rotate the head to look to side)
Outline the Facial Nerve (CN VII) and its palsy
Branches = temporal, zygomatic, buckle, mandibular, cervical
Function = muscles of facial expression (M), taste ant 2/3 tongue (SS), parasympathetic lacrimal/salivary glands (A)
Journey = bottom of pons –> internal auditory meatus –> petrous part of temporal bone –> few branches inside skull (SS) (A) –> exits skull –> 5 terminal branches (M)
Test = facial expression, corneal reflex
PALSY
- Ae = Bells (75%), trauma, infection (herpes zoster, HSV, HIV), tumour, preg, sarcoidosis, stroke, COM
- S+S = central (eyelid/forehead preserved), peripheral (all paralysed)
- Mx = lubricant ointment, cross taping, acyclovir, pred
***close relation ship to middle ear, parotid gland
Outline the Vestibulocochlear Nerve (CN VIII) and its palsy
Function = hearing (SS)
Journey = pons –> internal auditory meatus –> Cochlear
Test = hearing, enquire about balance
PALSY =
- Ae = bacterial meningitis, lyme disease, acoustic neuroma
- S+S = sensorineural hearing loss, vertigo, horizontal nystagmus, motion sickness
Outline the Glossopharyngeal Nerve (CN IX) and its palsy
Function = sensation of soft palate, tonsils, pharynx, middle ear (GS), posterior 1/3 tongue taste and general sensation (GS/SS), parotid gland (A)
Journey = medulla –> jugular foramen –> down the neck –> tongue, pharynx, carotid sinus, parotid gland
Test = gag reflex, testing in conjunction with vagus nerve
PALSY =
- Ae = idiopathic, compression by a blood vessel
- S+S = loss of the gag reflex, flaccid paralysis of soft palate (deviation of uvula away from lesion), sensory loss over soft palate, upper pharynx, posterior third of the tongue (including loss of taste sensation), mild dysphagia
***isolated lesions of glossopharyngeal are rare
Outline the Vagus Nerve (CN X) and its palsy
Function = sensation to lower pharynx, larynx (GS), muscles of soft palate, pharynx, larynx (M), parasympathetic to thoracic, abdo viscera (A)
Journey = medulla –> jugular foramen –> down the neck via carotid sheath –> Branches in the neck –> branches in the thorax
Test = noting speech, swallow, cough, say ‘ahhh’ observing uvula
PALSY
- Ae = trauma, DM, inflam, aortic aneurysms, tumours
- S+S = loss of the gag reflex, flaccid paralysis of soft palate (deviation of the uvula away), epiglottic paralysis (aspiration), dysphagia, features of vocal cord paralysis, gastroparesis
Outline the (spinal) Accessory Nerve (CN XI) and its palsy
Function = trapezius, SCM (M)
Journey = spinal roots from medulla -> enters foramen magnum –> exits jugular foramen –> down IJV –> SCM –> trapezius
Test = shrug shoulders against resistance, turn head against resistance
PALSY
- Ae = surgeries of lateral cervical region (LN)
- S+S = trap, SCM paresis
Outline the Hypoglossal Nerve (CN XII) and its palsy
Function = movement of the tongue (M)
Journey = medulla –> hypoglossal canal –> Runs down neck –> floor of the tongue
Test = move the tongue
PALSY =
- Ae = tumour, trauma
- S+S = atrophy/fasciculation of tongue on side of lesion, also deviates to side of lesion when protruded
What is an acoustic neuromas, which CN can they compress and how would this present?
Cerebellopontine angle (CPA) tumours, most common neoplasms in posterior fossa (5-10% intracranial tumours). Most CPA tumours are benign, 85% vestibular schwannomas (acoustic neuromas), lipomas, vascular malformations, haemangiomas
Benign tumour that develops on vestibular + cochlear Ns
COMPRESS:
- Vestibulocochlear = gradual hearing loss, ringing in the ear, and dizziness
- Facial = loss of facial expression
- Trigeminal = loss of sensation in the face
Mx = monitoring, brain surgery, RT
Outline Horner’s syndrome
Ae/Path = interrupted function of sympathetic nerve fibres (start in hypothalamus, run via upper spinal cord, near carotid artery, to face
- Birth trauma to the neck and shoulder
- Stroke in the brainstem
- Injury, blood clot, or dissection of the carotid artery
- Trauma/surgery to neck, upper spinal cord, chest
- Tumour: Pancoast, neuroblastoma
- Migraines or cluster headaches
- Demyelinating disease
S+S = miosis (constriction of the pupil), ptosis (drooping of the upper eyelid), and anhidrosis (absence of sweating of the face)
Mx = surgery, RT/chemo
What is CJD
Creutzfeldt–Jakob disease
Ae/Path = fatal degenerative brain disorder, prion (misfolded protein)
S+S = memory problems, behavioural changes, poor coordination, visual disturbances, dementia, involuntary movements, blindness, weakness, coma
Ix = MRI, EEG, spinal tap
Mx = no Tx, opioids for pain Na valproate/clonazepam for involuntary movements
*** most die of pneumonia due to impaired coughing reflexes
What is Argyll Robertson Pupil and how should it be Mx?
Bilateral small pupils that reduce in size on a near object (accommodation reflex), but do not constrict when exposed to bright light (absence of direct and consensual light reflex)
- highly specific sign of neurosyphilis
- can also be caused by DM neuropathy
Path = believed to be the result of bilateral damage to the pretectal nuclei in the midbrain
- hallmark of tertiary NEUROSYPHILIS
Mx = crystalline penicillin 24 mU intravenous per day for 10 to 14 d
Describe a syringomyelia
Generic term referring to a disorder in which a cyst (syrinx) or cavity forms within the spinal cord - can expand over time destroying spinal cord
Ae =
- Congenital: malformation in the brain, cerebellum protrudes into cervical spinal canal, syrinx may then develop
- Acquired: trauma, meningitis, haemorrhage, tumour, arachnoiditis
S+S = paraesthesia, paralysis, weakness, stiffness in the back, shoulders, and extremities
Ix = brain/spinal CT/MRI
Mx = surgery
Outline Cavernous sinus syndrome
Ae =
- metastatic tumours
- direct extension of nasopharyngeal tumours
- meningioma
- pituitary tumours or pituitary apoplexy
- aneurysms of the intracavernous carotid artery
- carotid-cavernous fistula
- bacterial infection causing cavernous sinus thrombosis
- aseptic cavernous sinus thrombosis
Path = result from the involvement of CNs passing through cavernous sinus (Oculomotor, Trochlear, Abducens)
S+S:
- Ophthalmoplegia = compression of the oculomotor nerve, trochlear nerve, and abducens N
- Sensory loss = from compression of Trigeminal 3 divisions (ophthalmic V1, maxillary V2, mandibular V3)
- Horner’s syndrome = involvement of the carotid ocular sympathetics
- Proptosis (pulsating exophthalmos suggests a direct C-C fistula)
Ix = CT, MRI
Mx =
- Mets: RT
- Pit tumour: prolactinoma dopamine agonists, resection
- Meningioma: RT
- Aneurysms: endovascular balloon occlusion
- Infection: Abx
What is Subacute combined degeneration of spinal cord (Lichtheim’s disease)?
Degen of the posterior and lateral columns due to vit B12 def (most common), vitamin E def, copper def, usually associated with pernicious anaemia
Ae = diet def, pernicious anaemia, CF (vit E def)
S+S =
- weakness of legs, arms, trunk, tingling and numbness that progressively worsens
- vision changes
- change of mental state
- bilateral spastic paresis
- pressure, vibration, touch sense diminished
- +ve Babinski sign may be seen
Ix = bloods
Tx = vit B12/E supplements
How do pituitary tumours present and how should they be Mx?
Benign adenoma, invasive adenoma, and carcinomas
S+S =
- Prolactinoma (prolactin) = amenorrhea, galactorrhoea, loss of axillary and pubic hair, hypogonadism, gynecomastia, ED
- Somatrotrophic (GH) = acromegaly in adults; gigantism in children
- Corticotropic (ACTH) = Cushing’s
- Visual field defects = bitemporal hemianopsia (compression of optic chiasm)
- RICP = headache, N+V, papilledema
Ix = CT, MRI, hormones
Mx =
- Prolactinoma = dopamine agonist (inhib prolactin)
- Somatotrophic = long-acting somatostatin analogues (inhib GH)
- Trans-sphenoidal adenectomy
- RT
What is the aetiology and pathophysiology of myasthenia gravis?
Ae = Autoimmune: AChR Ab, MuSK Ab
Path = autoantibodies (IgG) blocking postsynaptic acetylcholine receptors (AChR), impairing neuromuscular transmission
Associated with abnormalities in the thymus (thymic hyperplasia 65%, thymic tumour 30%) and other autoimmune disorders: thyroiditis, graves, RA, SLE, pernicious anaemia
Precipitated by = stress, preg, menses, sec illness, thyroid dys, trauma, temp extremes, hypoK, drugs (aminoglycosides, B-blockers, chloroquine, Mg, ACEi), surgery
How does myasthenia gravis present and what are the possible complications?
Bimodal pres = 20-30y, 50-70y
FATIGABILITY of skeletal muscle
- Extraocular muscle involvement (90%)
- Bulbar Sx: dysphagia, dysphonia, dysarthria
- Facial + limb weakness
- Resp muscle involvement
Ptosis (drooping of upper eyelid)
*** no sensory or reflex loss, no autonomic involvement, pupil unaffected
COMP = resp failure (spirometry monitoring), aspiration, resp infection, myasthenic crisis (slack facial muscles, weak neck, drooling, unsafe swallow), cholinergic crisis (excess AChase inhib - excess stim of striated muscle, flaccid paralysis, resp failure, miosis, SSLUDGE syndrome), DVT
How should suspected MG be Ix?
AChR Ab, MuSK Ab
Tensilon test - injection of Tensilon (edrophonium), then muscle strength is evaluated (caution asthma, MI, bradycardia)
Electromyography (EMG) - looking for fatigability, AP reduce
CT thorax - thymic tumours
Ice test - ptosis
