Neurology Flashcards
What are the DD for unilateral ptosis
III nerve palsy Horner's syndrome Myasthenia gravis Myotonic dystrophy congenital
causes of horner’s syndrome
peripheral; pancoast tumour neck sx cardiothoracic sx LAP Central venous cathetrisation central: syringomyelia demyelination neck trauma myasthenia gravis myotonic dystrophy
what are the complications of ventricular setpal defects?
infective endocarditis pulmonary hypertension left ventricular dysfunction aortic regurgitation ventricular arrhythmias Eisenmenger's syndrome
What is the muscle that open the eye?
Levator palpebrae superioris muscle, innervated by oculomotor nerve, under the levator is smooth muscle fibres, innervated by cervical sympathetic nerves. Ptosis results fr damage to these nerves or disorder of muscle or neuromuscular junction.
What are signs of oculomotor palsy?
Complete ptosis, unilateral,
When pt attempting to look straight ahead, the eye is ‘down and out’, there is weakness of adduction and vertical eye movement
Pupil is fixed and dilated.
If pupillary sparing, consider diabetes or hypertension
What are signs of Horner syndrome
Unilateral incomplete ptosis
Smaller pupil, normal reactive to lights
Anhidria
Other signs to localise lesion
Cornea reflex in the Se eye( orbital or retro - orbital lesions)
Weakness and loss of reflexes in the ipsilateral arm ( avulsion injury to the brachial plexus, pan coast tumour of lung apex)
Ipsilateral loss of facial pain and tolerate sensation and contralateral loss of pain and sensation in the trunk and limbs( brainstem lesion)
Ptosis due to myopathy or MG?
Ptosis with weakness of extra-ocular muscles and orbicularis oculi consider myasthenia gravis
Fatigability test in eyelid and deltoid muscles
Normal pupils signify disorder of muscle or neuromuscular junction
Senile ptosis has no associated neurological signs
Dystrophia myotonica: frontal balding, cataract, wasting of the masseters, sternomastoids and distal limb muscles.
What are the investigation of myasthenia gravis?
Respiratory function test
repetitive stimulation studies
Single fibre EMG looking for jitter Anti-acetylcholine receptor antibodies Anti- MuSK antibodies if negatives Tension test cT of chest to exclude thyma
What are three main vision abnormality
Abnormality of vision
Abnormality of eye movements
Pupillary abnormality
What are DD of abnormality of vision
Impairment of acuity in one eye Bilateral hemianopia Homonymous hemianopia Upper homonymous quadrantanopia Lower homonymous quadrantanopia
What are etiology of impairment of acuity in one eye?
Lies in the anterior visual system: the eye( Central retinal artery occlusion, retinitis pigments a) itself or the optic nerve ( optic neuritis or ischaemic optic neuropathy
Optic atrophy includes sub-frontal meningioma, pipuitary tumour, carotid aneurysm, anterior ischaemic optic neuropathy.
lateral medullary syndrome
vestibular nuclei
vestibular system: vomiting, vertigo, nystagmus,
inferior cerebellar peduncle Ipsilateral cerebellar signs including ataxia, dysmetria (past pointing), dysdiadokokinesia
lateral spinothalamic tract contralateral deficits in pain and temperature sensation from body (limbs and torso)
spinal trigeminal nucleus & tract ipsilateral loss of pain, and temperature sensation from face
nucleus ambiguus - (which affects vagus nerve and glossopharyngeal nerve) - localizing lesion (all other deficits are present in lateral pontine syndrome as well) ipsilateral laryngeal, pharyngeal, and palatal hemiparalysis: dysphagia, hoarseness, diminished gag reflex (efferent limb - CN.X)
descending sympathetic fibers ipsilateral Horner’s syndrome (ptosis, miosis, & anhydrosis)
5th cranial nerve testing
Sense: test light touch and pinprick in ophthalmic, maxillary and mandibular distributions
Motor: messeters (clech your teeth), pterygoids (resistance of chin)
what is light reflex
constriction of the pupil in response to light is relayed via the optic nerve and tract, the superior quadrigeminal brachium, the Edinger-Westphal nucleus and its efferent parasympathetic fibres, which terminate in the cilliary ganglion, there is no cortical involvment.
what is accommodation reflex
constriction of the pupil with accommodation originates in the cortex (in association with convergence) and is relayed via parasympathetic fibres in the third nerve.
causes of absent light refelx but intact accommodation reflex
midbrain lesion,
ciliary ganglion lesion
Bilateralanteriorisualpathway lesions
Parinaud’s syndrome
causes of absent convergence but intact light reflex
Cortical lesion
Midbrain lesions
Causes of pupil contrictin
Horner's syndrome Argyll Robertson pupil Pontine lesion (often bilateral, but reactive to light) Narcotics Pilocarpine drops Old age
Causes of pupil dilation
Mydriatics, atropine poisoning or cocaine Thrid nerve lesion Adie's pupil iridectomy, lens impalnt, iritis Post- trauma, deep coma, cerebral death Congenital
What is Adie’s syndorme
lesion in the efferent parasympathetic pathway.
signs:
dilated pupil,
decreased or absent reaction to light
slow or incomplete reaction to accommodation with slow dilation afterwards
decreased tendon reflexes
patients are commonly young women
What is Argyll Robertson Pupil?
lesion of the iridodilator fibres in the midbrain
as in syphilis, diabetes mellitus, alcoholic midbrain degenration, other midbrain lesions
Signs:
small, irregular unequal pupil, no reaction to light, prompt reaction to accommodation,
causes of papilloedema
space-occupying lesion hydrocephalus benign intracranial hypertension hypertension (grade IV central retinal vein thrombosis cerebral venous sinus thrombosis high cerebrospinal fluid protein level - Guillain-Barre syndrome
causes of optic atrophy
Chronic papilloedema or optic neuritis optic nerve pressure or divison Glaucoma Ischaemia Familial
causes of cataract
Old age endocrne - diabetes mellitus, steroids hereditary or congenital Ocular disease - glaucoma irradiation trauma
causes of ptosis
with normal pupils senile ptosis, myotonic dystrophy, ocular myopahty, thyrotoxic myopahty, myasthenia gravis congenital, fatigue, botulism, snake bite with constricted pupils: Horner's syndrome, tabes dorsalis with dilated pupils third nerve lesion
What is dominant parietal lobe signs and non dominant parietal lobe signs?
AALF orGerstmann's syndrome A acalculia A agraphia -write L left right disorientation F finger agnosia (name fingers) Non dominal Dressing apraxia constructional apraxia Both lobes: visual inattention Sensory inattention Cortical sensory loss ( loss of agraphaesthesia, two point discrimination, joint position, sense and stereognosis)
What are frontal lobe signs
reflexes - grasp, pout, palmar mental
preverb interpretation: “a rolling stone gathers no moss”
smell
Fundi
Gait: gross unsteadiness in walking - the feet typically behae as if glued to the floor, resulting in a hesitant shuffling gait with freezing
what is features of fluent speech (usually receptive, conductive or nominal dysphasia)
naming of objects - patients with nominal , conductive or receptive aphasia name objects poorly
repetition - conductive and receptive aphasics cannot repeat
comprehension - only receptive aphasic patients cannot follow commands
reading - conductive and receptive aphasic patients have difficulty reading
writing - conductive aphasic patients have impaired writing( dysgraphia), whereas receptive aphasic patients have abnormal content
what is nonfluent speech (expressive aphasia)
naming of objects - poor
repetition - may be possible with great effort, phrase repetition is poor
comprehension - nearnormal (written and verbal commands are followed)
writing - dysgraphia may be present
look for hemiparesis - arm more affected than leg
where is the lesion of conductive aphasia and nominal aphasia
conductive aphasia: arcuate fasciculus
nominal aphaisa: angular gyrus (temporallobe)- small localised lesion
other causes of nominal aphaisa: encephalopathies, pressure effects form space -occupying lesion, recovery pahse from any dysphasia