Clinical Neurology Flashcards
Optic nerve
One eye blindness > anterior to optic chasm (nerve or retina)
Bitemporal > optic chiasm (pineal/carnipharyngioma)
Left H hemianopia > right retrochiasm structure
Right H Hemianopia > left retrochiasm structure
Enlargement blind spot > disc swelling
Superior Quad > Contralateral optic irradiation lesion temporal lobe
Inferior Quad > Contralateral optic irradiation lesion parietal lobe
Cortical blindness > Occipital Cortex
Olfactory nerve
Only sensory nerve with NO thalamic relay
Unilateral anosmia > olfactory nerve/bulb/tract/filia lesion/frontal meningioma
A lesion distal to olfactory fibres decks satin causes no olfactory impairment (bilateral cortical representation)
Hyposmia > PD
Head injury most common cause of disturbance in olfaction
Funnel vision
Filed at 2m larger than field at 1m
Glaucoma, reinitis pigmentosa, CAR, hyaline bodies of the disc, optic atrophy, bilateral occipital infarcts with macula sparing, feigned visual loss
Tunnel vision
Patchy spirals of field loss
Malingering
Hysteria
Cortical blindness
PCA OCCLUSION
MAY HAVE MACULAR SPARING (keyhole)
Optic nerve tests
Snellen for ACUITY
Ishihara for colour
Confrontation test/perimetry for visual fields
Fundoscopy
Oculomotor Nerve
- Nucleus is in midbrain
- Supplies levator palpebrae superioris, superior/inferior/medial recti, inferior oblique muscles
- Lesion: paralysis of IPSILATERAL upper eyelid and pupil (cannot adduct or look up or down, and exotropia)
- Lesion at nucleus causes bilateral ptosis too
- Paralysis causes DIPLOPIA IN MORE THAN ONE DIRECTION
- Clue = pupillary involvement
- Pupil-sparing paralysis can occur in DM, MS
Trochlear Nerve
Nucleus is in MIDBRAIN
SUPERIOR OBLIQUE MUSCLE
Can therefore view tip of the nose!
Trigeminal Nerve
Midbrain > Pons > Cervical Region (spinal tract of V Nerve)
Three divisions: ophthalmic V1, maxillary V2, mandibular V3
Corneal reflex: Afferent V nerve, efferent facial nerve
Paralysis: ipsilateral dace sensory loss, weakness of mastication, deviation of jaw to paralysed side.
Abducens Nerve
Paramedian Pontine Region (4th ventricle)
LATERAL RECTUS
ABDUCTION
CAUSES DIPLOPIA ON HORIZONTAL GAZE ONLY “horizontal Homonymous hemianopia”
Paralysis is a false localising sign as can also be caused by raised ICP
Facial Nerve
Motor supply: facial muscles
Sensory supply: pinna and external auditory canal. Taste sensation anterior 2/3 tongue > sensory nucleus tractus solitarius
Secretomotor functions: parasympathetic relay to lacrimal, lingual, submandibular glands
LMN lesion: IPSILATERAL FACIAL PARALYSIS WITH IMPARIMENT OF EYE CLOSURE AND WIDER PALPEBRAL FISSURE = BELLS PALSY (idiopathic)
UMN lesion: lower half of face paralysed, eye closure preserved
Vestibulocochlear Nerve
Weber Test: vibrating fork on midline, in conductive loss skins louder in abnormal ear, in sensorineural loss sounds louder in normal ear
Rinne Test: vibrating fork over mastoid, then held at ear canal opening, normally continue to hers vibration. In conductive loss no sound, in sensorineural loss both air and bone conduction are decreased.
Romberg Test: patient falls toward side of dysfunction
Vestibular position transmits accelerations of head from utricle, saccule, semicircular canals to vestibular nucleus
Provocative Test: CALORIC, COWS.
Glossopharyngeal Nerve
Indistinguishable anatomically from Vagus nerve, both travel together
Sensory innervation posterior 1/3 tongue and pharynx.
Vascular afferents from aortic arch and carotid sinus travel via 9th never to nucleus solitarius (neuronal BP control)
Lesions: loss of taste posterior 1/3 and pain/touch same areas
Vagus Nerve
Starts at nucleus ambiguous
Longest peripheral course of all CN, stretches to splenic flex use colon
Motor supply: pharyngeal, palatoglossus, larynx, smooth muscles tracehobronchial tree, oesophagus and GI tract upto transverse colon.
Sensory: back of ear, external auditory canal, TM, pharynx, larynx, dura of posterior fossa
Paralysis: gag reflex and palatal reflexes decreases (uvula deviate to opposite side of lesion)
Hypoglossal nerve
Trapezius and Sternocleidomastoid muscles
Hypoglossal nerve
Extrinsic and intrinsically tongue muscles
Stick tongue out, if paralysed on one side tongue deviates to side of paralysis
Absent ankle jerks, up going plantars
SADC
FRIEDRICHS ATAXIA
MND
SYPHILIS
Anisocoria
Sympathetic dysfunction > Horners
Parasympathetic. > tonic pupil
Anosognosia
Right FrontoParietal lesions > left hemiplegia whichpatient denies
Visual agnosia due to occipital bilateral infarcts denial = Antons
Brown Sequard Syndrome = Hemisection of Spinal Cord
- Interruption lateral Corticospinal tract therefore ipsilateral spastic paralysis below level of lesion, ipsilateral babinski, and UMN hyperreflexia
- Interruption of posterior white column causing ipsilateral loss of vibration, position sense below level of lesion
- Interruption of lateral spinothalamic tracts causing Contralateral loss of pain and temperature (2-3 segments below level of lesion)
Friedrichs Ataxia
Trinucelotide repeat
Peas cavum Kyphoscoliosis Cérebellar signs Impaired joint/position senses Cardiomyopathy Optic atrophy
Holmes Adie Syndrome
Tonic pupil with absent patellar and Achilles reflexes
Horners Syndrome
PAMELA
PTOSIS, ANHYDROSIS, MIOSIS, ENOPTHALMUS, LOSS OF CILIOSPINAL REFLEX
SYNPATHETIC PATHWAY SAME SIDE, SEEN IN cervical lesions/carotid aneurysms
Mono neuritis multiplex
Painful asymmetric sensory and motor peripheral neuropathy
Due to: DM, VASCULITIS, AMYLOIDOSIS, DIRECT TUMOUR, AUTOIMMUNE DISORDERS
