Neuro Nerves Flashcards
CN I Olfactory
Sensory : smell
CN II Optic
Sensory: Sight
CN III Occulomotor
Motor: MR, SR, IR, IO, LPS
Parasympathetic: sphincter pupillae (light constriction)
Signs= fixed dilated, ptosis, outward deviation (down + out)
CN IV Trochlear
Motor: SO
signs: vertical diplopia (up + out), tilt head to compensate for function loss
CN V Trigeminal
Sensory: ophthalmic V1 + maxillary V2
(touch, pain, pressure, temperature, muscles of mastication: face, scalp, cornea, nasal, oral cavity, anterior 2/3 of tongue)
Motor: ophthalmic + maxillary + mandibular V3
(muscles of mastication, tensor, tympani muscles)
Signs: reduced sensation or dysesthesia, weakness of jaw clenching, side to side movement, jaw deviates to weaker side if LMN lesion
CN VI Abducens
Motor: LR
signs: inability to look laterally, eye deviated medially
CN VII Facial
Sensory: taste anterior 2/3 tongue
Motor: muscles of facial expression, upper face bilaterally innervated, lower face contralaterally innervated by motor cortex
Parasympathetic: lacrimal, submandibular, sublingual salivary glands
Signs: facial weakness, forehead paralysed/spared in LMN/UMN
CN VIII Vestibulocochlear
Sensory: hearing + balance
Signs: deafness, tinnitus
CN IX Glossopharyngeal
Sensory:
- taste posterior 1/3 tongue,
- general sensation: touch, pain, temp in pharynx, eustachian tube posterior 1/3 tongue
Motor: 1 pharynx muscle
Parasympathetic: parotid gland
CN X Vagus
Sensory: general sensation to pharynx, larynx, oesophagus, external auditory meatus, tympanic membrane
Motor: muscles of soft palate, pharynx, larynx (swallowing)
Parasympathetic: thoracic and abdominal viscera
Signs: palatal weakness can cause “nasal speech”, palate assymetrical when patient opens mouth, “bovine cough”, hoarseness
CN XI Accessory
Motor: sternocleidomastoid + trapezius muscles
Signs: weakness and wasting of those muscles
CN XII Hypoglossal
Motor: tongue muscles
Signs: wasting of ipsilateral side of tongue, fasciculations, tongue deviated towards affected side (away from lesion)
Which nerve is affected in Carpel Tunnel Syndrome?
Entrapment of Median Nerve
Causes: hypothyroidism, DM, pregnancy, acromegaly
S+S:
- aching pain esp at night, relieved by dangling,
- paraesthesia in thumb, index finger, middle finger,
- sensory loss and weakness of abductor pollicis brevis and thenar eminent
I: EMG shows slowing of conduction, Phalens + Tinels Test (tapping)
M: wrist splint, steroids, decompression surgery
Reflexes
S1-S2: Ankle
L3-L4: Knee
C5-C6: Biceps (flex elbow)
C7-C8: Triceps (extend elbow)
Foot Drop?
L5: common peroneal nerve (L4-S1), cannot dorsiflex –> inversion foot
Motor Exam/Myotomes
C5: elbow flexion
C6: wrist extension
C7: elbow extension
C8: finger flexion
T1: finger abduction
L2: hip flexion
L3: knee extension
L4: ankle dorsiflexion
L5: toe extension
S1: ankle plantar flexion
Dermatomes
C4: clavicles
T1: medial side of arms
T4: nipples
T10: umbilicus
L2-3: anterior + inner thigh
L4: knee
L5, S1, S2: posterior + lateral leg
S4: perianal area
Median Nerve (C6-T1)
nerve of precision grip
wasting of muscles at base of thumb
Ulnar Nerve (C7-T1)
- vulnerable to elbow trauma
- wasting of: medial wrist flexors, interossei (can’t cross fingers), medial 2 lumbricals (claw hand)
- wasting of hypothenar eminence: weak little finger abduction
- sensory loss over medial 1.5 fingers
- flexion of 4th and 5th DIP joint weak
Radial Nerve (C5-T1)
- wrist + finger drop when elbow flex + pronated
- dorsal aspect of thumb root sensory loss
- damage at axilla = triceps affected
Brachial Plexus (C5-T1)
- pain/paraesthesia + weakness in affected arm
Phrenic Nerve (C3-5)
phrenic palsy if orthopnoea with raised hemidiaphragm
Sciatic Nerve (L4-S3)
damanged by pelvic tumour/fractures to pelvis/femur
Tibial Nerve (L3-S3)
inability to tip toe, sensory loss over sole
Syringomyelia: Causes
Chiari malformation, trauma, tumours, idiopathic
Syringomyelia: S+S
- Impairment of lateral spinothalamic tracts:
- Cape-like (neck, shoulders, arm) loss of sensation to pain and temperature
- but preserved light touch, proprioception + vibration (due to crossing of spinothalamic tracts) - Impairment of ventral horns
- spastic weakness
- neuropathic pain
- upgoing planters
- bladder bowel dysfunction
Syringomyelia: I+M
MRI contrast to exclude tumour + tethered cord
MRI brain for chiari malformation
Treatment: shunt
B12 Subacute Degeneration fo Spinal Cord
BILATERAL!
1. Impairment of dorsal column: (affected 1st)
- tingling, proprioception, vibration loss
- Impairment of lateral corticospinal:
- UMN: muscle weakness, hyperreflexia, spasticity, brisk knee reflexes, absent ankle jerks, extensor plantars, legs first - Impairment of spinocerebellar tracts:
- sensory ataxia and +ve Rombergs
Brown Sequerd Syndrome (spinal cord hemisection)
UNILATERAL!
1. Impairment of dorsal column: (affected 1st)
- (ipsilateral) tingling, proprioception, vibration loss
- Impairment of lateral corticospinal:
- (ipsilateral below lesion) UMN: muscle weakness, hyperreflexia, spasticity, brisk knee reflexes, absent ankle jerks, extensor plantars, legs first - Impairment of lateral spinothalamic tracts:
- (contralateral) loss of pain and temp sensation
Friedrich’s Ataxia
BILATERAL! (same as B12 DEF SCDOSC)
1. Impairment of dorsal column: (affected 1st)
- tingling, proprioception, vibration loss
- Impairment of lateral corticospinal:
- UMN: muscle weakness, hyperreflexia, spasticity, brisk knee reflexes, absent ankle jerks, extensor plantars, legs first - Impairment of spinocerebellar tracts:
- sensory + cerebellar ataxia (intention tremor) and +ve Rombergs
Neurosyphilis
SENSORY only: dorsal columns: loss of proprioception, vibration and sensation
Parietal Lobe Lesions
- sensory inattention
- apraxia (can understand but can’t do)
- tactile agnosia (can’t recognise things by touch)
- inferior homonymous quadrantanopia
Gerstmann’s Syndrome: lesion of dominant parietal
- alexia, acalculia, finger agnosia, right-left disorientation
Occipital Lobe Lesions
- homonymous hemianopia (with macula spared)
- cortical blindness
- visual agnosia
Frontal Lobe Lesions
- Broco’s aphasia (inferior frontal gyrus- left superior MCA)
- disinhibition
- perseveration
- anosmia
Temporal Lobe Lesions
- Werknicke’s aphasia (superior temporal gyrus- left inferior MCA)
- auditory agnosia
- prosopagnosia
Cerebellum Lesions
- midline lesions: gait + truncal ataxia
- hemisphere lesions: intention tremor, past pointing, dysdiadokinosis, nystagmus
Amygdala Lesions
Kluver Bucy Syndrome: hypersex, hyperoral, hyperphagia, visual agnosia
Most common tumour causing brain metastases
(LBBSK)
Lung
Breast
Bowel
Skin
Kidney
Most common tumour causing bone metastases
(LBPTK)
Lung
Breast
Prostate
Thyroid
Kidney
Most common site:
Spine
Pelvis
Ribs
Skull
Long bones
Brain tumours
Glioblastoma Multiforme (most common): disruption of BBB
Meningioma (2nd most common): benign, compression sx, in falx cerebri or superior sagitttal sinus
Pituitary adenoma: ACTH/GH/prolactin/TSH producing
Pilocytic Astrocytoma: children
Medullablastoma: children, aggressive
Oligodendroma: benign, frontal lobe “fried egg”
Hemangioblastoma: cerebellum, von hippel lindau
Craniopharynglioma: children, Rathke’s pouch: early morning headache, vomiting, polydipsia, polyuria, and visual changes, benign tumor near the pituitary gland and hypothalamus.
First order Horners causes
- MS
- tumours
- Wallenberg’s Stroke
anhidrosis in face, arm, trunk
Second order Horners causes
- Pancoast tumours
- Thyroid malignancies
- Trauma
anhidrosis in face
Third order Horners causes
- Carotid artery dissections
- Cavernous sinus thrombosis
- Cluster headaches
no anhidrosis
failure to dilate if add hydroxyamphethamine
Congenital Horners
- Iris heterochromia
