Neurology Flashcards
Causes of bilateral facial palsy
Lyme’s disease
Guillain Barré
Sarcoidosis
What is synkinesia?
In Parkinson’s exam, whilst examining tone, getting them to tap their leg and it accentuating the cogwheel rigidity
What are the causes of a combined upper and lower motor deficit
Fred’s Tabby Cat Seeks Mice
Freidrich's Ataxia Taboparesis (syphillis) Cervical spondylosis Subacute degeneration of the cord Motor neurone disease
If a nystagmus is worse when looking to the left side, where is the lesion site if:
A. It is caused by a cerebellar lesion
B. It is caused by vestibular nerve/nuclear lesion (CN VIII)
A. Left (ipsilateral)
B. Right (contralateral)
Patient has ataxic gait and trunk but limbs have normal tone, coordination and no dysmetria evident. Where is the site of the lesion?
Cerebellar vermis (a central part) (Often alcohol may causes vermis atrophy)
Causes of unilateral cerebellar syndrome (DASHING SYMPTOMS)
Demyelination (MS) or brain stem stroke on ipsilateral side
Rarely: posterior fossa tumour, abscess
Causes of bilateral cerebellar syndrome
DADS HAR Drugs (anticonvulsants) Alcohol Demyelination (MS) Stroke (brain stem)
Hypothyroid
Antineuronal antibodies (paraneoplastic syndrome)
Rare- Freidrich’s, Ataxic telangiectasia
What is internuclear opthalmaplegia and which condition does bilateral opthalmaplegia occur in?
Inability to adduct eye when looking to opposite side, contralateral eye gets a nystagmus.
In MS due to demyelinating lesion of the medial longitudinal fasciculus
Young woman has pain on eye movement and rapid reduction in central vision, with tingling in her right arm. What is the diagnosis?
Multiple sclerosis- unilateral optic neuritis is often the first sign
Ishihara plates might show a reduction in red colour vision
What objective imaging or tests support a clinical diagnosis of MS?
Based on the McDonald criteria:
MRI plaques disseminated in time and space
Oligoclonal IgG bands in CSF (not serum)
Delayed evoked potentials- normal amplitude
Neuromyelitis Optica IgG antibodies (Devic’s syndrome)
Medications used in MS:
All the medications reduce relapses in relapsing and remitting MS but do not alter progression of the disease ultimately.
Relapse reducing:
Immunomodulation- IFN B + Glatiramer
Monoclonal antibodies: Alemtuzamab (anti-T cell) + Natalizumab (anti VLA-4 R that allows Abs to cross the BBB)
Symptomatic: Methylprednisolone reduces length of short relapses Baclofen- spasticity Botox- tremors Carbamezepine- seizures
How can Devic’s syndrome be distinguished from MS?
Devic’s syndrome- Anti-aquaporin 4 antibodies in CSF (60%)
Also known as neuromyelitis optica antibodies
Both may get transverse myelitis- loss of motor, sensory, autonomic, reflex + sphincter function below lesion
Both may get optic atrophy (pale disc, altered acuity)
Rx: for Devic’s is plasma exchange
Difference between decorticate and decerebrate posturing and their cause?
No-one celebrates in decerebrate posturing (hands by sides, no clapping) and means brain stem is affected ?vegetative state
If somone goes from decorticate to decerebrate = pontine tonsils at risk of herniation
In decorticate posturing, they look meek like they’re in court, arms bent up (cerebrum, internal capsule and thalamus may be involved)
In a stroke patient with decorticate posturing, which muscle groups would you expect to be stronger in upper and lower limbs?
Decorticate (not decerebrate where no one is celebrating because brain stem is involved)
Is extended legs and flexed arms, so on examination
Flexors stronger in upper limb
Extensors stronger in lower limb
Young patient (in 30s) presents with stroke-like findings, acute onset of focal neurological deficit. What other causes of stroke need to be considered?
Blood perfusion:
Sudden BP drop (ie sepsis, affects watershed zone)
Carotid artery dissection
Subarachnoid haemorrhage
Vessel changes:
Vasculitis (check ESR)
Blood components:
Venous sinus thrombosis
Thrombophilia (like antiphospholipid syndrome)
Inherited- Fabry’s (lysosomal storage), CADASIL
In Fabry disease, which parts of the body may there be problems with and what are the problems?
X linked lysosomal storage disease due to a-galactosidase A Skin- angiokeratoma (burgundy moles) Eyes- lens opacities Heart- MI, syncope, arrhythmia Kidneys- failure CNS- stroke Nerves- neuropathy
What is CADASIL?
Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts + Leucoencephalopathy
Main genetic cause of strokes due to Notch3 gene mutation (19q) affecting vascular smooth muscle
PC: Migrane, TIA, mood disorders, dementia ± psuedobulbar palsy
IHx: MRI
Nme 5 types of lacunar infarct:
- Pure motor
- Ataxic hemiparesis (cerebellar signs + weakness)
- Pure motor
- Dysarthria/clumsy hand
- Mixed sensorimotor
What are the 3 H’s of a total anterior circulation stroke?
Hemiparesis
Homonymous hemianopia
High cortical deficit (dysphasia, visual inattention, dyspraxia)
When would a UMN lesion mimic a LMN lesion?
In the first few hours, before the spasticity and hyper-reflexia develop. This occurs from ‘spinal shock’- not well understood
Patient has hemiparesis of the right leg and reduced cognition- broadly where is the site of the lesion?
Left cerebral hemisphere
If hemiparesis with epilepsy, reduced cognition or a homonymous hemianopia it is in the cerebral hemispheres
Cranial nerve palsy in CN 3-8 with contralateral hemiplegia means the site of the stroke is where?
Brainstem on the side of the cranial nerve deficit
Where does pain, temperature, proprioception and vibration sense travel in the spinal cord?
Pain + Temp- raise ALert = Anterolateral (immediate decussation to get away from danger)
Vibration + Proprioception = Dorsal columns (ring the DOORbell, open the door)
How does the side of sensory loss differ if the lesion is in the brainstem or above it?
In the brainstem- lesion is ipsilateral to cranial nerve sensory loss and contralateral to arm + leg
Above- contralateral for both (sensory nerves have all decussated by then)
Which artery predominantly supplies the motor cortex that controls the leg?
The anterior cerebral artery- think of the leg hanging over the sulcus edge.
Middle cerebral- arm + face
Where does the vertebrobasilar arteries supply and what symptoms occur from occlusion?
Brainstem, cerebellum + occipital lobes
Any symptoms of
Hemi/quadraplegia + hemisensory loss
Hemianopia, cortical blindness, diplopia
Vertigo, nystagmus, ataxia, dysarthria, dysphasia
Which 2 parts of the brain may be involved in lateral medullary syndrome and symptoms?
Lateral medulla or inferior cerebellum
Vertebral artery occlusion of posterior inferior cerebellar artery
Vertigo, dysphagia, nystagmus, ipsilateral ataxia, vomiting
Ipsilateral Horner’s, crossed sensory loss (ipsilateral facial, contralateral to trunk + limbs)
Locked in syndrome is caused by damage to which structure because of which artery?
Ventral pons
Pontine artery
Where is Wernicke’s area that if damaged may cause Wernicke’s aphasia?
Supramarginal gyrus of parietal lobe and upper part of the temporal lobe
Where is Broca’s area, that if damaged may cause Broca’s aphasia?
Inferior frontal gyrus
If a patient can’t repeat ‘no ifs, ands or buts’ what type of aphasia do they have and where might the lesion be?
Conductive aphasia- arcuate fasciculus
On the speech exam, the speech is slurred and the patient barely opens their mouth. What are the causes of a spastic dysarthria?
Bilateral UMN weakness:
Pseudobulbar palsy (brainstem lesion, cerebrovascular disease of vertebrobasilar circulation)
Motor neurone disease
How can the cause of dysphonia be distinguished during an exam using a simple request?
Normal cough- laryngitis
Fatiguable- myaesthenia gravis
Others: Guillain Barre (ascending weakness)
CN X damage
3 causes of slurred staccato speech dysarthria:
Cerebellar lesions:
Alcohol intoxication
Multiple sclerosis
Phenytoin toxicity
Rarely inherited ataxias
Common causes of spastic hemiparesis (seen as scissoring gait)
Cerebral palsy
Multiple sclerosis
Cord compression
Causes of apraxic gait (patient looks like they have forgotten how to walk)- uncoordinated, dithering at attempts to lift leg
Cortical integration of movement is impaired Normal pressure hydrocephalus Cerebrovascular disease (often frontal lobes)
Causes of high stepping gait:
Foot drop due to:
Common peroneal nerve lesion (wraps around the fibular bone)
L5 radiculopathy (root compression)
Bilateral: Cerebrovascular event
Where is the site of the lesion if L hemiplegia with R-sided drooping eyelid, fixed dilated pupil, looking down and out
A) Right midbrain- third nerve palsy
Posterior cerebral artery branches
Where is the lesion: R sided hemiparesis of arm + leg with double vision, on examination the L eye can’t look towards the left
Contralateral hemiparesis with ipsilateral 6th nerve palsy, may be 7th nerve involvement in these cases (facial muscle weakness with no sparing of the forehead)
= Pontine lesion
(3-4 midbrain, 5-8 pons, 9-12 medulla)
Patient has L sided weakness of arm and on sticking their tongue out, it deviates to the R. Where is the lesion?
Isolated R sided CN 12 weakness with L sided hemiparesis:
Medulla
Which cranial nerves may be implicated in a tumour in the cerebellopontine angle?
5, 7, 8
5- corneal reflex absent, numbness, weak muscles of mastication
7- facial muscle paralysis
8- hearing problem + balance
Which cranial nerves would be affected in a cavernous sinus lesion?
3, 6, 5a
Down + out eye, wide pupil, droopy lid
Difficulty abducting
Numbness over the forehead and nose
Which nerves are affected in jugular foramen syndrome?
9, 10 + 11
Impaired gag reflex
Weak sternocleidomastoid
Which autonomic nerves control the light reflex and accommodation reflex?
Parasympathetic nerves
Constrict
Cause of complete compared to a partial ptosis:
Complete- 3rd nerve palsy
Partial- Horner’s syndrome (symp nerves), age-related ptosis (weakening of levator muscles)
What is Argyll Robertson pupil and 3 causes?
Like the prostitute: reacts but does not accommodate + small pupil
Syphilis, diabetes mellitus, MS
Central and peripheral causes of Horner’s syndrome
Partial ptosis, meiosis, anhydrosis + enopthalmus
Central: hypothalamus, medulla, cervical cord (exits at T1)
Stroke- lateral medullary syndrome, demyelination
Peripheral: Pancoast’s, carotid dissection (travels with carotid)
Causes of reduced acuity, not correctable with pinhole test:
Corneal lesion: ulcer or oedema
Cataract
Age-related macular degeneration
Retinal haemorrhage
Optic neuropathy (MS, ischaemic, compressive)
Optic tract, medial longitudinal fasciculus, occipital cortex
Patient has a homonymous quadrantanopia, how do you know if the lesion is in the parietal or temporal lobe?
Lower quadrant missing in vision- parietal
Upper quadrant unseen- temporal
Loss of peripheral vision (constricted visual fields)
Glaucoma
Chronic papilloedema
Retinitis pigmentosa
In a patient with a CN 3 palsy, what feature would make you consider it was more likely to be due to diabetes than a posterior circulation aneurysm?
The constrictor (parasympathetic) fibres of the nerve are superficial, so compressing forces will affect them (= dilated) Whereas diabetic and ischaemic forces seem to affect the axon worst with sparing of the outer constrictor fibres
Top causes of isolated CN 3, 4 or 6 palsy
Diabetes mellitus
Atherosclerosis
Rarely Vasculitis, Guillain Barré
What is internuclear opthalmoplegia and where is the lesion located?
In a INO, on abduction there is a nystagmus looking temporally, but can adduct nasally slowly without nystagmus.
Affects medial longitudinal fasciculus which joins CN 3-4 in midbrain with CN 6 in the pons
Affected in MS
Describe the full function of cranial nerve VII:
Face, ear, taste, tear
Muscles of facial expression
Stapedius (dampen sound)
Anterior 2/3rds of tongue
Parasympathetic lacrimal gland (+)
Branches of the trigeminal nerve, which mediates the corneal reflex?
Ophthalmic does
Maxillary
Mandibular
On asking the patient to close their eyes what will you observe if they have a LMN seventh nerve palsy?
Bell’s sign: eyes roll back into head on that side
Causes of one sided CN 7 palsy, no forehead sparing:
Unilateral LMN CN VII palsy:
Bell’s palsy
Pontine vascular accident
Ramsay Hunt syndrome- vesicles in external auditory meatus
Parotid tumours, Lyme disease
Causes of bilateral CN VII weakness, no sparing of forehead:
Sarcoid
Guillain Barré
Myaesthenia gravis
Lyme disease
Causes of one-sided CN VII palsy, sparing of the forehead:
UMN CN 7 palsy
Cerebrovascular accidents
MS
Causes of bilateral CN 7 weakness, forehead sparing:
Bilateral UMN:
Pseudobulbar palsy- lower brainstem
MND
Which cranial nerves mediate the jaw jerk?
Sensory branches of V and the motor branches of V
You test the corneal reflex on a patient, how does the site of the lesion differ depending on whether one eye or both eyes blink?
If neither eye closes on touch, then the eye didn’t feel it (CN Va lesion)
If one eye doesn’t close there’s a CN 7 lesion
What type of tuning fork is used for Weber’s + Rinne’s compared to testing vibration sense?
Weber’s- 516Hz (got to add 5 + 1 to find your solution-6)
Vibration- 128Hz (got to prepare the patient, 1, 2..8!)
Which antiepileptic causes gum hypertrophy?
Phenytoin
In a patient with a R sided cerebrovascular accident in a hemisphere controlling CN 11, how would trapezius and sternocleidomastoid be affected?
L sided trapezius weakness
R sided sternocleidomastoid weakness (decussates twice so is ipsilateral to cerebral hemisphere)
In a patient with weak shoulder shrugging and sternocleidomastoid on the same side, what else should be tested?
CN 9 + 10 palsies- suggests jugular foramen lesion (like a glomus tumour or neurofibroma)
Test by ‘Ahhh’ (10) + gag reflex + making ‘gah’ sound (10)
Gag reflex 9 = afferent, 10 = efferent
Which nerve supplies:
- Arm extensors
- Intrinsic muscles of the hand mostly
- Radial nerve
2. Ulnar nerve (T1 supply)
Which intrinsic hand muscles does the median nerve supply?
LOAF Lateral two lumbricals Opponens pollicis Abductor pollicis brevis Flexor pollicis brevis
How can an UMN and LMN lesion of the accessory nerve (CN 11) be differentiated?
UMN- ipsilateral sternocleidomastoid weakness + contralateral trapezius weakness
(Sternoicleidomastoid nerves decussate twice)
LMN- weakness on the same side
Describe the nerve roots responsible for different actions in the arm:
Shoulder abduction: C5 Elbow flexion: C5, C6 Elbow + wrist + finger extension: C7 Finger flexion: C8 Intrinsic muscles hand: T1
Describe the muscle + nerves responsible for the movements of shoulder abduction:
Deltoid
Axillary nerve
C5
Describe the muscle + nerves responsible for the movement of elbow flexion
Biceps brachii
Musculocutaneous nerve
C5,C6
Describe the muscle + nerves responsible for the movements of elbow extension
Triceps
Radial nerve
C7
Describe the muscle + nerves responsible for the movements of finger extension
Extensor digitorum
Posterior interosseous nerve (radial branch)
C7
Describe the muscle + nerves responsible for the movements of finger flexion
Flexor digitorum superficialis + profundus
Ulnar nerve mostly
C8
Which nerve roots are responsible for the leg movements:
Hip flexion: L1, L2
Knee extension: L3, L4
Dorsiflexion + extension of big toe: L5
Hip extension, knee flexion, plantarflexion: S1
Describe the muscle + nerves responsible for the movements of hip flexion
Iliopsoas
Lumbar sacral plexus
L1-L2
Describe the muscle + nerves responsible for the movements of hip extension
Gluteus maximus
Inferior gluteal nerve
L5, S1
Describe the muscle + nerves responsible for the movements of knee flexion
Quadriceps femoris
Femoral nerve
L3, L4
Describe the muscle + nerves responsible for the movements of knee extension
Hamstrings (semitendonosis, semimembranosis, biceps femoris)
Sciatic nerve
L5, S1
Describe the muscle + nerves responsible for the movements of foot dorsiflexion
Tibialis anterior
Deep peroneal nerve
L4, L5
Describe the muscle + nerves responsible for the movements of planarflexion of the foot
Gastrocnemius
Posterior tibial nerve
S1
Describe the muscle + nerves responsible for the movements of big toe flexion
Extensor hallucis longus
Deep peroneal nerve
L5
For the reflexes of the body, which nerves mediate them?
Biceps- musculocutaneous
Triceps- radial
Supinator- radial (watch brachioradialis)
Knee- femoral
Ankle- tibial
Weak in arms and legs, brisk reflexes, positive Babinski sign
Where is the lesion?
Cervical cord or bilateral pyramidal tracts (go from cerebral hemispheres to brainstem/spinal cord)