Neuro Flashcards
Which lobe of the brain is responsible for voluntary motor function?
Frontal lobes
Which lobe of the brain is responsible for language and calculation?
Parietal lobes
Where is the primary sensory cortex?
Post-central gyrus, parietal lobe
Where is the primary motor cortex?
Pre-central gyrus, frontal lobes
Where is the primary visual cortex?
Occipital lobes
What are the basal ganglia responsible for?
Motor refinement
Modulation of cognitive and emotional responses
What three sections make up the brainstem?
Midbrain
Pons
Medulla
What is the bloody supply to the circle of willis?
2x vertebral arteries
2x internal carotid arteries
A clot in which artery would cause locked-in syndrome?
Basilar artery
At which level does the spinal cord terminate and become the caudal equina?
L1-2
What functions are carried within the dorsal columns?
Fine sensation, vibration and proprioception
What functions are carried within the spinothalamic tracts?
Pain, temperature and crude touch
Where do the dorsal column and spinothalamic tracts decussate?
Dorsal column tracts- decussate in medulla oblongata
Spinothalamic tracts decussate lower in the spinal cord
What is the neurological pattern of GBS?
Peripheral neuropathy- polyradiculopathy with no involvement of brain or spinal cord
Generally starts in the feet, spreading proximally to the legs, hands etc
Sensory symptoms often precede motor
Initially pain and paraesthesia -> progressive muscle weakness
Flaccid weakness and numbness
What are the clinical features of GBS?
Usually presenting following recent infection
- most commonly campylobacter gastroenteritis but can be a range of infections
Initially pain and paraesthesia affecting the feet -> spreading proximally
Followed by progressive weakness in similar pattern
Eventually central weakness -> dysarthria, extra ocular weakness, respiratory distress
LMN signs: areflexia, flaccid paralysis, ataxia
What are the triad of features which make up Miller Fisher Syndrome?
Ophthalmoplegia
Areflexia
Ataxia
How is GBS diagnosed?
Neuroimagine: NAD
Nerve conduction: slowed LMN conduction velocity
LP: elevated protein with normal cytology
Blood cultures and PCR for search for causative agent
How is GBS managed?
Regular spirometry & ABG to monitor respiratory function and need for intubation
VTE prophylaxis
IVIG for 5 days or plasma exchange if IVIG not available
NO BENEFIT of steroids
Physio, OT, neuro rehab
What are differential diagnoses for GBS?
Diabetic neuropathy- much more chronic course, prev DM, usually only sensation initially
MG- chronic, weakness varies throughout day, no pain, sensation and reflexes in-tact
Botulism- similar except DESCENDING paralysis rather than ascending, normal CSF, reflexes in-tact
Cauda equina- only affects lower body, sphincter involvement
Transverse myelitis- UMN syndrome
What is the cause of Myasthenia Gravis?
Auto-antibodies against acetylcholine receptors
What is the symptom pattern of MG?
Usually oculobulbar symptoms initially - worst in the evening
- Progressive ptosis and diplopia (horizontal mostly)
- Dysarthria, dysphagia aspiration
Progressive muscle weakness, mostly in proximal muscle groups e.g. raising arms, climbing stairs
Symptoms improve with rest
Reflexes and sensation remain in-tact
How is MG diagnosed?
Presence of AChR-autoantibodies
Nerve conduction studies: progressively decremental response on repetitive stimulation
PFTs to rule out MG crisis
How is MG managed?
1st line= pyridostigmine (AChE antagonist)
Corticosteroids
Thymectomy
Plasma exchange in crisis
What are differentials for MG?
LEMS: same but IMPROVES with repeated use rather than worsens
Botulism
Primary myopathy
What is a myasthenic crisis?
Worsened MG symptoms affecting respiratory muscles
Requiring respiratory support
Oropharyngeal involvement can also cause airway obstruction + aspiration
Most commonly triggered by supervening infection
Rx= IVIG or plasma exchange as soon as possible
What are the causes of botulism?
Clostridium botulinum toxin
- > GI via food ingestion
- > Respiratory via inhalation
- > Iatrogenic
- > Skin breaks
What are the symptoms of botulism?
Most common= GI so preceded by D&V
Descending flaccid paralysis with areflexia
- > Starts in cranial nerves and descends
- > Ptosis, diplopia, facial droop, ophthalmoplegia, mydriasis, poor reactivity/accomodation, hypoglossal weakness, dysarthria, dysphagia
Sensation remains in-tact, afebrile
Can cause respiratory failure
How is botulism diagnosed?
Mouse bioassay
Nerve conduction studies: small action potentials in response to supramaximal stimulation
Assessment of airway and respiratory function -> intubation
How is botulism managed?
Botulism anti-toxin administration ASAP
Respiratory support
Wound debridement and supportive care
Where do the corticospinal tracts decussate?
Lateral tract decussates in the medulla, anterior tract lower in the cord
What is acute cervical cord syndrome?
Hyperextension injury of the C-spine- mostly traumatic but can be caused by osteoporosis and collapse
Causes motor deficit in all 4 limbs but most pronounced in the arms
Sensory deficit in a cape-like distribution below level of injury- may have some arm sparing depending on level
Neck pain at site of impingement
Hyperreflexia and increased tone (UMN lesion)
May suffer urinary retention
How should anterior cervical cord syndrome be managed?
Cervical immobilisation and C-spine MRI
Steroids to reduce inflammation
Physio and OT
What are the causes of caudal equina syndrome?
Disc herniation= most common MSCC / bony tumour Epidural abscess Fracture Spinal dural haematoma
What are the symptoms of caudal equina syndrome?
> 97% suffer back pain and bilateral sciatica
Saddle anaesthesia, loss of anal tone +/- incontinence Urinary retention, erectile dysfunction Areflexia and lack of tone in the legs Bilateral leg weakness Ataxia
How is cauda equina diagnosed?
Emergency MRI spine
CT myelogram if MRI not available
Bladder scan
How should cauda equina be managed?
A-E assessment
Catheter
Adequate analgesia
Neurosurgical input
Surgery should be performed <24 hours to reduce the risk of tetraplegia
What is Bell’s palsy?
Acute unilateral palsy of the facial nerve (CN7)
LMN lesion
Commonly thought to be viral cause e.g. HSV1
How does Bell’s palsy present?
Subacute onset (72 hours) of facial nerve palsy affecting all branches of the nerve
Forehead involvement
Unilateral
Loss of blink-> dry eye and ulcerative keratitis if not managed
How is Bell’s palsy investigated?
Usually clinical diagnosis
NCS will show >90% decrease in amplitude compared to other side
How is Bell’s palsy managed?
High dose corticosteroids - oral prod tapering course starting at 60mg
Eye protection: tape shut, artificial tears, glasses
Most people with Bell’s palsy make a full recovery within 3–4 months
What is Ramsay-Hunt syndrome?
Reactivation of VZV in the geniculate ganglion of the facial nerve
Causes facial nerve palsy affecting all 3 branches- no forehead sparing
LMN lesion
Associated with vesicular rash in/on the ear, otalgia and may get tinnitus/vertigo/SN deafness
How is Ramsay Hunt syndrome managed?
Oral aciclovir <72 hours
Oral steroids
Carbamazepine for any neuropathic pain
Eye protection- sunglasses, taping shut, artificial tears/lubricants
What are the symptoms of common peroneal nerve palsy?
Footdrop -> high-stepping gait
Inability to dorsiflex or evert the foot
Sensory disturbance on dorsum of foot and lateral leg
Unable to walk on heels
Ankle reflexes spared
Tinel’s sign positive
How is common peroneal nerve palsy managed?
Footdrop splint
Physiotherapy
Surgical repair in some
What are the clinical features of tarsal tunnel syndrome?
Pain BEHIND medial malleolus + planter aspect of medial heel
Pain with dorsiflexion and eversion
Initially worse with walking -> constant
What nerve is affected in tarsal tunnel syndrome?
Posterior tibial nerve
What are the symptoms of obturator nerve palsy?
Numbness/paraesthesia of the medial thigh
Weakened thigh ADduction
Wide-based, circumducting gait
Wasting of medial thigh muscles
What are symptoms of pudendal nerve palsy?
Pain/paraesthesia/numbness of the perineum, genitalia
Urinary urgency and frequency
Erectile dysfunction
S2-4 control the pelvic floor
What are the symptoms of suprascapular nerve palsy?
Wasting of the supra/infraspinatous muscles
Inability to abduct/externally rotate the arm
Impingement pain
Compression WHERE tends to cause radial nerve palsy?
Compression against the humerus, where there is the radial groove
What are the symptoms of radial nerve palsy?
Wrist-drop
Weakened triceps
Loss of extension of fingers and thumb
Sensory loss to dorsum of lateral 3.5 digits
What is the most common cause of ulnar nerve palsy?
Prolonged pressure on the elbow
What are the symptoms of ulnar nerve palsy?
Inability to extend medial 1.5 fingers (little and ring)
Inability to abduct/adduct fingers
Impaired thumb ADDuction
Decreased grip strength
Sensory loss to medial half of the hand
Muscle atrophy
What does Froment’s sign indicated?
Ulnar nerve palsy
Inability to hold piece of paper with thumb- impaired thumb adduction
What causes median nerve palsy?
Carpal tunnel syndrome
What are the symptoms of carpal tunnel syndrome?
Numbness, tingling and pain in the palmar aspect of lateral aspect of lateral 3.5 fingers
Pain can radiate to wrist and forearm + generally worse in the morning
Pain can wake from sleep
Inability to grip properly, clumsiness
Wasting of the thenar eminence
What is Phalen’s test?
Test for carpal tunnel syndrome
Hold wrist in flexion for 60s-> elicits numbness or pain in median nerve distribution
What is the gold standard test for carpal tunnel syndrome?
EMG: slowed conduction velocity across carpal tunnel, decreased amplitude and prolonged latency
How is carpal tunnel syndrome managed?
Dorsiflexed splint (20degree extension)
Steroid injection
Surgical decompression
What should you consider when changing epilepsy medication?
Risk of breakthrough seizures
Consider interactions between new medication and current (both epilepsy and others)
Tolerability of new medication- new side effects etc
Implications for driving- recommended to stop driving for 6m during changeover, HAVE to after 6 months
Usual advice: no working at height/care near water etc
What considerations should be taken in pregnancy for epileptic women?
5mg folic acid
Lamotrigine = 1st line, carbemazepine also safe
MDT input into pregnancy
Change medication over when THINKING about getting pregnant to reduce the risk of breakthrough seizures
What are the driving rules with seizures?
Have to stop 6m after first seizure
Recommended to stop 6m when changing medication
Legally must stop for 6m after breakthrough seizure
In established epilepsy, must stop for 12m after an established seizure if not due to medication change
Can’t drive for work until seizure free for 10 years.
What is first line for absence seizures?
Ethosuximide
What is first line for myoclonic seizures?
Leviteracetam
What needs to be in place before initiating sodium valproate?
Pregnancy prevention plan
Baseline FBC and LFTs
Need counselling on signs of hepatotoxicity and thrombocytopenia
Which anti-epileptic is especially associated with SJS/TEN?
Lamotrigine
Which anti-epileptic can interact with SSRIs to increase availability?
Lamotrigine
Which anti-epileptics interact with the oral contraceptive pill?
Carbamazepine
Topiramate
What are the causes of optic neuritis?
MS Neuromyelitis optica Infection: encephalitis, meningitis SOL/compression of the optic nerve Medication: ethambutol Toxins: lead, methanol
What are the clinical features of optic neuritis?
Retrobulbar pain Visual disturbance- often central scotoma Photophobia Painful movement of the eye RAPD Papilloedema
How is optic neuritis diagnosed?
MRI of the optic nerve
How is optic neuritis treated?
Methylprednisolone: 1g IV 3 days, 500mg oral 5 days
+ gastroprotection
Most episodes resolve spontaneously in a matter of months
What are the causes of transverse myelitis?
MS Neuromyelitis optica Post-vaccine Rheumatological diseases Viral disease and encephalitis
How does transverse myelitis commonly present?
Acute/subacte onset
May have back/sciatic pain
Paraesthesia and sensory loss below spinal level of lesion
Weakness in the limbs below the lesion which can progress to paralysis
May have bladder/bowel/sexual dysfunction
Spasticity and hyper-reflexia
How is transverse myelitis diagnosed?
MRI brain and spinal cord to try and identify focus of inflammation
Bloods to rule out B12 deficiency, HIV, low copper, autoantibodies
LP + CSF analysis may show raised protein
What is the management of transverse myelitis?
IV methylprednisolone: 1g 3-5 days
IVIG/plas ex if no improvement
Analgesia
Antivirals if indicated
What is the clinical definition of MS?
2 discrete episodes of neurological dysfunction separated in space and time
Demyelinating disease with neuronal loss and axonal transection
How does MS classically present?
Classically white women 20-40s
Often starts with episode of optic neuritis
What is the most common pattern of MS?
Relapse-remitting: 85-90%
Often become secondary progressive (approx 50% of patients)
May also be primary progressive or progressive relapsing MS.
What is L’Hermitte’s phenomenon?
Electric-shock like sensations running down the back of the neck, spine and sometimes into the limbs
- Triggered by forward neck flexion
- Often due to lesion in the upper posterior cervical cord
How is MS diagnosed?
MRI brain and spinal cord- looking for areas of high signal which may indicate current or past inflammation
LP: oligoclonal banding in CSF, raised IgG
Evoked potentials in affected nerves
How is MS managed?
For a relapse: High dose methylprednisolone IV 1g 3/7 or 500mg PO 5/7
+ PPI + bisphosphonates
Disease modifying medication:
B-interferon + glatiramer = most common agents
Symptomatic: Baclofen for spasticity Sertraline for associated depression Pregabalin/gabapentin/TCAs for neuropathic pain Oxybutynin for urinary urgency/frequency
What are the differentials for MS?
Neuromyelitis optica
Standalone episode of optic neuritis or transverse myelitis
Stroke
GBS
Vitamin B12 deficiency- subacute combined degeneration of the cord
Autoimmune inflammatory conditions
What is neuromyelitis optica?
Auto-inflammatory condition affecting the optic nerve and spinal cord
Characterised by optic neuritis and transverse myelitis
Caused by auto-antibodies: Anti-AQP4 and MOG antibodies
How is NMO differentiated from MS?
MRI brain and spine- NMO only optic nerve and transverse myelitis, MS may show inflammation in other areas
Bloods: anti-AQP4 and MOG antibodies + rule out other causes
CSF analysis: no oligoclonal bands in NMO
How is NMO managed?
High-dose IV corticosteroids- methylprednisolone
Plasma exchange if limited response to steroids
Long-term immunosuppressants can be used to reduce the risk of relapse
Symptomatic treatment
What causes trigeminal neuralgia?
Compression of the nerve root at the skull base
- Cyst/tumour, skull malformation
- Meningeal inflammation
- Facial injury
- Demyelinating conditions, MS
How is trigeminal neuralgia managed?
Carbamazepine = first line
Gabapentin/Pregabalin second line
If treatment resistant: surgical decompression
How does venous sinus thrombosis cause death?
Mass effect from the thrombus + inflammation/oedema around it can cause trans-tentorial herniation and coning
Where is the most common site of a venous sinus thrombus?
Sagittal sinus
Headache, vomiting, seizures, papilloedema, reduced vision
How is venous sinus thrombosis diagnosed?
MRI/CT brain and venogram (venogram most diagnostic)
LP to rule out other causes- only FOLLOWING imagine
How is venous sinus thrombosis managed?
LMWH and warfarin for 6 months
May need decompressive hemi-craniotomy
What is the most common form of MND?
Amyotrophic Lateral Sclerosis
What are the symptoms of MND?
Combination of upper and lower motor neurone symptoms
Muscle fasciculation- especially tongue
Limb weakness, usually proximal muscles first
Stiffness, spasticity, poor balance, ataxia, painful spasm, hyperreflexia
Dyspnoea, dysphagia, aspiration
Which medication is thought to alter the disease course of MND?
Riluzole
What medications can be used to relieve migraine?
Paracetamol/ibuprofen
Domperidone for vomiting
Triptans
What medications can be used for migraine prophylaxis?
Propranolol first line
Topiramate but not in women of childbearing age
Amitriptyline
What can be used to treat cluster headaches?
High-flow oxygen (12-15L non-rebreathe)
Nasal/SC triptans
What can be used as cluster headache prophylaxis?
Verapamil
What are the initial measures for raised ICP?
Hyperventilation
Bed at 30-40 degrees
IV mannitol
Fluid restriction
What is the management for benign intracranial hypertension?
Acetazolamide +/- furosemide
Amitriptyline
CSF shunting
What is the treatment of choice for focal seizures?
Carbamazepine
What are the causes of spastic paraparesis?
Thoracic cord lesions- only legs affected
UMN
Trauma, tumour, TB, transverse myelitis, B12 deficiency, spinal artery thrombosis
What are the causes of flaccid paraparesis?
Lesion below the level of the spinal cord i.e. Cauda equina, Initial phases of GBS, trauma to spine lower than conus medullaris
LMN signs in both legs
What are the causes of spastic tetraparesis?
Cervical spine lesion, UMN
Neck trauma, catastrophic stroke
What is cervical myeloradiculopathy?
Compression of the nerve roots of the C-spine
Causes LMN symptoms in the arms +/- UMN symptoms in the legs depending on the compression of the cord
Most commonly result of osteoporosis or c-spine herniation
What is Brown-Sequard syndrome?
Hemi-cord syndrome: lesion affecting only one side of the cord e.g. stab wound
Loss of pain and temperature on contralateral side
Loss of fine touch and proprioception on affected side
UMN symptoms in the leg on the same side
What are the causes of peripheral neuropathy?
GBS Diabetic neuropathy Vitamin deficiency Alcohol-induced Thyroid disease
What pattern of symptoms would you expect in a brainstem lesion?
Cranial nerve palsy on the side of the lesion
Contralateral limb/long-tract signs
What is a RAPD?
Loss of afferent reflex on affected side but consensual constriction still in-tact
When swinging light test, paradoxical dilation of the affected eye when the torch is shone into it
Optic nerve palsy e.g. optic neuritis
What is internuclear ophthalmoplegia?
Impaired adduction of the affected eye
Affected eye does not adduct past the midline and the other eye abducts with nystagmus as if trying to pull the affected eye along with it
Caused by a lesion in the MEDIAL LONGITUDINAL FASCICULUS
Most commonly caused by MS or stroke
What is the management of status epilepticus?
5 min: 4mg IV lorazepam or 10mg buccal/rectal alternatives
Repeat if no improvement after further 5 mins
If still no improvement after further 5 mins: IV phenytoin 18mg/kg
After 30 mins, general anaesthesia, I&V
What monitoring is required in the patients needing phenytoin to terminate seizures?
Continuous BP and ECG monitoring due to arrhythmogenic quality
What is the most common cause of encephalitis?
Viral- particularly HSV 1 and other herpes viruses
What are the symptoms of encephalitis?
Prodromal: fever, rash, lymphadenopathy, cold sores, meningeal irritation, conjunctivitis
Altered mental state / lower GCS
Focal neurological signs
Seizures, meningism
How should you investigate suspected encephalitis?
Full neurological examination + A-E
Full set of obs
Bloods: cultures, viral PCR, FBC, U&E, LFT, glucose, ABG
Throat swabs / CXR
CT head with contrast- may show meningeal inflammation
LP: may show raised protein + lymphocytes, low glucose -> CSF send for viral PCR
EEG
How should you manage encephalitis?
IV aciclovir ASAP- treat if suspicious, don’t wait for any viral PCR
May need I&V and ICU care
Symptomatic and supportive treatment
What are differentials for encephalitis?
Meningitis Intracerebral abscess / SOL Hypoglycaemia Stroke Metabolic encephalopathy: uraemia, hypercapnic, hepatic Wernicke-Korsakoff Alcohol withdrawal
What are the features of epidural haematoma?
Biconcave lesion that will not cross suture lines
Caused by bleed of a meningeal artery- most commonly MMA after pterion fracture?
Patients often lose consciousness, come round and have a lucid period and then lose consciousness again due to raised ICP and brainstem compression
Signs: headache, vomiting, confusion, seizure
bradycardia with hypertension
ipsilateral pupil dilatation
What are the features of subdural haematoma?
Crescent-shaped lesion beneath the dura which can cross sutural lines
Caused by rupture in the bridging veins -> increased risk in elderly fall and alcoholic/coagulopathy
Often presents with confusion, drowsiness, headache, unsteadiness
Also: vomiting, seizures, ICP signs
Can cause midline shift and tentorial herniation -> coning
Small ones often conservative watch/wait management
What are the features of subarachnoid haemorrhage?
Bleeding from circle of willis
Usually due to berry aneurysms, AV malformation, trauma, severe HTN
Thunderclap occipital headache, reduced GCS, vomiting, meningism, seizures
May be visible on plain CT head
Xanthochromia on LP
CT angiogram can show source
How are subarachnoid haemorrhages managed?
A-E
Keep SBP<160
Nimodipine prevents vasospasm
Endovascular clipping or coiling
What are the complications of subarachnoid haemorrhage?
Rebleeding is the most common cause of death
Cerebral ischaemia due to vasospasm
Blocked venous sinuses -> hydrocephalus
Hyponatraemia due to SIADH
What is the name of the aphasia where people make little sense?
What area of the brain is responsible for this?
Wernicke’s aphasia
Left superior temporal gyrus
What is the name of the aphasia where people can’t form words properly?
What part of the brain is generally affected here?
Broca’s aphasia
Left inferior frontal gyrus.
It is typically supplied by the superior division of the left MCA.
How would you manage a patient with suspected TIA?
300mg aspirin loading dose - continue 2-3 weeks
Referral to TIA clinic in 24 hours
Secondary prevention of stroke: clopidogrel, statin 80mg (after 2 weeks), HTN and DM management
What is the most important thing to exclude before making a diagnosis of stroke?
Hypoglycaemia
What is the management of confirmed Ischaemic stroke?
- Loading dose 300mg aspirin
- <4.5 hours: thrombolysis +/- thrombectomy if eligible
Continue 300mg aspirin + PPI for 2 weeks
75mg clopidogrel should be continued following this + 80mg atorvastatin
Manage HTN, DM and other risk factors
How is stroke/TIA managed differently in people with AF?
After the 2 week interim period with aspirin, long-term anticoagulation should be initiated
EITHER
DOAC
Warfarin (INR target 2.5)
Anticoagulation should not routinely be prescribed in those in normal sinus rhythm
How long after a TIA can you drive?
1 month
3 months if you have had multiple TIAs- aka must be 3 month TIA free
What score can be used to identify stroke in ED?
ROSIER
Score >0 = increased risk of stroke
What are the three features of total anterior circulation stroke?
- Hemiplegia
- Homonymous hemianopia
- Higher cognitive dysfunction
What are the features of partial anterior circulation stroke?
Any 2 of:
- Hemiplegia
- Homonymous hemianopia
- Higher cognitive dysfunction
What are the features of lacunar stroke?
Presents with 1 of:
- Unilateral weakness of face and arm, arm and leg or all 3
- Pure sensory stroke
- Ataxic hemiparesis
What are the features of posterior circulation stroke?
Presents with 1 of:
- Cerebellar or brainstem syndromes
- Loss of consciousness
- Isolated homonymous hemianopia
What are contraindications to thrombolysis?
- Previous intracranial haemorrhage
- Seizure at stroke onset
- Intracranial neoplasm
- Lumbar puncture in last 7 days
- GI bleed in last 3 days
- Active bleeding
- Pregnancy
- Oesophageal varices
- Uncontrolled hypertension >200/120
- Stroke or traumatic brain injury in the past 3 months
