Neurology Flashcards
Define aphasia and list the 4 types
A disorder where a person has difficulty with their language and speech - the 4 types are:
1) Wernicke’s (receptive)
2) Broca’s (expressive)
3) Conduction
4) Global
What is Wernicke’s aphasia?
Due to a lesion of the superior temporal gyrus (supplied by the inferior division of the left MCA) - speech remains fluent but nonsensical - comprehension is impaired
What is Broca’s aphasia?
Due to a lesion of the inferior frontal gyrus (supplied by the superior division of the left MCA) - speech is non-fluent, laboured and halting w/ impaired repetition - comprehension is normal
What is Conduction aphasia?
Classically due to a stroke affecting the arcuate fasciculus (conneection between Wernicke’s and Broca’s areas) - speech is fluent but repetition is poor, aware that they are making mistakes - comprehension is normal
What is Global aphasia?
Large lesion affecting the superior temporal gyrus, inferior frontal gyrus and arcuate fasciculus - severe expressive and receptive aphasia
Define an Arnold-Chiari malformation
This is the downwards herniation of the cerebellar tonsils through the foramen magnum - may be congenital or acquired through trauma
Arnold-Chiari malformation features
Non-communicating hydrocephalus (CSF outflow obstruction), headache, syringomyelia
Define ataxia
Poor muscle control resulting in uncoordinated movements
Define Ataxia telangiectasia
An autosomal recessive primary immunodeficiency
Ataxia telangiectasia features
Cerebellar ataxia, telangiectasia, IgA deficiency, typically presents in early childhood w/ abnormal movements
Define Autonomic dysreflexia
A clinical syndrome which occurs in pts who have a spinal cord injury at, or above T6 spinal level. In response to a noxious stimulus below the level of the spinal cord injury (commonly faecal impaction or urinary retention), there is massive reflex sympathetic discharge. This results in vasoconstriction and hypertension. However, due to the lesion in the spinal cord, this sympathetic response cannot be regulated by the brain.
Above the level of injury, where neural connections are intact, parasympathetic activity via vagal stimulation tries to counteract this by causing vasodilation and bradycardia. However, this compensatory mechanism is only effective above the level of injury and cannot offset the hypertensive crisis occurring below it.
Autonomic dysreflexia features
Characterised by extreme hypertension, flushing and sweating above the level of the cord lesion, agitation, haemorrhagic stroke if HTN not treated
Autonomic dysreflexia management
Removal/control of the stimulus and treatment of any life-threatening HTN and/or bradycardia
Bell’s palsy features
Facial nerve palsy that DOES NOT spare the forehead, post-auricular pain, altered taste, dry eyes, hyperacusis
Bell’s palsy managment
All pts should receive oral prednisolone w/in 72 hours of symptom onset, eye care to avoid exposure keratopathy (prescribe artificial tears and eye lubricant, tape eye closed at bedtime), consider adding antivirals - if no improvement after 3 weeks then refer to ENT
Define Erb-Duchenne paralysis
Damage to the C5/6 roots in the brachial plexus (commonly by breech presentation) - causes winged scapular
Define Klumpke’s paralysis
Damage to T1 at the brachial plexus (usually due to traction) - causes a loss of intrinsic hand muscles
Brain abscess management
Surgery (craniotomy performed and the abscess cavity is debrided), IV abx (cephalosporin + metronidazole), dexamethasone to control ICP
Define Brown-Sequard syndrome
A lateral hemisection of the spinal cord
Brown-Sequard features
Ipsilateral weakness below the lesion, ipsilateral loss of proprioception and vibration sensation, contralateral loss of pain and temp (spinothalamic)
Define cataplexy
The sudden and transient loss of muscular tone caused by a strong emotion (ranging from buckling knees to collapse) - related to narcolepsy
Cerebellar syndrome features
DANISH = Dysdiadochokinesia, dysmetria, ataxia, nystagmus, intention tremor, speech disturbance, hypotonia
Causes of Cerebellar syndrome
Inherited (Freidreich’s ataxia, ataxia telangiectasia), cerebellar haemangioma, stroke, alcohol, MS, hypothyroidism, drugs (anti-epileptics, lead poisoning), paraneoplastic secondary to lung cancer
Define cerebral perfusion pressure
The net pressure gradient causing blood flow to the brain. A sharp rise in CPP may cause in a rise in ICP, a fall in CPP may result in cerebral ischaemia - calculated using:
CPP = mean arterial pressure - intracranial pressure
Where does CFS fill?
The space between the arachnoid and pia mater (subarachnoid space)
Where is CSF produced?
70% by ependymal cells in the choroid plexus, 30% by blood vessles
CSF circulation
1) Lateral ventricles
2) 3rd ventricle
3) Cerebral aqueduct
4) 4th ventricle
5) Subarachnoid space
6) Reabsorbed into venous system via arachnoid granulations into superior sagittal sinus
Define Charcot-Marie-Tooth disease
The most common hereditary peripheral neuropathy - predominantly causes motor loss
Charcot-Marie-Tooth disease features
Foot drop (may have a Hx of frequent sprained ankles), high-arched feet (pes cavus), hammer toes, distal muscle weakness/atrophy, hyporeflexia, Stork leg deformity
Cluster headache investigations
Most pts will have an MRI w/ gadolinium contrast to look for underlying brain lesions
Cluster headache management
Acute = 100% O2, subcutaneous triptans
Prophylaxis = verapamil
Common peroneal nerve lesion features
Most common feature is foot drop - other features include: weakness of foot dorsiflexion/eversion, weakness of extensor hallucis longus, sensory loss over the dorsum of the foot and the lower lateral part of the leg, wasting of the anterior tibial and peroneal muscles
Where do common peroneal nerve lesions occur?
Most commonly occurs at the neck of the fibula
Oculomotor nerve palsy features
Ptosis, ‘down and out’ eye, fixed dilated pupil
Trochlear nerve palsy features
Defect in downwards gaze - vertical diplopia
Trigeminal nerve lesions features
They may cause: trigeminal neuralgia, loss of corneal reflex (afferent), loss of facial sensation, paralysis of mastication muscles, deviation of jaw to weak side
Abducens nerve palsy features
Defective eye abduction - horizontal diplopia
Facial nerve lesions features
May cause: flaccid paralysis of upper and lower face, loss of corneal reflex (efferent), loss of taste, hyperacusis
Vestibulocochlear nerve lesions features
Hearing loss, vertigo, nystagmus
Glossopharyngeal nerve lesions features
May result in: hypersensitive carotid sinus reflex, loss of gag reflex (afferent)
Vagus nerve lesions features
May result in: uvular deviation away from the side of the lesion, loss of gag reflex (efferent)
Accessory nerve lesions features
Weakness in turning head and raising shoulders on contralateral side
Hypoglossal nerve lesions features
Tongue deviates towards the side of the lesion
Which nerves innervate the afferent an efferent arms of the corneal reflex?
Afferent = Ophthalmic nerve
Efferent = Facial nerve
Which nerves innervate the afferent an efferent arms of the jaw jerk reflex?
Mandibular nerve (CN V) for both
Which nerves innervate the afferent an efferent arms of the gag reflex?
Afferent = glossopharyngeal
Efferent = vagus
Which nerves innervate the afferent an efferent arms of the pupillary light reflex?
Afferent = optic
Efferent = oculomotor
Define Degenerative cervical myelopathy
Cord compression in the cervical spine due to disk degeneration and ligament hypertrophy
Degenerative cervical myelopathy features
Signs on cord compression, +ve Hoffman’s sign
What is Hoffman’s sign?
A reflex test to assess for cervical myelopathy. It is performed by gently flicking one finger on a patient’s hand. A positive test results in reflex twitching of the other fingers on the same hand in response to the flick
Degenerative cervical myelopathy management
Urgent referral to neurosurgery for decompressive surgery
5 drugs which cause peripheral neuropathy
Amiodarone, isoniazid, vincristine, nitrofurantoin, metronidazole
Define Muscular dystrophy
An X-linked recessive condition resulting in a mutated dystrophin (where actin binds to the muscle membrane)
What are the 2 types of muscular dystrophy and what does the mutation cause?
Duchenne = frameshift mutation so both binding sites are lost, more severe
Becker = non-frameshift insertion so both binding sites are preserved, more mild
Duchenne muscular dystrophy features
Progressive proximal muscular weakness from 5 years, calf pseudohypertrophy, Gower’s sign (child uses arms to stand from squat position), 30% have IQ impairment
Becker’s muscular dystrophy features
Progressive proximal muscle weakness from aged 10
How can you distinguish between a neuropathy and a myopathy?
Myopathy = usually has proximal weakness (as this is where the bulky muscles are, so the weakness is more obvious), no sensory deficits, normal reflexes, no fasciculations, EMG shows decreased action potential duration/amplitude
Neuropathy = usually has distal weakness (length dependent), mixed motor and sensory deficits, reflex changes, fasciculations, EMG shows increased action potential duration/amplitude
West Syndrome features
Salaam attacks which last 1-2 secs and may repeat up to 50 times, progressive mental handicap, onset at the beginning of life, EEG = hypsarrhythmia
Typical absence seizures features
Suddenly stopping, staring blankly, automatisms, lasts 2-30 seconds, recover quickly, no warning, often many in a day, onset 4-8 years, EEG = 3Hz, generalised, symmetrical
Typical absence seizures management
Sodium valproate, ethosuximide
Lennox-Gastaut syndrome features
Atypical absenses, falls, jerks, 90% have moderate IA impairment, may be an extension of infantile spasms, onset 1-5 years, EEG = slow spike
Juvenile monoclonal epilepsy (Janz syndrome) features
Infrequent generalised seizures often upon waking/sleep deprived, daytime absences, sudden shock-like myoclonic seizers, onset in teenage years
Juvenile monoclonal epilepsy management
Sodium valproate
Focal temporal lobe seizure features
An aura for up to 2 mins which may or may not progress into an abscence seizure w/ automatisms - this then may (rarely) progress to a generalised tonic-clonic.
Aura symptoms = Deja Vu, sudden intense feelings of joy/fear/anxiety, a rising sick feeling from the stomach, audio/gustatory/olfactory hallucinations
Focal frontal lobe seizure features
Head/leg movements, posturing, post-ictal weakness, Jacksonian march (clonic movements traveling proximally)
Focal parietal lobe seizure features
Paraesthesia
Focal occipital lobe seizure features
Floaters/flashes
Generalised tonic-clonic seizures management
Males = sodium valproate
Females = lamotrigine or levetiracetam
Focal seizures management
1st line =lamotrigine or levetiracetam
2nd line = carbamazepine
Absence seizures management
1st line = ethosuximide
2nd line = Males = sodium valproate, Females = lamotrigine or levetiracetam
NOTE - carbamazepine may exacerbate absence seizures
Myoclonic seizures management
Males = sodium valproate
Females = levetiracetam
Tonic/atonic seizures management
Males = sodium valproate
Females = lamotrigine
When do you start treatment for epilepsy?
After a second seizure, or after a first with obvious EEG signs
Essential tremor features
Postural tremor (worse if arms outstretched) which usually affects both upper limbs, improves w/ alcohol and rest
Essential tremor management
Propranolol - Primidone if can’t take beta blockers
Which artery is usually responsible for an extradural haematoma
Middle meningeal artery
Extradural haematoma features
Hx of head trauma w/ LOC, followed by a lucid interval and then a second LOC, fixed and dilated pupil (due to compression of the oculomotor nerve from uncal herniation)
Extradural haematoma CT appearance
Biconvex (lemon), hyperdense collection limited by the suture lines
Extradural haematoma management
Craniotomy and evacuation of the haematoma
Causes of facial nerve palsy (unilateral and bilateral)
Bilateral = sarcoidosis, GBS, Lyme disease, bilateral acoustic neuromas, Bell’s palsy
Unilateral = as above, Ramsay-Hunt syndrome, parotid tumours, HIV, MS, diabetes mellitus, stoke
Which cause of facial palsy spares the forehead?
UMN lesions
Define Foot drop
A gait abnormality where the pt has difficulty lifting the front of the foot due to weakness in the dorsiflexors
Causes of foot drop
Common peroneal nerve lesion (most common), L5 radiculopathy, sciatic nerve lesion, superficial or deep peroneal nerve lesions, stroke
Trochlear nerve palsy features
Vertical diplopia, inability to adduct the eye, subjective tilting of objects, head tilt, eye upwards and outwards when looking forwards
Guillain-Barre syndrome pathophysiology
Cross-reaction resulting in the formation of anti-ganglioside antibodies (anti-GM1) usually triggered by Campylobacter jejuni infection - leads to demyelination
Guillain-Barre syndrome features
Initially pt commonly experience back/leg pain
Characteristically causes progressive, symmetrical weakness of all the limbs, in an ascending pattern
Also causes hyporeflexia, resp muscle weakness, CN involvement, autonomic involvement (urinary retention and diarrhoea) but causes very few sensory signs
Guillain-Barre syndrome investigations
Lumbar puncture (rise in protein w/ a normal WCC found in 66%), nerve conduction studies (decreased motor neve conduction velocity due to demyelination)
Define Miller-Fisher syndrome
A variant of Guillain-Barre syndrome due to anti-GQ1b antibodies (still commonly after Campylobacter infection)
Miller-Fisher syndrome features
DECENDING paralysis, ophthalmoplegia, areflexia, ataxia - eye muscles are typically affected first
Guillain-Barre syndrome management
No cure, treatment is to aid recovery and symptoms - Plasmapheresis or IVIg, gabapentin/amitriptyline/pregabalin
Define Holmes-Adie pupil
An enlarged pupil that reacts slowly to light and near stimulus - due to damage to parasympathetic chain
Holmes-Adie pupil features
- Anisocoria = unequal size of pupils
- Tonic pupillary response = when exposed to light the affected pupil demonstrates slow and prolonged constriction followed by gradual re-dilation
- Vermiform movements = undulating movements seen under slit-lamp biomicroscopy
- Accommodation reflex dysfunction = blurriness of near vision
Holmes-Adie syndrome features
Holmes-Adie pupil + other neuro features (e.g. a/hyporeflexia esp of Achilles tendon)
Define Horner’s syndrome
Unilateral ptosis, myosis and anydrosis due to disruption to the sympathetic chain
Define Huntington’s disease
An A.dominant trinucleotide repeat disorder resulting in the degeneration of cholinergic and GABAergic neurones in the striatum of the basal ganglia - death usually occurs w/in 20 years of onset of symptoms
Huntington’s disease features
Chorea, personality changes, intellectual impairment, dystonia, saccadic eye movements - usually develop after 35
Huntington’s disease investigations
Genetic testing (1st line), neuroimaging to support diagnosis (CT or MRI may show caudate nucleus atrophy)
Huntington’s disease management
Neuro management = Tetrabenazine for chorea, antipsychotics for psychosis and chorea, levodopa for bradykinesia/rigidity
Other management = SALT for dysphagia, psychiatric for depression, physiotherapists for mobility, dietitians for nutrition, social workers
Risk factors for raised ICP
Female, obesity, pregnancy, medication (COCP, tetracyclines, retinoids, lithium, thyroxine, nitrofurantoin)
Idiopathic intracranial hypertension features
Headache, transient visual obscurations, pulsatile tinnitus, photopsia, back pain, retrobulbar pain
Papilledema, visual field loss, 6th nerve palsy, relative afferent pupillary defect
Idiopathic intracranial hypertension investigations
All pts should be referred urgently for neuroimaging to rile out secondary causes
Idiopathic intracranial hypertension management
Conservative = WL, stop causative agents, regular visual field testing
Medical = Acetazolamide for all pts w/ visual field loss, loop diuretics may be used in refractory cases, repeat LPs
Surgical = Optic nerve sheath fenestration for pts who lose vision despite maximum medical management, Ventriculoperitoneal shunt
Define Idiopathic intracranial hypertension
Raised ICP w/out a clear secondary cause on investigations
Define Lambert-Eaton syndrome
An autoimmune disorder that usually occurs as a paraneoplastic syndrome seen in SCLC (and breast and ovarian cancer to a lesser extent), but can occur on its own - it’s caused by an antibody directed against the presynaptic voltage-gated Ca channels in the peripheral nervous system
Lambert-Eaton syndrome features
Weakness which decreases with muscle use, hyporeflexia, autonomic dysfunction
Lambert-Eaton syndrome investigations
EMG shows incremental response to repetitive electrical stimulation
Lambert-Eaton syndrome management
Treat underlying cancer, immunosuppression (pred, azathioprine)
Migraine management
Acute = Triptans (oral for adults, nasal for 12-17) +/- NSAIDs or paracetamol
Prophylactic = Propranolol, topiramate (avoid in women of child bearing age), amitriptyline
Migraine complications
Acute = status migrainosus (severe, debilitating attack lasting more than 62 hrs despite treatment), migrainous infarction (causes an ischaemic stroke), persistent aura w/out infarct (aura lasting more than 1 week after headache resolves)
Chronic = chronic migraines, medication overuse headaches, transformed migraine (AKA chronic daily headache)
Migraine with aura is linked to an increased risk of venous thromboembolism
Motor Neurons Disease features
A mix of UMN and LMN signs, fasciculations, the absence of sensory signs, wasting of the small muscles of the hand or tibialis anterior
Classically doesn’t affect the external ocular muscles, no cerebellar signs, abdominal reflexes preserved, sphincter dysfunction is a last sign, usually presents after 40
Motor Neurons Disease investigations
Clinical diagnosis, but nerve conduction studies will show normal motor conduction - EEG will show a reduced number of action potentials w/ increasing amplitude
MRI is done to exclude cervical cord compression and myelopathy
Motor Neurons Disease management
Riluzole = prevents stimulation of glutamate re4ceptors, mainly used in ALS, prolongs life by about 3 months
Supportive care
Motor Neurons Disease subtype examples
Amyotrophic lateral sclerosis (ALS) = starts w/ muscle twitching and weakness - most common subtype
Progressive muscular atrophy = causes a lot of muscle wasting
Bulbar palsy
Motor Neurons Disease prognosis
50% of pts die w/in 3 years
Define Multiple Sclerosis
An inflammatory demyelinating disease, clinically defined as 2 episodes of neurological dysfunction separated in anatomical location and time
Multiple Sclerosis calssification
Relapsing-remitting = relapses are followed by periods of neurological stability, relapses last days-months, remits last months-years, ~85% of MS cases
Primary progressive = steady progressive worsening of neuro symptoms from the onset
Secondary progressive = steady progressive worsening of neuro symptoms after an initial relapsing-remitting pattern
Multiple Sclerosis features
Optic neuritis, fatigue, neuropathic pain, altered sensation, Lhermitte’s phenomenon (shock-like sensation radiating down the spine induced by neck flexion), muscle spasticity/stiffness/weakness, mobility issues, bowel and bladder dysfunction, sexual dysfunction, cognitive impairment, speech and swallowing issues
Multiple Sclerosis investigations
Neuro bloods, MRI brain, MRI spine (in primary progressive), CSF analysis (oligoclonal bands)
Multiple Sclerosis indications for drug management
RRMS + 2 relapses in past 2 years + able to walk 100m unaided
SPMS + 2 relapses in past 2 years + able to walk 10m (aided or unaided)
Multiple Sclerosis management
Steroids in acute relapse, natalizumab, ocrelizumab, beta-interferon
Define Multiple system atrophy
A fatal neurodegenerative disorder defined chiefly by autonomic dysfunction and parkinsonism - is an alpha-synucleinism
Multiple system atrophy features
Autonomic dysregulation is the key feature (urinary incontinence, erectile dysfunction, orthostatic hypotension, constipation)
Parkinsonism that usually has a poor response to Levodopa
REM sleep behaviour disorder
Onset is between 30 and 75
Multiple system atrophy investigations
Primarily a clinical diagnosis, can only be confirmed on post-mortem
MRI brain will show putaminal, pontine and middle cerebellar peduncle atrophy
Multiple system atrophy management
Levodopa response poor so manage parkinsonism w/ physio, Midodrine for orthostatic hypotension, desmopressin for incontinence, long-term catheters for retention
Define Narcolepsy
A chronic neuro disorder due to the loss of hypocretin-producing neurons in the hypothalamus, which regulate wakefulness and sleep
Narcolepsy features
Type 2 = excessive daytime sleepiness resulting in sleep attacks (sudden and involuntary episodes of sleep) which last from minutes to an hour, sleep paralysis, hypnagogic (when falling asleep) and hypnopompic (when waking up) hallucinations
Type 1 = as above + cataplexy (sudden loss of muscle tone triggered by a strong emotion e.g. laughter or anger) - also have low levels of orexin in their CSF
Narcolepsy management
CNS stimulants (Modafinil, dexamphetamine, methylphenidate), anti-depressants for cataplexy (SSRIs, clomipramine, venlafaxine), good sleep hygiene, scheduled naps
Define Neuromyelitis optica
A spectrum of rare AI demyelinating CNS conditions that primarily affect the optic nerve and spinal cord - due to anti-apuaporin-4 antibodies (located on brain, spine and optic nerve)
Neuromyelitis optica features
Hallmark presentation is of attacks of optic neuritis and/or transverse myelitis but can also present w/: Area postrema syndrome (intractable hiccups, N&V w/ no other neuro problems), pruritus (due to inflammation of spinothalamic tract, pain
Optic neuritis features
Sub/acute loss of vision, retrobulbar and peri-ocular pain that is exacerbated by eye movements, photopsia’s exacerbated by eye movements, visual field loss, relative afferent pupillary defect
Define Transverse myelitis
Horizontal inflammation through a cross-section of the spinal cord
Optic neuritis investigations
Visual acuity test, colour vision test, testing for RAPD, fundoscopy (may show swelling of the optic nerve), testing eye movements, MRI w/ gadolinium contrast (will show optic nerve enhancements)
Optic neuritis management
High-dose IV methylprednisolone for 3 days, followed by oral prednisolone taper over 11 days
Neuromyelitis optica diagnostic criteria
At least 1 core clinical symptom (optic neuritis, Area postrema syndrome or transverse myelitis)
+ve Aquaporin-4 antibodies
Alternative diagnosis exclusion (primarily MS)
Transverse myelitis features
Pain, weakness in affected limbs, sensory deficits, bladder and bowel problems
Neuromyelitis optica management
Acute = IV methylprednisolone for 5 days, plasma exchange therapy if unresponse to steroids
Prophylaxis = Oral prednisolone + immunosuppressive drug (azathioprine, mycophenolate mofetil or monoclonal abs)
Neurofibromatosis Type 1 features
Cafe-au-lait spots (>6, 15 mm in diamemter), axillary/groind freckles, peripheral neurofibromas, iris hamartomas, scoliosis, pheochromcytomas
Neurofibromatosis Type 2 features
Bilateral vestibular schwannomas, multiple intracranial schwannomas/meningiomas/ependymomas
Define Normal pressure hydrocephalus
A neurological disorder due to accumulation of CSF in the ventricles causing them to enlarge - this occurs w/out an increase in ICP
Normal pressure hydrocephalus features
A triad of gait disturbance, cognitive impairment and urinary incontinence (wet, wobbly and weird)
Normal pressure hydrocephalus management
Ventriculoperitoneal shunt insertion
Parkinson’s disease features
Resting tremor (4-6 Hz frequency), muscle rigidity (cogwheel), bradykinesia, postural instability, hypomimia, dysphagia
Parkinson’s disease management
Levodopa (a dopamine precursor which is converted both in the CNS and periphery) + carbidopa (dopamine decarboxylase inhibitor which reduces the amount of levodopa converted in the periphery)
Monoamine oxidase B inhibitors
Dopamine agonist
Supportive care
Key prognostic factors in Parkinson’s disease
Early-onst PD (before 50) progresses more slowly than late-onset
Pts presenting w/ tremor have a slower progression than pts presenting w/ bradykinesia and rigidity
Cognitive impairment is associated w. faster disease progression
Define Paroxysmal hemicrania
A trigeminal autonomic cephalgia which causes attacks of severe unilateral headache (orbital, supraorbital or temporal regions) associated w/ autonomic features which last less than 30 min and occur multiple times in a day
Paroxysmal hemicrania features
Presents very similarly to cluster headaches
Paroxysmal hemicrania management
Completely treated by a therapeutic dose of 150 mg indomethacin (an NSAID) - this is how you can differentiate it from cluster headaches
Progressive supranuclear palsy features
Impairment of vertical gaze (down gaze worse than up gaze), parkinsonism, falls, slurring of speech, cognitive impairment
Define Psychogenic non-epileptic seizures
A type of seizures that are not caused by abnormal electrical activity in the brain, but by psychological factors (e.g. stress or emotional events) - Pts typically have a Hx of trauma or other psych disorders
How do you distinguish Psychogenic non-epileptic seizures from epileptic seizures?
PNES has an absence of ictal autonomic symptoms (tachycardia, HTN, hypersalivation), gradual onset and offset, emotional triggers, pelvic thrusting during seizure
Causes of peripheral neuropathy
Predominately motor loss = Guillain-Barre syndrome, porphyria, lead poisoning, Charcot-Marie-Tooth, chronic inflammatory demyelinating polyneuropathy, diphtheria
Predominately sensory loss = diabetes, uraemia, leprosy, alcoholism, B12 def (SCDC), amyloidosis
Radial nerve motor innervation
Main nerve = triceps, anconeus, brachioradialis, extensor carpi radialis
Posterior interosseous branch = supinator, extensor muscles of the forearm (excluding carpi radialis), abductor pollicis longus
Radial nerve sensory innervation
Sensation of the dorsal aspect of the proximal phalanges of the first 3.5 fingers
What is the most common pattern of radial nerve injury?
Wrist drop (commonly from a mid-humeral fracture)
What is Cushing’s triad of raised ICP?
Widening pulse pressure, bradycardia., irregular breathing
Raised ICP management
Head elevation to 30 degrees, IV mannitol (osmotic diuretic)m controlled hyperventilation (aims to reduce pCO2 thus reducing vasoconstriction of the cerbral arteries and reducing ICP), repeat LPs (e.g. in IIH), ventriculoperitoneal shunts (e.g. for hydrocephalus), treat underlying cause
Raised ICP features
Headache, vomiting, reduced conciosness, papilloedema, Cushing’s triad
Ankle jerk reflex nerve roots
S1-S2
Knee jerk reflex nerve roots
L3-L4
Biceps tendon reflex nerve roots
C5-C6
Triceps tendon reflex nerve roots
C7-C8
Brachioradialis (supinator) reflex nerve roots
C5-C6
Define Restless leg syndrome
A syndrome of spontaneous, continuous LL movements that may be associated w/ paraesthesia
Restless leg syndrome features
Akathisia of LL (symptoms initially occur at night, but as condition progresses they occur during the day), paraesthesia, periodic limb movements of sleep (PLMS), symptoms worse at rest
Restless leg syndrome management
Simple measures (walking, stretching, massaging), treat any iron def, dopamine agonists are 1st line (Pramipexole, ropinirole), benzos, gabapentin
Define Reye’s syndrome
A severe, progressive encephalopathy accompanied by fatty infiltration of the liver, kidneys and pancreas - affects children typically after they have taken aspirin
Define spastic paraparesis
An UMN pattern of weakness of the lower limbs
Causes of spastic paraparesis
Demyelination, cord compression, parasagittal meningioma, tropical spastic paraparesis, transverse myelitis, syringomyelia, hereditary, osteoarthritis of C spine
ACA stroke features
Contralateral hemiparesis and sensory loss - LL > UL
MCA stroke features
Contralateral hemiparesis and sensory loss - UL > LL
Contralateral homonymous hemianopia
Aphasia
PCA stroke features
Contralateral homonymous hemianopia w/ macular sparing
Visual agnosia
Define Weber’s syndrome
A midbrain stroke due to issues w/ the supplying branches of the PCA
Weber’s syndrome features
Ipsilateral CN III palsy (below the decussation for this)
Contralateral weakness of UL and LL (above the decussation for this)
Define Lateral medullary syndrome
AKA Wallenberg syndrome - a stroke brainstem, specifically the lateral part of the medulla oblongata, due to issues in the posterior inferior cerebellar artery
What is the role of the Medulla oblongata?
Contains the:
- Respiratory centre = controls ventilation
- Cardiovascular centre = controls HR
- Vasomotor centre = controls BP
- Reflex centres for vomiting, coughing, sneezing and swallowing
Location of the decussation of the corticospinal tracts
Nuclei for CN 9-12
What are the 3 parts of the brain stem?
Midbrain (top)
Pons
Medulla oblongata (bottom)
What is the role of the Pons?
Links the medulla to the rest of the brain
Coordinates autonomic functions
Part of the reticular activating system
Nuclei for CN 5-8
What is the role of the midbrain?
Tegmentum (anterior surface):
- Reticular formation (part of the reticular activating system)
- Processes pain signals
- Autonomic function
- Nuclei of CN 3 and 4
- Conduit for spinothalamic and corticospinal tracts
- Contains the Red nucleus (involved in motor coordination)
- Contains the substantia nigra (has cells which produce dopamine)
Tectum (posterior surface):
- Process visual signals and sends them to the occipital lobe
- Process auditory signals and sends them them to the temporal lobe
What is the reticular activating system?
Nerve bundles which regulate wakefulness and sleep-wake transitions - it does this my altering brain electrical activity and releasing hormones
Lateral medullary syndrome (PICA stroke) features
Ipsilateral facial pain and temp sensation loss
Contralateral limb/torso pain and temp sensation loss
Ataxia
Nystagmus
Anterior inferior cerebellar artery stroke (lateral pontine syndrome) features
Ipsilateral facial paralysis and deafness
Contralateral limb/torso pain and temp sensation loss
Ataxia
Nystagmus
Define Amaurosis fugax
Temporary loss of vision in one eye which returns to normal - usually due to transient loss of blood flow to the back of the eye
Retinal/ophthalmic artery stroke features
Amaurosis fugax
Basilar artery stroke features
Locked-in syndrome
Lacunar stroke features
Isolated hemiparesis +/- limb ataxia
Isolated hemisensory loss
What are the basal ganglia?
Several structures in the centre of the brain which primarily help coordinate voluntary movement (approves or rejects motor signals to filter out unnecessary/incorrect signals)
Also play a role in processing risk, habit forming and addiction
Acute ischaemic stroke management
Aspirin 300mg orally or rectally ASAP after exclusion of haemorrhagic
Thrombolysis with alteplase or tenecteoplase if fit the criteria
Thrombectomy to those who fit the criteria
Clopidogrel long-term for secondary prevention (unless A.fib, then give DOAC)
Criteria for thrombolysis in an acute ischaemic stroke
Standard criteria:
- Haemorrhagic stroke has definitively been excluded
- Administered w/in 4.5 hours of symptom onset
Consider if:
- Between 4.5-9 hours of symptom onset (or 9 hours since mid point of sleep and have woken w/ stroke symptoms)
AND
- There is evidence from a CT/MR perfusion or MRI of the potential to salvage brain tissue
BP should be lowered to 186/110 before thrombolysis
Absolute contraindication for stroke thrombolysis
- Previous intracranial haemorrhage
- Seizure at onset of stroke
- Intracranial neoplasm
- Suspected subarachnoid haemorrhage
- Stroke or traumatic brain injury w/in 3 months
- Lumbar puncture w/in 7 days
- GI haemorrhage w/in 3 weeks
- Active bleeding
- Oesophageal varices
- Uncontrolled HTN > 200/120
Criteria for thrombectomy in an acute ischaemic stroke
If w/in 6 hours in people w/ a confirmed occlusion of the proximal anterior circulation
This criteria extents to w/in 24 hours if CT/CR demonstrates salvageable brain tissue
Define Anterior Spinal Artery Infarcts
An ischaemic stroke occurring in the anterior 2/3rds of the spinal cord - typically due to disruption of the blood flow from the anterior spinal artery
Causes of anterior spinal artery infarcts
- Damage to the aorta - aneurysm repair, dissection
- Atherosclerosis
- Cardiac arrest
- Cardiac emboli
- Vasculitis
- Shock
Anterior Spinal Artery Infarct features
Present w/ a unique pattern of neurological deficits, with the dorsal columns being preserved:
- loss of pain sensation
- loss of temp sensation
- motor function impairment
- loss of autonomic function
Anterior Spinal Artery Infarcts Investigations
MRI - shows hyperdense signals on T2-weiggted imaging of the anterior 2/3rds of the spinal cord
Causes of autonomic neuropathy
DM, neurodegenerative conditions, infections, AI diseases, amyloidosis
Autonomic neuropathy features
Cardiovascular system = orthostatic hypotension, resting tachycardia, silent MI’s
GI system = dysphagia, gastroparesis, constipation, diarrhoea
Genitourinary system = bladder dysfunction, ED, reduced vaginal lubrication
Thermoregulatory system = anhidrosis, hyperhidrosis
Define Cervical spondylosis
Age-related degeneration of the spinal cord leading to nerve impingements
Cervical spondylosis features
Neck pain, radiculopathies (flaccid paresis), myelopathy (sensory changes and spastic paresis), bladder and bowel disturbance
Cervical spondylosis management
Non-surgical = Physio, NSAIDs, cervical collars and traction
Surgical = anterior cervical decompression (discectomy, corpectomy), posterior decompressions (laminoplasty, laminectomy) and fusions
Types of diabetic neuropathy
Distal symmetrical sensory neuropathy (most common), small-fibre predominant neuropathy, diabetic amyotrophy, mononeuritis multiplex, autonomic neuropathy
Distal symmetrical sensory neuropathy features
Sensory loss in glove and stocking distributions, typically affecting touch, vibration and proprioception (dorsal column predominant)
Results from the loss of large sensory fibres due to DM
Small-fibre predominant neuropathy features
Deficits in pain and temp sensation (spinothalamic predominant) in a glove and stocking distributions, often accompanied by episodes of burning pain
Results from the loss of small sensory fibres due to DM
Diabetic Amyotrophy features
Severe pain around the thighs and hips, along w/ proximal weakness
Due to inflammation of the lumbosacral or cervical plexus due to DM
Define Charcot arthropathy
AKA neuropathic arthropathy - a chronic, progressive conditions characterised by painful/painless bone and joint destruction in limbs which have lost sensory innervation
Primarily affects pts w/ peripheral neuropathy (most commonly DM)
Charcot arthropathy features
6D’s:
- Destruction of bone and joints
- Deformity
- Degeneration
- Dense bones (sclerosis)
- Debris of bone fragments
- Dislocation
Typically affects the tarsometatarsal joints
Charcot arthropathy management
Conservative = prolonged off-loading (special footwear or plaster casts) to allow healing, use of orthotics long term
Medical = bisphosphonates, neuropathic pain agents, topical anaesthetics
Surgical = resection of bony prominences to prevent ulcer formation, correction of severe deformities, amputations if severe infections
Haemorrhagic stroke management
Acute:
- Neurosurgical evaluation for potential surgical interventions (e.g. decompressive hemicraniectomy)
- Admission to neuro ICU or stroke unit
- BP control < 140/80
Long-term:
- Rehabilitation
- Secondary prevention
Define Internuclear ophthalmoplegia
An ocular movement disorder arising from a lesion in the medial longitudinal fasciculus, affecting coordination of horizontal gaze
Internuclear ophthalmoplegia features
Impaired adduction in the ipsilateral eye during horizontal gaze
Nystagmus in the abducting eye
Some pts may retain the ability to converge on near targets
Define Jugular foramen syndrome
A disorder resulting from a unilateral lesion of the glossopharyngeal, vagus and accessory CN’s, which transverse the jugular foramen
Jugular foramen syndrome features
Ipsilateral weakness of the Trapezius and sternocleidomastoid muscles
Deviation of the uvula and soft palate towards the unaffected side
Dysphagia and changes in voice
Hoarseness and loss of gag reflex
Sensory loss in the distribution of the glossopharyngeal nerve
How does hyperventilation help to reduce raised ICP?
Hyperventilation reduces pCO2, which causes vasoconstriction of the cerebral arteries - causes a rapid reduction in ICP
What is the difference between medical and surgical 3rd nerve palsy?
Medical = no pupil involvement
Surgical = pupil involvement - this is due to external compression of the oculomotor nerve which compresses the parasympathetic (constrictive) fibres that run on the outside of the nerve, causing pupil dilation
Define Meralgia paraesthetica
Compression of the lateral femoral cutaneous nerve (usually under the inguinal ligament) - a purely sensory nerve which supplies the outer aspect of the thigh
Meralgia paraesthetica features
Neuropathic pain, numbness, paraesthesia in the distribution of the lateral femoral cutaneous nerve
Symptoms may be exacerbated by standing, walking or hip extension
No motor loss
Meralgia paraesthetica management
Conervative = WL, wearing loss clothes, over-the-counter analgesia, physio
Medical = pregabalin or gabapentin
Interventional = local steroids or nerve blocks
Surgical = decompression of the nerve (rare)
Define Mononeuritis multiplex
A type of peripheral neuropathy characterised by simultaneous or sequential involvement of individual con-contiguous nerve trunks, evolving over days to years
Mononeuritis multiplex features
Asymmetrical patterns of neuropathic pain and weakness
Mononeuritis multiplex causes
- DM
- Vasculitis = polyarthritis nodosa, granulomatosis w/ polyangiitis, eosinophilic granulomatosis w/ polyangiitis
- AI = RA, SLE
- Infections = leprosy, Lyme’s disease, Parvovirus B19, HIV
- Sarcoid
Define Myotonic dystrophy
A multi-system, trinucleotide repeat disorder that affects specific chloride channels in the muscles
Myotonic dystrophy features
Face = frontal balding, myopathic face (long and thin), bilateral ptosis, cataracts
Speech = dysarthria due to myotonic tongue and phalangeal muscles
Neck = wasting of sternocleidomastoid
Hands = Distal muscle wasting and weakness, slow relaxing grip and percussion myotonia
Internal features = metabolic syndrome, cardiomyopathy/arrhythmias, testicular atrophy
Cortico-basal degeneration features
Parkinsonism, spontaneous activity by an affected limb, akinetic rigidity
Define Bulbar palsy
A subtype of LMN lesions which impact the 9th, 10th and 12th CNs - the resulting impediment primarily involves the mechanisms of speech and swallowing
Bulbar palsy causes
- MND (Progressive bulbar palsy variant)
- Myasthenia gravis
- GBS
- Brainstem strokes
- Syringobulbia
Bulbar palsy features
- Absent or normal jaw jerk
- Absent gag reflex
- Flaccid, fasciculation tongue
- Nasal speech
- Dysarthria
- Dysphagia
Define Pseudobulbar palsy
A condition caused by bilateral lesions affecting the corticobulbar tracts (which runs from the motor cortex to the motor nuclei of CNs 9, 10 and 12 in the medulla). Bilateral lesions are necessary due to the CNs having bilateral cortical representation - this is an UMN lesion affecting speech and swallowing
Pseudobulbar palsy causes
- Vascular = bilateral internal capsule stroke
- MND
- Progressive supranuclear palsy
- Neoplasm of the brainstem
- MS
- Trauma
Pseudobulbar palsy features
- Spastic tongue
- Slow, thick (hot-potato) speech
- Brisk jaw jerk
- Emotional lability
Define Pyramidal pattern of weakness
A specific UMN lesion sign where there is motor weakness involving the UL extensors and LL flexors - so arm is held in flexion and leg is held in extension (causes pt to trace a semicircle with their foot instead of bending their knee when the walk)
Define Spinal stenosis
A condition characterised by narrowing of the spinal canal in the lumbar region - resulting in compression of the spinal nerves
Spinal stenosis features
Neurogenic claudication (intermittent pain/weakness/numbness in the proximal thigh or buttocks), pain aggravated by physical activity or extended spinal positions (e.g. descending stairs), pain relieved by stooped posture or bending over (e.g. when going uphill) absence of vascular risk factors or signs
Spinal stenosis management
Non-operative (1st line) = NSAIDs, opioids, nerve blocks, physio, WL, lifestyle changes
Surgical = laminectomy, laminoplasty or spinal fusion
Define Subacute combined degeneration of the cord
Degeneration and demyelination of both the dorsal columns and the corticospinal tracts, whilst preserving pain and temp sensation (spinothalamic tracts intact) - due to vitamin B12 def
Subacute combined degeneration of the cord features
- Symmetrical distal sensory symptoms (typically starting and the feet and progressing to the hands)
- Varying degrees of ataxia
- Spastic paresis and weakness
- Loss of vibration sense and proprioception
- Mixed UMN and LMN signs (e.g. hyper/hypo/areflexia)
- Autonomic bladder and bowel symptoms
Subacute combined degeneration of the cord management
Vit B12 replacement w/ hydroxocobalamin 1mg IM on alternating days until no further improvement, followed by maintenance IM injections of 1mg every 2 months
Subarachnoid haemorrhage investigations
- CT head
- LP if CT not definitive (look for xanthochromia) - not reliable w/in 12 hrs of symptom onset
- CT angiogram is CT suggestive of subarachnoid haemorrhage
Subarachnoid haemorrhage management
Medical = Nimodipine to prevent vasospasm post-ischaemia
Radiological = endovascular coiling/stenting to stop the bleeding
Surgical = clipping to stop the bleeding
Subdural haematoma cause
Sheering forces which tear the bridging veins between the cortex and dura mater
Subdural haematoma features
Headache, N&V, confusion, reduced GCS, focal neuro signs
Presentation is typically subacute (w/in 3 days - 3 wks of trauma) or chronic (>3 wks after trauma)
Subdural haematoma investigations
CT head - clot appears differently based on its age:
- Hyperacute (<1 hr) = isodense, w/ underlying cerebral oedema
- Acute (<3 days) = crescent-shaped hyperdense extra-axial collection
- Sub-acute (3 days - 3 wks) = isodense, possible midline shift and sulcal effacement - can use enhanced contrast CT or MRI to aid diagnosis
- Chronic (>3 wks) = hypodense
Subdural haematoma management
Acute = craniotomy
Chronic = Burr holes
Causes of a surgical 3rd nerve palsy
Most common = posterior communicating artery aneurysm
Other = cavernous sinus lesions (infections, thrombosis, tumour)
Define Syringomyelia
The formation of a fluid-filled cavity of cyst, known as a syrinx, w/in the spinal cord - it often expands and elongates over time, exerting pressure on the spinal cord and damaging nerve fibres
Syringomyelia causes
- CSF blockage or disruption - often secondary to conditions such as arachnoiditis or SOL
- Spina Bifida
- Post-trauma
- Idiopathic
- Familial predisposition
Syringomyelia features
- Pain and temp loss due to dmg to the spinothalamic tract- classically in a ‘shawl-like’ distribution over the arms, shoulders and upper back
- Dorsal column involvement as syrinx enlarges
- Muscle weakness as syrinx extends and dmgs anterior horn cells
- Autonomic dysfunction
Syringomyelia management
Physio and rehab, surgical
TIA management
Clopidogrel, lifestyle modifications, control of vascular risk factors, carotid endarterectomy if > 50% stenosis
TIA investigations
Immediate CT head followed up w/ an MRI to assess ischaemia/haemorrhage, carotid USS, echo, 24 hr Halter
Trigeminal neuralgia causes
Primary = idiopathic
Secondary = compression (malignancy, AV malformations), MS, sarcoidosis, Lyme disease
Trigeminal neuralgia management
Medical:
- Carbamazepine (1st line)
- Phenytoin
- Lamotrogine
- Gabapentin
Surgical:
- Microvascular decompression (if vessels are compressing the nerve)
- Treat underlying cause (e.g. remove tumour)
- Alcohol or glycerol injections (dmg the trigeminal nerve and reduce pain signals)
Define Vertigo
The sensory misperception or illusion of motion
Causes of vertigo
Peripheral = BPPV, acute labyrinthitis, Meniere’s disease, vestibular neuritis, Ramsey Hunt syndrome
Central = Migraine, MS, cerebrovascular disease
Systemic = orthostatic hypotension, arrhythmias, medication (aminoglycosides, loop diuretics)
Which optic pathway is involved in monocular vision loss?
Optic nerve
Which optic pathway is involved in bitemporal hemianopia?
Optic chiasm
Which optic pathway is involved in contralateral homonymous hemianopia?
Optic radiations
Which optic pathway is involved in quadrantanopias?
Optic radiation
Macular sparing homonymous hemianopia?
Occipital lobe
What causes a contralateral homonymous superior quadrantanopia?
A temporal lobe lesion (PITS - P - parietal I - inferior; T - temporal S - superior)
What causes a contralateral homonymous inferior quadrantanopia?
A parietal lobe lesion (PITS - P - parietal I - inferior; T - temporal S - superior)
Wernicke’s encephalopathy features
Triad of:
- Ataxia
- Confusion
- Ocular abnormalities
Neurological features of Wilson’s disease
Akinetic-rigid syndrome similar to Parkinson’s
- Tremor
- Ataxia
- Dystonia
- Drooling
- spasticity
- Chorea
- Myoclonus
Define Thoracic outlet syndrome
A disorder involving compression of the brachial plexus, subclavian artery or vein at the thoracic outlet - occurs when neck trauma occurs in a pt w/ a genetic predisposition (such as a cervical rib)
Thoracic outlet syndrome features
Neurogenic:
- painless muscle wasting of hand muscles, with patients complaining of hand weakness e.g. grasping
- sensory symptoms such as numbness and tingling may be present
- if autonomic nerves are involved, the patient may experience cold hands, blanching or swelling
Vascular:
- subclavian vein compression leads to painful diffuse arm swelling with distended veins
- subclavian artery compression leads to painful arm claudication and in severe cases, ulceration and gangrene
