Neurology Flashcards
Name the upper limb and lower limb dermatomes
Upper - C5-T1
Lower - L1-S1
What would be the difference in examination findings of someone with Bell’s palsy and someone who has had a stroke?
Bell’s palsy (LMN lesion) - complete facial paralysis on one side
Stroke (UMN lesion) - forehead movements are spared due to bilateral innervation of the upper branches of CNVII
In a CNX palsy, which side would you expect the uvula to deviate?
Deviate away from the side with the lesion
This is because the “pulling” muscles of the same side (ipsilateral) are disabled
In a CNXII palsy, which side would you expect the tongue to deviate to?
Deviate towards the side with the lesion
This is because the “pushing” muscles of the same side (ipsilateral) are disabled
What does the pronator drift sign indicate?
Upper motor neuron lesison
Lesion in the pyramidal tracts
How can you tell the difference between rigidity and spasticity in a patient with increased tone on examination?
What do each suggest?
Rigidity - tone remains stiff through tough entire movement, regardless of speed. Suggests extra pyramidal lesion (e.g lead pipe rigidity seen in Parkinson’s)
Spasticity - stiffness is velocity dependant, and is exacerbated by attempt to move limb quickly. Suggests pyramidal lesion
How can you illustrate clonus, what does this suggest?
Briefly dorsiflex the foot
If the foot plantarflex’s in a “beating” motion this is clonus
If you can illustrate this more than 3x, it suggests an UMN lesion
How is power graded on neurological examination?
0 - no power
1 - twitching, no movement
2 - movement, but cannot overcome gravity
3 - movement can overcome gravity
4 - movement against resistance but weaker
5 - normal muscle strength
What does it mean if the plantar’s are “up going” or “down going”
Observation of toes when object is run along plantar aspect of foot
Up going - upper motor neuron pathology
Down going - normal
What does impaired vibration sensation suggest?
Pathology in dorsal columns of spinal cord
What does impairment pinkprick sensation suggest?
Pathology in the spinothalamic tracts of the spinal cord
How does the differential diagnosis vary in neurology dependant on the onset of symptoms?
Sudden events - vascular (infarction, ICH, SAH)
Acute onset (mins-hours) - infections (meningitis, encephalitis)
Subacute (days-weeks) - autoimmune (MS)
Chronic (months, years) - genetic, neurodengerative (Parkinson’s), neoplastic
What are the UMN signs found in neurology?
Weakness (pyramidal signs) Increased tone (Spasticity and rigidity) Up going plantars Hyperreflexia Pronator drift
What are the LMN signs found in neurology?
Muscle wasting Fasciculations (receptor induced contractions) Focal weakness Hyporeflexia Reduced tone
What is the difference between the pyramidal tracts and the extrapyramidal tracts?
Both are motor descending pathways
Pyramidal control voluntary movements (e.g, corticospinal)
Extrapyramidal control involuntary and fine tuning movements (E.g, basal ganglia, cerebellum))
What is pyramidal pattern weakness?
Upper limbs: extensors weakened more than flexors
Lower limbs: flexors weakness more than extensors
What are extrapyramidal signs?
Involuntary movements
Tremors
Muscle contractions
What are the main sensory ascending tracts and what information do they carry?
Spinothalamic tracts - touch, pressure, pain, temp
Dorsal columns - vibration, proprioception
Where do the spinothalamic and dorsal columns tracts dessucate?
Spinothalamic - dessucates immediately and travels up contralateral side to thalamus
Dorsal columns - travels up ipsilateral side, and desscuates at the medulla, before traveling to thalamus on contralateral side
What is the main motor descending pathway
Corticospinal tract
What is brown sequard syndrome?
Where you get different neurological symptoms because of a hemi section of the spinal cored . This is due to how the tracts dessucate? Below level of damage you would see:
- Ipsilateral UMN signs (corticospinal tract damage)
- Ipsilateral loss of vibration and proprioception (dorsal columns damage)
- Contralateral loss of pain and temp (spinothalamic damage)
What is the difference between a bulbar and psudobulbar palsy?
Bulbar palsy - LMN palsy affects IX, X, XI and XII cranial nerves
Will have LMN signs like tongue wasting
Psuedobulbar palsy - UMN that affects the corticobulbar tracts of the V, VII, IX, X, XI and XII cranial nerves
Will have UMN signs like exaggerated jaw jerk
What are the 4 types of motor neuron disease?
Amyotrophic lateral sclerosis (ALS) - (most common) limbs initially affected
Progressive bulbar palsy (PBP) - speech and swallowing affected initially
Progressive muscular atrophy (PMA) - LMN affected only
Primary lateral sclerosis (PLS) - UMN affected only (rare disease)
How does motor neuron disease present?
Usually begins by affecting a single limb or aspect of motor function, then becomes more generalised as the disease progresses
People initially only have LMN or UMN signs but typically develop a combination of both as the disease progresses
What are the 3 P’s of motor neuron disease?
Painless
Progressive
Pure motor symptoms
What is motor neurone disease (MND)?
A disease in which the motor neurons are degenerated
Motor neurons control the muscles which control movement, speech, breathing and swallowing
As these neurons die muscles gradually weaken and waster, this can cause a pattern of weakness
Can affect both UMN and LMN or just one set
What medication is licensed for use in amyotrophic lateral sclerosis (ALS) and progressive bulbar palsy (PBP)
How does it work?
Riluzole
Prevents stimulation of glutamate receptors, which helps slow down the motor neuron death
How would you exaggerate the tremor seen in Parkinson’s disease?
Tremor is moist easily seen when patient is distracted
Get the patient to count back from 20 seconds
How would you examine a Parkinson’s patient for bradykinesia?
Get the patient to continually snap their fingers and see if the movement slows down
What are the main symptoms of motor neuron disease?
Muscle weakness and fasciculations
Mixture of upper and lower motor neuron signs
Wasting of small hand muscles/tibilais anterior is common
LACK OF SENSORY SIGNS/SYMPTOMS
Which type of dementia is motor neuron disease associated with?
Frontotempral dementia
What is the prognosis for motor neuron disease?
50% of patients die within 3 years
How are the respiratory symptoms of motor neuron disease managed?
Non invasive ventilation (BIPAP) used at night
Which type of motor neuron disease carries a genetic link?
Amyotrophic lateral sclerosis
In familial cases the gene lies on chromosome 21 and codes for superoxide dismutase
Which type of motor neruon disease carries the worse prognosis?
Progressive bulbar palsy
Which type of motor neuron disease carries the best prognosis?
Progressive muscular atrophy
What is the differential diagnosis for a patient presenting with weakness in all 4 limbs?
UMN cause - acute cervical myelopathy e.g, transverse myelitis
LMN cause - guilian barre syndrome
Mixed UMN and LMN - motor neuron disease
What is guillian barre syndrome?
Demyelinating disease of the peripheral nervous system
Characterised by symmetrical cranial or limb weakness
What causes guillian barre syndrome?
Usually triggered by infection (most common campylobacter)
This triggers molecular mimicry to occur and for the body to start attack the myelin sheath of peripheral nerves
How does GBS usually present?
Initially sensory symptoms (paraesthesia and pins and needles)
Motor symptoms - muscle weakness usually beings in the legs (weakness is classically ascending)
Can get cranial nerve involvement - difficulty speaking, facial muscle weakness
Can get respiratory involvement if respiratory muscles are affected
What is the most common type of GBS?
Acute inflammatory demyelinating polyradicuoneuropathy (AIDP)
What is miller-fisher syndrome?
Type of GBS Consists of a triad of: - ophthalmoplegia - areflexia (loss of reflexes) - ataxia (loss of balance)
How is GBS diagnosed?
Lumbar puncture - CSF will show cytoalbuminologic dissociation
(Normal WBCs, elevated protein)
Nerve conduction studies - can point to diagnosis
What are the typical lumbar puncture findings in someone with GBS?
Cytoalbuminologic dissociation Normal WCC (<5) Raised protein (>0.45)
How would you monitor someone’s respiratory function with GBS?
Pulmonary function tests
FVC should be monitored regularly
How is GBS managed?
Intravenous immunoglobulins - reduce the immune response
Plasmapheresis - plasma is filtered from the blood to help remove the autoantibodys
What is the prognosis of GBS?
Individuals make a slow recovery over several months as there is regrow the of the myelin on the peripheral nerves
How does subacute combined degeneration of the spinal cord present?
Dorsal columns affected - loss of proprioception, light touch and vibration
Lateral corticospinal tract affected - causes spastic weakness and up going plantars (UNM signs)
Damage to peripheral nerves - results in LMN signs
What causes subacute combined degeneration of the spinal cord?
Vitamin B12 deficiency
What is Bell’s palsy?
Temporary weakness affecting one side of the face
Due to a lesion in the facial nerve
How does Bell’s palsy differ from a stroke?
Bell’s palsy is complete weakness of one side of the face whereas stroke spares the muscles above the eyebrow
Bell’s palsy is more gradual onset (hours-days) - stroke is more sudden
Bell’s palsy symptoms are purely limited to facial movement
Bell’s palsy may come with some prodromal symptoms
What are the prodromal symptoms that can occur with Bell’s palsy?
Pain behind the ears
Hearing or taste changes
Strange feeling in the face
What is the cause of Bell’s palsy?
Cause is unknown
Viral aetiology suspected, but unproven
How is Bell’s palsy managed?
Prednisolone - 7 day 60mg course given within 3 days of symptoms
Acyclovir - some doctors use, but evidence is week
Eye drops - to stop affected eye drying out
What is the progression and prognosis of Bell’s palsy?
Symptoms worsen over first few days
Recovery can take 4-6 months
Majority of cases make full recovery
The time taken to recovery relates to severity of initial weakness
What is Ramsay Hunt Syndrome?
Shingles infection that affects the facial nerve
Caused by herpes zoster infection of the geniculate ganglion of the facial nerve
How does Ramsay hunt syndrome present?
Painful vesicles around affected external ear, can also get them in inside the mouth
Weakness of affected side of face causing facial drooping
Altered taste on affected side of tongue
How is Ramsay hunt syndrome investigated?
MRI - to look for inflammation along facial nerve
Nerve conduction studies - to assess damage to facial nerve
How is Ramsay hunt syndrome managed?
Antivirals (Acyclovir)
High dose steroids