Neurology Flashcards
Patient presents with abrupt onset diplopia, left-sided loss of pain and temperature, right facial weakness without sparing of the frontalis.
Right sided pontine stroke - lateral pontine syndrome.
Patient has a BATH and develops a pontine stroke!
What are classic findings of the ‘lateral pontine syndrome’?
What is are the neuroanatomical substrates for this?
BATH (ipsi-face and contra-body)
B: bell’s palsy of ipsilateral face - LMN CN VII
A: ataxia and vertigo - vestibular nucleus and cerebellar peduncle
T: temp and pain loss of contralateral body) - spinothalamic tract
H: horner’s syndrome - sympathetic tract
How does a radial nerve palsy present?
describe motor and sensory components
Motor: wrist drop, hand pronation and thumb adduction
Sensation: loss of sensation to dorsum of thumb and fingers to up to PIPJ and middle of the ring finger.
Patient has winging of the scapula, which nerve supplying which muscle is underlying the problem?
Long thoracic nerve that supplies serratus anterior.
For the 2 following substances, which causes an increase vs a decrease in INR?
What is the mechanism?
- Cranberry juice
- St John’s Wort
- Cranberry juice inhibits cytochrome p450 and therefore INCREASES INR
- St John’s Wort induces cytochrome p450 and therefore DECREASES INR
What are the 2 types of complex regional pain syndrome (CRPS)?
CRPS I occurs in the absence of a proceeding nerve injury
CRPS II is caused by an injury to the nerve
Heavy smoker presents with weight loss, proximal lower limb muscle weakness and dry mouth. Examination reveals normal sensation and no wasting or fasciculations. Patient is areflexia that normalises with repetitive muscle contraction.
- What is the diagnosis?
- What test should be performed to confirm diagnosis?
- What is a common association of this condition?
- Lambert-Eaton Syndrome (LES)
- Voltage gated calcium channels antibodies
- 50% LES associated with small cell lung carcinoma
Which 3 common anti-epileptic drugs (AEDs) are enzyme-inducing?
Which enzyme is induced?
PCP:
Phenobarbitol
Carbamazepine
Phenytoin
Enzymes: cytochrome p450 3A4
Enzyme-inducing AEDs may DECREASE the efficacy of which 4 types of medications?
What are the unwanted consequences of this?
Mnemonic: ORCA
ORCA:
OCP - lowered levels leads to increased unwanted pregnancies
Retrovirals - anti-retrovirals used in HIV, lowered levels leads to AIDS
Cytotoxics - lowered levels increases cancer mortality and increased transplant rejection
AED - lowered levels increases seizures by lowering the seizure threshold
What is the complete list of enzyme-inducing AEDs?
Clue: PCP-F-TOP
What enzyme is induced?
PCP = phenobarbitol, carbamazepine, phenytoin
F-TOP = felbumate, topiramate, oxcarbazepine, primidone
All induce cyt450 3A4
T/F: lamotrigine is an enzyme-inducing AED
False - is not.
What is the effect of OCP on lamotrigine levels?
What is the consequence of this?
OCP reduce the levels of lamotrigine leading to increased risk of seizures.
What percentage of strokes are lacunar strokes?
25%
What are the clinical features of stiff person syndrome?
- As the name suggests: stiffness / rigidity / increased tone
- Pain muscle spasms triggered by emotional and sensory stimuli - usually involving the legs and lumbar spine.
How is stiff person syndrome diagnosed?
- HIGH levels of anti-GAD Ab (99% specific)
- LOW levels of anti-GAD are found in DM patients
What is the treatment of stiff person syndrome?
Acute episodes: IV-IG or plasmaphoresis
Muscle spasms: benzodiazepine or gabapentin
Which 4 neurological conditions may cause a structural cardiomyopathy?
Becker’s muscular dystrophy
Duchennes muscular dystrophy
Myotonic dystrophy
Myofibrillary myopathy
In the treatment of multiple sclerosis, what it the MOA of the following medications:
- Fingolimod
- Dimethyl fumerate
3 Alemtuzumab - Teriflunomide
- Natalizumab
- Fingolimod:
sphingosine-1phosphate receptor antagonist - Dimethyl fumerate:
activation of nuclear erythroid-derived 2 related factor (Nrf2)
3 Alemtuzumab:
human mAb to CD52
- Teriflunomide:
Inhibition of PYRIMIDINE SYNTHESIS via high affinity binding and inhibition of the enzyme Dihydroorotate dehydrogenase (DHODH) - Natalizumab:
human mAB to cell-adhesion molecule alpha-4-integrin
Patient with distal arms and proximal leg weakness with muscle wasting. CK is elevated and a muscle biopsy reveals the following:
- eosinophilic sarcoplasmic inclusions in vacuoles
- perivascular inflammation (CD8+ T-cell predominance)
What is the diagnosis?
Inclusion body myositis
In temporal order, what is the treatment approach to inclusion-body myositis (IBM)?
- Non-pharmacological physical therapy first
- Steroid
- Steroid-sparing agents (MTX / AZA)
NB: IBM-related weakness is unlikely to be responsive to immunotherapies, physical therapy is key to prevent further weakness.
Patient has a diagnosis of IBM and a connective tissue disease (SLE, Sjogrens, cutaneous dermatomyositis).
Is the patient likely to respond to steroids?
Yes - unlike a diagnosis of IBM alone, which is usually steroid resistant.
Patient develops SYMMETRIC, GRADUAL onset of muscle weakness in BOTH upper and lower limbs with some SENSORY involvement predominantly in the large nerve fibres. (distal numbness/tingling). Patient is hyporeflexic or areflexic.
Patient reports previous episode of the same that lasted more than 2 months and resolved spontaneously.
What is the likely diagnosis?
Chronic Inflammatory Demyelinating Polyneuropathy
There is a lesion in the basal ganglia, what symptoms do you expect?
Parkinsonism: bradykinesia, rigidity, tremor (BRT)
What is the triad of symptoms in normal-pressure hydrocephalus?
- Magnetic gait
- Urinary dysfunction
- Cognitive impairment
Patient has multisystem atrophy (MSA).
What 3 clusters of symptoms would you expect?
Man with MSA always wears a CAP:
- Cerebellar ataxia
- ANS symptoms - brainstem involvement
- Parkinsonism - basal ganglia
ANS symptoms: bladder dysfunction, erectile dysfunction, orthostatic hypotension, bowel dysfunction.
Which Abx cause myasthenia crisis?
What is the treatment?
Macrolides and Quinolones
Treatment: plasma exchange OR IVIG
What 2 conditions is Natalizumab used in?
Multiple sclerosis and Crohn’s disease
Patient is immunocompromised and noted to have hemiparesis, ataxia, speech disturbance, cognitive impairment, sensory loss, vertigo and visual disturbance.
Aside from being unlucky, what might be the problems here?
Progressive multifocal leucoencephalopathy - inflammation of the white matter from an opportunistic JC viral infection.
What neurological complication can Natalizumab cause?
When factors reduce the risk of this occurring?
PML (Progressive multifocal leucoencephalopathy)
- Short period of treatment with Natalizumab
- Nil previous immunosuppressants
- Negative for anti-JV virus Ab
Which of the following is NOT consistent with Wernicke’s Encephalopathy:
- Nystagmus
- Tachycardia
- Cerebellar dysfunction
- Pappiloedema
- Horner’s syndrome
Horner’s syndrome - as it is suggestive of a localised lesion
In the treatment of Parkinson’s disease, what is the MOA of the following drugs:
- L-DOPA
- Carbidopa
- Selegeline
- Amantadine / Bromocriptine / Pergolide / Pramipexole
- Entacapone
- L-DOPA
Substrate for dopamine - Carbidopa
inhibits conversion of L-DOPA to dopamine in the PERIPHERY therefore more for CNS - Selegeline
Prevents CENTRAL degradation of dopamine by MAO-B inhibition - Amantadine / Bromocriptine / Pergolide / Pramipexole
Variety of dopamine antagonists - Entacapone
Prevents degradation of dopamine by COMT inhibition in CNS and PERIPHERY
What is the most common cause of optic neuritis?
Multiple sclerosis
What are the clinical features of brachial neuritis?
- Winging of the scapula - weakness with external rotation of the shoulder.
- Pain in should and numbness in thumb and index finger
- Normal reflexes
Restless leg syndrome:
- Associated with which deficiency?
- T/F: associated with pregnancy?
- Treated with which medication?
- Associated with which deficiency?
Iron deficiency - T/F: associated with pregnancy?
True - Treated with which medication?
Dopaminergic medications
Periodic leg movements in sleep (PLMS):
- Occurs in which stage of sleep?
- If it occurs in patient with OSA patient on nasal CPAP, does it require treatment?
- Occurs in which stage of sleep?
Stage 1 and 2 - If it occurs in patient with OSA patient on nasal CPAP, does it require treatment?
No
What type of patients get PML?
HIV patients and chronically immunosuppressed patients. (JC-virus mediated)
Patient has:
- Slurred speech and difficulty swallowing
- Slowing of vertical saccades / decreased blink rate
- Bilateral symmetrical bradykinesia
- Increased neck tone but normal tone at extremities
- Slow gait with positive pull test
Where is the lesion?
Midbrain
Patient has Parkinson’s disease with dyskinesia, aside from decreasing levodopa dose, what else should be considered?
- Add Amantadine
2. Add, change or increase dose of dopamine agonist
In a pregnant woman with epilepsy:
- What are the safer AEDs?
- What are teratogenic/unknown?
- What are the safer AEDs?
- Valproate at lower doses (less than 1400mg)
- Lower risk: carbamazepine / lamotrigine - What are teratogenic/unknown?
- Unknown: levetiracetam
- Risk: topiramate
With regards to bowel complications from a spinal cord lesion ‘above’ T12:
- T/F: the ability to feels the rectum is full is lost
- T/F: the anal sphincter tone is lost
- T/F: the defecation reflex is lost
- T/F: the ability to feels the rectum is full is lost - TRUE
- T/F: the anal sphincter tone is lost - FALSE
- Anal sphincter remains tight. - T/F: the defecation reflex is lost - FALSE
- Defecation reflex is preserved.
- Although the fullness of the rectum is not
Above which level of spinal cord injury does a ‘neurogenic bladder’ occur?
Is the neurogenic bladder spastic or flaccid?
Above T12 - a neurogenic bladder is spastic.
Above which level of spinal cord injury does an ‘atonic bladder’ occur?
Is the atonic bladder spastic or flaccid?
Below T12 - an atonic bladder is flaccid.
Sympathetic nerves fibers in the spinal cord maintain relaxation of the bladder detrusor muscle for urine storage.
Which levels of the spinal cord are these sympathetic fibres found?
T11 to L2
Parasympathetic nerve fibers in the spinal cord produce contraction of the bladder detrusor muscle and sphincter relaxation to allow voiding.
Which levels of the spinal cord are these parasympathetic fibres found?
S2 to S4
There are 2 sphincters that control voiding. The internal sphincter and external urethral sphincter are both under the control of the sacral parasympathetic nerve fibres.
Which of these 2 sphincters are under voluntary control?
The external urethral sphincter is under voluntary control.
The external urethral sphincter contracts under voluntary control.
Which 2 other triggers cause contraction of this sphincter?
Cough and Valsalva manoeuvre
T/F: spinal shock is associated with flaccid weakness and unreactive plantars
True
What is the difference between spinal shock and neurogenic shock?
Spinal shock:
- Immediate temporary loss of total power, sensation and reflexes below the level of the injury
- Peripheral nerves become temporarily unresponsive to brain stimuli
Neurogenic shock:
- Sudden loss of SNS signals
- Disruption of autonomic pathways leading to decreased SNS tone (hypotension and bradycardia)
Which of the following differentiates spinal shock from neurogenic shock:
- BP
- Heart rate
- Bulbocavernosus reflex
- Motor function
- Time to clinical manifestation post-spinal injury
Often difficult to differentiate:
- BP - hypotension in both
- Heart rate - bradycardia in both
- Bulbocavernosus reflex - ABSENT in spinal shock and VARIABLE in neurogenic shock
- Motor function - FLACCID in spinal shock and VARIABLE in neurogenic shock
- Time to clinical manifestation post-spinal injury - both occur at 48-72h post spinal cord injury
What is does the bulbocavernosus reflex indicate in spinal shock?
Bulbocavernosus reflex:
- Polysynaptic reflex mediated by S2-S4
- Squeezing of the glans penis or clitoris leads to contraction of the anal sphincter.
- Reflex is absent in a patient with spinal shock and return of reflex suggests the resolution of spinal shock
Describe the 4 phases of spinal shock.
Comment on timing and state of reflexes
Phase 1 (0-1 day): arelfexia/hyporeflexia
Phase 2 (1-3 days): initial return of reflexes
Phase 3 (1-4 weeks): initial hyperreflexia
Phase 4 (1-12 months): final hyperreflexia
Regarding the spinal cord, comment on the ‘autonomic function’ of the following spinal cord levels:
- Cranial nerves
- T1-L5
- L5-S3
- Cranial nerves:
- PSNS control of heart and GIT - T1-L5:
- SNS control of CVS / lung / GIT / kidneys / sweat glands - L5-S3:
- PSNS control of bowel and bladder
In the context of thrombolysing stroke, under which time frame do the best outcomes occur?
A. greater than 4.5h
B. 3 to 4.5h
C. less than 3h
C. less than 3h
What is the risk in terms of Odd Ratio (OR) of the following type of haemorrhage in a patient with a thrombolysed stroke compared to controls without tPA:
- Symptomatic haemorrhage
- Fatal intracranial haemorrhage
- Symptomatic haemorrhage: OR = 5.5
2. Fatal intracranial haemorrhage: OR = 7
What might occur as a complication of a patient that has recovered from an adequately treated episode of Bell’s Palsy 3 months down the track?
Abberant reinnervation leading to ‘synkinesis’ (involuntary movements that accompany voluntary movements).
Examples:
- Salivation accompanied lacrimation (tears)
- Eye closure associated with mouth twitching
Patient has a denovo diagnosis of Guillain-Barre Syndrome (GBS) presenting less than 2 weeks from onset of symptoms and is unable to walk.
What treatment is recommended?
Should this treatment be preceded by a trial of IV steroid therapy?
IVIg or plasma exchange.
Steroids (PO or IV) alone are NOT beneficial in GBS
A patient previously diagnosed with Gullain Barre Syndrome has 3 subsequent deteriorations and presents again 2 months after the first episode.
What diagnosis should be considered?
What is the treatment?
Acute onset CIDP (Chronic Inflammatory Demyleinating Polyneuropathy).
Retreat with IVIg or plasma exchange and may consider steroid treatment.
Which vessel within the circle of Willis is at highest risk of aneursymal rupture?
Anterior Cerebral Artery
In a patient with intracerebral haemorrhage, the BP target range that yields the BETTER outcome is which of the following:
A. Aim BP 110 - 139 mmHg (intensive reduction)
B. Aim BP 140 - 179 mmHg (conventional)
B. Aim BP 140 - 179 mmHg (conventional)
Intensive BP reduction lead to higher renal adverse events.
Patient present with an ischaemic stroke and nil aetiology is ascertained with routine investigations (i.e. including no AF).
What is the likely yield of a insertable cardiac monitor yielding AF by 12m follow-up?
Detection of AF (for greater than 30 secs) in patients with cryptogenic stroke with an insertable cardiac monitor at 12 months is 12%.
About 10%.
What does SUDEP stand for?
Sudden Unexpected Death in EPilepsy (SUDEP)
What are the 2 ‘main’ risk factors for SUDEP?
- Uncontrolled or frequent seizures
2. Generalised convulsive seizures
Describe the motor unit potentials in an electromyography in the following conditions:
- Neuropathic condition
- Myopathic condition
- Myasthenia gravis
- Neuropathic condition = long duration
- Myopathic condition = shorter duration and small amplitude
- Myasthenia gravis = normal morphology
Which type of electromyography (EMG) is most SENSITIVE to neuromuscular junction abnormalities like Myasthenia Gravis?
Is this test also specific?
- SFEMG (single-fiber EMG) is the most sensitive test for Myasthenia Gravis but NOT specific.
- Jitter is increased in SFEMG (even on anticholinesterase inhibitors) in Myasthenia Gravis patients.
Comment about the following aspects of Giant Cell Arteritis (GCA) histology:
- Continuous vs. skip lesions
- Involvement of intracranial arteries
- Involvement of neck and thoracic arteries
- Likelihood of finding multinucleated giant cells (as a percentage)
- Evidence of inflammation in arteries several weeks after commencing steroids.
- Continuous vs. skip lesions - - usually skip lesions
- Involvement of intracranial arteries - spared.
- Involvement of neck and thoracic arteries - involved.
- Likelihood of finding multinucleated giant cells (as a percentage) - 50%
- Evidence of inflammation in arteries several weeks after commencing steroids - persists.
Which viral antigen if often found in biopsy specimens of GCA?
Varicella Zoster Virus (VZV) antigen.
Symptomatic GCA should be treated expeditiously within 24h to avoid visual impairment.
Which of the following approximates the risk of irreversible visual damage if treatment is delayed beyond 2 days?
A. 2x B. 5x C. 10x D. 15x E. 20x
E. 20x
There is a 22-fold increase in risk if treatment is delayed beyond 2 days.
What 3 factors may increase the diagnostic yield of a GCA biopsy?
- Biopsy within 2 weeks of commencing steroids
- Biopsy a tender or swollen segment of the temporal artery
- Adequate length of segment (3-5cm) to avoid skip lesions.
Give 5 GOOD prognostic factors in Multiple Sclerosis.
- Optic neuritis
- Isolated sensory symptoms
- Long interval to second relapse
- No evidence of disability after 5 years
- Female gender
Give 6 POOR prognostic factors in Multiple Sclerosis.
- ‘Multifocal’ Clinically Isolated Syndrome
- Efferent (motor/cerebellar) systems
- High relapse rate in 5 years
- Substantial disability after 5 years
- Male gender
- Abnormal MRI with heavy lesion load
An elderly patient presents with new-onset severe vertigo, nausea and vomiting, and unsteady gait. DDx include acute vestibular neuritis and posterior circulation stroke.
What 4 additional clinical features would make stroke MORE likely?
- Presence of general neurological signs
- Direction-changing horizontal nystagmus
- Skew deviation present or untestable
- Horizontal head impulse test NORMAL or untestable
In acute vestibular neuritis related nystagmus:
- In which direction is the ‘vector’ of nystagmus?
- In which direction does the nystagmus increase and decrease?
- Is it present in the primary position?
- In which direction is the ‘vector’ of nystagmus?
- Horizontal vector - Gazing towards which phase (i.e. fast/slow) does the nystagmus increase and decrease?
- Increases when gaze is towards the fast phase (corrective saccadic phase) and vice versa. - Is it present in the primary position?
Yes.
Patient presents with acute vestibular neuritis. You note horizontal nystagmus beats predominantly towards one direction and occurs regardless of the eye position in the orbits.
Is the lesion towards the side of the fast or slow phase?
- Slow phase suggests side of pathology.
- Fast phase is the corrective saccade.
Patient presents with dizziness and has a POSITIVE head tilt test.
Is acute vestibular neuritis (AVN) more or less likely compared to posterior circulation stroke?
What reflex is tested by the head tilt?
POSITIVE head tilt test suggests AVN.
Head tilt test the vestibular-ocular reflex.
Patient presents with dizziness and is noted to have direction-changing nystagmus.
Is acute vestibular neuritis (AVN) more or less likely compared to posterior circulation stroke?
What lesion does direction-changing nystagmus suggest?
Direction-changing nystagmus suggests posterior circulation stroke (brainstem or cerebellar lesion).
Nystagmus ‘reverses’ direction when the patient looks in the direction of the slow phase.
This is due to failure of the gaze-holding circuits in the cerebellum or brainstem,
How does visual fixation differentiate a peripheral from central cause of nystagmus?
Visual fixation suppresses PERIPHERAL causes of nystagmus.
Removal of fixation therefore lead to exacerbation of pre-existing nystagmus, whereas a central cause will yield NO change upon removal of fixation.
Patient is noted to have positive measles virus serology and presents with fever, myalgia, neck stiffness, photophobia and confusion. His MRI suggest multiple lesions in the brain and a spinal cord lesion.
What is the diagnosis?
ADEM (acute disseminated encephalomyelitis)
Neuromyelitis Optica is a demyelinating condition.
What nerve fibres does it have a predilection for?
Spinal cord and optic nerves (as name suggests)
Patient presents with a history of distal right arm weakness with new-onset left arm weakness. No swallowing difficulties. Anti-GM1 Abs (ganglioside GM1 Abs) are positive. What are the likely diagnoses?
MMN (multifocal motor neuropathy)
Possibly:
GBS: usually symmetrical
Motor neuron disease: no bulbar involvement
What Abs are associated with the following conditions:
- Distal acquired demyelinating symmetric neuropathy
- GBS acute motor axonal neuropathy variant
- Limbic encephalitis
- Paraneoplastic encephalitis
- Neuromyelitis optica
- GBS Miller fisher variant
- Myasthenia Gravis
- Lambert eaten syndrome
- Stiff person syndrome
- Acute disseminated encephalomyelitis
- Distal acquired demyelinating symmetric neuropathy = MAG
- GBS acute motor axonal neuropathy variant = GM-1
- Limbic encephalitis = voltage gated potassium channels
- Paraneoplastic encephalitis = Hu/Yo/Ri/Ma
- Neuromyelitis optica = aquaporin 4 or MOG
- GBS Miller fisher variant = GQ1b
- Myasthenia Gravis = AchR or MusK
- Lambert eaten syndrome = pre synaptic VGCC
- Stiff person syndrome = GAD
- Acute disseminated encephalomyelitis = MOG
Elderly patient with AF on therapeutic warfarin presents with ICH. Warfarin is ceased. ICH remains stable after 14d, should the patient be recommenced on warfarin or shoulder it be ceased herein.
Recommence warfarin - resumption of anticoagulation survivors of ICH improves function, decreases mortality and reduced stroke at 1 year.
REM sleep behaviour disorder is associated with which 3 conditions?
Prodromal syndrome of alpha-synuclein neurodegeneration and heralds:
- PD
- MSA
- LBD
What is the risk of REM sleep behaviour disorder developing into PD, MSA or LBD within 10 years?
50%
What are the top 5 AEDs that are teratogenic in pregnant women?
valproate > phenobarbitol > topiramate > carbamazepine > phenytoin
