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