Neurology Flashcards
Mechanism of action of sumatriptan?
5-HT1 agonist
How soon after LP do post-LP headaches usually develop and what is the mechanism?
Usually within 3 days
Worsens when upright
Thought to be due to leakage of CSF from the dura - when withdrawing the stylet a piece of the arachnoid can be pulled through, keeping the dural hole open
What can you treat post-LP headache with if needed?
Blood patch, epidural saline, IV caffeine
What are the symptoms of brachial neuritis?
Acute onset of unilateral severe pain, followed by shoulder and scapular weakness several days later
May be wasting of the arm muscles
What is the treatment for brachial neuritis?
Self-resolves, prognosis is good
What is the pathophysiology of GBS and most common Abs responsible?
Infection causes a production of Abs which attack the bodys nerve myelin (molecular mimicry). This demyelination then causes an acute, inflammatory, ascending polyneuropathy of peripheral nerves.
Anti-GM1 Abs in 25%
What is the most common/other infections that can cause GBS?
Campylobacter jejuni
CMV
Mycoplasma etc
What are the symptoms of GBS?
1-2 weeks post-infection: symmetrical, ascending muscle weakness +/- numbness
Progresses from distal to proximal over 4 weeks
Can get loss of reflexes, develop neuropathic pain and autonomic dysfunction (sweating, tachy etc)
In 20%, resp muscle and facial muscles are affected
What are the investigations in GBS?
LP: increased proteins, WCC normal
Nerve conduction studies: slow nerve conduction (due to lack of myelin), prolonged distal motor latency and increased F wave latency
Spirometry to monitor FVC
Management and prognosis of GBS?
IVIg
Can also do plasma exchange but less common
Monitor respiratory function
15% have ongoing muscle weakness
5% die
Poor prognostic factors associated with GBS?
age > 40 years poor upper extremity muscle strength previous history of a diarrhoeal illness (specifically Campylobacter jejuni) high anti-GM1 antibody titre need for ventilatory support
What is Miller Fisher syndrome? Triad of symptoms? Antibody?
Variant of GBS
Opthalmoplegia, ataxia, areflexia
Usually a descending paralysis
Anti-GQ1b positive in 90%
What is the management of medication-overuse headaches?
simple analgesics and triptans should be withdrawn abruptly (may initially worsen headaches)
opioid analgesics should be gradually withdrawn
When does neuroleptic malignant syndrome occur and what are the symptoms?
Occurs within a few days of starting antipsychotic
fever
muscle rigidity
autonomic lability: typically HTN, tachycardia and tachypnoea
Confusion
Investigations (e.g. blood test) and management in neuroleptic malignant syndrome?
Raised CK
Mx: stop drug, IV fluids to prevent renal failure
Can treat with dantrolene or bromocriptine
What is the pathophysiology and symptoms of acoustic neuromas?
- Usually benign SOLs arising from proliferation of Schwann cells around the nerve
- Many are symptomless and only found on autopsy
Unilateral SN hearing loss
Unilateral tinnitis
Vertigo
Absent corneal reflex
CN VIII: vertigo, unilateral sensorineural hearing loss, unilateral tinnitus
CN V: absent corneal reflex
CN VII: facial palsy
Investigations and management of acoustic neuromas?
Audiometry
MRI
Mx is with either surgery, radiotherapy or observation
What is Creutzfeldt-Jakob disease (CJD)?
A rapidly progressive neurological condition caused by PRION proteins. These proteins misfold and induce the formation of amyloid folds resulting in tightly packed beta-pleated sheets resistant to proteases.
sporadic: accounts for 85% of cases
10-15% of cases are familial
mean age of onset is 65 years
What are the features of Creutzfeldt-Jakob disease (CJD)?
dementia (rapid onset)
behavioural changes
Focal signs
myoclonus
(think of the woman found wandering the streets)
Investigations in CJD?
CSF is usually normal
EEG: biphasic, high amplitude sharp waves (only in sporadic CJD)
MRI: hyperintense signals in the basal ganglia and thalamus
Which should you replace first, B12 or folate?
B12
What are the symptoms of subacute degeneration of the spinal cord?
UMN + LMN signs
Investigations in MS? Diagnostic criteria?
Visual evoked potential studies - delayed nerve conduction
MRI FLAIR scan - periventricular lesions, >90% show white matter irregularities, see Dawson’s Fingers
CSF - oligoclonal bands of IgG, increased protein
Over 2 CNS lesions disseminated in time and space
What type of MRI scan should be performed to visualise thyroid Abs in thyroid eye disease?
MRI STIR
What are the three main RFs for degenerative cervical myelopathy?
SMOKING
Genetics
Occupation
Symptoms of degenerative cervical myelopathy? Specific sign to look for?
Pain
Numbness
Weakness
Loss of autonomic function (urinary/bowel continence)
HOFFMAN’S SIGN - flicking one fingers causes the other fingers on that hand to flicker
How do you investigate and treat degenerative cervical myelopathy?
Investigation: MRI
Tx: Urgent referred for assessment by specialist spinal service - early surgery gives best outcomes
Which chromosomes code for neurofibromatosis T1 and T2?
T1 = chr 17 T2 = chr 22
Symptoms of neurofibromatosis T1?
Café-au-lait spots (>= 6, 15 mm in diameter) Axillary/groin freckles Peripheral neurofibromas Iris hamatomas (Lisch nodules) in > 90% Scoliosis Pheochromocytomas
CLAPPS
Symptoms of neurofibromatosis T2?
Bilateral vestibular schwannomas
Multiple intracranial schwannomas, mengiomas and ependymomas
What triad of symptoms is seen in sturge weber syndrome?
Port-wine stain on face
Brain abnormality called a leptomeningeal angioma
Glaucoma
In webs, there are lots of GAPs
What is the inheritence pattern and what are the features of an essential tremor?
AD
postural tremor: worse if arms outstretched
improved by alcohol and rest
most common cause of titubation (head tremor)
Management of an essential tremor?
propranolol is first-line
primidone is sometimes used (e.g. in asthmatics)
What type of Ca is Lambert-Eaton myasthenic syndrome associated with?
SCLC
What are anti- Hu/Yo/GAD/Ri associated with?
Anti-Hu associated with SCLC and neuroblastomas sensory neuropathy - may be painful cerebellar syndrome encephalomyelitis
Anti-Yo
associated with ovarian and breast cancer
cerebellar syndrome
Anti-GAD antibody
associated with breast, colorectal and SCLC (BSc)
stiff person’s syndrome or diffuse hypertonia
Anti-Ri
associated with breast and SCLC
ocular opsoclonus-myoclonus -> dancing eye syndrome
What type of anaemia is seen with anti-epileptics?
Folate deficiency anaemia
What is the pathophysiology of Parkinson’s disease?
Progressive degeneration of dopaminergic neutrons in the substantiated nigra pars compacts of the basal ganglia
Lewy bodies develop -> eosinophilic cytoplasmic inclusions of ubiquitin and alpha-synuclein
Loss of dopamine and melanin in the striatum
Symptoms of Parkinson’s disease?
Asymmetrical
Rigidity
Bradykinesia (cogwheel - due to superimposed tremor)
Resting tremor (pill-rolling, 3-5Hz, worse when stressed/tired)
Other: mask-like facies flexed posture micrographia drooling of saliva psychiatric features: depression is the most common feature (affects about 40%); dementia, psychosis REM sleep behaviour disorder postural hypotension
What are the features of drug-induced parkinsonism?
Slightly different features to Parkinson’s disease:
motor symptoms are generally rapid onset and BILATERAL
rigidity and rest tremor are uncommon
Main differentiating factor = ASYMMETRY of symptoms in idiopathic Parkinson’s
If difficult to differentiate between essential tremor and Parkinson’s, what can you use?
single photon emission CT (SPECT)
SEs and limitations of levodopa?
N&V, palpitations, hypotension, dry mouth
Induces dyskinesia (involuntary muscle movements)
On-off effect: fluctuations in motor performance
Reduced efficacy over time
Which medications should you start with in Parkinson’s?
if the motor symptoms are affecting the patient’s quality of life: levodopa
if the motor symptoms are not affecting the patient’s quality of life: dopamine agonist (non-ergot derived), levodopa or monoamine oxidase B (MAO‑B) inhibitor
What are the SEs and examples of dopamine agonists?
Ropinirole, pramiprexole
SEs: drowsiness, nausea
HALLUCINATIONS, COMPULSIVE BEHAVIOUR
Note: bromocriptine/carbergoline - may cause pulmonary, retroperitoneal and cardiac fibrosis, therefore need close monitoring
What are examples of MAO-B inhibitors, MOA and SEs?
selegiline, rasagiline
MOA: reduce dopamine breakdown
SEs: postural hypotension, AF
What are examples of COMT inhibitors, MOA and SEs?
Entacapone, tolcapone
Inhibit the enzyme COMT which is involved in the breakdown of dopamine
Tolcapone can cause liver damage
What is the MOA and SEs of Amantadine?
M2 inhibitor
mechanism is not fully understood, probably increases dopamine release and inhibits its uptake at dopaminergic synapses
side-effects include ataxia, slurred speech, confusion, dizziness and livedo reticularis
How do you treat balance, speech and gait disturbances in parkinson’s?
Don’t respond to medication
Need physiotherapy
Which drugs are CI in Parkinson’s?
ANTIPSYCHOTICS
What are the four criteria where you would start anti epileptics after the first seizure in epilepsy?
1) the patient has a neurological deficit
2) brain imaging shows a structural abnormality
3) the EEG shows unequivocal epileptic activity
4) the patient or their family consider the risk of having a further seizure unacceptable
First line medication for T-C/myoclonic/focal/absence seizures?
T-C: Na valproate
Myoclonic: Na valproate
Absence: Na valproate or ethosuxamide
Focal: Carbamazepine or lamotrigine
Where is Broca’s area located?
Inferior frontal gyrus
Where is Wernicke’s area located?
Brodmann area 22 in the superior temporal gyrus
Where is the arcuate fasiculus and what is caused by a problem here?
The connection between Wernicke’s and Broca’s area
Conductive aphasia
Speech is fluent but repetition is poor
NICE treatment steps for neuropathic pain?
first-line treatment: amitriptyline, duloxetine, gabapentin or pregabalin
Try 2 out of 4 as monotherapies before moving on
tramadol may be used as ‘rescue therapy’ for exacerbations of neuropathic pain
topical capsaicin may be used for localised neuropathic pain (e.g. post-herpetic neuralgia)
What is the inheritance pattern, pathophysiology and symptoms of otosclerosis?
Management?
AD, affects young adults
replacement of normal bone by vascular spongy bone causes fixation of the stapes bone at the oval window
conductive hearing loss, tinnitus and positive family history
Mx: hearing aid
stapedectomy
What does CADASIL stand for?
cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy
genetic condition due to a mutation in the NOCTH3 gene
Rare cause of multi-infarct dementia
Patient usually present with migraines
What occurs if there are lesions in each part of the brain?
Parietal lobe
sensory inattention
apraxias
Gerstmann’s syndrome (lesion of dominant parietal): alexia (can’t write), acalculia (can’t do maths), finger agnosia (can’t identify fingers) and right-left disorientation
Occipital lobe
cortical blindness
visual agnosia
Temporal lobe
Wernicke’s aphasia
auditory agnosia
prosopagnosia (difficulty recognising faces)
Frontal lobe expressive (Broca's) aphasia: in the inferior frontal gyrus disinhibition perseveration anosmia inability to generate a list
Absolute CI to thrombolysis in stroke?
- Previous intracranial haemorrhage
- Seizure at onset of stroke
- Intracranial neoplasm
- Suspected SAH
- Stroke or traumatic brain injury in preceding 3 months
- LP in preceding 7 days
- GI haemorrhage in preceding 3 weeks
- Active bleeding
- Pregnancy
- Oesophageal varices
- Uncontrolled hypertension >200/120mmHg
Relative CI to thrombolysis in stroke?
- Concurrent anticoagulation (INR >1.7)
- Haemorrhagic diathesis
- Active diabetic haemorrhagic retinopathy
- Suspected intracardiac thrombus
- Major surgery / trauma in the preceding 2 weeks
What pre-stroke functional status is needed for thrombectomy to be considered? And what type of stroke can it be given in?
<3 on the modified Rankin scale
>5 on the National Institutes of Health Stroke Scale (NIHSS)
<6hrs since stroke, offer if: confirmed occlusion of the proximal anterior circulation demonstrated by CT/MR angio
6-24hrs since stroke, offer if: above, plus confirmed evidence on scans of salvageable brain tissue
CONSIDER within 24hrs, if: confirmed occlusion of the proximal posterior circulation (that is, basilar or posterior cerebral artery) and confirmed evidence of salvageable brain tissue
Who should be offered a carotid artery endarterectomy?
If patient has suffered stroke/TIA in the carotid territory and are not severely disabled
Only consider if carotid stenosis > 70% according ECST criteria or > 50% according to NASCET criteria
Outside of the immediate CT criteria, what is the criteria for doing a CT within 8hrs?
CT head scan within 8 hours of the head injury - for adults with any of the following RFs who have experienced some LOC/amnesia since the injury:
age 65 years +
any Hx of bleeding or clotting disorders
dangerous mechanism of injury
>30 mins retrograde amnesia of events immediately before the head injury
Which neuropathic drugs are CI in glaucoma and why?
Amitriptyline - antimuscarinic
What drug can be given to manage spasticity in MS and what is its mechanism of action?
Baclofen - acts on GABA AGonist
Can also give gabapentin
After that - diazepam etc
Causes of cerebellar syndrome?
Friedreich's ataxia, ataxic telangiectasia neoplastic: cerebellar haemangioma stroke alcohol multiple sclerosis hypothyroidism drugs: phenytoin, lead poisoning paraneoplastic e.g. secondary to lung cancer
What causes normal pressure hydrocephalus and what is the pathophysiology?
SAH, meningitis, head injury
Thought to be due to decreased levels of absorption at the arachnoid villi