Neurology Flashcards
MS - pathophys, Epid, Clinical, Ix, Dx, Tx, Cx?
immune-mediated disorder characterized by activation of T-helper cells induce B-cells to produce Ab and cytokines that drive an inflammatory process directed at myelin and erosion of BBB, resulting in demyelination and axonal damage.
Epid:
F>M
20-40 y
Aetiology:
Genetics
Environmental - toxins, EBV
relapses triggered by infections, surgical procedures
Clinical
visual disturbance in one eye
peculiar sensory phenomena - odd sensations of a patch of wetness, burning, tingling, hemibody sensory loss, Lhermitte’s sign (electric shock like sensations extending down the cervical spine radiating to limbs)
foot dragging or slapping
Ix:
MRI brain - hyperintensitits in periventricular white matter
MRI spinal cord - demyelinating lesions in spinal cord, particul cervical spinal cord
TSH - exclude alternative Dx
Vit B12 - exclude alternate Dx
ant-NMO ab - present in neuromyelitis optica
CSF - oligoclonal bands and elevated CSF IgG present in 80%
evoked potenitals - prolongation of conduction, asymmetrical prolongation in visual evoked potenitals
Dx:
Dissemination in space and time
2 or more attacks, objective clinical evidence of 2 or more lesions or objective clinical evidence of 1 leision with reasonable historical evidence of prior attack
Tx:
1st line - Methylprednisolone
2nd line - IVIG
With severe worsening quadriplegia - plasma exchange
relapse remitting MS - immunomodulators, low dose anticonvulsants for sensory symptoms, antisapcity medication for increased muscle tone
Cx: UTI Osteopenia and OP Depression Visual impairment Erectile Dysfucntion (ED) Cognitive impairment Impaired mobility
What is the most common CNS tumour? Tx?
Glioblastoma
Tx: Surgical resection + concurrent Chemo (Temzolamide - oral alkylating agent) and stereotactic RTx
Types of nerve fibres?
A- myelinated
subtypes a (propioception), b (touch, pressure, motor), y (motor to muscle spindles), o (pain, cold, touch)
B - myelinated (paraganglionic autonomic)
C - unmyelinated slow conducting (pain)
Large fibres are concerned primarily with propioceptive sensation, somatic motor function, conscious touch and pressure.
Small fibres - pain and temperature sensations and autonomic function
What features indicate a poor prognosis in Bell’s palsy?
Older age > 60 y
Severe complete paralysis
Hyerpacusis
Altered taste
EMG evidence of axonal degeneration
Which antiepileptic drug reduces the serum levels of lamotrigine?
Phenytoin
Carbamazepine
(Think BS CRAP GPS)
What signs will a right Parietal stroke will produce?
Homonymous hemianopia
Hemispatial neglect
- cannot draw clockface
Dressing apraxia
What signs will an occipital infarct produce?
Homonymous heminopia with macular sparing
Pt with receptive aphasia. Which lobe affected?
Temporal (Wernicke’s area)
Which area is affected in global aphasia?
Perisylvian area
Triad of normal pressure hydrocephalus? MRI findings? Tx?
Dementia
Gait impairment - gait ataxia
Urinary incontinence
MRI:
Ventriculomegaly
Tx:
CSF drainage
Surigcal placement of ventriculoperitoneal shunt
Which antibodies are associated with paraneoplastic syndromes?
(sub-acute progressive neurological disease)
Anti Hu and Anti-Yo antibodies in CSF
why does Sodium valproate cause lamotrigine toxicity?
Valproate causes a significant rise in plasma concentration of lamotrigine by competitively inhibiting glucoronidation. Lamotrigine is extensively metabolsised by N-gluocoronidation
Which SSRI has been shown to improve motor recovery post stoke?
Fluoxetine
- serotonin mediated suppression of post stroke hyper-excitability (lancet 2011)
Meniere disease: Triad?
Vertigo
Unilateral low freq hearing loss
Tinnitus - associated with fullness
(Nystagmus to opposite side affected)
Acoustic neuroma: Presentation? Imaging of choice?
Nystgamus - rapid
Slowly progressive symptoms of hearing loss
Tinnitus
Loss of corneal reflex
MRI:
detect tuomours as small as 1-2 mm
What Tx is Dx for BPPV? Tx?
Hallpike manoeuvre
Tx with Epsley manoeuvre
What features predict a stroke mimic?
known CI
LOC or seizure at onset
Migration of symptoms
Positive symptoms e.g. paraesthesia, jerks
Brown Sequard Syndrome: Presentation?
Characterised by:
Ipsilateral motor deficit below the level of the lesion
Ipslateral impairment of vibration and position sense below the level of the lesion
Contralateral loss of pain and temperature from one or two segments below the lesion
Syringomyelia, subacute degeneration of cord and Friedrich’s ataxia can cause cerebellar signs and patchy sensory loss but would be bilateral.
painful eye with decreased visual acuity and relative afferent pupillary defect. Dx?
Optic neuritis
Most likely underlying cause is MS.
Myasthenia Gravis. Pathophy? Presentation? NCS demonstrate? Tx?
Antibody to the neuromuscular junction AChR or MuSK
Presentation:
fluctuating fatigable symmetric painless weakness
Fluctuating dysarthria
ptosis
Bulbar symptoms - Difficulty chewing, slurred speech
NCS:
Reduced amplitude
Tx:
Pyridostigmine (ACh inhibitor)
Thymectomy
Which symptoms in PD are not related to levodopa?
Falls, instability, gait disturbance Dysphagia, speech disturbance Incontinence, constipation Insomnia, REM sleep behaviour disorder Depression, cognition, pain
Tx for PD?
◦Dopamine Gold Standard
L-Dopa is 1st line Tx for:
- severe motor impairment
- >60 y, especially with CI
Levodopa +/- entacopone (COMT inhibitor acts by reducing extra cerebral metabolism of dopamine). COMT responsible for metabolism.
levodopa is the main precursor in dopamine synthesis.
- superior benefits in motor function, ADLs and QOL compared with other classes
- decreased chance of requiring add on therapy
Dopamine agonists: Stimulate dopamine by binding directly to receptors in the striatum
Non ergot
- pramiprexole, discontinuation in 8% due to AE e.g. somnolence, GIT, Impulse control disorder
- ropinirole
- transdermal rotigotine
Ergot derived
- cabergoline
- bromocriptine
- pergolide
- complications of heart valve and retroperitoneal fibrosis
AE: impulse control disorder, punding (repeated pointless actions)
MAO B inhibitors - rasigiline and selegeline ◾mild benefit ◾may slow progression of disease AE: hepatic dysfunction, higher overall mortality
◾apomorphine◾SC injection, powerful
◾moderate motor benefit
◾defer onset of motor fluctuations
◾AE: impilse control disorders, sleppiness, psychosis
◾Rotigotine - transdermal patch
◦Stalevo◾triple medication consisting of Levodopa, carbidopa and entacapone
Wallenberg’s syndrome (aka lateral medullary syndrome). What? Clinical features?
Due to occlusion of the posterior inferior cerebellar artery
– Ipsilateral loss of facial pain and temperature(due to trigeminal spinal nucleus and tract involvement).
– Contralateral loss of pain and temperature(due to damage to the spinothalamic tract).
– Ipsilateral palatal, pharyngeal, and vocal cord paralysis with dysphagia and dysarthria (due to involvement of the nucleus ambiguus).
– Ipsilateral Horner syndrome (due to affection of the descending sympathetic fibers).
– Ipsilateral cerebellar signs and symptoms (due to involvement of the inferior cerebellar peduncle and cerebellum).
– Vertigo, nausea, and vomiting (due to involvement of the vestibular nuclei).
– Occasionally, hiccups (singultus) attributed to lesions of the dorsolateral region of the middle medulla and diplopia (perhaps secondary to involvement of the lower pons).
What is Foster Kennedy Syndrome?
due to an inferior frontal lobe tumour.
It causes optic atrophy in one eye and papilloedema in the other.
What is Gerstmann syndrome?
Gerstmann syndrome causes agraphia, acalculia, finger agnosia, left right disorientation.
CT/MRI should precede LP in which group of pts?
1) presence of papilledema on physical examination
2) history of recent head trauma
3) known or suspected intracranial lesions (immunosuppressed, known malignancy)
4) focal neurologic findings.
5) depressed level of consciousness
Which mutation occurs in familial form of ALS?
SOD1 mutation
What is Kennedy’s syndrome? Presentation?
– X-linked lower motor neuron disorder
– No UMN signs.
– Associated with gynaecomastia and infertility.
Underlying molecular defect is an expanded trinucleotide repeat (-CAG-) in the first exon of the androgen receptor gene on the X chromosome
– X-linked lower motor neuron disorder
– No UMN signs.
– Associated with gynaecomastia and infertility.
Underlying molecular defect is an expanded trinucleotide repeat (-CAG-) in the first exon of the androgen receptor gene on the X chromosome
MOA of riluzole?
sodium channel blocker that inhibits glutamate release.May slow progression of disease marginally.
Does not prolong survival
UMN signs only? Dx
Primary lateral sclerosis
LMN signs only?
Primary muscular atrophy
ALS. Presentation?
UMN LMN Bulbar dysfunction Respiratory failure Cramps and fasciculation NORMAL SENSATION
majority of anti-epileptics block Na channels except?
Tiagabine
GABA re-uptake inhibitor
MOA of Vigabatrin? indication
GABA transaminase inhibitor
Refractory complex partial seizures
Partial seizures with or without secondary generalisation
Which antiepileptic may cause OP?
Other AE of this anti-epileptic?
Phenytoin
Osteoporosis, ataxia, nystagmus, gingival hyperplasia, coursening of facial features, loss of libido, hormone dysfucntion, bone marrow hypoplasia.
Which of anti-epileptic has the most teratogenic effect in pregnancy?
NaValproate
Major malformations, such as congenital heart disease, neural tube defects, urogenital defects and cleft lips or palates, occur in about 3-7% of women with epilepsy who take antiepileptic drugs, although a substantially higher risk is attributed to high doses of valproate (greater than 1400 mg/day).
Which anti-epileptic drugs may cause visual field changes?
Vigabatrin
- visual field changes!
Drowsiness(most common), neuropsychiatric symptoms, weight gain
Which anti-epileptics cause weight gain and weight loss?
Gain:
Vigabatrin
Pregabalin
Valproate.
Loss:
Topiramate
Which AED may cause renal calculi?
Topiramate
Which AED may cause insulin resistance?
Valproate causes insulin resistance and changes in sex hormone levels (anovulatory cycles, amenorrhea and PCOS).
Also causes metabolic abnormalities such as hypocarnitinemia, hyperglycinemia and hyperammonemia
Presentation of PCA aneurysm?
Headache painful 3rd nerve palsy 3rd nerve palsy - eye deviated down and out -ptosis - pupils maybe dilated
Which AED does not affect the OCP?
Sodium Valproate (Cyp inhibitor)
Which AED may aggravate juvenile myoclonic epilepsy and should be avoided?
Tx?
Carbamazepine
Tx: NaValproate
What is the most common symptom of excess Levodopa?
Nausea and vomiting
Common AE: orthostatic hypotension dyskinesia anorexia agitation insomnia drowsiness depression hallucinations confusion
MOA of amantadine?
Indications?
Amantadine enhances dopamine release and blocks cholinergic receptors.
Acts as NMDA antagonist.
Indications:
PD
Influenza A
MOA of COMT inhibitors?
prolong dopamine activity by blocking breakdown
Domperidone crosses BBB. T/F
False.
Safe to use in PD.
Indications:
N/V
Gastroparesis (idiopathic or diabetic)
Smoking is protective against PD. T/F
True
List the dopamine agonist. AE?
Pramiprexole
Apomorphine
AE:
Impulse control disorder
Somnolence
Psychosis
Radial nerve supplies (C5-8)? Presentation of lesion?
Supplies triceps, brachioradialis. extensors of the hand
Lesion: wrist drop absent sensation over the anatomical snuff box weakness of finger and thumb extension loss of triceps reflex
Median nerve (c6-T1). Supplies? Presentation of lesion?
Supplies all the muscles of the forearm except flexor carpi ulnaris and ulnar half of flexor digitorum
Lesion:
Carpel tunnel syndrome
failure of flexion of index finger - cubital fossa lesion
Loss of sensation over the palmar aspect of thumb, index and middle and lateral half of ring finger
weakness of abduction/opposition of thumb
Ulnar nerve (C8-T1. Supply? Presentation of lesion?
Supplies all the small muscles of the hand (except LOAF), flexor carpi ulnaris and ulnar half of flexor digitorum profundus
Presentation:
Clawing of ring finger
loss of sensation over the palmar and dorsal aspect of the little finger and medial half of ring finger
weakness of small finger flexion, abduction and adduction
If the peripheral nerve lesion involves more than one nerve and distribution of the sensory loss is wider (e.g. involves the distal forearm). Where is the lesion?
Brachial plexopathy.
Pt post ortho Sx. Foot drop and ankle reflex absent. Where is the lesion?
Sciatic Nerve.
if reflexes were intact, think of common peroneal or L5 radiculopathy
Cervical spinal cord compression. Presentation?
Upper cervical
C5
C8
Upper cervical
- UMN signs in UL and LL
C5
- UMN in UL and LL
- biceps jerk lost
- LMN weakness and wasting of rhomboids, deltoids, biceps and brachioradialis
- brachioradialis jerk inverted
C8
- UMN signs in LL
- LMN weakness and wasting of intrinsic muscles of hands
Haemophilia pt develops haematoma. Weak knee extension, absent knee jerk and loss of sensation over inner aspect of thigh and leg. lesion?
Femoral nerve (L2, 3, 4)
Which antibiotic reduces the therapeutic effects of NaValproate?
Carbapenem (imipenem, meropenem, ertapenem)
Unknown mechanism
List the 4 pre-requisites to exclude before a pt is considered brain dead
1) Clinical or neuroimaging evidence of an acute CNS catastrophe that is compatible with the clinical diagnosis of brain death.ie: the cause of brain death should be known.
2) Exclusion of complicating medical conditions that may confound clinical assessment (no severe electrolyte,acid base or endocrine disturbance)
3) No drug intoxication or poisoning, which may confound the clinical assessment.
4) Core temperature >32 degrees celcius.
Why should phenytoin be avoided in Asians (Han chinese, Thai and malay)?
More likely to have HLA-B 1502 allele which sig increases the risk of severe skin reactions.
Routine testing is not recommended.
Where is the lesion- difficulty making the ok sign?
right anterior interosseous nerve
Ventral (motor) tract? Dorsal (sensory) tracts?
Ventral (front-V shape) - corticospinal (motor) and spinothalamic tract (pain and temp)
Dorsal - Dorsal comum meniscus (sensory, vibration), spinocerebellar (limb and joint propioception)
Which drugs cause an i) axonal neuropathy ii) demyelinating neuropathy?
axonal - ethanol, pyridoxine, thalidomide
demyelinating - Cholorquine, Procainamide, Perhexiline, Tacrolimus
GBS is associated with which abs?
Anti-ganglioside (GM1, GD1a, GT1a and GQ1b)
GQ1b
What are the hallmarks of Supranucelar palsy?
Distinctive eye findings (impairment of vertical gaze movement, square wave jerks, slow saccades and a spuranuclear gaze paresis)
Facial dystonia
Axial rigidity
How to differentiate Multi systems atrophy (MSA) from PD?
- poor initial response to l-dopa
- autonomic failure
- speech and bulbar dysfunction
- early falls
- progression (50% wheelchair by 5 y)
- preserved cognition
Hallmarks of corticobasal ganglionic degeneration?
- asymmetric dystonic syndrome with apraxia
- cortical sensory loss
- tremor
- myoclonus
- dementia
Clinical findings of a sciatic nerve lesion?
Loss of knee flexion
Loss of ankle dorsiflexion (L4 deep peroneal)
Loss of toe extension (L5 deep peroneal)
Loss of sensation on dorsum of foot and sole
Loss of ankle jerk (sciatic nerve)
Clinical hx typically - hip dislocation, fracture or replacement, prolonged bed rest, deep seated pelted mass, performs syndrome
Clinical features of frontal lobe damage?
Attention disorder, ditractability, poor attention
poor memory
perservation, concrete thinking -> leads to difficulty with arithmetic calculations, serial sevens or carryover subtraction
aphasia, urinary, faecal incontinence
Epilepsy
Reduced activity, lack of drive, inability to plan ahead, lack of concern
Patient having difficulty drawing animals, all the animals look the same. Where is the lesion?
Lateral temporal lobe/cortex.
Pt has a semantic problem, having lost the sense of what features make an animal distinct from other animals.
Which lobe is responsible for visuospatial function?
Non dominant parietal lobe
What is the 1st line Tx for Juvenile Myoclonic Epilepsy? What medication will exacerbate myoclonic epilepsy?
Valproate and topiramate
Lamotrigine may exacerbate myoclonus
MCA infarct. Clin pres? Which segment of MCA affected?
Dense hemoplegia
Hemianopis
Aphasia if dominant
M1 of MCA segment. Increased attenuation of the proximal portion of the MCA is typically seen within 90 minutes
ACA infart. Clin Pres?
Sensory and Motor deficits of LL predominantly.
Medical frontal lobe affected.
What sign is classic of a lacunar infarct?
Pure motor deficit
What is the pathophys of Lewy body disease?
Misfolding and intracellular aggregation of alpha synuclein.
Extracellular aplha synuclein is internalised into neighbouring cells and degraded into lysosomes.
In Lewy body a higher proportion of excreted alpha synuclein is in aggregated form which promotes further aggregation ind is pro inflammatory.
ACHR-Ab negative MG with positive MusSK Ab is not associated with underlying thymoma. T/F
True
50% of patients with REM sleep behaviour disorder progress to Parkinson’s D? Tx?
True
Clonazepam or benzo suppress REM
Steps in Apnea Testing for the declaration of Brain Death?
- Pre-oxygenate pt to 100% FiO2
- Ensure pt is not hypoxic via ABG
- Disconnect the ventilator but supply oropharyngeal O2
- Monitor the patient for any signs of respiration
- Obtain ANGs at selected intervals q3-4 min
- Stop the test and return to mechanical ventilation if
- haemodynamic instability occurs or
- the patient exhibits attempts to breathe or
pCO2 is > 60 mmHg or rises > 20 mmHg above baseline in the setting of arterial pH
Pregabilin - MOA, Indications, AE?
Binding to vgated calcium channels in the CNS to modulate calcium influx and inhibit release of excitatory neurotransmitters
Indications
Adjuvant treatment in focal seizures with or without secondary generalisation
Neuropathic pain
AE
dizziness, drowsiness, confusion, irritability, visual disturbanve, ataxia, tremor, insomnia, euphoria, odema
Gradually reduce dose over one week
Smoking is associated with increased risk of cerebral aneurysm rupture. T/F
False
What RF are associated with cerebral aneurysm rupture?
Age > 70 y
Aneurysm size > 7 mm
HT
ACA, Posterior circulation and posterior communicating aneurysm
Earlier SAH from another aneurysm
How long does HSV remain positive after antiviral therapy?
Positive for first week of antiviral therapy
