Neurology Master Flashcards
Femoral nerve:
- Nerve Roots
- Motor function
- Reflex
- Sensory
- Clinical causes of neuropathy
- Lumbar plexus L2-4
- Knee extension, hip flexion
- Knee jerk
- Anterior thigh and medial lower leg (saphenous nerve)
- Diabetes, femoral nerve block, pelvic fractures, THR, childbirth, psoas abscess, posterior abdoinal neoplasms
Obturator nerve:
- Nerve Roots
- Motor function
- Reflex
- Sensory
- Clinical causes of neuropathy
- L 2-4
- Thigh adductors
- N/A
- Skin of medial thigh
- Damage during surgery involving the pelvis/abdomen; obturator nerve block
Sciatic nerve:
- Nerve Roots
- Motor function
- Sensory
- Reflexes
- Clinical causes of neuropathy
- L4 - S3
- Thigh extensors then divides into tibial and common fibular nerve
- No direct sensory functions but indirectly innervates skin of lateral leg, heel and both dorsal and plantar aspects of the foot
- Ankle
- Piriformis syndrome
Tibial Nerve:
- Nerve Roots
- Motor function
- Sensory
- Clinical causes of neuropathy
- L4 - S3
- Posterior compartment of the leg and majority of intrinsic foot muscles
- Unlocking knee
- Flexes toes and plantar flexes ankle
- Foot inversion
- Some knee flexion
- Posterolateral side of leg, lateral side of the foot and sole of the foot
- Tarsal tunnel syndrome due to OA, RA< trauma
Common peroneal nerve:
- Nerve Roots
- Motor function
- Sensory
- Clinical causes of neuropathy
- L4 - S2
- Lateral and anterior compartments of the leg
- Foot eversion
- Dorsiflexsion of the foot
- Toe extension
- Upper lateral and lower posterolateral leg. Also supplies (via branches) cutaneous innervation to the skin of the anterolateral leg, and the dorsum of the foot
- Fracture of the fibula/tight cast
Multiple sclerosis is a disease primarily affecting which cells?
Oligodendrocytes
MS involves the attack of the following proteins..
Myelin basic protein and myelin oligodendrocyte glycoprotein (MBP and MOG)
Internuclear opthalmoplegia to right clinical finding
If R) sided INO - R) eye cannot adduct and L) eye horizontal nystagmus to the right
transverse myelitis on MRI - signal change in which sequence?
T2 hyperintense signal change
what criteria (dissemination in space or time) can oligoclonal bands substitute for the diagnosis of MS?
dissemination in time
Typical MS lesions (5)
- Juxtacorticaol lesions
- Dawson’s fingers
- Pontine lesions
- Spinal cord lesions
- GAD-enhancing lesions
Natalizumab (Tysabri)
- Route
- MOA
- AE
- IV monthly
- Monoclonal antibody that binds to alpha4 subunit of 2 integrin adhesion molecules. Tries to prevent the extravasation of inflammatory cells through the BBB into the CNS
- PML
Alemtuzumab
- Route
- MOA
- AE
- IV daily for 5 days then in another 12 months
- Recombinant humanised monoclonal antibody that binds to CD52 antigen (present on the surface of most B and T lymphocytes)
- Infusion reactions, autoimmune disorders, infections, lymphopenia
Dimethyl fumarate
- Route
- MOA
- AE
- Oral
- Unknown
- Nausea, vomiting, diarrhoea, lymphopenia
Fingolimod
- Route
- MOA
- AE
- PO daily
- Sphingosine 1‑phosphate receptor modulator; reduces lymphocyte infiltration of the CNS by preventing lymphocytes leaving lymph nodes, thus reducing inflammation and demyelination
- Bradycardia, first degree AV block, infection, leukopenia, macula oedema, PRES, PML
Interferon beta
- Route
- MOA
- AE
- Subcut
- Antagonism of gamma interferon, reduction of cytokine release and augmentation of suppressor T cell function
- Rash, myalgia, headache, abdominal pain
Ocrelizumab
- Route
- MOA
- AE
- IV
- Recombinant humanised monoclonal antibody that selectively depletes CD20-positive B lymphocytes
- Infusion reactions (34% in clinical trials), infection, neutropenia
Approved for PBS for primary progressive MS
Teriflunomide
- Route
- MOA
- AE
- PO
- Inhibits pyrimidine synthesis in leucocytes by inhibiting activity of dihydro-orotate dehydrogenase (DHODH)
- Teratogenic and immunosuppressive
Cladrabine
- Route
- MOA
- AE
- PO
- Synthetic deoxyadenosine analogue - reduction in peripheral T and B lymphocytes and resting cells as well
- Significant lymphopenia
PML imaging findings
One or more hyperintense lesions on T2-weighted or FLAIR sequences with a sharp border at the grey-white junction and less distinct borders toward the white matter
- Large >3cm lesions
- Contrast enhancement in 41% with early PML
- U-fibers (subcortical)
MS disease activity in pregnancy
Encourage conception when stable
Relapse declines during pregnancy but increases post partum
Control disease activity prior conception
What MS meds are not recommended during pregnancy
fingolimod and tysabri (natalizumab) - both have high risk of rebound
Teriflunomide (VERY TERATOGENIC) - need chelation and drug elimination prior contraception
alemtuzumab (high risk of autoimmune thyroiditis)
Anti-MOG disease clinical features
- Clinical features
- Initial episode – optic neuritis, ADEM, transverse myelitis
- Relapse – optic neuritis
- Course
- Monophasic or relapsing
- OCB in <15% • MOG Ab in serum
anti-MOG MRI findings
- ADEM like fluffy white matter, deep grey matter, brainstem
- Optic nerve enhancement
- Multiple spinal lesions; can be long or short segment
What DMARD is approved for primary progressive MS?
Ocrelizumab
Intracranial haemorrhage with blood around the Sylvia fissure - aneurysm location?
MCA aneurysm
Intracranial haemorrhage with blood along floor of the anterior cranial fossa - aneurysm location?
ACA aneurysm
Risk of stroke in the first week after TIA (untreated)
10%
When are PFO closure in strokes indicated?
Otherwise cryptogenic stroke age <60
When to do left atrial appendage closure for AF
contraindication to anticoagulation
Blood pressure management in acute ischaemic stroke
- Gently lower <185/105 if thrombolysis
- Otherwise only treat if >220/120
Longer term: aim SBP <140 mmHg
Management of symptomatic cartoid stenosis:
- 70-99%
- 50-69%
- Occlusion/trickle
- Carotid endarterectomy between 2 days and 2 weeks if not alr severely disabled
- Carotid endarterectomy if low surgical morbidity and good life expectancy
- Low risk of recurrent stroke - generally not suitable for surgery
Rate of orolingual angiooedema post tPA
2% (5% if taking ACEI)
IV thrombolysis in parallel with endovascular thrombesctomy?
Yes if eligible
What criteria for extended timing for endovascular thrombectomy (6-24hr)
<70ml core (and other generic thrombectomy criteria)
Subarachnoid haemorrhage centred anteriorly to the pons and midbrain - diagnosis and investigations
Likely perimesencephalic subarachnoid hemorrhage
CTA only, does not need DSA if normal CTA as 95% of cases are non-aneurysmal
Reversible vasoconstriction syndrome clinical features
- Month-6 weeks of episodic thunderclap headaches
- Most have good prognosis and a very small proportion can have cerebral ischaemia and have neurological sequalae
Treatment of reversible vasoconstriction syndrome
Calcium channel blockers but mainly exert opinion
Mechanism of trigeminal neuralgia
Microvascular compression
Clinical features of trigeminal neuralgia
Electric sudden pain, recurrent, often triggered by sensory stimulus in other affected area
Ephaptic transmission of sensory/compression input
Can rarely be seen in patient in MS
Treatment for trigeminal neuralgia
Carbamazepine
Characteristic of migraine aura
- Starts off as central visual disturbance, then spreads and expands
- The edge has a shimmering quality and zim zag (fortification spectra)
- Persists for ~20min
- Key features is that it migrates
- Generally preceds headaches
Pathogenesis of migraine aura
Neuronal dysfunction - spreading depression of Leao
New monoclonal antibody available for migraines
CGRP inhibitor (Erenumab)
MOA for tripans
- 5HT1B and 5HT1D agonist
- Those things are thought to inhibit the release of CGRP
What CN is affected in IIH
CN VI due to its long and vertical course and predisposition to be compressed by the increased pressure
(lateral visual palsy)
Ventricle size in IIH
Small unlike NPH
Pathophysiology of the trigeminal autonomic cephalagias
Incompletely understood..
Abnormality in the hypothalamus leading to hypothalamic activation with secondary activation of the trigeminal autonomic reflex, probably via a trigeminal-hypothalamic pathway
Which trigeminal autonomic cephalagias have a strong indomethacin effect?
Paroxysmal hemicrania and hemicrania continua
Acute management of cluster headache
High flow oxygen at least 8L/min
Triptan - sumitriptan by subcut injection
Long-term management of cluster headaches
- Verapamil - start at 160mg, uptitrate up to 720mg+ (need ECGs)
- Can use prednisolone (75mg) as transitional therapy
- GON block
Where does surface electrode for median nerve go?
APB (abductor pollicis brevis)
Are amplitudes of sensory conduction responses bigger or motor responses?
Motor because you are getting the response from the whole muscle rather than over a nerve directly
What is the pathology of nerve compression and what is the finding on NCS?
Focal demyelination localised slowing
NCS finding of guillian barre/conduction block
segmental nerve demyelination - decreased amplitudes across different segments
What does very very slow conduction velocities suggest?
Inherited demyelinations - e.g. charcot marie tooth
Critical illness myopathy - why does it produce low amplitude on NCS
low amplitude due to decrease in muscle mass
Normal EMG findings
- No response at rest
- Gradual recruitment of individual muscle fibres
- Interference pattern when multiple muscle units are recruited
Findings of deinnervation and reinnervation of EMG
- Deinnervation = fibrillation
- Reinnervation - larger amplitude
fibrillation happens first
EMG findings in myopathy
- No fibrillation (generally); no spontaneous activity
- Activity is low amplitude and brief
- Often polyphasic because the the muscle fibre is damaged and there is re-innervation between the muscle fibres
The exception to fibrillation is conditions with a lot of degeneration (ICU myopathy, duchenne in active phase, active myositis, necrotising myositis)
EMG findings in myasthenia gravis
Fast repetitive stimulation to see decremental response (Lambert eaton is incremental response)
What is the pathology that causes fasciculations
single motor unit firing by itself happens in chronic deinnervation
What is myokymia and what is the pathology?
involuntary, spontaneous, localized quivering of a few muscles, or bundles within a muscle, but which are insufficient to move a joint
Commonly eyelid twitching
Post radiotherapy common in limbs due to spontaneous firing of individual fibres
Findings of demyelination on NCS
Increased latency and dispersion - due to different degrees of demyelination in different nerves
Causes of a painful neuropathy
Generally small fibre
B6 toxicity proximal
small fibre amyloid paraneoplastic
HIV assoc cryoglobuliaemia
Where does demyelination most commonly occur in GBS (which part of a nerve)
Proximally so f waves are important in GBS
anti GQ1 positive GBS variant clinical syndrome
Miller Fischer variant - ataxia bulbar ophthalmoplegia
dive bomber EMG
myotonia