Neuro Flashcards
What are the criteria for thrombolysis?
Presentation within 4.5 hours
Not haemorrhage
What are the components of NIHSS score?
Consciousness
Month + age
Follow commands
Horizontal gaze palsy (remember oculocephalic reflex)
Visual loss
Facial palsy
Arm drift (10s)
Leg drift (10s)
UL/LL Ataxia
Sensation
Aphasia (recognise items, read sentence)
Dysarthria
Inattention
What are the contra-indications for thrombolysis?
Absolute
Intra-cranial haemorrhage
Seizure at onset
Stroke/TBI <3m
LP <7d
GI bleed <3w
Active bleeding
Pregnancy
Varices
Uncontrolled HTN
Relative
Concurrent anticoag
Bleeding disorder
Retinal haemorrahge
Suspected intracranial thrombus
Major surgery <2w
What is the MRS score?
Modified Rankin Score (MRS) of DISABILITY not frailty.
0 = nil
1 = symptoms without disability
2 = Can look after own self for 1 week
3 = Cannot look after own self for 1 week
4 = Needs help with ADL’s
5 = Bed-bound
What do you do if a patient is on a DOAC and needs thrombolysis?
Contra-indicated if received DOAC within 24 hours of stroke (move towards 48 hours)
How do you manage blood pressure control in a candidate for thrombolysis?
No clear evidence that high blood pressure is a risk - there is a theoretical risk of bleeding.
Blood pressure is a protective mechanism in stroke. I
If thrombolysing, - need to bring the blood pressure down
In thrombolysis - Labetolol boluses then infusion (provided HR>60)
How do you manage blood sugars in a candidate for thrombolysis?
Hyperglycaemia related to poor outcomes
Sliding scale, stat novorapid, long-acting low dose insulin - no right answer.
(bear in mind volumes of infusions if on sliding scale and labetolol infusions!)
Can you ever thrombolyse a wake up stroke?
Theory is that the stroke wakes patients up.
Can thrombolyse if you can get an urgent MRI to look at the T2/DWI mismatch to assess penumbra.
What are the indications for thrombectomy?
- Ischaemic stroke
- Large vessel occlusion - intra-cranial carotid, MCA (M1, M2), basilar, and most recently posterior circulation strokes.
- Need CTA!!!! Not just non-contrast CT. Need the scan BEFORE you refer.
- MRS 0-1 (latest guidelines)
- NIHSS >6 (or >10 for basilar)
Patients will get thrombolysis + thrombectomy together.
After 12 hours - need CT or MR perfusion scan to assess flow to brain and salvageable brain.
Even the larger strokes with large cores will now get thrombolysed - there isn’t actually as big a risk of bleeding as we predicted, so if there is a potentially salvageable penumbra - thrombolysis is on the table (based on data from 2023 trials)
What are the causes for spastic paraparesis?
Inflammatory
Autoimmune: Multiple Sclerosis (cerebellar signs)
Vasculitis
Sarcoidosis
Infection
Tropical spastic paraparesis
Post infection: Dengue, Schistosomiasis, Mycoplasma
Ischaemic
Anterior spinal artery occlusion
Trauma
Metabolic
B1,6,12 deficiency
SCDC
Taboparesis
Copper deficiency
Structural
Tumours (intramedullary) - ependymoma, astrocytoma, glioblastoma
(extramedullary) - schwannoma, meningioma, neurofibroma
Cord compression (sensory level)
Cervical myelopathy/disc prolapse
Hereditary
Hereditary spastic paraparesis
Differential for peripheral neuropathy?
Toxin
Alcohol
Chemotherapy
Idiopathic
Sarcoidosis
Inflammatory
CIDP
ANCA+ Vasculitis
Inherited
Hereditary Sensory motor neuropathy (CMT) - muscle wasting
Metabolic
Diabetes
SCDC
B1,6,12 deficiency
Uraemia
Endocrine
Hypothyroidism
Paraneoplastic
Lung cancer
Paraproteinaemia
What do you know about HSMN?
2 types
Type 1: demyelinating
Type 2: axonal pathology
Type 1 is more common and inherited in an AD pattern
Defect in PMP 22 gene
Motor symptoms predominate
Distal muscle wasting
What are some causes for demyelinating polyneuropathies?
CIDP
MM
MGUS
HSMN
HIV
Investigations for a peripheral neuropathy?
- Blood glucose, urinalysis
- Fundoscopy
- Urea
- LFTs
- Thyroid function
- Immunoglobulins
- HbA1c
- Nerve conduction studies (is this demyelinating - eg. inflam or axonal)
Talk to me about nerve conduction and EMG studies
Nerve conduction - problem with nerve
EMG - problem with muscle response to nerve stimulus
Nerve conduction studies
Axon problem or myelin problem and evaluation of conduction blocks
Axon problem:
Reduced amplitude of conduction
Trauma, toxin, ischaemia, metabolic, genetic
Myelin problem (usually immune mediated)
Slow conduction velocity
GBS, CIDP
What types of peripheral nerves do you know?
Pain: thinly myelinated A-delta
Warmth: unmyelinated C
Vibration/proprioception: large calibre myelinated
What causes a predominant motor disturbance?
Porphyria
Lead toxicity
Diphtheria
CIDP/GBS
Drugs
What are the neurophysiology test findings of CMT?
Severe and uniformly reduced responses
Might be possible to differentiate an axonal vs. myelin pathology to direct genetic testing (Type 1 is pred. demyelinating and inherited in AD with mutation in PMP22)
What is your differential for cerebellar ataxia?
Acute:
Stroke
Chronic:
MS
Drugs (lithium, carbamazapine, chemotherapy)
Alcoholic cerebellar degeneration
SOL
Vit E deficiency
Friedreichs ataxia (cerebellum, cord, peripheral nerves)
MSA
Paraneoplastic
What are the causes of myelopathy by time frame?
Hyper-acute
Vascular infarct
Acute
Disc prolapse
Weeks
Inflammatory: MS
Infective: VZV
Months
Metabolic
Infective (HIV), HLTV-1
Tumours
MND
Hereditary Spastic Paraparesis
What are the clinical signs of Friedrich’s Ataxia?
Brain:
Cerebellar syndrome
Cord:
Upgoing plantars
Dorsal column signs
Pyramidal pattern of weakness that affects the lower limbs more than upper limbs
Peripheral nerves:
Depressed DTR’s
Muscle weakness
Non-neuro:
Diabetes
Optic atrophy
Sensorineuronal deafness
HOCM
Conduction defects
What do you know about Friedrich’s ataxia’s genetic inheritence and pathophysiology?
AR trinucleotide repeat disorder that does not demonstrate anticipation
Mutation in the Frataxin gene that regulates iron and oxidative phosphorylation
Particularly affects the spinocerebellar tract and peripheral nerves
What types of inherited cerebellar ataxias do you know?
Friedrich’s
AD Cerebellar ataxia
AR Ataxic telangiectasia
AR Ataxia with Vitamin E deficiency
AR Ataxia with Occulomotor apraxia
AR Mitochondrial recessive ataxic syndrome
What do you know about the genetics of Myotonic Dystrophy
AD trinucleotide repeat disorder that DOES demonstrate anticipation and expansion
CTG TNR in myotin protein kinase
Manifests age 20-30
What are the non-cardiac manifestations of myotonic dystrophy?
Cardiac: prolonged QT, mitral valve prolapse, cardiomyopathy
Endocrine: DM, Hypogonadism, nodular thyroid enlargement
Neuro: mild cognitive impairment
GI: dysphagia, reflux, delayed gastric empyting, SIBO
Resp: Hypoventilation
Clinical signs of myotonic dystrophy?
Frontal balding with smoothened forehead and ptosis
Wasting of facial muscles
Depressed DTRs
High stepping gait
Distal to proximal pattern of weakness
Dorsal guttering of hands
Inability to relax clenched hand
Are there any treatments for Myotonic Dystrophy?
Phenytoin
Maxilitine (however concern due to cardiac safety profile)
MDT to address home, work, and transport environments and make adaptations.
What other causes of myotonia do you know?
Startle myotonia
Paramyotonia congenita
Hyperkalaemic periodic paralysis
what are the common types of muscular dystrophy?
Fascioscapulohumeral dystrophy
Becker’s
Duchenne’s
What are the clinical signs of fascio-scapulo-humeral dystrophy?
Facial weakness
NO ptosis/balding
Weakness in upper limb girdle - shoulder weakness, winging of scapula. Forearms spared.
Weakness and protuberance of abdomen
Weakness in foot dorsiflexion with foot drop
Sensosineuronal deafness
Retinal telangiectasia
What is the inheritence of facio-scapulo-humeral dystrophy?
AD
Presents age 20
Normal life expectancy
What do you know about Duchenne’s?
More severe than Becker’s
X-lined recessive inactivating mutation in the dystrophin gene that leads to muscle loss in skeletal, cardiac, smooth muscle, and brain tissue
Proximal to distal weakness
Calf pseudohypertrophy with wasting in anterior shin
Contractures
Loss of DTRs
Kyphoscoliosis
Non-cardaic
Dilated cardiomyopathy
Pulmonary hypertension
Resp failure
What do you know about Becker’s?
X-linked recessive inactivating mutation in dystrophin gene that leads to muscle breakdown in skeletal, cardiac, smooth, brain
Less severe than Duchenne’s
Survive into 40’s
Proximal to distal weakness
Hyper-lordosis (to offset hip extensor weakness)
Loss of DTR’s
Mild pseudohypertrophy
Non-neuro comps
Dilated cardiomyopathy
Pulmonary Hypertension
Respiratory failure
What are some causes for median nerve palsy/carpel tunnel syndrome?
Endocrine
Acromegaly
Hypothyroidism
Metabolic
Gout
Renal Failure
Diabetes
Paget’s
Trauma
Occupational
Idiopathic
What are common sites of compression of the median nerve?
Elbow
Pronator teres
Carpel tunnel
What are common sites of injury of the radial nerve?
Axilla
Spiral groove (ulnar side)
Arcade of Frohse
Wrist
How do you differentiate a C8/T1 radiculopathy vs. ulnar nerve lesion?
- Both with have weakness in ulnar innervated muscles
- In C8/T1 there will be weakness of thumb abduction, and finger extension
- There will be more diffuse sensory loss with a C8/T1 radiculopathy
Motor neuropathy
Anterior Horn cells
-MND
Peripheral nerves
-Multifocal peripheral neuropathy