Neuropathy / Myelopathy / Radiculopathy / MND Flashcards
What is peripheral neuropathy
Damage to peripheral nerves (LMN)
If mononeuropathy i.e. single nerve affected what is this usually due to
Compression or trauma
If polyneuropathy
General symmetrical degeneration
What is a mono neuritis multiplex
Painful asymmetrical motor and sensory neuropathy
Isolated damage to 2+ separate nerve area
LMN
Suggest systemic inflammation
What causes
Suffest systemic inflammation
- DM = most common
- Vasculitis
- Immune - RA / SLE
- Infection - Lyme / HIV
- Sarcoid
- Cyroglublinaemia
WARDS PLC Wegener Amyloid RA / SLE DM = Sarcoid Polyarteritis Leprosy Cancer
What are the types of neuropathy
Nerve root disease
- Inflammation
- Infiltration
- Degeneration
Individual nerve
- Compression
- Vasculitis
What are the most common causes of peripheral neuropathy
Alcohol
DM
B12
What is the ABCDE I causes of neuropathy
A = alcohol B = B12 / botulism C = cancer - paraprotein / CKD (uraemia) or Charcot D = DM / drugs E = every vasculitis I = infection (HIV / HCV / Lyme's / leprosy) I = inflammation (GBS / demyelination / Sjogren's / SLE / sarcoid / coeliac )
How does alcohol affect nerve
Direct toxic nature
Reduced B12 absorption
Cerebellar degeneration
Usually sensory prior to motor
What does B12 cause
Subacute combined degeneration of spinal cord
Dorsal first - proprioception / vibation
Then paraestesia
What drugs / chemicals
Amiadarone Isonazid Nitrofurantoin Metronidazole Quinolones Lead / mercury
What causes motor symptoms predominantly
GBS Lead poison Charcot-Marie Chronic inflammation Diphtheria
What causes sensory symptoms predominantly
DM Uraemia Alcohol B12 Amyloid Leprosy
What are symptoms of neuropathy
Unilateral Myotomal wasting Myotomal weakness Dermatomal sensory change Reflex changes Hypotonia Neuropathic pain
If neuropathy due to axonal damage what happens e.g.DM
Length dependent Start distal affecting long nerves e.g. fingers and toes Glove and stocking loss Distal reflex loss Decreased amplitude on EMG
If neuropathy due to demyelination
Symptoms occur anywhere Diffuse loss Non-length dependent Amplitude normal as axons fine Decreased conduction velocity on EMG
What are acute causes of neuropathy
GBS
Lambort
Botulism
More reversible but most dangerous
What should you always screen for
DM
B12
Alcohol
Serum electrophoresis - not common but can mean catch cancer early
How do you investigate
Bloods - FBC, U+E, LFT - TSH - B12 - Glucose / HbA1c ANCA / autoimmune screen Infection screen Urinanalysis Serum electrophoresis for paraprotein CXR Genetics for Charcot Nerve conduction / EMG LP Nerve biopsy - NOT MOTOR MRI
LP result Bacterial Viral Inflammation GBS
Bacteria = low glucose Viral = increased WCC Inflammation = high Ig / WCC GBS = high protein + normal WCC
How do you treat
Treat underlying cause
Physio
OT
What is Charcot-Marie Tooth Disease
AD
Most common inherited peripheral neuropathy
How does it present
Predominant LMN signs Distal weakness / atrophy Hyporeflexia Hypotonia FOOT DROP HIGH ARCH HAMMER TOES Can get sensory loss
What is GBS
Immune mediated demyelination of peripheral nervous system
Molecular mimicry
Known as post-viral MS in PNS
What causes
Usually post infectious Cambylobacter Influenza Mycoplasma pneumonia CMV / EBV
What has poor prognosis
Age
Hx diarrhoea illness
How does it present
Proximal usually affected first and LL Rapidly progressive muscle weakness - Limbs - Resp muscle - Face and eyes Muscle wasting Paraesthesia Neuropathic pain Ataxia Arreflexia Autonomic - Loss of bladder / retention (sphincter usually spared) - suggests cord compression - Tachycardia - Labile HR and BP - Arrhythmia Resp muscle weakness CN involvement
What is typical pattern
Progresses over 4 weeks then resolves
Spectrum of presentations from mild weakness to diaphragm paralysis requiring intubation
Who is at risk
Age 20-50
Swine flu immunisation
Resp infection
What do you do
Always admit as can rapidly deteriorate
What investigation
Bloods - FBC, U+E, LFT - CK - ESR / CRP - Mg, Ca, phosphate Stool culture ECG to look for autonomic CXR to exclude other resp causes LP MRI if suspect spinal pathology as differential Nerve conuction + EMG = diagnostic Vital capaciy / PFT = very important
Why bloods
Exclude hypoglycaemia
Exclude hypokalaemia as cause
Exclude active infection
If high CK suggests myositis
What should be shown on LP
High protein
Normal WCC
Inflammation without infection
What will nerve conduction show
Demyelination pattern
Why is vital capacity / PFT so important
Monitor severity
IF FVC falls <20ml / kg then intubated required
Phrenic nerve affected = diaphragm paralysis
What is general Rx
Analgesia - avoid opiate May need long term neuropathic pain DVT EYe car Physio O2 if resp Steroids = NO benefit unlike most inflammatory
How do you monitor
Lung function ECG BP Autonomic - pupils / ileus Check swallow
If severe i.e. can’t walk / rapid progression what Rx
IV Ig or plasma exchange
No benefit in both
When is ICU indicated
Require intubation / ventilation Resp muscle affected Labile HR / BP Risk of aspiration pneumonia Rapidly progressive
What are complications
Respiration Talking Swallowing Bladder and bowel Persistent pain and fatigue Autonomic failure = arrhythmia and BP fluctuation
What if present with would give doubt to Dx
Fever
WCC
What is compressive myelopathy
Spinal cord injury due to compression of anterior horn cell
Occurs at level of spinal cord so get UMN symptoms at everything below
What causes
Trauma
Tumour
Disc herniation
Degeneration
How will patient present
Hemi-cord lesion Bilaterally Ipsilateral propriception Contralateral pain and temp Ipsilateral UMN weakness Babinski +Ve Hypertonia and reflex Spastic below due to loss of UMN moderation
How do you investigate
Bloods
X-ray
CT
MRI
How do you treat
NSAID to reduce inflammation
Steroid
Surgical decompression
What is degenerative cervical myelopathy
Degeneration of cervical vertebrae putting present on anterior spinal horn
How does it present
Pain in neck + UL
Can affect LL
Loss of fine motor = clumsy / digit dexterity / impaired gait
Loss of sensation
Loss of autonomic = incontinence / impotence
Hoffman’s
What is it misDx as
Carpal tunnel
What is Hoffmans
Flick middle finger and others twitch especially thumb
Suggestive of cervical spine issue
What puts you at risk
Smoking
Occupation
Genetics
How do you Dx
MRI = gold standard
- Look for disc degeneration and ligament hypertrophy
How do you Rx
Refer neuro or ortho for consideration of surgical decompression
Early treatment aids recovery
What can occur
Recur at different spinal levels
Refer urgently
What are non-compressive causes of myelopathy
Demyelination Autoimmune inflammatio Infectious Metabolic Vascular Parenoplastic Drugs
Demyelination
MS
ADEM
Autoimmune
SLE
Sarcoid
Devics’s
Vasculitis
Infection
Viral - HSV / EBV / CMV / HIV
Bacterial - syphillis / Lyme’s / TB
Fungal
Schistosomiasis
Metabolic
B12
Folate
Copper
Vit A
Vascular
AV fistula
Anterior spinal artery stenosis
AVM
Ischaemia
What artery in spinal stroke / ischaemic myelopathy
Anterior spinal (branch of vertebral) Posterior spinal (intercostals) Usually occurs at mid-thoracic region
What causes
Atheroma Thromboembolism Arterial dissection Hypotension Vasculitis Meningovascular syphillis AV malformation Occasionally haemorrhage
What are the symptoms
Pain in back Often radiates around IC nerve Sudden onset weakness below infarct Numb Urinary - Retention then incontinece as shock settles
What happens with spinal shock
Gives you flaccid paralysis initially then spastic
what are RF
Vascular High BP Smoking High cholesterol DM Obesity Inactivity
How do you Dx
CT / MRI
How do you Rx
Lower bP
Anti-platelet
Reverse hypovolaemia
Manage vascular RF
What must you rule out
Any condition putting pressure on cord Slipped disc Tumour Inflammation Abscess Cauda equina
What is radiculopathy
Nerve root disorder that presses on LMN
What causes
Disc herniation
Tumour
Degeneration
What are degenerative causes
Age Disc prolapse Ligamentum hypertrophy OA - osteophyte Cervical spondyloiss Scoliosis
How does it present
Unilateral Dermatomal sensory loss Neuropathic pain in dermatome Single myotome weakness Loss of reflexes Autonomic features Sciatica if sciatic nerve compressed
How do you Dx
CT MRI X-ray Nerve conduction Bloods
How do you treat
NSAID
Corticosteroid
Surgery
What causes nerve pain
Compression of any nerve or Pain following damage to nervous system - DM - Post herpes - Trigeminal neuralgia
What is nerve pain like
Shooting
Stabbing
Hot
In a dermatomal region
How do you manage
Exclude easily treated e.g. capsulitis Early physio to decrease inflammation and compression Neuropathic analgesia = 1st line Topical capsaicin if local Specialist pain team
What is neuropathic analgesia
Gabapentin Amitryptilline Pregabalin All 1st line Tramadol if exacerbation but refer to pain management team
What is 1st line in trigeminal
Carbamazepine
What is MND
Group of diseases which affect nerves in brain and spinal cord
What are the types
ALS
- Most common
- UMN and LMN signs
Primary Lateral Sclerosis
- UMN only
Progressive muscular atrophy
- LMN only
Progressive bulbar
- Palsy of tongue / muscles and swallowing
- LMN
- Has worst prognosis
What causes
Sporadic
Can be familial
- SOD gene that catalyses conversion of intracellular superoxide which damages nerve
- Expressed highly in motor nerves
What are UMN and LMN signs
Weakness Extensor plantar Hypertonia Hyper-reflexia Stiff Wasting Fasiculation
What does MND not have
Cerebellar
External ocular muscle
Sensory signs
How will patient present
What dementia
Weakness / tripping Spastic gait Weight loss Slurred speech Foot drop Weak grip Aspiration Dysarthria Sx of front-temporal dementia Later bulbar and respiratory
How do you Dx
History Dx = clinical Blood = increased CK EMG wil show muscle losing nerve supply Nerve conduction normal which excludes neuropathy MRI to rule out compression
How do you treat
PEG NIV - BiPAP Physio Anti-glutamate (Riluzole) as glutamate may damage nerve but small evidence Prognosis = 3-5 years from symptom onset
What is thoracic outlet syndrome
Compression of brachial plexus or subclavian at origin of thoracic outlet
What causes
Neck trauma in presence of anatomical variant
Cervical rib
How does neurogenic present
Painless muscle wasting
Motor weakness
Sensory - numb / tingling
Autonomic - cold hands
How does vascular present
Painful diffuse arm swelling
Distended veins
Claducation
How do you Dx
Neuro exam
Adson
Exclude other pathology - cervical radiculopathy, Carpal tunnel, shoulder injury
What investigation
CXR and C-spine- rib, degeneration, tumour
CT / MRI to rule out compression
Angio for vascular
How do you treat
Rehab / physio
Surgical decompression
What would be main DDX
Cervical spondylosis
- Not worse on raising arm or using
- No vascular Sx
What is it different from subclavian steal
Steal has deceased blood flow to brain on movement of arm
What causes autonomic dysreflexia
Spinal cord injury above T6
What happens
Central mediated para response is blocked by lesion
Sympathetic stimulated eg. by retention or constipation via thoracocolumbar
No blockage by para
What does this lead too
Unbalanced physiological response
Extreme hypertensoin
Flushing
Sweating
How do you Rx
Remove or control stimulus e.g. catheter
Treat any life threatening BP or bradycardia
What are complications
Haemorrhage stroke if untreated
Agitation
What is complex regional pain syndrome
Occurs following surgery or minor trauma
Type 1 = no lesion
Type 2 = lesion
What are Sx
Progressive / disproportionate Sx to injury Allodynia Temp + skin colour change Oedema Sweating Motor dysfunction
What criteria
Budapest diagnostic
How do you Rx
Physio
Neuropathic
Specialist pain team
What types of gait
Spastic
- Stiff / UMN
Extra-pyramidal
- Shuffling
- Postural instability
Apraxic
- Suggest normal pressure hydrocephalus
- Wide based
- Unsteady
- Falls
Ataxia = cerebellar
- Wide based
- Falls
- No heel to toe
- Worse in dark and closed eye
Myopathic
- Waddling
- Limb girdle
Psychogenic
- Bizzare
- No signs
How do you investigate
X-ray MRI Bloods - FBC, U+E, LFT - B12 - PSA Serum electrophoresis CXR LP EMG Muscle biopsy
What does clinical neurophysiology look at
Peripheral neuropathy
Entrapment
Radiculopathy
Myelopathy
What is an EEG
Shows electrical activity in brain
Decide if epilepsy and type
If focal
Starts in one area so high amplitude there and doesn’t spread
What is an EMG
Test to look at muscle and nerve supply
Electrode places into muscle to measure activity
Examines velocity and apmplitue of nerve
What is done at same time and what does that look at
Nerve conuction
Measures how fast an impulse moves and strength
Indicates nerve damage
Neuropathy
Increased amplitude and duration
Myopathy
Decreased amplitude and duration
Myasthenia Gravis
Decreased response to stimuli
Fewer receptors so smaller EPSP and big variation = jitter
Little variation
Lambort Eaton
Incremental response
MND
Detects muscle losing nerve supply
If axonal loss neuropathy
Decreased amplitude
Normal velocity on NCS
If demyelimation
Normal amplitude
Decreased velocity on NCS
If MND
Nerve conduction normal which excludes neuropathy
Myelopathy
Level of spinal cord
UMN
Radiculopathy
Nerve root
LMN in one myotome / dermatome
Brain
Contralateral to anatomical place in the head
What is in lumbar spine
Very little spinal cord as only extends to L1 then its the cauda equine
What do you want to know
Anatomical level of lesion
Aetiology
How it affects patient
e.g. UMN signs but none in arm
Most likely thoracic level
Worry about malignancy as degeneration unlikely
What is important to remember
Spinal cord ends at L1/L2 so will get LMN signs if below this
If cord compressed
LMN flaccid + radicular pain at level
UMN spastic + sensory loss below lesion
What else does it depend on
If whole cord compressed or partial
e.g. if posterior would get loss of proprioception
if anterior = loss of pain / temp
What is hereditary spastic parapersis
UMN signs
FH
MRI = often normal
