Guillain Barre Syndrome Flashcards
What is spinal shock?
In an UMN pathology when at first patient can get initial normal tone and absent reflexes. Later, classic UMN lesions would emerge.
What investigations would be done for presentation of four limb weakness?
- FBC, U+Es, LFTs, Ca, phosphate, Mg
- CRP + ESR
- CXR (for SOB)
What are the characteristic features of GBS?
- Progressive symmetrical weakness of all 4 limbs
- Weakness is classically ascending i.e. legs are affected first
- Reflexes are reduced/absent
- Sensory symptoms tend to be mild e.g. distal paraesthesia with sensory signs
- Back/leg pain in initial stages of illness
What are other features of GBS?
- May be a history of gastroenteritis - campylobacter
- Respiratory muscle weakness
- Cranial nerve involvement: diplopia, bilateral facial nerve palsy, oropharyngeal weakness
- Autonomic involvement: urinary retention, diarrhoea
- Less common: papilloedema (thought to secondary to reduced CSF resorption
What are the investigations for GBS?
- Lumbar puncture: rise in protein with normal WBC count (albuminocytologic dissociation), <10 cells and normal glucose
- Nerve conduction studies: decreased motor nerve conduction velocity (due to demyelination), prolonged distal motor latency, increased F wave latency
What is Guillain-Barre Syndrome?
- GBS is a poly-radiculo-neuropathy
- Predominantly motor disorder, some sensory symptoms
- No sphincter disturbance or encephalopathy
- No sex difference
- Affects all ages but is slightly more frequent in older age range
- Most common cause of acute neuromuscular weakness in developed world
What are the types of GBS?
- Acute inflammatory demyelination polyradiculoneuropathy (AIDP)
- Acute motor axonal neuropathy (AMAN)
- Acute motor and sensory axonal neuropathy (AMSAN)
- Miller-Fisher syndrome
- Pure sensory neuropathy
- Acute pandysautonomia
What are time ranges for the duration of these disorders?
- Acute - peak disability by 4wks
- Subacute - 4-8wks
- Chronic - >8wks
Describe AIDP
- 2/3 have identifiable trigger
- Begins with paraethesias and pain followed by muscle weakness in legs (10% begins in arms and rarely in face)
- Complete ophthalmoplegia in 3-5%, partial 15%
- Autonomic manifestations: labile BP, arrhythmia, constipation, abdominal distension
- Progresses days to 4 weeks
What are the differential diagnoses of GBS?
- Acute myelopathies
- Botulism
- Diphtheria
- Lyme disease and tick borne paralyses
- Porphyria
- Vasculitis neuropathy
- Poliomyelitis
- CMV polyradiculitis
- Critical illness neuropathy
What is the therapy for GBS?
- Thromboprophylaxis - TEDS and sc LMWH
- Respiratory obs - FVC, if ABGs/RR/SaO2 abnormal then often patient will be in peri-arrest. Don’t be afraid to intubate and refer to ITU at signs of respiratory problems.
- IPPV if FVC <15ml/kg
- IV immunoglobulin 0.4g/kg/day for 5 days (evidence in non-ambulant patients)
- DO NOT use corticosteroids
What infections can trigger GBS?
Viral: - EBV - HIV - Influenza - Hep A+C Bacterial: - Campylobacter jejuni - Mycoplasma pneumoniae - E. coli - Haemophilius influenzae Parasites: - Malaria
What systemic illnesses can trigger GBS?
- Hodgkin’s disease
- Hyperthyroidism
- Sarcoidosis
- Renal disease
What other medical conditions can trigger GBS?
- Pregnancy
- Surgery
- Bone marrow transplant
- Immunisation
How does campylobacter jejuni cause GBS?
This is a common cause, different strains can have different effects. Shared epitopes lipo-oligosaccharide and human gangliosides (antibody attacks its own tissues) (molecular mimicry).
What are the normal ranges for measurements in lumbar puncture?
- Opening pressure (patient needs to be lying down) <20cm
- WCC <5 WBC
- RCC none
- Protein <0.45g/l
- Glucose approx 2/3 of plasma (check blood glucose at same time) - 50-66
What are extra tests that can be performed on the CSF?
- Microbiological stains
- Culture and sensitivity
- Viral/bacterial PCR
- Oligoclonal bands
- Cytology (requires at least 10ml of CSF, so is difficult to perform)
- Spectrophotometry/xanthocromia - spectrophotometry looks for oxyhaemoglobin and bilirubin peaks
What are the bacterial results of an LP?
- Opening pressure (cm) - high
- Cells - 100-50,000 (neutrophils)
- Protein (g/l) - >1.0
- Glucose (% of plasma) - <40
What are the viral results of an LP?
- Opening pressure (cm) - normal
- Cells - 5-1000 (lymphocytes)
- Protein (g/l) - 0.5-1.0
- Glucose (% of plasma) - 50-66
What are the tuberculosis results of an LP?
- Opening pressure (cm) - high/very high
- Cells - 5-500 (lymph)
- Protein (g/l) - 1.0-5.0
- Glucose (% of plasma) - <33
What are the fungal results of an LP?
- Opening pressure (cm) - very high
- Cells - 0-1000 (lymph)
- Protein (g/l) - 0.5-2.0
- Glucose (% of plasma) - 30-50
What are the characteristic features of TB in CSF?
- Very low glucose, less than 1/3 of plasma
- Very high protein (sometimes >5 g/l)
- Very high opening pressure
- Lymphocytosis
What does MS look like in CSF?
- Often normal CSF, except oligoclonal bands +ve
- Oligoclonal bands would not be seen in normal blood, hence limited to CNS
What would cancer look like in CSF?
- High WBC and protein
- Very low glucose
- Abnormal cytology
What would SAH look like in CSF?
- High RBC
- Xanthacromia (sensitive after 12hrs) - raised bilirubin and oxyhaemoglobin
What results from an LP can you get in herpes simplex encephalitis?
Commonest viral encephalitis
- Haemorrhage CSF (raised RBC count)
- Viral infection: lymphocytes, modest elevation in protein, normal glucose
What is transverse myelitits?
- Acute inflammation of grey and white matter in >/= 1 adjacent spinal cord segments, usually thoracic
- Causes: MS, neuromyelitis optica, infections, autoimmune or post infectious inflammation, vasculitis and certain drugs
- If the patient presents with signs of myelopathy (spinal cord syndrome) + CSF has unmatched oligoclonal bands, consider transverse myelitis, need more clinical info to rule out MS
What is acute cervical cord syndrome?
- Patients presenting with this would be expected to have a mixture of 4 limb motor and sensory signs, some have pain
- Many patients will have sphincteric symptoms - bladder urgency and frequency
- Examination may show increased tone and brisk reflexes in all 4 limbs. However, in very acute cord syndromes tone may be flaccid and reflexes absent (spinal shock).
- Some patients will have a sensory level on the chest determined by pin prick sensory examination
- In patients with posterior cord involvement there may be no motor symptoms or signs - these patients may be very unsteady due to sensory ataxia
What are the features of cauda equina syndrome?
- Patients presenting with this will have lower limb signs and symptoms but normal upper limbs. Most will have motor and sensory problems.
- Pain may be present, especially if syndrome is due to compressive pathology
- Examination will reveal LMN signs
What are the symptoms of cauda equina syndrome?
- Loss of sensation around buttocks, anus, genital (saddle anaesthesia)
- Shooting pain down back/side of legs
- Bladder + bowel incontinence
- Lack of sensation +/or weakness in legs
What are the features of Myasthenia Gravis?
- Autoimmune condition - patients muscles become weak after use, no sensory problems (functional fatigue) - get patient to move limb and test power before and after
- The weakness can affect any muscle, typically affected areas include eyes (ptosis, diplopia), mouth (dysarthria + dysphagia) + proximal limbs, proximal myopathy with symptoms worse at the end of the day (face, mask, limb girdle)
- Respiratory muscles, check for SOB, especially when lying down (weak diaphragm)
- Weakness is fatigable
- Thymoma
- Other autoimmune disorders: pernicious anaemia, thyroid disorders, RA, SLE
What are the investigations for myasthenia gravis?
- ACh receptor antibodies
- If negative then neurophysiology with repetitive stimulation +/- single fibre studies (electron myography to see fatigue ability of nerves)
- CT thorax do exclude thymoma (common in young people) and MRI brain to exclude pathology - not diagnostic
- Put ice on ptosis: diagnostic of MG if it resolves
What is the management of myasthenia gravis?
- Long acting AChE inhibitors e.g. pyridostigmine
- Immunosuppression: prednisolone initially
- 3rd line: cyclophosphamide, monocloncal antibodies e.g. rituximab
- Thymectomy
- Management of myasthenic crisis: plasmapheresis (plasma removed from body, either replaced by saline/albumin, or treated and returned to body) + IV immunoglobulins
What is acute myosotis?
- Symmetrical, proximal muscle weakness + myalgia
- Progresses over weeks to months (insidious onset)
- Usually neck, shoulders and pelvis affected first
- Often mild - can find it difficult to walk upstairs, standing up
- Rare: can get dysphagia/dysarthria
- Associated with ILD, Raynaud’s phenomenon, polyarthritis, SLE
- On examination, reflexes and sensation should be normal
What is dermatomyositis?
- Polymyositis only affects muscle, but dermatomyositis involves skin as well
- Signs: heliotrope rash (butterfly rash on face, similar to malar rash in SLE)
- Gottron’s papules- erythematous scaly lesions specifically on MCPs, PIPs, DIPs (this confirms diagnosis for dermatomyositis)
- Gottron’s sign - scaly lesions found beyond the hands, like elbows, neck etc
- Shawl sign - hyperpigmented skin (rash) on shoulders, neck and upper back
- V sign - rash on neck and upper chest
- Holster sign - rash on lateral thigh
- Periungual erythema - redness around fingernails
- Calcionosis cutis - calcium deposits under skin (usually in kids, very painful)
What are the investigations for dermatomyositis?
- Creatine kinase
- ALT + AST - leaks out of muscles
- ANA
- Autoantibodies: Anti-Jo, Anti-Mi, Anti-SRP
- EMG
- Muscle biopsy - muscle inflammation and fibrosis
What are the treatments for dermatomyositis?
- Corticosteroids
- Immunosuppression e.g. methotrexate
- Hydroxychloroquine - dermatomyositis rash
- Physical and occupational therapy
- Assess for possible malignancies
What do the results of nerve conduction testing mean?
- As long as the nerve speed is >49m/s for a motor nerve, the result is normal
- If it’s <49m/s there is a problem with the myelin sheath surrounding the nerve - can indicate demyelinating neuropathy
- The waveform/amplitude of the graph (when conducting study) displays the strength of the muscle twitch - if it’s not the right shape it can indicate nerve axon damage (being cold can slow nerve impulses)
What is acute cervical cord syndrome/central cord syndrome?
- Weakness in upper extremities (arms) + less severe weakness of lower extremities (legs)
- Difficulty getting dressed
- Often affects 50+ who have sustained neck (cervical) hyperextension injury
What are the causes of cervical cord syndromes?
- Inflammatory - MS, post infective, NMO/Devic’s, CTD related
- Compressive - discs, tumours
- Infective - viral (VZV, HIV)
- Metabolic (B12, copper deficiency)
What is a supinator catch?
Hyperreflexia and contraction of muscle groups not expected in the usual reflex - extra movements (problem with spinal cord across myotomes).
How would bladder/bowel issues present in U/LMN lesions?
LMN lesion: won’t be able to feel they have a full bladder and need to go to toilet
UMN lesion: urge incontinence
What are the causes of ptosis?
- Myasthenia Gravis - weakness starts in face and descends, bilateral ptosis, ocularbulbar lesion
- Horner’s - unilateral, lower medullary lesion
- 3rd nerve palsy - unilateral, midbrain lesion
What is myelopathy?
Anything affecting spinal cord (spinal lesion)
What is myeloradiculopathy?
Nerve root/radicals affected - shooting pain
Describe the symptoms of damage to the anterior spinal artery
- Affects anterior 2/3s of spinal cord
- Dorsal column spared
- Ascending spinothalamic and descending corticospinal tract affected below level of lesion - weakness in all limbs
- Reflexes absent in beginning - flaccid, not spastic
- Sensory change and acute onset
What is syringomyelia/bulbia?
Fluid filled cyst within the spinal cord (bulbia extends to Brainstem - medulla)
- Compression of spinal cord - pain, weakness, stiffness
- Swallowing difficulties
- Lose pain and temperature in hands bilaterally
- In medulla can affect cranial nerves causing facial palsies
What is the significance of B12 deficiency with spinal cord symptoms?
Damages dorsal columns and corticospinal tracts - combined degeneration. Nitrous oxide precipitates this, causes a functional deficiency in B12 so need to ask in history.
Tx: replace B12
What are the causes of spinal cord conditions? VIN MDT
Vascular/vasculitic Infected/inflammatory Nutritional/neurodegenerative Metabolic/mitochondrial Developmental/degenerative Toxic/trauma
