GBS And Transverse Myelitis

Question 1

What is GBS?

Answer 1

Guillain-Barré syndrome (GBS) is a disorder causing demyelination and axonal degeneration resulting in acute, ascending and progressive neuropathy, characterised by weakness, paraesthesia without objective sensory loss and hyporeflexia (absence of deep tendon reflexes).

Question 2

What is the most common preceding infection in GBS?

Answer 2

About 75% of patients have a history of preceding infection, usually of the respiratory and gastrointestinal tract. Campylobacter jejuni is the most common cause. EBV, CMV and mycoplasma are also linked.

Question 3

What is the classification of GBS?

Answer 3

GBS is classified according to symptoms and is divided into axonal and demyelinating forms.

Sensory and motor: acute inflammatory demyelinating polyradiculoneuropathy (AIDP) (most common) or acute motor and sensory axonal neuropathy (AMSAN).

Motor: acute motor demyelinating neuropathy (AMAN)

Miller-Fisher syndrome: ophthalmoplegia, ataxia, and areflexia (also referred to as Fisher’s syndrome).

Bickerstaff’s brainstem encephalitis: similar to Miller-Fisher syndrome but also includes altered consciousness (encephalopathy) or long tract signs (hyper-reflexia), or both.

Pharyngeal-cervical-brachial: acute arm weakness, swallowing dysfunction, and facial weakness.

Acute pandysautonomia: diarrhoea, vomiting, dizziness, abdominal pain, ileus, orthostatic hypotension and urinary retention, bilateral tonic pupils, fluctuating heart rate, decreased sweating, salivation, and lacrimation.

Pure sensory: acute sensory loss, sensory ataxia, and areflexia but no motor involvement

Question 4

What is the aetiology of GBS?

Answer 4

GBS is characterised by an immune-mediated attack on the myelin sheath or Schwann cells of sensory and motor nerves. This is due to cellular and humoral immune mechanisms, frequently triggered by an antecedent infection.
•
C jejuni infection precedes about 60% to 70% of AMAN and acute motor-sensory axonal neuropathy (AMSAN) cases and up to 30% of acute inflammatory demyelinating polyradiculoneuropathy (AIDP) cases

In C jejuni-related infections, carbohydrate mimicry between the bacterial capsular lipooligosaccharide and specific myelin gangliosides and glycolipids is thought to induce antibodies against myelin.

Question 5

What are the risk factors for GBS?

Answer 5

History of gastrointestinal or respiratory infection from 1-3 weeks prior to the onset of weakness.

Recently, an association has been suggested with the Zika virus.

Vaccinations: live and dead vaccines have been implicated.

Malignancies – e.g., lymphomas, especially Hodgkin’s disease.

Pregnancy: incidence decreases during pregnancy but increases in the months after delivery.

Older age

Question 6

What is the hx of a patient presenting with GBS?

Answer 6

Weakness:

• In 60% of cases, onset occurs approximately three weeks after a viral illness.
• The condition usually presents with an ascending pattern of progressive symmetrical weakness, starting in the lower extremities.
• This reaches a level of maximum severity two weeks after initial onset of symptoms and usually stops progressing after five weeks.
• Facial weakness, dysphasia or dysarthria may develop.
• In severe cases, muscle weakness may lead to respiratory failure.

Pain: neuropathic pain may develop, particularly in the legs. Back pain may be another feature.

Reflexes: these may be reduced or absent.

Sensory symptoms: these can include paraesthesiae and sensory loss, starting in the lower extremities.

Autonomic symptoms: involvement of the autonomic system may present, with reduced sweating, reduced heat tolerance, paralytic ileus and urinary hesitancy. Severe autonomic dysfunction may occur.

Question 7

What are the examination findings in a person presenting with GBS?

Answer 7

Hypotonia.
Demonstrable altered sensation or numbness.
Reduced or absent reflexes.
Fasciculation may occasionally be noted.
Facial weakness - may be asymmetrical.
Autonomic dysfunction - fluctuations of heart rate and arrhythmias, labile blood pressure and variable temperature.
Respiratory muscle paralysis.

Question 8

What are the differentials of GBS?

Answer 8

Brain: stroke, brainstem compression, encephalitis

Spinal cord: cord compression, poliomyelitis, transverse myelitis

Peripheral nerve: vasculitis, lead poisoning, porphyria

Neuromuscular junction: myasthenia gravis, botulism

Muscle: hypokalaemia, polymyositis

Question 9

What are the investigations for GBS?

Answer 9

•Diagnosis is usually made on clinical grounds. However, the following may be helpful:
Electrolytes: inappropriate antidiuretic hormone secretion occurs in some patients; serum and urine osmolarity studies are indicated if it is suspected.

LP: Classic finding is elevated cerebrospinal fluid (CSF) protein with normal cell count (albuminocytological dissociation). Occurs in up to 90% of patients at week 1 after symptom onset.

Antibody screen: antibodies to peripheral and central nerves may be present.

Spirometry: forced vital capacity is a major determinant of the need for admission to ICU and then the need for intubation.

Nerve conduction studies: are the most useful confirmatory test and are abnormal in 85% of patients, even early on in the disease. They should be repeated after two weeks if they are initially normal. A decrease to less than 20% of predicted normal is associated with a poorer prognosis.

ECG: many different abnormalities may be seen - eg, second-degree and third-degree AV block, T-wave abnormalities, ST depression, QRS widening and a variety of rhythm disturbances.

Question 10

What is the management of GBS?

Answer 10

Plasma exchange:
-The dose for plasma exchange, given through a central venous catheter (Mahurkar), is 50 mL/kg bodyweight every other day for 7 to 14 days.

• During administration, patients should be closely monitored for electrolyte abnormalities and coagulopathies.
• Complications include severe infection, blood pressure instability, cardiac arrhythmias, and pulmonary embolus.

Intravenous immunoglobulin:

• Intravenous immunoglobulin started within two weeks from the onset hastens recovery as much as plasma exchange.
• Intravenous immunoglobulin is significantly much more likely to be completed than plasma exchange.
• Giving intravenous immunoglobulin after plasma exchange did not confer significant extra benefit.

Corticosteroids

DVT prophylaxis due to immobility- gradient compression stockings and sc LMWH

Pain relief for neuropathic pain

Admission to the ICU as intubation and assisted ventilation may be required.

Rehabilitation: all patients should undergo an individual programme of rehabilitation in the acute phase, comprising of gentle strengthening involving isometric, isotonic, isokinetic, and manual resistive and progressive resistive exercises. The focus is on proper limb positioning, posture, orthotics, and nutrition.

Question 11

What are the complications of GBS?

Answer 11

Persistent paralysis

Respiratory failure requiring mechanical ventilation

Hypotension or HTN

Thromboembolism, pneumonia and skin breakdown

Cardiac arrhythmia

Ileus

Aspiration pneumonia

Urinary retention

Psychiatric problems such as depression and anxiety

Question 12

What is the prognosis of GBS?

Answer 12

With modern intensive care support, the outcome is excellent for most patients.

However, neurological problems persist in up to 20% of patients; half of these patients are severely disabled.

Approximately 20% of patients cannot walk unaided six months after the onset of the condition.

Question 13

What is transverse myelitis?

Answer 13

Transverse myelitis (TM) is a pathogenetically heterogeneous focal inflammatory disorder of the spinal cord characterised by acute or subacute development of motor weakness, sensory impairment, and autonomic dysfunction

TM causes motor weakness, a sensory impairment below the lesions, and bowel and bladder dysfunction.

Question 14

What is the aetiology of transverse myelitis?

Answer 14

Multiple sclerosis and neuromyelitis optica spectrum disorder: these are the most common causes of TM.

Para-infectious causes: note that the causative organism is usually not identified.

• Antecedent viral infection: known causative agents include herpes simplex, varicella zoster, cytomegalovirus, Epstein-Barr virus, enteroviruses, HIV, influenza, human T-cell leukaemia virus, West Nile virus, Zika virus, and rabies.
• Antecedent bacterial or fungal infection: known causative organisms include Mycoplasma pneumoniae, TB, syphilis, Lyme borreliosis.

Post-vaccination: TM has been reported with almost all vaccines.

Systemic autoimmune causes: systemic lupus erythematosus and Sjogren’s syndrome are associated with TM.

Systemic inflammatory causes: sarcoidosis is associated with TM.

Paraneoplastic syndromes: TM can occur in the context of paraneoplastic syndromes.

Question 15

What is the classification of transverse myelitis?

Answer 15

Acute partial TM

Longitudinally extensive TM

Question 16

What is acute partial TM?

Answer 16

Para-infectious, occurring at the time of, and in association with, an acute episode of infection at a site remote from the central nervous system

Characterised by asymmetric spinal cord lesions typically of 1 or 2 vertebral segments in length

The clinical syndrome is typically mild to moderate in severity and the motor and sensory symptoms and signs are asymmetric.

Although heterogeneous, acute partial TM is most commonly associated with high risk for multiple sclerosis when the brain magnetic resonance imaging reveals white matter lesions compatible with demyelination.

Question 17

What is longitudinally extensive TM?

Answer 17

Characterised by asymmetric or symmetric spinal cord lesions that span ≥3 contiguous vertebral segments

The clinical syndrome is usually moderate to very severe, and the motor symptoms and signs are typically bilateral and more symmetric than in acute partial TM

Although heterogeneous, longitudinally extensive TM is most commonly associated with high risk for neuromyelitis optica spectrum disorder in the setting of seropositivity for neuromyelitis optica-IgG.

Question 18

What are the risk factors for transverse myelitis?

Answer 18

Preceding infectious illness

Recent vaccination

Female sex

Hx of recent physical trauma

Spinal injection

Question 19

What is the presentation of transverse myelitis?

Answer 19

Progressive weakness involving the lower extremities or all extremities.

Weakness follows a pyramidal pattern (arm abduction; elbow, wrist, and digit extension; hip and knee flexion; and ankle dorsiflexion), is accompanied by upper motor neuron signs such as hyper-reflexia and spasticity, and can reach its nadir at any time from 24 hours to 4 weeks.

Concomitant with motor weakness, most patients develop ascending tingling and/or numbness, beginning in the distal limbs and settling at or a few levels below the spinal lesion level

Urinary frequency, urgency, incontinence or retention

Bowel incontinence or constipation

A hallmark of demyelination, L’hermitte sign consists of paraesthesias (tingling, an ‘electrical sensation’) in the limbs, elicited by neck flexion.

McArdle’s sign- a hallmark of demyelination. Consists of an increase in the degree of pyramidal weakness with neck flexion.

Recurrent, stereotypical, painful, involuntary motor spasms of ≥1 limbs, each lasting 15 to 45 seconds.

Motor weakness is typically associated with hyperreflexia, Babinski’s signs, and limb spasticity.

Question 20

What are the investigations for transverse myelitis?

Answer 20

MRI spinal cord:

• Required in all patients to exclude compressive myelopathy
• Detection of intrinsic cord lesion assists in confirmation of myelitis

MRI brain may show MS

CSF fluid analysis- may suggest MS or neuromyelitis optica spectrum disorder

• Increased cell count supports inflammatory myelitis
• Normal CSF fluid does not exclude transverse myelitis

Question 21

What is the management of transverse myelitis?

Answer 21

Acute neurological deficits:

• Corticosteroids
• Spasticity is managed by stretching exercises, anti-spasticity drugs (e.g., baclofen, tizanidine), and therapeutic botulinum toxin injections.
• Acute urinary retention may be managed by bladder catheterisation.
• Deep vein thrombosis prophylaxis (heparin or enoxaparin with compression) should always be considered in immobilised patients.
• Acute rehabilitation consists of passive and active therapy to maintain the range of motion of limbs, reduce spasms and the risk of contractures, and to reduce risk of decubitus ulceration.
• Plasma exchange is 2nd line if steroids doesn’t work.

Question 22

What are the complications of Transverse myelitis?

Answer 22

MS 
Motor weakness 
Spasticity 
Neuropathic pain 
Bladder dysfunction 
DVT 
Pressure ulcers