Guillain-Barré syndrome: A case report

G. Rengaraj

Physician Assistant, Kauvery Hospital, Cantonment, Trichy

Background

The clinical journey through Guillain-Barré syndrome follows a typical pattern that can be readily divided into its constituent phases and components. Demyelinating and axonal forms of the syndrome occur in varying proportions across different geographical regions, and clinical variants. Within the typical disease course there are many less well understood biological variations, which are considered chronologically in this paper.

Guillain-Barré syndrome is usually preceded by an infection or other immune stimulation that induces an aberrant autoimmune response targeting peripheral nerves and their spinal roots.

Molecular mimicry between microbial and nerve antigens is clearly a major driving force behind the development of the disorder. The acute progression of limb weakness, often with sensory and cranial nerve involvement 1–2 weeks after immune stimulation, proceeds to its peak clinical deficit in 2–4 weeks.

When patients present with rapidly progressive paralysis, the diagnosis of Guillain-Barré syndrome needs to be made as soon as possible. Although establishment of the diagnosis in typical cases is usually straightforward, there are many clinical and investigative components to consider, especially in atypical cases.

The diagnosis is largely based on clinical patterns, because diagnostic biomarkers are not available for most variants of the syndrome. Identification of biomarkers and establishment of their pathophysiological roles, if any, in experimental models has been a major research challenge.

Pathophysiology

Case presentation

A 26-year-old man, with no significant past medical history, presented to the emergency department for evaluation of progressive quadriparesis predominantly involving face and upper limbs, along with dysphagia and areflexia. Neck flexion and extension strength was grade ⅕, lower extremity weakness (MRC grade ⅘, upper extremity weakness ⅖ proximally and 3/5 distally) and global areflexia were noted. Light touch, temperature, and vibration sensations were normal

He had woken six days before with fever-associated rhinorrhea, and a feeling of weakness in his upper and lower extremities. He had been unable to complete his routine workout but could still ambulate independently. On the day of presentation his weakness progressed to the point that he was unable to get out of a chair, necessitating an emergency evaluation

Initial evaluation outside revealed no numbness, tingling, bowel or bladder incontinence, dysarthria, dysphagia, or exertional dyspnea. His mental status and cranial nerve examinations were normal.

In-hospital evaluation

MRI spine and brain were normal. Nerve conduction study was within normal limbs.

He was diagnosed with GBS and IV Ig therapy was initiated. He developed progressive respiratory distress requiring intubation and mechanical ventilation on the day of admission. Patient had left > right lung collapse consolidation. Pulmonologist opinion was obtained and a bronchoscopy was done that showed thick mucus plug obstructing bronchial tree, and toileting was done. Bronchial fluid aspirate was sent for culture. In view of weaning, Tracheotomy was planned. Started on antibiotics and DVT prophylaxis. Aggressive physiotherapy was done. Tracheostomy was done. High-grade fever spikes persisted, tracheal and urine cultures were normal.

Variants, formes frustes, and paediatric presentations

Guillain-Barre syndrome is a remarkably clinically diverse disorder and includes several clinically distinctive variants, formes frustes,(an atypical or attenuated manifestation of a disease or syndrome, with the implications of incompleteness, partial presence or aborted state.) and atypical cases. The frequency of these variant forms in part relates to the geographical area in which the disease is reported. Guillain-Barré syndrome can be restricted to specific nerve fibers, as 15% of patients with a pure motor form do not have any sensory deficits.Pure motor Guillain-Barré syndrome can occur both in patients with acute motor axonal neuropathy or acute inflammatory demyelinating polyneuropathy. Acute pure sensory neuropathies are well recognised, but do not meet existing diagnostic criteria of Guillain-Barré syndrome. Whether or not acute pure sensory neuropathies can be considered a variant of Guillain-Barré syndrome is unclear.

Electrophysiological classification: current considerations

Guillain-Barré syndrome is a clinically diagnosed disorder, but nerve conduction studies (NCS) can help to support the diagnosis, to discriminate between axonal and demyelinating subtypes, and could relate to prognosis. Nerve conduction abnormalities are most pronounced two weeks after start of weakness. NCS findings can be normal especially early in the course of disease.

To increase the diagnostic yield, at least four motor nerves, three sensory nerves, F-waves, and H-reflexes, should be examined. NCS enables clinicians to divide Guillain-Barre syndrome into acute inflammatory demyelinating polyneuropathy, acute motor axonal neuropathy, or acute motor and sensory axonal neuropathy. NCS in patients with acute inflammatory demyelinating polyneuropathy show features of demyelination, including prolonged distal motor latency, reduced nerve conduction velocity, prolonged F-wave latency, increased temporal dispersion, and conduction blocks.

The sural sensory potential is often preserved. Features of axonal Guillain-Barré syndrome (acute motor axonal neuropathy or acute motor and sensory axonal neuropathy) are decreased motor, sensory amplitudes, or both. Some patients turn out to have transient conduction blocks or slowing that rapidly recovers during the course of the disease, so-called reversible conduction failure. This transient feature might initially suggest acute inflammatory demyelinating polyneuropathy instead of acute motor axonal neuropathy, and shows that serial NCS over weeks are needed to reliably distinguish between these two forms of Guillain-Barré syndrome. Transient blocks are probably caused by impaired conduction at the node of Ranvier, because of the effects of anti-ganglioside antibodies in those cases in which they are found. NCS might also have prognostic value because patients with features of demyelination more often need mechanical ventilation, and low compound muscle action potentials (CMAPs) are the most consistent findings predictive of poor outcome.

Patients diagnosed with acute motor axonal neuropathy can either improve very slowly and incompletely, or recover rapidly, probably because of restoration of transient conduction blocks. Based on clinical trial evidence so far, distinguishing between acute inflammatory demyelinating polyneuropathy and acute motor axonal neuropathy does not imply that a patient needs a specific or tailored immunological treatment.

Outcome and prediction of outcome

Guillain-Barré syndrome is still a life-threatening disorder with frequent morbidities, even with the best treatment available. Mortality rates in Europe and North America vary between 3% and 7%, and more widely in other countries where data are available.Patients can die in the acute progressive stage, most probably because of ventilatory insufficiency or pulmonary complications, or from autonomic dysfunction including arrhythmia.

However, death can occur at a late stage when a patient is discharged from an ICU to a general neurology ward, which further shows the importance of prolonged accurate monitoring and general care. Emergency situations can occur after delayed diagnosis, especially in young children.Patients who survive Guillain-Barré syndrome frequently have residual complaints and deficits, which can have a substantial effect on daily activities and quality of life. About 20% of patients with Guillain-Barré syndrome cannot walk unaided 6 months after onset.

Most patients have residual pain and fatigue, which can in part be attributed to persistent axonal loss.Many patients have to change their work and daily activities, even after reaching a good functional level.Most improvement happens in the first year, but patients might show further recovery even after 3 or more years.

To improve the outcome of Guillain-Barré syndrome, more effective treatments and good outcome assessments are needed.However, the clinical course and outcome of the disease is highly variable and early recognition of patients with poor outcome is needed to personalize and improve treatment. Prognostic models could help to identify patients who need additional treatment and monitoring. Patient characteristics consistently related to poor prognostic outcome in Guillain-Barré syndrome are higher age (aged 40 years and over), preceding diarrhea , and high disability at nadir.

The EGOS, which is based on these three clinical characteristics, can be used 2 weeks after admission to predict the ability of the patient to walk at 6 months. The mEGOS requires the Medical Research Council (MRC) Scale for muscle strength score instead of disability and can predict outcome as soon as one week after admission, when therapeutic interventions are probably even more effective.

The risk of respiratory failure is associated with rate of disease progression, severity of limb weakness, peroneal nerve conduction block, and low vital capacity. This risk can be predicted for individual patients using EGRIS; based on the severity of weakness (expressed as MRC sum score); onset of weakness; and facial palsy, bulbar weakness, or both.These models need to be validated for use in children and patients with axonal forms of Guillain-Barré syndrome.

Assessment scales

Over the past few decades, the GBS Disability Scale have been used as an outcome scale in the majority of clinical trials in GBS. The GBS Disability Scale has six levels:

  • 0 (healthy)
  • 1 (minor symptoms and capable of running)
  • 2 (able to walk 10 m without assistance but unable to run)
  • 3 (able to walk 10 m across an open space with help)
  • 4 (bedridden or wheelchair-bound)
  • 5 (requiring assisted ventilation for at least part of the day)
  • 6 (dead).

GBS assessment scales must be valid, sensitive, reliable, and able to capture subtle clinical changes over time.

Conclusion

Early cranial nerve and respiratory involvement in patients presenting with GBS are associated with poor outcomes warranting immediate critical care involvement. It is imperative to recognize these symptoms, identify the subtype of GBS, and rapidly implement treatment. Patients treated with IV Ig. Both PLEX and IV Ig had similar functional outcomes. Given the variability of infection, disease, and triggers in different populations, further prospective clinical trials with a well-defined population will help us evaluate the impact of different treatment modalities on this disease.

 

G. Rengaraj
Physician Assistant

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