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A 54-year-old man presents to the emergency department with four days of progressive leg weakness. One week earlier he had a three-day episode of bloody diarrhoea that resolved spontaneously. He now cannot climb stairs, cannot stand without support, and this morning noticed tingling in his fingers. On examination: pulse 108/min, BP 154/92 mmHg, respiratory rate 22/min, oxygen saturation 96 percent on air. He has symmetric weakness in the legs (MRC 3) and arms (MRC 4), absent ankle and knee jerks bilaterally, downgoing plantars, mild distal sensory loss to pinprick in the feet, and a palpable bladder. His forced vital capacity is 1.1 L (predicted 4.2 L) and falling.
Questions
a) What is the most likely diagnosis, and what two features in the history support it? (2 marks)
Diagnosis: Guillain-Barre syndrome (AIDP phenotype). The diagnosis is clinical: symmetric ascending weakness reaching nadir over days with areflexia, preceded by an antecedent infection. The two supporting features are:
- The recent Campylobacter jejuni gastroenteritis (bloody diarrhoea one week earlier) — Campylobacter is the commonest antecedent infection in GBS (25 to 30 percent) and classically drives the AMAN/AIDP phenotype.
- The pattern of progressive symmetric ascending weakness with areflexia over four days, plus distal paraesthesia and a palpable bladder — the classic clinical picture, with sphincter function relatively spared compared with a cord lesion.[1]
b) Outline the investigations that confirm the diagnosis and define the subtype. (2 marks)
- CSF (lumbar puncture): look for albuminocytological dissociation — elevated protein (over 0.55 g/L) with a normal white cell count (under 5 per microlitre). Note that the CSF may be normal in the first week; if so, repeat it after one to two weeks.
- Nerve conduction studies: define the subtype — AIDP shows prolonged distal latencies, conduction block, slow velocity, temporal dispersion and prolonged F-waves (demyelination); AMAN shows reduced CMAP amplitudes with normal sensory studies and normal velocity (axonal).
- Bloods: FBC, U&E (check sodium for SIADH), LFT, glucose, CK (to exclude myopathy), ECG (autonomic involvement), and Campylobacter / CMV / Mycoplasma serology to identify the trigger. Send an HIV test — HIV-associated GBS can show CSF pleocytosis.
- Anti-ganglioside antibodies (anti-GM1, anti-GQ1b) are confirmatory but not required for diagnosis of classic AIDP.
- MRI spine only if a cord lesion cannot be excluded clinically (here the areflexia, ascending pattern and sphincter sparing make a cord lesion unlikely).[1][2]
c) What are the intubation criteria, and does this patient meet them? Justify your management of his respiratory status. (3 marks)
The intubation criteria in GBS are (any one): FVC under 20 mL/kg (or under 1 L in an adult); negative inspiratory force weaker than minus 30 cmH2O; FVC falling by more than 30 percent over 24 hours; or clinical deterioration — bulbar weakness, weak cough, tachypnoea, hypoxaemia, exhaustion.[1][3]
This patient meets the criteria: his FVC is 1.1 L (and falling), he is tachypnoeic (respiratory rate 22) and tachycardic, and he has bulbar-risk markers (autonomic signs). He should be transferred to ICU and intubated electively now, before a crash intubation in a dysautonomic patient. Plan an elective rapid-sequence intubation with reduced-dose induction agent (propofol), rocuronium (avoid suxamethonium — hyperkalaemia risk in a denervating illness), and atropine, a vasopressor and a transcutaneous pacer immediately available because laryngoscopy can precipitate severe bradycardia. He will need continuous ECG, blood-pressure monitoring and serial FVC before and after intubation.
d) What is the definitive disease-modifying treatment, the regimen, and the treatment that must NOT be used? (2 marks)
- Intravenous immunoglobulin (IVIg): 0.4 g/kg per day for 5 days (total 2 g/kg), started within 2 to 4 weeks of onset. It is equally effective as plasma exchange and simpler.
- Alternative: plasma exchange, 5 sessions of one plasma volume each (about 50 mL/kg) on alternate days over 1 to 2 weeks.
- The two are never combined — no additional benefit.
- Corticosteroids must NOT be used: the Cochrane meta-analysis shows they do not speed recovery or improve outcome; using them delays the appropriate disease-modifying therapy.[1]
- Supportive bundle: DVT prophylaxis (enoxaparin 40 mg subcutaneously daily plus compression stockings), nasogastric feeding, pressure-area care, pain management (gabapentin or pregabalin), and early multidisciplinary rehabilitation.
e) Name two poor prognostic factors in this patient and the score used to predict his need for ventilation. (1 mark)
Poor prognostic factors present: antecedent diarrhoea (Campylobacter), severe weakness at nadir (MRC sum score will be under 40), the need for mechanical ventilation, and older age (over 50). The score that predicts the need for ventilation is the Erasmus GBS Respiratory Insufficiency Score (EGRIS), validated internationally in the IGOS cohort; the modified Erasmus GBS Outcome Score (mEGOS) at 7 days predicts the inability to walk at four weeks and six months.[3]
References3ShowHide
- [1]Leonhard SE, Mandarakas MR, Gondim FAA, et al. Diagnosis and management of Guillain-Barré syndrome in ten steps. Nature Reviews Neurology, 2019.PMID 31541214
- [2]Fokke C, van den Berg B, Drenthen J, Walgaard C, van Doorn PA, Jacobs BC. Diagnosis of Guillain-Barré syndrome and validation of Brighton criteria. Brain, 2014.PMID 24163275
- [3]Walgaard C, Lingsma HF, Ruts L, et al. Prediction of respiratory insufficiency in Guillain-Barré syndrome. Annals of Neurology, 2010.PMID 20517939