Introduction Guillain-Barre syndrome (GBS) and acute transverse myelitis (ATM) may rarely coexist in children. We present a case of dual diagnosis following Mycoplasma pneumoniae infection.

Case A previously well two year old boy presented with cough and fever for two days. He developed progressive ascending weakness with areflexia, initially unable to stand or sit. This progressed to involve his respiratory muscles, requiring intubation and ventilation. He was treated promptly with intravenous immunoglobulin for suspected GBS. CSF protein on Day 2 was normal. He was also treated with antibiotics including clarithromycin. Spinal MRI showed intrinsic signal change in the cervical, lower thoracic cord and conus, in keeping with ATM. He received high dose intravenous methylprednisolone for three days. Nerve conduction studies were consistent with acute motor axonal neuropathy (AMAN). There was no improvement in his condition so he was treated with plasma exchange for five days. Mycoplasma serology was strongly positive. He required a tracheostomy and was ventilated for 15 weeks after which his tracheostomy was removed. He made gradual neurological improvement and was discharged 7 weeks later, mobilising with support and communicating normally.

Discussion Cases of concurrent ATM and GBS are rarely reported in children. Literature suggests that a common epitope may trigger both central and peripheral nervous system demyelination. Causes reported include systemic lupus erythematosus, influenza vaccination and infections such as Mycoplasma Legionella, Bartonella, influenza, and mumps. Recognising dual diagnoses is important as this may have an impact on recovery and prognosis. The concept of transverse myelitis plus syndrome suggests that patients with ATM and concomitant nerve root involvement usually have a poorer prognosis.

Conclusion In patients with spinal imaging in keeping with ATM but a clinical history not consistent with this, consideration should be given to the presence of co-existing GBS, which may benefit from more aggressive treatment.