Pyruvate dehydrogenase deficiency presenting as Guillain-Barré syndrome

Backround and methods: We analyse a case of pyruvate dehydrognease (PDH) deficiency, presenting as an acute disease of the peripheral nervous system.

Case report: The today 12 years old boy showed a normal development until the age of four years. Then, following an upper respiratory tract disease, he developed a symmetrical flaccid paresis in a rapidly ascending fashion. Eventually, he lost the ability to walk and showed respiratory impairment. Tendon reflexes were absent. Protein (1570mg/l) and lactate (4.4mmol/l) in CSF were increased, a GM1 IgG antibody in serum was found. Guillain-Barré syndrome was assumed and he was treated with intravenous immunoglobulins. There was slow recovery, which finally led to near normal motor abilities.

When he was eight years old, he fell ill with a mycoplasma pneumoniae infection and developed an encephalopthy with a concurrent ascending flaccid paralysis and bulbar muscles involvement. Protein in CSF during this second attack was normal, while lactate (4.6 mmol/) and the amino acids alanine and glycine were elevated. Electrophysiology revealed a motor polyneuropathy. Cranial MRI demonstrated a symmetrical T2 hyperintensity of the globus pallidus on both sides and signs of necrosis of these structures on follow-up four weeks later. The boy now suffers from a severe dystonic hypokinetic tetraparesis (GMFCS level IV).

In muscle, the subunit E1alpha of the PDH complex was decreased, which was caused by the hemicygotic mutation c.262C>T p.Arg88Cys within the PDHA1 gene. The mild lactate acidosis normalized with ketogenic diet without improvement of clinical symptoms or MRI results.

Conclusion: A GBS like clinical picture seldom is described as the initial manifestation of a PDH deficiency. This possibility has to be considered, when an atypical clinical course or elevated lactate values in plasma or CSF are observed.