Hyperammonemic coma in a post-partum patient with undiagnosed urea cycle defect

Abstract

Urea cycle disorders (UCD) are common during neonatal period, and it is rarely reported in adults. We are reporting a patient presenting with post-partum neuropsychiatric symptoms rapidly progressing to coma. Markedly raised serum ammonia level on presentation with an initial normal magnetic resonance imaging (MRI) of brain and normal liver function tests led to the suspicion of UCD, which was confirmed on the basis of urine orotic acid and elevated serum amino acid levels. We had to resort to hemodialysis to correct the hyperammonemic coma, which was unresponsive to conventional anti-ammonia measures. She exhibited remarkable improvement with a progressive decline in serum ammonia with repeated hemodialysis and made a full recovery. Timely diagnosis and early institution of hemodialysis in the setting of a poor neurological status maybe considered a suitable treatment option.

Keywords: Hyperammonemic coma; post-partum patient; urea cycle defect.

Figure 1

Urea cycle and diagnosis of probable argininosuccinate lyase deficiency in our case

Figure 2

Serum ammonia levels in relation to hemodialysis

Figure 3

Diffusion restriction in peri-sylvian area and thalamic region bilaterally

Figure 4

Bilateral temporal lobe flair hyperintensity with occipital sparing

Figure 5

Diffusion weighted images showing bright areas in splenium