Unilateral basal-ganglia involvement likely due to valproate-induced hyperammonemic encephalopathy

Abstract

A male child suffering from generalized tonic clonic epilepsy, on treatment with valproate, developed fulminant hepatic failure, hyperammonemia and encephalopathy due to drug toxicity. The most extraordinary feature was his MRI (FLAIR image) of brain which showed unilateral hyperintensities in right putamen and caudate nucleus. The patient recovered on withdrawal of valproate with mild residual left sided athetotic movements during remission. Repeat investigation confirmed an improved MRI imaging and normalised blood ammonia levels. The case report is unique because of unilateral involvement of basal ganglia due to valproate-induced encephalopathy.

Gait instability in valproate-treated patients: Call to measure ammonia levels

“…[2][3][4][5]7,13 One interesting observation in our cases was that all five patients with FLE developed prominent gait instability symptoms that led to disability, while having only mild encephalopathy, and in the presence of serum VPA levels within the reference range and normal or slightly elevated liver enzymes. [2][3][4][5]7,13 One interesting observation in our cases was that all five patients with FLE developed prominent gait instability symptoms that led to disability, while having only mild encephalopathy, and in the presence of serum VPA levels within the reference range and normal or slightly elevated liver enzymes.…”

“…Mental status changes are the most common manifestations of VPA-induced encephalopathy. [2][3][4][5]7,13 One interesting observation in our cases was that all five patients with FLE developed prominent gait instability symptoms that led to disability, while having only mild encephalopathy, and in the presence of serum VPA levels within the reference range and normal or slightly elevated liver enzymes.…”

“…Encephalopathy is the most common clinical feature of hyperammonemia, although extrapyramidal, gastrointestinal, and metabolic changes, as well as seizure exacerbation have also been described. [1][2][3][4][5][6][7] Gait instability and recurrent falls as one of the predominant sequelae are rare manifestations. Ammonia levels are not routinely measured for the investigation of unexplained symptoms in patients having serum VPA levels in the reference range in the absence of evidence of liver dysfunction.…”

Valproic Acid–Associated Hyperammonemia

“…Manual search of reference lists and gray literature did not identify additional studies. After screening and assessing for eligibility, 240 studies were included with the remaining articles being excluded for meeting the exclusion criteria 6,7,12–245 . Among the excluded 350 articles, 37 were literature reviews, 5 were pharmacokinetically related, 41 were VPA overdose related, and 267 articles were unable to clearly answer our objectives listed.…”