Globi pallidi may showcase changes in magnetic resonance imaging (MRI) due to neurotoxic substances inherent in Alagille syndrome (ALGS) that have not yet been assessed, according to a new study published in Pediatric International.

The case reported by Nagai and colleagues describes a 9-month-old female previously diagnosed with ALGS. During the preoperative studies for a liver transplant proposed due to progressive liver injury, a brain MRI revealed bilateral globi pallidi hyperintensities on the diffusion-weighted images. 

The healthcare team hence ordered manganese plasma levels, which came out normal (1.0 𝜇g/dL). Other neurotic substances such as ammonia, glucose, iron, and copper blood concentrations were also within the normal range. These results allowed the providers also to rule out entities that may produce abnormal globi pallidi imaging in the MRI, such as acute hyperammonemia, Wilson disease, neurodegeneration secondary to iron accumulation, Wernicke encephalopathy, hyperglycemia, hypoglycemia, and mitochondrial diseases.


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“Since iron, copper, and manganese levels were normal before liver transplantation, we assume that hitherto unidentified neurotoxic agents other than manganese caused her transient [globi pallidi] signal abnormality,” the authors said.

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Three months after performing the liver transplant, MRI changes in globi pallidi disappeared, and serum manganese concentrations remained stable, suggesting that the possible neuropathy secondary to liver failure in ALGS is reversible. 

Previous reports of abnormal globi pallidi in the MRIs in the context of patients with liver damage include mostly adults. Hepatic encephalopathy is the medical term responsible for this clinical entity and courses with increased manganese plasma levels that subsequently deposit in central nervous tissue, especially the basal ganglia.

Only 1 case reported in the literature also regarded an infant with ALGS. Regardless, the patient had the same laboratory pattern regarding manganese levels as the adults. In all liver transplant cases, brain MRI changes also normalized after surgery.

“We present a case of abnormal signals in the [globi pallidi] that could not be explained by manganese deposition. This [globi pallidi] abnormality disappeared after liver transplantation,’ the authors concluded. “Further accumulation of similar cases and in-depth investigation will be needed to fully elucidate the neuropathology seen in our patient.”

Reference

Nagai Y, Hayakawa I, Tsutsumi Y, Kasahara M, Abe Y. Globi pallidi injury not caused by manganese in cirrhosis of Alagille syndrome. Pediatr Int. Published online April 08, 2022. doi:10.1111/ped.15088