case_images: PMC9109486_01
case_images: Electroencephalography on admission showing generalized, irregular
  delta-theta activity as well as triphasic waves in average montage. EEG was
  recorded by surface electrodes following the 10/20 system using the
  following parameters: sensitivity 7 microV/mm, time constant 0.3 s, 70 Hz
  low-pass filter and 50 Hz notch filter.
case_images: 10.1177_17562864221097614-fig1.jpg
case_images: PMC9109486_01_10.1177_17562864221097614-fig1.jpg
case_images: fig1-17562864221097614
case_images: Electroencephalography (EEG) showed generalized, irregular delta-theta activity as well as triphasic waves (see Figure 1) and laboratory testing revealed hyperammonemia of 121 mug/dl (reference range 19-55 mug/dl) despite normal liver and kidney function.
case_images: Serum levels of ammonia over time during hospitalization.
case_images: 10.1177_17562864221097614-fig2.jpg
case_images: PMC9109486_01_10.1177_17562864221097614-fig2.jpg
case_images: fig2-17562864221097614
case_images: Serum levels of ammonia decreased (see Figure 2) and clinical improvement was observed under this treatment regimen.
case_images: Portocaval shunt from inferior mesenteric vein (IMV) to left renal vein and
  inferior vena cava (IVC), respectively, on coronally reformatted computed
  tomography (CT, a) and digital subtraction angiography (b-g). (a) Initial CT
  imaging showed a vascular convolute left of the aorta (bracket), connecting
  the IMV (arrowhead) to the left renal vein (arrow). After percutaneous
  puncture of the right portal vein (b, arrowhead) selective catheterization
  of the superior mesenteric vein (c, arrowhead) showed main drainage of blood
  through retrogradely perfused IMV (c, curved arrow). Diagnostic contrast
  injection into IMV visualized feeding portal vein (d, arrowhead) and
  draining vessels into left renal vein (e, arrow) and IVC (e, arrowhead).
  Stationary contrast agent (f, *) after coil embolization of draining vessels
  with IDC and microplex coils (f, arrowheads) proved efficient occlusion.
  Final diagnostic contrast injection confirms change of perfusion direction
  of IMV toward the liver (g, curved arrow).
case_images: 10.1177_17562864221097614-fig3.jpg
case_images: PMC9109486_01_10.1177_17562864221097614-fig3.jpg
case_images: fig3-17562864221097614
case_images: Finally, computed tomography (CT) angiography revealed a left abdominal venous convolute with portosystemic shunts between the inferior mesenteric vein and the left renal vein as well as the inferior vena cava (see Figure 3(a)). The patient underwent percutaneous transhepatic coil embolization and the shunts were successfully obliterated (Figure 3(b)-(g)), resulting in full and sustained clinical recovery with serum ammonia levels remaining within the normal range.
case_images: Electroencephalography after portocaval shunt obliteration showing a
  posterior alpha rhythm with no encephalopathic changes in average montage.
  EEG was recorded by surface electrodes following the 10/20 system using the
  following parameters: sensitivity 7 microV/mm, time constant 0.3 s, 70 Hz
  low-pass filter and 50 Hz notch filter.
case_images: 10.1177_17562864221097614-fig4.jpg
case_images: PMC9109486_01_10.1177_17562864221097614-fig4.jpg
case_images: fig4-17562864221097614
case_images: EEG before discharge showed a posterior alpha-rhythm with no encephalopathic changes (see Figure 4).