The term hepatic encephalopathy (HE) includes a spectrum of neuropsychiatric abnormalities occurring in patients with liver dysfunction. Most cases are associated with cirrhosis and portal ...hypertension or portal-systemic shunts, but the condition can also be seen in patients with acute liver failure and, rarely, with portal-systemic bypass and no associated intrinsic hepatocellular disease. Although HE is a clinical condition, several neuroimaging techniques, particularly MR imaging, may eventually be useful for the diagnosis because they can identify and measure the consequences of central nervous system (CNS) increase in substances that under normal circumstances, are efficiently metabolized by the liver. Classic MR imaging abnormalities include high signal intensity in the globus pallidum on T1-weighted images, likely a reflection of increased tissue concentrations of manganese, and an elevated glutamine/glutamate peak coupled with decreased myo-inositol and choline signals on proton MR spectroscopy, representing disturbances in cell-volume homeostasis secondary to brain hyperammonemia. Recent data have shown that white matter abnormalities, also related to increased CNS ammonia concentration, can also be detected with several MR imaging techniques such as magnetization transfer ratio measurements, fast fluid-attenuated inversion recovery sequences, and diffusion-weighted images. All these MR imaging abnormalities, which return to normal with restoration of liver function, probably reflect the presence of mild diffuse brain edema, which seems to play an essential role in the pathogenesis of HE. It is likely that MR imaging will be increasingly used to evaluate the mechanisms involved in the pathogenesis of HE and to assess the effects of therapeutic measures focused on correcting brain edema in these patients.
This case report highlights a rare complication of root canal treatment involving the inadvertent extrusion of sodium hypochlorite solution, resulting in a sodium hypochlorite-induced facial ...hematoma. A 44-year-old female patient presented significant right hemifacial swelling and ecchymosis following root canal therapy. Computed tomography imaging confirmed a hematoma involving the facial region without active signs of bleeding. Sodium hypochlorite, a potent cytotoxic agent commonly used in root canal procedures, was identified as the causative agent. Treatment consisted of prednisone, antibiotics, and NSAIDs, resulting in gradual improvement over a month. The cytotoxic properties of sodium hypochlorite, its variable concentrations, and risk factors associated with facial hematomas are discussed. It is essential to emphasize the rarity of such hematomas and highlight the need for precise technique, vigilant monitoring, and interdisciplinary collaboration to mitigate risks and prioritize patient safety.
Focal T2‐weighted white matter lesions (WML) on brain magnetic resonance imaging (MRI), mimicking those seen in cerebrovascular small‐vessel disease described in patients with persistent hepatic ...encephalopathy, decreased in volume with the improvement of hepatic encephalopathy. This outcome has been interpreted as a decrease in the edema that it is proposed to be involved in the pathogenesis of hepatic encephalopathy. We designed a study to further investigate potential changes in focal WML in the brains of patients with cirrhosis following liver transplantation and to study the relationship between these changes and overall cognitive function. We used MRI to measure the volume of supratentorial focal WML and a neuropsychological examination to assess cognitive function before and after liver transplantation in 27 patients with cirrhosis without signs of overt hepatic encephalopathy. Baseline MRI identified focal T2‐weighted lesions in 19 patients (70.3%). The presence of WML was associated with older age but not with vascular risk factors, severity of liver function, or psychometric tests. A significant reduction in lesion volume was observed after liver transplantation (from a median of 1.306 cm3 to 0.671 cm3, P = 0.001). This decrease correlated with an improvement in an index of global cognitive function (r = −0.663; P < 0.001). This evolution indicates that lesion volume is partially related to a reversible type of tissue damage, which is compatible with brain edema. Conclusion: Focal WML probably induced by age‐related microvascular injury can decrease their volume with liver transplantation. The associated improvement of cognitive function supports a relationship between brain edema and minimal hepatic encephalopathy. (HEPATOLOGY 2007.)
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