Amyloid deposition and CBF patterns predict conversion of mild cognitive impairment to dementia.

Mild cognitive impairment (MCI) can include the transition from a normal state to dementia. To explore biomarkers for the development of dementia, we performed an 18-month follow-up study in 28 patients with amnestic MCI. Amyloid deposition was examined using PiB PET, and cerebral blood flow (CBF) was examined using SPECT. Cognitive function was periodically assessed. The rate of conversion to dementia was higher in the PiB-positive/equivocal group (74%) than in the PiB-negative group (33%) (p = 0.041). Perfusion SPECT was performed in 16 patients. MCI patients with an AD-characteristic pattern of reduced CBF had a higher PiB-positive/equivocal rate (82%) than those with a non-AD pattern (20%) (p = 0.018), and patients with an AD pattern had a higher conversion rate (82%) than those with a non-AD pattern (40%) (p = 0.094). Clinically, all PiB-positive converters were diagnosed as having Alzheimer's disease (AD), whereas PiB-negative converters were thought to have some form of dementia other than AD. Amyloid PET is useful for predicting conversion to AD in MCI patients. A pattern analysis of perfusion SPECT findings might also be helpful for predicting conversion to AD, but with a lower specificity.

Liver injury after methylprednisolone pulse therapy in multiple sclerosis is usually due to idiosyncratic drug-induced toxicity rather than autoimmune hepatitis.

BACKGROUND: In patients with multiple sclerosis (MS), development of hepatic injury has been sporadically reported after methylprednisolone (MP) pulse therapy. Some studies suggest autoimmune hepatitis, while other studies reported direct hepatotoxicity as a cause for hepatic injury. Here, we studied the pathological mechanism of such liver injury in patients with MS. METHODS: From 2005 to 2016, eight patients with MS developed liver injury after MP pulse therapy. Their average age was 38 years (range: 28-49 years, all female). Autoimmune antibodies were measured and a liver biopsy was performed in seven patients. RESULTS: Liver injury developed within two weeks in two patients and later (30-90 days after MP) in six patients. No hepatitis-related autoantibody or hepatitis virus were found. All cases were classified as hepatocellular injury and none as cholestatic or mixed. A liver biopsy in five cases revealed centrilobular necrosis with lobular infiltrates of inflammatory cells, suggesting drug-induced acute hepatitis. The biopsy findings in another case suggested a residual stage of acute hepatitis. Only one patient showed portal expansion with periportal fibrosis, suggesting autoimmune hepatitis. All patients recovered spontaneously or with only hepatoprotective drugs, although one patient with possible autoimmune hepatitis recovered slowly. CONCLUSION: Liver injury develops usually later than two weeks after MP treatment. The prognosis is good in most cases and rarely autoimmune hepatitis may be involved.

[A case of acute hyperammonemic encephalopathy with extensive cortical high-intensity lesions in diffusion weighted imaging].

A 49-year-old woman with hepatic failure owing to alcoholic liver cirrhosis went into a deep coma. Her serum ammonia concentration was elevated at 436 µg/dl, and she had a generalized convulsion. Electroencephalogram and cerebrospinal fluid examination did not suggest encephalitis and epilepsy. Hyperammonemia may be occur because of generalized convulsions; however, it can spontaneously resolve if the convulsions are stopped. If hyperammonemia is the primary cause of generalized convulsion, the serum ammonia concentration will remain high until the cause is eliminated. However, despite stopping the convulsions, her ammonia concentration remained high. Diffusion-weighted brain MRI revealed symmetric high-intensity lesions in the frontal, temporal, and parietal cortices, especially the cingulate and insular cortices of the bilateral hemispheres. These findings were in line with those of previous reports that revealed symmetric cortical lesions, including cingulate and insula cortices that are distinctive in acute hyperammonemic encephalopathy. Therefore, we diagnosed that the coma, generalized convulsions, and abnormal brain MRI findings were caused by acute hyperammonemic encephalopathy.