Coexisting pathologies in the brain: influence of vascular disease and Parkinson’s disease on Alzheimer’s pathology in the hippocampus

The finding of more than one coexisting brain pathology in dementia sufferers is not unusual. However, it is unclear how these different diseases may interact or influence the evolution of one another. In this study we analyse the hippocampal expression patterns of hyperphosphorylated tau, paired helical filament (PHF)-related protein, β-amyloid and synaptophysin in a group of Alzheimer’s disease (AD) sufferers with and without additional pathology. Compared to cases with only AD-type pathology we found that the presence of additional vascular disease augmented the accumulation of hyperphosphorylated tau in the CA1 region of the hippocampus without affecting PHF formation in cases with mild AD changes and reduced the extent of PHF formation in the CA2/3 and CA4 regions of the hippocampus in cases with severe AD pathology. We also found that synaptophysin immunoreactivity in the CA4 and dentate gyrus in pure AD was inversely related to the extent of amyloid accumulation but not to neurofibrillary pathology in the same regions. These relationships were lost when additional pathology was present. Memory scores obtained during life correlated closely with hyperphosphorylated tau and PHF-related protein expression in CA1 in pure AD but not in AD with additional pathology. Total amyloid and synaptophysin expression in the hippocampus did not correlate with memory scores in any patient group. Our findings suggest that the interactions of two pathologies in the hippocampus are complex and may differ depending on the stage reached in the evolution of a progressive disease such as AD. Received: 26 July 1999 / Revised, accepted: 12 October 1999     

Decerebrate-like posturing with mechanical ventilation in brain death

Complex spinal cord, spontaneous, or upper limb reflexes are rarely observed in brain death. The authors describe two brain-dead heart-beating cadavers (out of 400 consecutive cases in their hospital in the past 9 years) that, immediately after brain-death diagnosis, exhibited symmetric upper limb movements resembling decerebrate posture that were triggered by each mechanical pulmonary insufflation, and also by superficial pressure and noxious stimuli applied to the arms, thorax, or abdomen. These movements persisted until disconnection from mechanical ventilation.     

Vascular injuries within the hepatoduodenal ligament

BACKGROUND: Lesions of vascular structures are rare but serious complications of laparoscopic cholecystectomy. The purpose of this blind randomized animal study was to investigate the possibility of detecting different vascular lesions within the hepatoduodenal ligament using laparoscopic color Doppler ultrasound (LCDU). METHODS: Twenty-four lesions of the hepatic artery and portal vein were created laparoscopically in six farmer pigs using titanium clips. The following injuries were studied: (a) partial occlusion of the hepatic artery (eight cases), (b) complete occlusion of the hepatic artery (eight cases), (c) partial occlusion of the portal vein (eight cases). There were also eight cases without lesions of the vascular vessels. The order in which the injuries were created was randomly assigned. The study was performed in a blind fashion. Recognition of the injuries was attempted with LCDU. RESULTS: All injuries were recognized correctly by LCDU. There were no false positive results. The clips were reliably located. Using color Doppler imaging, partial occlusions of the hepatic artery and portal vein were visualized by changes of the blood flow from laminar to turbulent behind the clip. Complete occlusion of the hepatic artery was recognized as a complete cessation of the colored blood flow. CONCLUSION: LCDU is a very efficient tool for visualizing vascular structures and evaluating the bloodstream. Partial or complete vascular occlusion by clips that may occur as a result of difficult dissection during laparoscopic cholecystectomy can be visualized reliably using this technique.     

Maladie de Rendu-Osler

Hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu syndrome) is a development disorder of the vasculature characterized by telangiectases and arteriovenous malformations in specific locations. Among monogenic disorders, it is one of the most common, though affected individuals are widely underdiagnosed. The most common features of this disorder, nosebleeds, and telangiectases on the lips, hands, and oral mucosa are often quite subtle. Mutations in at least five genes may result in hereditary hemorrhagic telangiectasia, but mutations in two genes (ENG and ACVRL1/ALK1) account for approximately 85% of cases. Optimal management requires understanding the specific clinical patterns of these vascular malformations, especially their locations and timing during life. Therapeutic modulation of angiogenesis may be an effective therapy.