Hypertensive Brainstem Research Articles

Bruns-Cushing–Like Nystagmus in a Patient With Hypertensive Brainstem and Cerebellar Infarcts

Bruns-Cushing–Like Nystagmus in a Patient With Hypertensive Brainstem and Cerebellar Infarcts

Evidence of specific inflammatory condition in nucleus tractus solitarii of spontaneously hypertensive rats

Since the nucleus tractus solitarii (NTS) is a pivotal region for regulating the set-point of arterial pressure, we proposed a role for it in the development of neurogenic hypertension. Recent studies have suggested that proinflammatory molecules, such as junctional adhesion molecule 1 (JAM-1) are highly expressed in the NTS of an animal model of human essential hypertension, the spontaneously hypertensive rat (SHR), compared with normotensive rats (Wistar-Kyoto, WKY). Moreover, we have also shown endogenous leukocyte accumulation inside capillaries within the NTS of SHR but not WKY rats. Based on this evidence, we hypothesized that gene expression of cytokines/chemokines is altered in the NTS of SHR. We have screened for abnormally expressed inflammatory mediators in the NTS of SHR using the RT2 Profiler PCR arrays, which were designed specifically to target major cytokines/chemokines. The specific PCR array revealed that seven genes were less expressed in the NTS of SHR compared with WKY rats (more than twofold differences), while only two genes were more expressed in the SHR. Moreover, we identified that some of these validated molecules exhibit important functional roles for cardiovascular homeostasis at the level of the NTS. We suggest that abnormal gene expression of proinflammatory molecules, such as JAM-1, causes leukocyte accumulation within the vasculature in the NTS of SHR. Consequently, gene expression of specific cytokines/chemokines may be downregulated to avoid further strong inflammatory activity in the NTS of SHR at the expense of an alteration in neuronal activity that leads to cardiovascular autonomic pathology. Importantly, to allow translation of our work, these novel insights need to be assessed in hypertensive human brainstem tissue; their confirmation could lead to novel therapeutic approaches for one of the world's most prevalent diseases.

A case of hypertensive encephalopathy with extensive spinal lesions on MRI

A 14-year-old female had repeated vomiting, headache, abdominal pain, visual field deficit and lethargy at the onset of hypertensive encephalopathy. Cerebrospinal fluid (CSF) test revealed a high level of IgG and protein. MRI demonstrated no supratentorial cerebral lesions but hyperintense lesions were observed from the lower pons to the Th8 level of spinal cord and cerebellar cortex on T2 weighted and FLAIR images without contrast enhancement. The two antihypertensive drugs stabilized to control her blood pressure and improved her clinical symptoms. Reexamination of MRI and cerebrospinal fluid test also revealed clear improvement of the above abnormalities. The abnormal findings on abdominal CT and renography led us to suspect renal infarction. Abdominal angiography demonstrated multifocal stenoses of renal interlobar arteries, which were supposed to supply the renal infarcted regions. These suggested that the renal infarctions due to fibromuscular dysplasia caused systemic hypertension. There have been only two reports that demonstrated spinal cord lesions in reversible posterior leukoencephalopathy syndrome (RPLES). We report extensive spinal lesions on MRI and a high level of IgG in CSF at the subacute phase in a young female with RPLES associated with hypertensive (brainstem) encephalopathy.

Angiotensin II in the brain and brainstem of the DOCA salt hypertensive rat.

We previously reported that immunoreactive angiotensin II (AII) containing nerve fibers and cell bodies were increased in the brain and brainstem of the spontaneously hypertensive (SH) rat compared with its normotensive control, the Wistar Kyoto (WKY) rat. Since earlier studies from other laboratories described the distribution of AII in normotensive Sprague Dawley rat brain, it was the intent of this investigation to examine the localization of AII in the only DOCA-salt hypertensive rat. We unilaterally nephrectomized Sprague Dawley rats and administered multiple subcutaneous injections of 30 mg/kg body weight of DOCA, with saline substituted for drinking water to significantly increase blood pressure. Using the peroxidase anti-peroxidase method for immunocytochemical localization of a tissue antigen, we characterized AII distribution and density in the brain and brainstem of DOCA-salt hypertensive rats. Positively stained cell bodies and fiber profiles were found in discrete anatomical subdivisions, including the limbic system, hypothalamus, basal ganglia, circumventricular organs, reticular formation and ependymal tissue immediately adjacent to the ventricles. These findings support the hypothesis that AII is widely distributed in discrete regions of the DOCA-salt hypertensive rat brain and brainstem, and that the distribution of AII is consistent with a potential functional significance in the regulation of cardiovascular activity and neuroendocrine function.