Spontaneous Elevation of Blood Pressure After SAH: An Epiphenomenon of Disease Severity and Demand, But Not a Surrogate for Outcome?

BACKGROUND

Spontaneous blood pressure increase is frequently observed after aneurysmal subarachnoid hemorrhage (aSAH). These episodes of spontaneous blood pressure alterations are usually tolerated under the assumption of an endogenous response to maintain cerebral perfusion. The relevance of blood pressure variability and its relationship to disease severity and outcome, however, remain obscure.

METHODS

A total of 115 consecutive patients with aSAH were included for this retrospective analysis of a continuously collected data pool. Demographics, initial clinical severity of aSAH (HH°, mFS), treatment modality, clinical course, and outcome (development of DCI, cerebral infarction, and GOS after 3 months) were recorded. Hemodynamic information-recorded automatically with a frequency of 1/15 min-was analyzed for spontaneous blood pressure increase (SBI) and endogenous persistent hypertension (EPH) after exclusion of iatrogenic factors and relevant co-medication. Subgroup analysis included stratification for day 0-3, 4-14, and 14-21.

RESULTS

SBI and EPH incidence varied from 17 to 84% depending on detection threshold (15-35 mmHg) and time period under scrutiny. Incidence of blood pressure increase correlated with disease severity upon admission (p < 0.05), but the anticipated association with outcome was not observed. SBI and EPH were more likely to occur between day 4 and 14 (p < 0.001), but only early occurrence (day 0-3) was associated with higher incidence of DCI (p < 0.05). Persistent blood pressure elevation between day 4 and 21 was associated with fewer DCI. However, no influence of spontaneous upregulation on clinical outcome after three months was observed.

CONCLUSIONS

Spontaneous hemodynamic upregulation is a frequent phenomenon after aSAH. Our data support the hypothesis that spontaneous blood pressure alterations reflect an endogenous, demand-driven response correlating with disease severity. Early alterations may indicate an aggravated clinical course, while later upregulation in particular-if permitted-does not translate into a higher risk of unfavorable outcome.

[Effect of Hypericin on the Function of the Neuroretina: An Electroretinographic Study]

BACKGROUND

Hypericin is an important component of the Saint John's wort (Hypericum perforatum). It is assumed to inhibit intracellular signalling cascades, which contribute to neoangiogenesis. The phototoxic effect of hypericin on the retina was investigated in human retinal pigment epithelium (RPE); hypericin induces oxidative stress and has also been described to be an inhibitor of Ca(2+) influx channel in cultured RPE cells. The aim of our study is to evaluate the effect of hypericine on the function of the neuroretina.

METHODS

Isolated bovine retinas were perfused with an oxygen saturated nutrient solution (1 mL/min). We exposed the retina to a flashlight of 6.3 mlx every 5 min. The electroretinogram (ERG) was recorded as a transretinal potential using Ag/AgCl electrodes. ERGs were monitored before, during and after hypericin exposure.

RESULTS

In three independent experiments we investigated the effect of hypericin on the amplitude of the b-wave. In our experiments we observed a significant reduction of the amplitude of the b-wave to 87.1 ± 3.5 % (p = 0.02). This reduction was in all our experiments partially reversible. After hypericin wash-out the b-wave amplitude did not recover completely and did not return to the initial value (91.0 ± 5.1 %; not significant). We did not observe a significant effect of hypericin on the implicit time of the b-wave.

CONCLUSION

This study shows for the first time that hypericin influences retinal signal transduction, suggesting that hypericin impairs not only the RPE, but also affects retinal signalling and function.

Ligamentum flavum cyst in the lumbar spine: a case report and review of the literature

Degenerative changes in the lumbar spine can be followed by cystic changes. Most reported intraspinal cysts are ganglion or synovial cysts. Ligamentum flavum pseudocyst, as a cystic lesion in the lumbar spine, is a rare and unusual cause of neurologic signs and symptoms and is usually seen in elderly persons (due to degenerative changes). They are preferentially located in the lower lumbar region, while cervical localization is rare. Complete removal of the cyst leads to excellent results and seems to preclude recurrence. We report the case of a right-sided ligamentum flavum cyst occurring at L3–L4 level in a 70-year-old woman, which was surgically removed with excellent postoperative results and complete resolution of symptoms. In addition, we discuss and review reports in the literature.