Acute physiological derangement is associated with early radiographic cerebral infarction after subarachnoid haemorrhage

Background

Cerebral infarction after aneurysmal subarachnoid haemorrhage (SAH) is presumed to be due to cerebral vasospasm, defined as arterial lumen narrowing from days 3 to 14.

Methods

We reviewed the computed tomography scans of 103 patients with aneurysmal SAH for radiographic cerebral infarction and controlled for other predictors of outcome. A blinded neuroradiologist reviewed the angiograms. Cerebral infarction from vasospasm was judged to be unlikely if it was visible on computed tomography within 2 calendar days of SAH or if angiography showed no vasospasm in a referable vessel, or both.

Results

Cerebral infarction occurred in 29 (28%) of 103 patients with SAH. 18 patients had cerebral infarction that was unlikely to be due to vasospasm because it was visible on computed tomography by day 2 (6 (33%)) or because angiography showed no vasospasm in a referable artery (7 (39%)), or both (5 (28%)). In a multivariate model, cerebral infarction was significantly related to World Federation of Neurologic Surgeons grade (odds ratio (OR) 1.5/grade, 95% confidence interval (CI) 1.1 to 2.01, p = 0.006) and SAH‐Physiologic Derangement Score (PDS) >2 (OR 3.7, 95% CI 1.4 to 9.8, p = 0.01) on admission. Global cerebral oedema (OR 4.3, 95% CI 1.5 to 12.5, p = 0.007) predicted cerebral infarction. Patients with cerebral infarction detectable by day 2 had a higher SAH‐PDS than patients with later cerebral infarction (p = 0.025).

Conclusions

: Many cerebral infarctions after SAH are unlikely to be caused by vasospasm because they occur too soon after SAH or because angiography shows no vasospasm in a referable artery, or both. Physiological derangement and cerebral oedema may be worthwhile targets for intervention to decrease the occurrence and clinical impact of cerebral infarction after SAH.Subarachnoid haemorrhage (SAH) is a common and serious disorder, affecting approximately 11 in every 100 000 people.¹ Cerebral infarction after SAH is a well‐described complication and is strongly associated with a poor outcome.² Strategies to improve outcome after SAH usually focus on preventing or treating vasospasm.Nimodipine reduces the risk of cerebral infarction after SAH due to vasospasm³; yet, cerebral infarction still occurs and remains a major predictor of poor outcome in multivariate models.⁴ Vasospasm is traditionally defined as arterial narrowing 3–14 days after SAH.⁵ Cerebral infarction after SAH is generally assumed to be due to vasospasm, but causality is difficult to prove in critically ill patients. Radiographic cerebral infarction allows different observers to independently review studies at leisure, but may not be symptomatic. Acute cerebral infarction may be due to the acute effects of haemorrhage and the spike in intracranial pressure, but there are few objectively defined risk factors. We sought to identify patients with cerebral infarction associated with SAH in whom the cerebral infarction was unlikely to be due to vasospasm and to describe novel risk factors for targeted intervention.     

Comparison of hypercapnia‐based calibration techniques for measurement of cerebral oxygen metabolism with MRI

MRI may be used to measure fractional changes in cerebral oxygen metabolism via a metabolic model. One step commonly used in this measurement is calibration with image data acquired during hypercapnia, which is a state of increased CO₂ content of the blood. In this study some commonly used hypercapnia‐inducing stimuli were compared to assess their suitability for the calibration step. The following stimuli were investigated: (a) inspiration of a mixture of 4% CO₂, 21% O₂ and balance N₂; (b) 30‐s breath holding; and (c) inspiration of a mixture of 4% CO₂ and 96% O₂ (i.e., carbogen). Measurements of BOLD and cerebral blood flow made on nine subjects during the different hypercapnia‐inducing stimuli showed that each stimulus leads to a different calibration of the model. We argue that of the aforementioned stimuli, inspiration of 4% CO₂, 21% O₂ and balance N₂ should be preferred for the calibration as the other stimuli produce responses that violate assumptions of the metabolic model. Magn Reson Med 61:391–398, 2009. © 2009 Wiley‐Liss, Inc.     

Carotid artery dissection following a minor household accident in a 10-month-old child

Introduction  

Dissection of the carotid arteries is an important cause of ischaemic stroke in childhood. Rarely, blunt trauma to the soft palate can result in an internal carotid artery (ICA) dissection leading to thrombosis, embolism and stroke.     

Posttraumatic stress disorder symptom severity predicts aggression after treatment

This study examined the relation between posttraumatic stress disorder (PTSD) severity and aggression (verbal, psychological, and physical aggression) in a longitudinal dataset. Participants were 175 males in PTSD residential treatment who were assessed at pre-treatment, post-treatment, and at 4-month follow-up. Post-treatment PTSD severity predicted aggression at post-treatment and 4-month follow-up, adjusting for age, pre-treatment PTSD severity, and pre-treatment aggression. When examining the relation between aggression and specific PTSD symptom clusters, post-treatment Reexperiencing, Avoidance/Numbing and Hyperarousal symptoms predicted aggression at posttreatment and 4-month follow-up. These results support the hypothesis that post-treatment PTSD severity may be an important marker of post-treatment aggression risk and may offer unique information important to clinicians and patients focused on the development and maintenance of adaptive, non-aggressive relationships after intensive PTSD treatment.     

Inhibition of monocyte esterase activity by organophosphate insecticides

Organophosphate insecticides, such as Vapona, Naled, and Rabon, are highly potent inhibitors of an enzyme found in human monocytes. The enzyme, a specific monocyte esterase, could be inhibited by Vapona in blood samples via airborne contamination at levels easily achieved from commercial slow-release insecticide strips. Fifty percent inhibition (I50)--as measured on the Hemalog D (Technicon Corp.)--occurred at solution concentrations of 0.22, 1.5, and 2.6 X 10(-6) g/liter for Vapona, Rabon, and Naled, respectively. Parathion (a thiophosphate) and Baygon (a carbamate) were less potent, with I50 values of 3.7 X 10(-5) and 1.5 X 10(-4) g/liter, respectively. Dursban (another thiophosphate) and Carbaryl (a carbamate) showed only marginal inhibition. Eserine, malathion, nicotine and pyrethrum had no inhibitory effect up to 0.5 g/liter. The occurrence of this effect in vivo has not yet been shown, nor is it clear what the implications of such an effect would be. The inhibition of this enzyme by airborne contaminants, however, may interfere with the proper functioning of the Hemalog D.     

Hairy cell leukemia and myelomatosis: chance association or clinical manifestations of the same B-cell disease spectrum

We describe three patients who had typical features of hairy cell leukemia (HCL) and multiple myeloma (MM) at the same time. In two, both diagnoses were made within a short period of time, and in the third, HCL had been present for 2 yr before the appearance of a paraprotein, bone lesions, and plasma-cell infiltrates established the diagnosis of MM. Although this association has not been previously reported, cases of HCL with osteolytic lesions or a paraprotein band have been described. The cases described may represent clinical manifestations of closely related disorders arising from divergent differentiation from a common B-cell precursor rather than a chance association.     

Percutaneous cecostomy: controlled transperitoneal approach

The authors present two cases of percutaneous cecostomy performed with a modified approach previously described for percutaneous gastrostomy and cholecystostomy. T-fastener devices were used to affix the cecum to the anterior abdominal wall; thus, the potential problem of fecal spillage was prevented. In both cases, adequate fecal drainage was provided without complication.