Herniation

Chymopapain [9001 -90-6] derived from the latex of the papaya tree, produces improvement in lower back pain and sciatica in the majority (75%) of recipients (185—189) when injected into the lumbar intervertebral disks of patients suffering from herniated disk (the nucleus pulposus). This treatment degrades the proteoglycans of the diseased nucleus pulposus, resulting in shrinkage of the disk and reduction of pressure on the nerve roots (190). 

CoUagenase specifically cataly2es the hydrolysis of coUagen, and is used in debridement of dermal ulcers and bums (191). It, like chymopapain, is also useful in the treatment of herniated lumbar disks (192,193). The rationale for coUagenase treatment in this instance is based on the preponderance of coUagen in herniated disk tissue, and the inabiUty of other en2ymes to dissolve coUagen (194). 

An estimated oral dose of 260 mg endosulfan/kg caused severe seizures in a 43-year-old man, and brain death from cerebral herniation and massive cerebral edema occurred within 4 days of exposure (Boereboom et al. 1998) there were no signs of myocardial infarction and only slight congestion of the heart, but pulmonary congestion and atelectasis were evident at autopsy. 

Human once 260 M (convulsions, cerebral edema, cerebral herniation, sustained epileptic state) Boereboom et al. 1998 Technical... 

Although surgery can improve outcome in patients with imminent infratentorial herniation, the selection of patients, timing of surgery, and the type of surgery is widely disputed and treated differently across institutions. " Following... 

Schwab et al. Stroke 1999 30(5) 1153 Prospective pilot study moderate hypothermia in severe stroke and ICP 25 of 25 tx with hypothermia Hypothermia to 33-34°C with cooling blankets in pts with compete MCA infarct and ICP monitor 44% mortality, all by herniation after secondary rise in ICP after rewarming period. Good control of ICP during hypothermia period. Forty percent rate of pneumonia... 

To date, only nonrandomized smdies of hemicraniectomy in massive hemispheric stroke have been performed. Rieke et al. found that mortality was reduced from 79% in control patients to 34% in those who underwent DC, with a concomitant reduction in poor functional outcome from 95% to 50%. The mean time interval from stroke to surgery was 39 hours in this study, relatively early in the time course, which may have prevented the patients from having secondary injury due to herniation. Schwab et al. reduced mortality with DC to 16%. Both of these studies, however, found that functional outcome was consistently less improved in the elderly population. The Swedish Malignant Middle Cerebral Artery Infarction Study looked at the long-term (median 3.4 years) outcome... 

Many clinicians are concerned about the use of DC for dominant hemisphere strokes, but Kastrau et al. found in a retrospective review of 14 dominant hemisphere stroke patients with aphasia that significant improvement (13/14 patients) was achieved in these preselected younger patients who underwent early poststroke DC. In contrast, a retrospective study by Foerch et al. found that older patients fared quite poorly in terms of functional outcome and quality of life, especially in those with severe neurological deficit at admission. These results were replicated by Curry et al., who also found that younger patients also were more likely to require reoperations for continued herniation. Uhl et al. ° found no prognostic value to the side of infarction in their analysis of 188 patients who underwent DC for massive hemispheric infarction. 

FIGURE 8.3 Massive cerebellar stroke with herniation. 

Intracranial neoplasm, mass lesion, or evidence of cerebral herniation... 

Brain metastases are among the most feared complications of cancer and generally carry a poor prognosis. One serious consequence of brain metastases is elevated intracranial pressure, which can rapidly lead to fatal intracranial herniation and death. Rapid identification of the signs and symptoms of brain metastases is critical to improve long-term outcome and avoid mortality. 

In cases of elevated intracranial pressure (ICP) owing to cerebral herniation, mechanical hyperventilation to decrease the arterial Pco2 down to 25 mm Hg (3.33 kPA) acutely decreases ICP by causing cerebral vasoconstriction. Elevation of the patient bed also may quickly reduce the ICP. It should be noted that these strategies only relieve symptoms and that definitive therapy is still required. 

Mannitol is an agent that may be used in patients with I impending cerebral herniation. Mannitol is an osmotic diuretic that shifts brain osmolarity from the brain to the blood. Doses of 100 g (1-2 g/kg) as an intravenous bolus should be used. Repeated doses typically are not recommended because mannitol may diffuse into damaged brain tissue, leading to rebound increased ICP.21... 

Herniation A protrusion through an abnormal bodily opening. 

If uncontrolled, hyponatremia may cause increased intracranial pressure, brain herniation and death 595... 

The presence of blood in the brain parenchyma causes damage to surrounding tissue through a mass effect and the neurotoxicity of blood components and their degradation products. Compression of tissue surrounding hematomas may lead to secondary ischemia. Much of the early mortality of hemorrhagic stroke is due to an abrupt increase in intracranial pressure that can lead to herniation and death. 

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