Given an abstract, generate a keyword (a noun phrase) that best describes the focus or contribution of the paper. Such keywords can be directly from the given abstract or outside it.

[EX Q]: Abstract: A case of a cavernous angioma of the cauda equina is presented. The patient was a 28-year-old man who experienced sudden low-back pain and headache without neurological symptoms. Lumbar puncture revealed subarachnoid hemorrhage. He had suffered a similar episode 3 years previously. Selective spinal angiography did not demonstrate any abnormal vascularity. Metrizamide myelography and magnetic resonance imaging were useful in demonstrating the presence of a tumor. Laminectomy at L1-3 and total removal of the tumor were performed without neurological deficit.
[EX A]: Adult

[EX Q]: Abstract: Seventy-six white and black low-income families were interviewed weekly during 1 month to determine how much they spent on food using Food Stamps, WIC coupons, and cash and how much additional food they obtained from different food and meals programs. After families had received their public assistance and Food Stamp allotments for the month, a 24-hour recall was obtained each week from each family member so that food intake could be monitored from the recalls as food-buying resources were depleted. Although families bought most of their food the first 2 weeks, they maintained a relatively constant food intake through the last week of the month. However, when nutrient intakes were compared with Recommended Dietary Allowances, the diets were found to be well supplied in protein, ascorbic acid, thiamin, niacin, riboflavin, vitamin B-12, vitamin A, and phosphorus, and inadequately supplied in vitamin B-6, vitamin D, vitamin E, iron, calcium, magnesium, zinc, and pantothenic acid. Since that finding was true not just at the end of the month but from the beginning, it indicated that the nutrition problems of low-income families are not intermittent, but continuous.
[EX A]: Adolescence

[EX Q]: Abstract: Two cases of ventriculitis with Staphylococcus epidermidis that failed on therapy with an antistaphylococcal penicillin are presented. Both infections responded to a combination of intravenous and intraventricular vancomycin and rifampin. Vancomycin and rifampin represent an important antibiotic regimen for the management of resistant infections of the central nervous system, especially with those due to S. epidermidis or methicillin-resistant Staphylococcus aureus.
[EX A]:
Antibiotics