Spreadsheet Tools for Quantifying Seepage Flux Across the GW-SW Interface.

Identifying the spatial distribution and magnitude of seepage flux across the groundwater-surface water (GW-SW) interface is critical for assessing potential impairments and restoration alternatives for water bodies adjacent to sites with groundwater contamination. Measurement of the vertical distribution and time-varying characteristics of temperature in sediments provides an indirect way to map out spatial and temporal patterns of seepage flux into surface water. Two spreadsheet-based calculation tools are introduced that implement four one-dimensional analytical solutions to calculate the magnitude and direction of seepage flux based on measurement of steady-state vertical temperature profiles or transient diel temperature signals at two depths within sediment. Performance of these calculation tools is demonstrated for a pond receiving contaminated groundwater discharge from an adjacent landfill. Transient versus steady-state model performance is compared, and limitations of transient modelsare illustrated for a situation with unfavorable sediment characteristics and inadequate sensor spacing. The availability of a range of analytical solutions implemented within Microsoft Excel® is intended to encourage practitioners to explore use of this seepage flux characterization method and develop greater insight into best practices for model selection and use.

Magnetic resonance imaging of intracranial hypotension syndrome with pathophysiological correlation.

OBJECTIVE: To correlate the pathophysiology of intracranial hypotension syndrome with abnormalities in the brain and spine found through magnetic resonance imaging. METHODS: In a series of 11 patients with intracranial hypotension syndrome, brain magnetic resonance scans were evaluated for the thickness, distribution, morphology, and pattern of meningeal enhancement coincident with subdural fluid collections and the descent of the brain toward the skull base. Spinal magnetic resonance studies were reviewed for extra-arachnoid fluid collections, meningeal enhancement, and distended epidural veins. RESULTS: Diffuse, continuous dural-arachnoid enhancement was present in all patients with abnormal brain studies. The dura was thickest in patients with very low intracranial pressures. Subdural fluid collections and descent of the brain were seen in patients with the thickest meninges and were not present in the absence of meningeal enhancement. Extra-arachnoid or paraspinal fluid collections were found in all patients who had spinal magnetic resonance scans. CONCLUSIONS: In the brain, diffuse dural-arachnoid enhancement is the most common imaging abnormality and is probably the earliest magnetic resonance manifestation of intracranial hypotension syndrome, while subdural fluid collections and descent of the brain are indicators of a more severe hypotensive state. Extra-arachnoid fluid collections are common spinal imaging abnormalities.

Gamma knife treatment of refractory cluster headache.

Four men and two women were treated for refractory cluster headache by gamma knife radiosurgery of the trigeminal nerve root entry zone. The maximum dose of radiation was 70 Gy to the isocenter. Of five patients treated who had refractory chronic cluster headache and one with refractory episodic cluster headache, four had relief judged excellent. Of the two remaining patients with refractory chronic cluster headache, one had relief judged good and the other fair. Five of the six patients treated had relief within a few days to a week following gamma knife radiosurgery. Three with chronic cluster headache had remissions allowing cessation of all preventive and abortive medication. Although one patient experienced complete relief of chronic cluster headache, he continued to have migraine requiring medication. None of the patients treated developed significant postradiation side effects during a follow-up period of 8 to 14 months. The authors conclude that gamma knife radiosurgery of the trigeminal nerve affords great promise in the management of chronic and refractory cluster headache. The technique seemingly carries negligible short- and long- term risk.

Geographical change in residential care provision for the elderly in England, 1988-93.

This paper offers an investigation of the spatial consequences of changes in the structural organization of residential care in England between 1988 and 1993. Data from various government publications were analysed using descriptive and spatial statistical methods. While the study period witnessed an overall levelling of residential care growth, the independent (i.e. private and voluntary) sector's share of all elderly residents in England increased from 56% to 73%. At both national and intra-regional scales, the structural changes resulted in an increasing geographical concentration of public sector residents and a moderate trend towards a more uniform spatial distribution of private residents.

Continuous intravenous dihydroergotamine in the treatment of intractable headache.

We reviewed data on 171 patients with refractory headache treated by continuous intravenous dihydroergotamine mesylate (i.v. DHE 45) and repetitive i.v. DHE and compared the efficacy of continuous i.v. DHE to repetitive i.v. DHE. One hundred (58.5%) patients had refractory chronic daily headache. Seventy-one (42%) had drug rebound headache. One hundred thirty-eight (81%) had refractory migraine without aura, and 28 (16%) had migraine with aura. Treatment consisted of either continuous i.v. DHE by infusion pump or repetitive i.v. DHE and withdrawal of excessively used analgesics, analgesic narcotics, ergotamines, or benzodiazepines. Eighty-nine (92.5%) patients treated with continuous i.v. DHE became headache-free; the majority, 62 (64.5%), within 3 days. Sixty-five (86.5%) patients treated by repetitive i.v. DHE became headache-free, 50 (66.5%) within three days. The average hospital stay for both treatment groups was 4 days. Twelve (12.5%) of the continuous group and 12 (16%) of the repetitive group were headache-free within 24 hours. The average length of time to become headache-free was similar for the two groups, 3.06 days for continuous i.v. DHE and 2.94 days for repetitive i.v. DHE. The most common side effect was nausea, followed by diarrhea, vomiting, and leg cramps. We conclude that DHE can be accurately and easily administered by continuous i.v. infusion pump, and that continuous i.v. DHE is a safe and efficacious mode of treatment producing results similar to repetitive i.v. DHE.

Thermography in the diagnosis of headache.

We reviewed thermograms of 993 suitable patients with migraine with and without aura, chronic daily headache, cluster headache, posttraumatic headache, and a variety of other headache types. Eight hundred fifty-five (86.1%) had abnormal thermograms usually characterized by decreased supraorbital thermal emission. Six hundred ninety-four (69.9%) of 993 had migraine without aura of whom 593 (85.4%) had abnormal thermograms. Two hundred two (20.3%) of 993 had migraine with aura, of whom 180 (89.1%) had abnormal thermograms. Thirty of 35 (85.7%) patients with cluster headache, and 28 of 33 (84.8%) with posttraumatic headache had abnormal thermograms. Twenty-four of 29 (82.8%) of patients with various less common headaches and head pain syndromes had abnormal thermography. Previous studies have indicated that about 67 to 84% of patients with migraine have abnormal thermograms. Some reports have indicated fewer have thermal asymmetries in migraine without aura, and even fewer with "mixed or muscle contraction" headaches. Our study indicates a somewhat greater number of headache patients have abnormal thermograms than has generally been reported. We conclude digital infrared thermography is a useful diagnostic test in the management of headaches.

Fiorinal with codeine in the treatment of tension headache--the contribution of components to the combination drug.

The contribution of the Fiorinal and codeine phosphate components to the effectiveness of the Fiorinal with Codeine combination in the treatment of tension headache symptoms was evaluated in a randomized, placebo-controlled, multicenter double-blind study. Patients admitted to the trial took two capsules of Fiorinal with Codeine, Fiorinal alone, codeine alone, or placebo during each of two tension headache attacks. Immediately before and at intervals up to four hours after drug ingestion, patients rated pain severity, pain relief, the tense and uptight feeling, and muscle stiffness. The response to treatment was evaluated in 154 patients. Despite a high placebo response, a factor known to obscure the contribution of components, Fiorinal and codeine were each found to contribute significantly to the therapeutic effect of the Fiorinal with Codeine combination. Statistical or borderline superiority of the combination drug over Fiorinal alone was seen most frequently at the early evaluations, a finding that reflected the rapid onset of action of codeine. Statistically significant differences between Fiorinal with Codeine and codeine alone seen principally at the later assessments reflected the long duration of action of the Fiorinal component. The frequency of adverse reactions did not differ significantly among the four study groups.