A community-based evaluation of proximity to unconventional oil and gas wells, drinking water contaminants, and health symptoms in Ohio

Over 4 million Americans live within 1.6 km of an unconventional oil and gas (UO&G) well, potentially placing them in the path of toxic releases. We evaluated relationships between residential proximity to UO&G wells and (1) water contamination and (2) health symptoms in an exploratory study. We analyzed drinking water samples from 66 Ohio households for 13 UO&G-related volatile organic compounds (VOCs) (e.g., benzene, disinfection byproducts [DBPs]), gasoline-range organics (GRO), and diesel-range organics. We interviewed participants about health symptoms and calculated metrics capturing proximity to UO&G wells. Based on multivariable logistic regression, odds of detection of bromoform and dibromochloromethane in surface water decreased significantly as distance to nearest UO&G well increased (odds ratios [OR]: 0.28-0.29 per km). Similarly, distance to nearest well was significantly negatively correlated with concentrations of GRO and toluene in ground water (r_Spearman: -0.40 to -0.44) and with concentrations of bromoform and dibromochloromethane in surface water (r_Spearman: -0.48 to -0.50). In our study population, those with higher inverse-distance-squared-weighted UO&G well counts within 5 km around the home were more likely to report experiencing general health symptoms (e.g. stress, fatigue) (OR: 1.52, 95%CI: 1.02-2.26). This exploratory study, though limited by small sample size and self-reported health symptoms, suggests that those in closer proximity to multiple UO&G wells may be more likely to experience environmental health impacts. Further, presence of brominated DBPs (linked to UO&G wastewater) raises the question of whether UO&G activities are impacting drinking water sources in the region. The findings from this study support expanded studies to advance knowledge of the potential for water quality and human health impacts; such studies could include a greater number of sampling sites, more detailed chemical analyses to examine source attribution, and objective health assessments.

Long-term outcome of skull base surgery with microvascular reconstruction for malignant disease

BACKGROUND

Successful resection of malignant skull base disease depends implicitly on the ability to reconstruct the resulting defects in the craniovisceral diaphragm, to support neural structures, and to prevent ascending intracranial infections. Microsurgery reliably achieves these objectives and has increased the scope of curative oncologic surgery. The authors assessed the reconstructive results and the long-term oncologic outcome of patients having skull base surgery with free tissue transfer.

METHODS

A retrospective review of cases between 1989 and 2001 was undertaken. Demographics, histology, surgical management, complications, locoregional control, and survival were analyzed.

RESULTS

Predominantly male patients (n = 53; 62 percent) with an average age of 60 years had microvascular reconstruction following oncologic surgery. There was a preponderance of cutaneous malignancies (56 percent), and most lesions involved the anterior skull base (53 percent). Tumors were mostly resected with a combined intracranial or extracranial approach, and reconstruction was undertaken with radial forearm, rectus abdominis, or latissimus dorsi flaps with 94 percent success. Complications occurred in 23 percent of patients, and no specific risk factors for developing intracranial complications were identified. Specifically, extensive reconstructions did not increase the complication rate. The 5-year locoregional control and survival rates were 74 percent and 60 percent, respectively. A positive resection margin significantly increased the risk of locoregional recurrence and worsened disease-specific survival on Cox regression. Survival was also influenced by grade of malignancy.

CONCLUSIONS

Microsurgery is highly reliable for reconstructing defects resulting from oncologic resections of the cranial base. It can and should be undertaken using a small number of highly dependable flaps.

Proximal migration of a lumboperitoneal unishunt system

Proximal migration of a lumboperitoneal (LP) shunt is a rare complication associated with unishunt systems. We report three cases with a hypothesis that raised intra-abdominal pressure may be a factor responsible for the proximal migration of a LP unishunt. A rare case of proximal migration of LP shunt into the quadrigeminal cistern is also reported.

Cranial-base surgery: a reconstructive algorithm

Skull-base surgery is associated with a high risk of cerebrospinal fluid (CSF) leak, infection, and functional and aesthetic deformity. Appropriate reconstruction of cranial-base defects following surgery helps to prevent these complications. Between March 1998 and May 2000, 28 patients (age: 1-68 years) underwent reconstruction of the anterior and middle cranial fossae. The indications for surgery were tumours, trauma involving the anterior cranial fossa, midline dermoid cysts with intracranial extension, late post-traumatic CSF leak, craniofacial deformity and recurrent frontal mucocoele. We used local anteriorly based pericranial flaps (23 flaps, alone or in combination with other flaps), bipedicled galeal flaps (seven patients) and free flaps (nine patients; radial forearm fascial/fasciocutaneous flaps, rectus abdominis muscle flap and latissimus dorsi muscle flap). Follow-up has been 4-24 months. We had no deaths, no flap failure and no incidence of infection. Complications included two CSF leaks, three intracranial haematomas and one pulsatile enophthalmos. All patients had a very good aesthetic result. We present an algorithm for skull-base reconstruction and comment on the design and vascularity of the bipedicled galeal flap. The monitoring of intracranial flaps and the difficulties of perioperative management of free flaps in neurosurgical patients are also discussed.

Delayed cerebral ischaemia: the pathological substrate

Ischaemic complications both at the level of the cortex and the hypothalamus are well recognised after an aneurysmal subarachnoid haemorrhage. We have studied histological changes in the cortex (53 patients) and hypothalamus (48 patients) in patients who died after an aneurysmal subarachnoid haemorrhage. Cortical ischaemic lesions were demonstrated in 41 of the 53 patients studied. These changes were more common in patients who had impaired control of systemic blood pressure (p = 0.0004) and in patients who died gradually (p = 0.0003). Hypothalamic lesions were found in 24 of 48 patients studied; 23 of these patients had widespread associated changes in the cerebral cortex. Patients with moderate/severe cortical changes tended to have hypothalamic lesions and it was uncommon for patients with no cortical lesions to have changes in the hypothalamus (p = 0.0007). We believe that these histological changes are due to diffuse microangiopathy which develops slowly after a subarachnoid haemorrhage and affects the cortex and hypothalamus. Because the cortical lesions are widespread we postulate that they may be implicated in the aetiology of the well described psychosocial or cognitive problems in patients who survive a subarachnoid haemorrhage.

An alternative surgical approach to aneurysms of the posterior cerebral artery

The value of a skull base approach (the transzygomatic approach) is assessed in the treatment of patients with posterior cerebral artery aneurysms. The operative approach is outlined, and the advantages and disadvantages of the procedure are discussed.

A simple scoring system for accurate prediction of outcome within four days of a subarachnoid haemorrhage

This study was designed to examine the consistency of a number of easily identifiable predictive factors in assessing outcome within four days of a subarachnoid haemorrhage. Patients with a proven subarachnoid haemorrhage, aged between 15-65, of any neurological grade who had bled within 72 hours of admission, and who had undergone a CT scan within 96 hours of the ictus, were included. Three groups of patients were studied prospectively. The studies were separated in time and place. The series were similar overall but there were some variations between the three groups of patients because of alterations in referral patterns and management strategies between the series. There were significant differences in the patients' ages, grades on admission, timing of angiography, negative angiography rate and timing of operation. This did not affect overall outcome; 57%, 61% and 59% of the patients in series 1, 2 and 3 respectively making a good recovery. The proportion of patients with a poor outcome was also similar. To identify the level of risk of an individual patient within the first few days of haemorrhage, we considered a number of early predictive factors. Two emerged as strong predictors of outcome; the early neurological grade and the distribution of blood on the CT scan. We developed a simple scoring system from the first series, based on these findings, designed to predict outcome at three months. The scoring system was calculated on the basis of the distribution of blood seen on the CT scan and the patients' neurological grade on admission. Two points each were scored for interhemispheric, intraventricular, basal or intracerebral blood (excluding blood in the sylvian fissures). Patients in grade 1-3 scored -1, grade 4 scored 0, grades 5 & 6 scored +5. The scan score and grade score were summated to give the overall score. Patients were placed in risk groups (low, score -1; medium, score 0-2; high, score 3+). The scoring system was then applied prospectively to the two subsequent groups of patients. In each of the three series there was a clear correlation between the patients' scores and their outcomes but more importantly the probability of each outcome for each risk group was considered. In both the second and third series the probability of a full recovery in the low risk group was very likely--P = 0.000.(ABSTRACT TRUNCATED AT 400 WORDS)

A review of the management of 15 cases of aneurysms of the posterior cerebral artery

The presenting features of 15 cases of posterior cerebral artery aneurysm are discussed. The use of the axial radiographic view in determining the anatomy of these aneurysms is highlighted. Ten out of 15 patients underwent surgery. In three patients the aneurysm was approached by the transzygomatic route, in six via the subtemporal route and in one using the pterional approach. There was no operative mortality. Nine out of 10 patients made good long-term recoveries following surgery, one patient remains moderately disabled. Three out of five patients in the non-surgical group made a good recovery. The advantages and disadvantages of the various operative approaches are discussed with particular reference to ease of access, brain retraction and adequate exposure of the aneurysm. It was possible to clip the aneurysm and spare the parent vessel in all three cases using the transzygomatic approach, but this was possible in only one of the remaining cases.

Changes in the sleep and waking EEGs of nondemented and demented elderly subjects

Sleep and waking EEGs from 11 healthy nondemented elderly men and from ten inpatients for whom the diagnosis was probable senile dementia of Alzheimer's type (SDAT), were monitored in the subjects' typical home or ward environments or in the sleep laboratory, according to their customary sleep schedules. Aged normal subjects (age range, 56-85 years) had less Stage 3 and Stage 4 sleep, less REM sleep, and more wakefulness than normally observed in young adults. Patients with SDAT (age range, 56-88 years) had even less Stage 3 sleep, no Stage 4 sleep, and very little REM sleep, and experienced fragmentation of their sleep, with frequent awakenings. These sleep variables were significantly different in the SDAT and control groups (MANOVA). Examination of the 24-hour plots of sleep/waking patterns revealed prominent fragmentation of the diurnal sleep/waking rhythm in SDAT patients, with frequent daytime napping and nighttime periods of wakefulness. In addition, significant group differences were observed for the EEG variable, dominant occipital frequency. More qualitative EEG variables (diffuse slowing, spindle activity, and paroxysmal discharges) also differed between groups. It is suggested that correlative neuropathologic data might provide an understanding of the basis for the sleep, EEG, and mental-function factors that undergo change in SDAT.

Pimozide versus chlorpromazine in chronic schizophrenia: a 52 week double-blind study of maintenance therapy

This study compared the effectiveness and safety of pimozide and chlorpromazine in the maintenance therapy of chronic schizophrenic outpatients. Forty-three patients were assigned in double-blind fashion to one of the drugs for the 52 week study. Both medication groups showed a general pattern of improvement over the course of the study, but there was no significant difference between the two groups. The results demonstrated the effectiveness and safety of pimozide in once daily administration. Previous research results showing the special utility of pimozide for the improvement of emotional withdrawal and social competence in schizophrenia were not replicated.

Physostigmine in rigid Huntington's disease

Physostigmine, a centrally active anticholihesterase agent, was given to three patients with rigid Huntington’s disease (RHD). Neurologic examinations before, during and after the administration showed no change in the manifestations of RHD. The theoretical implications of these data are discussed.