Pre-operative DTI and probabilisitic tractography in four patients with deep brain stimulation for chronic pain.

This study aimed to examine, using diffusion tensor imaging (DTI), differences in electrode placement in four patients undergoing deep brain stimulation for chronic neuropathic pain of varying aetiology. A pre-operative DTI was obtained for each patient, who was then implanted with deep brain stimulation electrodes in the periventricular/periaqueductal grey area with good pain relief. Using seeds from the postoperative MRI scan, probabilistic tractography was performed from the pre-operative DTI.

Preoperative DTI and probabilistic tractography in an amputee with deep brain stimulation for lower limb stump pain.

This study aimed to find out whether preoperative diffusion tensor imaging (DTI) and probabilistic tractography could help with surgical planning for deep brain stimulation in the periaqueductal/periventricular grey area (PAG/PVG) in a patient with lower leg stump pain. A preoperative DTI was obtained from the patient, who then received DBS surgery in the PAG/PVG area with good pain relief. The postoperative MRI scan showing electrode placement was used to calculate four seed areas to represent the contacts on the Medtronic 3387 electrode. Probabilistic tractography was then performed from the pre-operative DTI image. Tracts were seen to connect to many areas within the pain network from the four different contacts. These initial findings suggest that preoperative DTI scanning and probabilistic tractography may be able to assist surgical planning in the future.

Connectivity of an effective hypothalamic surgical target for cluster headache.

The purpose of this study was to look at the connectivity of the posterior inferior hypothalamus in a patient implanted with a deep brain stimulating electrode using probabilistic tractography in conjunction with postoperative MRI scans. In a patient with chronic cluster headache we implanted a deep brain stimulating electrode into the ipsilateral postero-medial hypothalamus to successfully control his pain. To explore the connectivity, we used the surgical target from the postoperative MRI scan as a seed for probabilistic tractography, which was then linked to diffusion weighted imaging data acquired in a group of healthy control subjects. We found highly consistent connections with the reticular nucleus and cerebellum. In some subjects, connections were also seen with the parietal cortices, and the inferior medial frontal gyrus. Our results illustrate important anatomical connections that may explain the functional changes associated with cluster headaches and elucidate possible mechanisms responsible for triggering attacks.

Deep brain stimulation for neuropathic pain.

Deep brain stimulation (DBS) for pain was one of the earliest indications for the therapy. This study reports the outcome of DBS of the sensory thalamus and the periventricular and peri-aqueductal grey area (PVG/PAG) complex for different intractable neuropathic pain syndromes. Forty-seven patients (30 males and 17 females) were selected for surgery; they were suffering from any of the following types of pain: post-stroke neuropathic pain, phantom limb pain, post-herpetic neuralgia, anaesthesia dolorosa, brachial plexus injury and neuropathic pain secondary to neural damage from a variety of causes. Of the 47 patients selected for trial stimulation, 38 patients proceeded to permanent implantation. Patients suffering from post-stroke pain were the most likely to fail trial stimulation (33%), in contrast to individuals with phantom limb/post-brachial plexus injury pain and anaesthesia dolorosa, all of whom underwent permanent implantation. PVG stimulation alone was optimal in 17 patients (53%), whilst a combination of PVG and thalamic stimulation produced the greatest degree of analgesia in 11 patients (34%). Thalamic stimulation alone was optimal in 4 patients (13%). DBS of the PVG alone was associated with the highest degree of pain alleviation, with a mean improvement of 59% (p <0.001) and a > or =50% improvement in 66% of patients. Post-stroke pain responds in 70% of patients. We conclude that the outcomes of surgery appear to vary according to aetiology, but it would appear that the effects are best for phantom limb syndromes, head pain and anaesthesia dolorosa.

The periaqueductal grey area and the cardiovascular system.

In this chapter, we report that blood pressure can be increased or decreased depending on whether an electrode is in ventral or dorsal PAG. We also describe that it is theoretically possible to treat orthostatic hypotension. These are exciting developments not only because they provide an example of direct translational research from animal research to humans but also because they highlight a potential for future clinical therapies. The control of essential hypertension without drugs is attractive because of the side effects of medication such as precipitation of heart failure [10]. Similarly, drug treatment of orthostatic hypotension cannot differentiate between the supine and standing positions and can therefore lead to nocturnal hypertension [22, 29]. A stimulator could be turned off at night or contain a mercury switch that reacts to posture.

Deep brain stimulation: a new treatment for hypertension?

We report a 61-year-old hypertensive man who underwent deep brain stimulation of the periventricular/periaqueductal grey area for the relief of chronic neuropathic pain affecting his oral cavity and soft palate. During intraoperative stimulation, we were able to modulate his blood pressure up or down, depending on electrode location. This is the first evidence that hypertension could be effectively treated with electrical stimulation of the midbrain.

Deep brain stimulation for neuropathic cephalalgia.

The aim of this study was to determine the efficacy of deep brain stimulation (DBS) in the treatment of various types of intractable head and facial pains. Seven patients underwent the insertion of DBS electrodes into the periventricular/periaqueductal grey region and/or the ventroposteromedial nucleus of the thalamus. We have shown statistically significant improvement in pain scores (visual analogue and McGill's) as well as health-related quality of life (SF-36v2) following surgery. There is wide variability in patient outcomes but, overall, DBS can be an effective treatment. Our results are compared with the published literature and electrode position for effective analgesia is discussed.

Continuous subcutaneous glucose monitoring in children with type 1 diabetes.

PURPOSE: To determine whether the use of continuous subcutaneous glucose monitoring will help in detecting unrecognized nocturnal hypoglycemia and in lowering hemoglobin A1c (HbA1c) levels (without increasing the risk for severe hypoglycemia) in children with type 1 diabetes. METHODS: Eleven children with type 1 diabetes and HbA1c values consistently >8.0% were randomized either to the Continuous Glucose Monitoring System (CGMS) group or to the control group. The CGMS group used 6 3-day sensors within a 30-day period. Both groups self-monitored their blood glucose levels a minimum of 4 times daily. HbA1c levels were measured at the start, at 1-month, and after 3 months of study. RESULTS: The 5 children using the CGMS had 17 asymptomatic episodes (85%) of glucose levels below 60 mg/dL (3.25 mmol/L) and 3 symptomatic episodes (15%) during the night in the study month. The 6 control children had 4 symptomatic nocturnal low episodes during the month. After the 30-day period of wearing the CGMS, the 5 children had a significantly lower mean HbA1c value compared with their initial value (mean +/- standard error of the mean [SEM] decrease =.36% +/-.07%). The mean decrease for the controls was.2% +/-.2%. After 3 months, 4 of the 5 children who used the CGMS continued to have lower HbA1c values in comparison to their initial values (mean +/- SEM decrease = 1.04% +/-.43%). Three of the 6 control participants also had lower HbA1c values at 3 months (mean +/- SEM decrease for the group =.62% +/-.44%). No severe hypoglycemic events occurred in either the CGMS or the control groups. CONCLUSION: In this pilot trial, continuous subcutaneous glucose monitoring was helpful in detecting asymptomatic nocturnal hypoglycemia as well as in lowering HbA1c values without increasing the risk for severe hypoglycemia in children with type 1 diabetes.

Impact of cost problems on morbidity in a hypertensive population.

Researchers disagree about the extent to which limited access to health services negatively affects health. In this study, we investigated the association of health status with access to high blood pressure medication among hypertensive respondents drawn from two random household surveys conducted in the state of Georgia during 1981 and 1983. We compared hypertensive respondents reporting difficulties in paying for medication (n = 616) with hypertensive respondents not reporting cost problems (n = 616) who were matched on race, sex, age (+/- 3 years), and per capita family income (+/- $3,000). Because questions were not identical in the 1981 and 1983 surveys, we compared responses of the matched groups separately for each year in the analysis. In the 1981 comparison, a significantly higher (P less than .05) percentage of hypertensive individuals experiencing cost problems reported being in fair or poor health (60.5%) and having had a stroke (11.4%) than those without cost problems (39% for fair or poor health status and 5% for occurrence of stroke). Those with cost problems also reported a higher frequency of cardiac problems (24.6%) than those without cost problems (18.1%), although these differences are not statistically significant (P greater than .05). In the 1983 survey, a significantly larger number of those with cost problems (57.4%) reported being in fair or poor health than those without cost problems (43.1%, P less than .05).

In situ and slot hybridization analysis of RNA in colorectal tumours and normal colon shows distinct distributions of mitochondrial sequences.

cDNA clones of mRNAs with an abnormal abundance in familial adenomatous polyposis were used to examine the levels and distribution of the mRNAs in tissues from 15 patients with colorectal cancer. Of 12 cloned sequences studied by slot hybridization, one was substantially reduced in tumours compared with normal tissue. Sequence analysis showed this to code for IgA. In situ hybridization was consistent with slot hybridization and immunohistochemistry. Two mitochondrially encoded sequences had distinct distributions detected by in situ hybridization but did not have detectable quantitative differences in whole tumour or mucosa extracts.

Selecting and recruiting health programs for the School Health Education Evaluation.

The School Health Curriculum Project (SHCP) and three promising health education approaches, Project Prevention, 3 Rs and High Blood Pressure (HBP), and Health Education Curriculum Guide, were the curricula used in the School Health Education Evaluation (SHEE) project. This paper contains program descriptions of each, and a brief description of the process that led to their selection. Inclusion of the School Health Curriculum Project (SHCP) was mandated by the use of government funds to support the SHEE. The three alternative curricula, Project Prevention, 3 Rs and High Blood Pressure, and Health Education Curriculum Guide, were selected on the basis of a protocol devised jointly by contractors, government project officers, and the project advisory panel.

Comprehensive school health education: a practical definition.

This article identifies 10 essential elements of comprehensiveness related to school health education that have been agreed upon by key personnel long involved in one or more of the four school health curriculum programs studied in the School Health Education Evaluation (SHEE) study. Each element is briefly described and followed with one or two examples of practical applications selected from the four curricula. The authors further concur with the concept that a Consumer Reports type of reporting of school health curriculum models might be useful in further SHEE data analysis and that the "elements of comprehensiveness" concept might be a valuable adjunct to such reporting.