Role of diffusion-weighted imaging and in vivo proton magnetic resonance spectroscopy in the differential diagnosis of ring-enhancing intracranial cystic mass lesions

OBJECTIVES: Proton magnetic resonance spectroscopy (PMRS) and diffusion-weighted imaging (DWI) were compared to determine which technique is more effective in the differential diagnosis of cystic intraparenchymal ring-enhancing lesions with variable perifocal edema. METHODS: Fifty-two patients (abscesses [n = 29], tumor cysts [n = 20], and benign cysts [n = 3]) formed the basis for comparative evaluation in this study. The criteria for abscess diagnosis were apparent diffusion coefficient (ADC) values less than 0.9 +/- 1.3 x 10 mm/s and presence of lactate cytosolic amino acids (AAs) with/without succinate, acetate, alanine, and glycine on PMRS. Criteria for nonabscess cyst identification were ADC values of 1.7-3.8 x 10 mm/s and presence of lactate and choline on PMRS. On the basis of these criteria, patients were categorized into abscess (n = 29) and nonabscess (n = 23) groups. Sensitivity and specificity of PMRS and DWI with respect to the final diagnosis were calculated based on the efficacy of these techniques. RESULTS:: Apparent diffusion coefficient values in 21 patients with abscesses were observed within the range of defined criteria, whereas in 8 patients, ADC values were beyond the range of defined criteria. Lactate and AAs with or without other metabolites were observed in 25 of 29 cases of abscesses on PMRS. In the nonabscess group, ADC values of cystic lesions in all patients were consistent with respect to the defined criteria. Only lactate was seen in 14 of 23 patients, whereas both lactate and choline were visible in 6 patients. In 3 patients with neurocysticercosis, AAs (n = 2), lactate (n = 3), acetate (n = 1), succinate (n = 3), choline (n = 2), and alanine (n = 3) were seen. The sensitivity of DWI and PMRS for differentiation of brain abscess from nonbrain abscess was 0.72 and 0.96, respectively, whereas the specificity was 1 for both techniques. CONCLUSION: Demonstration of restricted diffusion on DWI with reduced ADC is highly suggestive of brain abscess; however, in the absence of restriction, PMRS is mandatory to distinguish brain abscesses from cystic tumors.     

Bilateral stimulation of the subthalamic nucleus in Parkinson's disease: surgical efficacy and prediction of outcome

OBJECTIVE: Over the last decade neurosurgery has reemerged as a valid therapy for patients with advanced Parkinson's disease. Previously, we have addressed safety and efficacy of subthalamic nucleus (STN) deep brain stimulation (DBS). In this study, we extended these observations and analyzed factors that affect surgical outcome and its predictive value. METHODS: Thirty-nine patients were enrolled in an open-label prospective protocol designed to evaluate safety and efficacy of bilateral STN DBS in patients with advanced Parkinson's disease between January 1999 and July 2002. Electrodes were stereotactically implanted with electrophysiological conformation of the target location. All patients were evaluated in the medication 'off' and 'on' state preoperatively and at 3, 6, and 12 months after surgery in medication 'on' and 'off' as well as in the stimulation 'off' and 'on' state. Tests included Unified Parkinson's Disease Rating Scales (UPDRS) as well as timed tests. All data was analyzed by means of Analysis of Variance. For outcome prediction, correlation and linear regression analyses were utilized. Stimulation produced significant improvements in all 'off' mediation conditions, resulting in a 42% improvement in UPDRS III score at 12 months compared to the preoperative status. Stimulation in conjunction with medication did not produce any significant change when compared to the preoperative medication 'on' state. Dyskinesia, motor fluctuations, and duration of 'off' periods were significantly reduced with stimulation. Significant outcome predictor variables were age, preoperative percent change of UPDRS III score from medication 'off' to medication 'on' state, and the duration of disease. CONCLUSIONS: Bilateral STN DBS produces robust improvements in parkinsonian motor symptoms. Surgical outcome can reliably be predicted.     

Administration of N-acetylcysteine after focal cerebral ischemia protects brain and reduces inflammation in a rat model of experimental stroke

Free radicals and inflammatory mediators are involved in transient focal cerebral ischemia (FCI). Preadministration of N-acetylcysteine (NAC) has been found to attenuate the cerebral ischemia-reperfusion injury in a rat model of experimental stroke. This study was undertaken to investigate the neuroprotective potential of NAC administered after ischemic events in experimental stroke. FCI was induced for 30 min by occluding the middle cerebral artery (MCA). NAC (150 mg/kg) was administered intraperitoneally at the time of reperfusion followed by another dose 6 hr later. Animals were sacrificed after 24 hr of reperfusion. The cerebral infarct consistently involved the cortex and striatum. Infarction was assessed by staining the brain sections with 2,3,5-triphenyltetrazolium chloride. Animals treated with NAC showed a significant reduction in infarct area and infarct volume and an improvement in neurologic scores and glutathione level. Reduction in infarction was significant even when a single dose of NAC was administered at 6 hr of reperfusion. Immunohistochemical and quantitative real-time PCR studies demonstrated a reduction in the expression of proinflammatory cytokines such as tumor necrosis factor alpha (TNFalpha) and interleukin 1beta (IL-1beta) and inducible nitric oxide synthase (iNOS) in NAC compared to that in vehicle-treated animals. The expression of activated macrophage/microglia (ED1) and apoptotic cell death in ischemic brain was also reduced by NAC treatment. These results indicate that in a rat model of experimental stroke, administration of NAC even after ischemia onset protected the brain from free radical injury, apoptosis, and inflammation, with a wide treatment window.     

Three-in-one weight,height and body mass index charts for children and adults

The aim of the study was to develop four appropriate three-in-one weight, height and built in body mass index (BMI) charts, for under-fives, 0-5-year-olds, > 5-10-year-olds, > 10-18-year-olds, and adults and to delineate the normal range, underweight, overweight and obesity on the above charts. Four different charts were designed for the various age groups as indicated above. Height was made available on the x-axis, weight on the y-axis, and corresponding BMI values on the right margin. Shading of the normal range to denote the health path and marking of the cut-off curves to denote normal status, overweight, and obesity were done selecting appropriate round figures to suit both sexes in accordance with the International Obesity Task Force (IOTF) recommendations for the various age groups. Field trials were done on appropriate subjects belonging to various age groups. 500 in each group with equal male to female ratio. The field trials showed that all the studied subjects belonging to both sexes came within the purview of the chart and those with normal nutritional status, underweight, overweight, and obesity could easily be identified looking at the chart without doing any further calculation. Early intervention also could be advised as the chart could demonstrate how much weight should be gained or reduced to come within the health path. In conclusion, the charts are applicable to both sexes and are user friendly. These are appropriate for general screening of nutritional status and to determine underweight, overweight, and obesity from birth to adulthood. They give a visual display of the ideal health path with respect to weight, height, and BMI and the adjustment in weight required to reach the normal range.     

Abdominal compartment syndrome related to noninvasive ventilation

OBJECTIVE: To study the effects of noninvasive positive pressure ventilation (NIPPV) on intra-abdominal pressure. DESIGN AND SETTING: Single case report from a tertiary teaching hospital. PATIENTS AND METHODS: A 65-year-old man who experienced a sudden respiratory and cardiovascular collapse during NIPPV. This was caused by gastric overdistension due to aerophagia followed by raised intra-abdominal pressure leading to intra-abdominal hypertension and abdominal compartment syndrome. RESULTS: The respiratory and cardiovascular problems resolved immediately after the introduction of a nasogastric tube. This resulted in normalization of IAP. CONCLUSIONS: This is the first case reported of an abdominal compartment syndrome related to NIPPV. Clinicians should be aware of this possible complication while using NIPPV.     

Modified glasgow coma scale to predict mortality in febrile unconscious children

A prospective hospital based study was conducted in the Department of Pediatrics of the Kasturba Hospital, Mahatma Gandhi Institute of Medical Sciences, Sevagram, Wardha to predict the mortality in children admitted with fever and unconsciousness using the Modified Glasgow Coma Scale (MGCS) score. Forty eight children were admitted with fever and unconsciousness; cases of febrile convulsions, epilepsy and cerebral palsy were excluded. MGCS scores were assessed on admission and repeated at 12 hours, 24 hours, 48 hours and 72 hours after admission in each case. Diagnosis in each case was confirmed by history, examinations and investigations. All the cases were regularly followed up till death/discharge. The overall mortality was 29.1% (14/ 48) out of which 85% (12/14) died within the first 24 hours. Mortality was highest in the toddler age group and in patients with pyogenic meningitis. There was a significant association between death and MGCS scores on admission with a post test probability for discharge being only 10% with a score of less than 5 and 99% with a score of more than 10 respectively. MGCS scores on admission can be used to predict mortality in patients hospitalized with fever and unconsciousness. The scale is simple, easy, can be applied at bed side and does not need any investigations. Its application in developing countries with limited investigative and intensive care facilities can help the treating physician decide regarding referral and counseling the parents regarding the probable clinical outcome.     

Progressive peripheral agraphia

We describe RW, a patient who presented with writing difficulty that deteriorated over time. While her graphemes were typically legible, her writing was extremely slow, and her letters were written in an inconsistent and heterogeneous manner (e.g. each "a" in the word "banana" was produced in a different way). Her mental imagery of letters was impoverished, and she also produced allographic errors in her writing. She had some spelling errors as well, but many of these were due to omissions, perseverations, and motor operations. A positron emission tomography scan demonstrated superior parietal occipital and superior frontal defects that were more evident on the left than the right. Our observations are consistent with the hypothesis that RW has a deficit retrieving physical letter forms as manifested by her heterogeneous and slow production of letter forms. This disruption of grapheme retrieval is associated with interruption of a superior frontal-parietal system in the left hemisphere.