Oral and oropharyngeal tumors.

There is a large variability of tumors and tumor-like lesions, which are located in the oral cavity and oropharynx. But more than 90% of all tumors in this area are squamous cell carcinomas (SCCs). Other malignancies in this location are rare. About 10% of all oral and oropharyngeal tumors are benign. Congenital lesions, like vascular malformations, lingual thyroid or (epi-)dermoid cyst, usually become present in youth or childhood. Acquired lesions can be inflammatory (abscess) or neoplastic (pleomorphic adenoma and hemangioma). Preferred imaging in childhood are ultrasound and magnetic resonance imaging (MRI), while in adults usually computed tomography (CT) and MRI are more frequently used.

Regional cerebral glucose metabolism in anorexia nervosa measured by positron emission tomography.

Regional cerebral glucose metabolism was measured in five female anorectic patients, during the anorectic state and after weight gain, using the fluorodeoxyglucose method and positron emission tomography. In addition, these results were compared with those of 15 young male normals. During the anorectic state, significant caudate hypermetabolism was found bilaterally, unlike the finding in repeat measurements or in male normals. In some other brain structures (temporal cortex, lentiform nucleus, thalamus, and brainstem), significant hypermetabolism was also found during the anorectic state, but these results were not concordant for both sides and in both comparisons. There was no difference between patients after improvement and young male normals.

Anatomical-functional correlation using an adjustable MRI-based region of interest atlas with positron emission tomography.

A procedure is described for combining anatomical information from magnetic resonance imaging (MRI) or computerized tomography (CT) and functional information from positron emission tomography (PET) in a rapid fashion. MRI data are combined with a procedure for the definition, storage, and recall of anatomically based regions of interest. An atlas of standard regions of interest, defined for a set of 18 parallel planes spaced at 6-mm intervals, provides an initial region of interest template for each patient slice. Global adjustments to scale, orientation, and position are applied to obtain an initial match. Individual regions of interest may then be moved, deleted, or redrawn as needed. The ability to store region of interest templates ensures reproducibility of analysis over long periods and introduces a standardization of analysis technique. In 25 brain structures, the mean coefficient of variation in cerebral glucose utilization rate (CMRGlc) measurements among five neuroanatomically trained observers was reduced from 8.1% for manual region of interest definition to 4.0% using the template approach with MRI. Template analysis for space-occupying lesions such as tumors or infarcts is illustrated with PET data from a stroke study, emphasizing the facility for rapid, reproducible analysis of multifunctional studies. MRI-PET matching for a structurally intact caudate nucleus having reduced CMRGlc in Huntington's disease emphasizes the accuracy of anatomical localization required to quantify small structures.

Comparative analysis of regional brain blood flow and glucose metabolism in focal cerebrovascular disease measured by dynamic positron emission tomography of fluorine-18-labelled tracers.

Regional cerebral blood flow (rCBF) and glucose metabolism (rCMRglc) were measured in 44 patients with various kinds of focal vascular brain lesions, using multislice positron emission tomography (PET). Haemodynamic data were obtained by a recently developed, non-invasive clearance method utilizing (18F)-methyl fluoride as a diffusible, gaseous indicator. Shortly after completion of each flow study, rCMRglc was dynamically determined by standard procedures using 2(18F)-fluorodeoxyglucose. While blood flow and glucose consumption in the structurally damaged area were often uncoupled during the acute phase, metabolism-to-flow ratios were markedly less scattered at later stages of cerebrovascular disease. Individual maximum-likelihood cluster analysis of brain regions revealed remarkable similarity between deactivation patterns of rCBF and rCMRglc, with Tanimoto coefficients averaging 0.56. This similarity was inversely related to the residual rCMRglc of the lesion. These findings are in line with results obtained by PET of other tracers, suggesting that the pair of methods provides valuable and somewhat complementary information on brain function and mechanisms of cerebral vascular disease.

Quantitation of lymphocyte subsets in cerebrospinal fluid and blood during the clinical course of aseptic and bacterial meningitis.

Mononuclear cell subsets in cerebrospinal fluid (CSF) and peripheral blood (PB) were monitored during the clinical course in 23 patients with acute meningitis using 6 monoclonal antibodies. Significant differences between aseptic and bacterial meningitis mainly consisted of a higher percentage of OKT4-positive cells in PB in the acute phase of bacterial meningitis. Significant differences between CSF and PB are found in the amount of most cell subtypes at all times except the acute phase of bacterial meningitis. The OKT4/OKT8 ratio was always significantly higher in CSF and correlated with the acuity of inflammation in bacterial meningitis.

[Cerebral glucose metabolism in presenile dementia of the Alzheimer type--follow-up of therapy with muscarinergic choline agonists]. / Zerebraler Glukosestoffwechsel bei präseniler Demenz vom Alzheimer-Typ--Verlaufskontrolle unter Therapie mit muskarinergem Cholinagonisten.

In 8 patients who had clinically diagnosed presenile dementia (Alzheimer's disease) the cerebral glucose metabolism was repeatedly determined via FDG-PET under therapy with a muscarinergic choline agonist. The pattern of glucose metabolism disturbance characteristic of Alzheimer's disease, which had been determined previously by examining the metabolism, was confirmed. Whereas the total cortical glucose metabolism was significantly reduced, the regions of the parietal and the adjacent regions of the temporal and occipital association cortex were preferably affected. The primary somatosensory and visual cortex were largely excepted from the reduction in metabolism or showed slightly enhanced metabolic rates, as for example the cerebellum. The disturbance was not equilaterally pronounced and correlated with the neuropsychological deficiency. Despite biochemically "on target" therapy the glucose metabolism decreased progressively (mean value with large interindividual and intraindividual variations. No relationship between the degree of reduced metabolism and the clinical pattern was seen. Rather, it appears that the clinical pattern is much more strongly influenced by mutual adjustment of metabolic differences in various areas of the brain. Results obtained by the authors are communicated besides a review of update knowledge and interpretation of pathophysiological and biochemical linkups in Alzheimer's disease, taking into consideration the glucose metabolism studies published in the literature.

Positron emission tomography in depression research: principles--results--perspectives.

At present, PET is the only technology affording the quantitative, three-dimensional imaging of various aspects of brain function. In the few PET studies of mood disorders performed so far, usually cerebral glucose metabolism was investigated by the fluorodeoxyglucose method. Its largest individual diagnostic potential was demonstrated in certain forms of organic depression, while metabolic abnormalities in major unipolar and bipolar depression were more subtle--albeit significantly different. Other PET tracers for investigation of transmitter systems are available, but have not been systematically applied in depression research.

[Symptomatic biliary stones at the lower end of the common duct following hepaticoduodenostomy]. / Symptomatische Steine im distalen Ductus-choledochus-Stumpf nach Hepatikoduodenostomie.

A 66-year-old patient developed episodes of severe pain due to recurrent cholangitis and pancreatitis. 2 years prior to this referral the patient had undergone an end-to-side hepaticoduodenostomy and a cholecystectomy because of choledocholithiasis and obstructive jaundice. 20 years previously a Billroth II operation had been carried out for the treatment of ulcer disease. Since the hepaticoduodenostomy the patient has suffered from recurrent epigastric pain, nausea and postprandial vomiting. An oedematous pancreatitis following a recurrent chronic cholangitis was assumed. As the intrahepatic biliary ducts appeared to be normal on radiological studies and hepatobiliary scintigraphy showed a downright transit of the tracer, recurrent cholangitis appeared at first to be a rather unlikely explanation. However, follow-up MRI and MRCP showed large calculi at the lower end of the common duct, which was also enlarged up to 1 cm. For this reason an open duodenotomy with subsequent papillosphincterotomy and retrograde choledochoscopy was carried out. The diagnosis was confirmed hereby and all calculi were removed during the operation. Since then the patient has been free of symptoms and complaints. This case shows that remaining calculi at the lower end of the common bile duct can cause severe clinical problems. Therefore the bile ducts should be inspected endoscopically and stones removed prior to, or during the primary operation.

[Diagnosis and prognosis of acute cerebellar infarcts. A retrospective study]. / Zur Diagnostik und Prognose von akuten Kleinhirninfarkten. Eine retrospektive Studie.

37 patients with acute cerebellar infarction were analysed retrospectively. Diagnosis of cerebellar infarction cannot be made by clinical symptoms alone rather together with CT and MRT displaying the localisation and size of the lesion. Evoked potentials do predict clinical outcome more accurately than EEG or doppler sonography do.

Effect of nimodipine on glucose metabolism in the course of ischemic stroke.

We investigated the effect of the calcium channel-blocking agent nimodipine on regional cerebral metabolic rate of glucose in acute ischemic middle cerebral artery infarction diagnosed clinically and by computed tomography. Twenty-seven patients entered the study within 48 hours after onset of symptoms and randomly received either nimodipine (2 mg/hr constant intravenous infusion for 5 days, 120 mg/day orally for another 16 days) or placebo. Four of the 27 patients died within the first 3 weeks and could not be evaluated. Of the remaining 23 patients, 11 were assigned to the nimodipine group and 12 to a control group. We analyzed data from positron emission tomography, performed twice before and after completion of therapy, and clinical data from the treatment period and the next 6 months based on the Mathew Score for early assessment and the Barthel Index for late assessment. During the post-treatment period, two patients from the nimodipine group and three from the control group died. The evaluated patients were comparable for age and sex distribution, initial clinical deficit, and infarct size and localization. We found significant metabolic changes between both treatment groups for contralateral infarct mirror region, ipsilateral and contralateral cerebral gray matter, and contralateral and ipsilateral cerebellar hemispheres (side x region x treatment interaction p less than 0.025). The nimodipine group had bilaterally increased regional cerebral metabolic rate of glucose of morphologically intact cerebral (14.6% and 17.1%, respectively) and cerebellar structures (6.9% and 10%, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

[Doctor reports of a neurological clinic in the view of permanent resident neurologists and nerve doctors]. / Arztbriefe neurologischer Kliniken in der Sicht niedergelassener Neurologen und Nervenärzte.

Eight discharge reports involving five diagnoses (anterior territory ischemic stroke, epilepsy, Parkinson's syndrome, multiple sclerosis, polyneuropathy) from five neurological departments were peer-reviewed by five neurologists working in out-patient (private) practice. The review considered the diagnosis, case history, clinical status, laboratory investigation, differential diagnosis and treatment. Criticism mainly involved the quality of the clinical assessment, lack of clinical status at discharge, narrow or incomplete differential diagnosis and the quality of the neurophysiological investigations for epilepsy and polyneuropathy. Improvement potential was seen for the speed of reporting, better comprehensibility, omission of irrelevant information, greater participation of experienced neurologists in report writing, and standardization.

Generalized decrease in brain glucose metabolism during fasting in humans studied by PET.

In prolonged fasting, the brain derives a large portion of its oxidative energy from the ketone bodies, beta-hydroxybutyrate and acetoacetate, thereby reducing whole body glucose consumption. Energy substrate utilization differs regionally in the brain of fasting rat, but comparable information has hitherto been unavailable in humans. We used positron emission tomography (PET) to study regional brain glucose and oxygen metabolism, blood flow, and blood volume in four obese subjects before and after a 3-wk total fast. Whole brain glucose utilization fell to 54% of control (postabsorptive) values (P less than 0.002). The whole brain rate constant for glucose tracer phosphorylation fell to 51% of control values (P less than 0.002). Both parameters decreased uniformly throughout the brain. The 2-fluoro-2-deoxy-D-glucose lumped constant decreased from a control value of 0.57 to 0.43 (P less than 0.01). Regional blood-brain barrier transfer coefficients for glucose tracer, regional oxygen utilization, blood flow, and blood volume were unchanged.