From over 100 children studied with 2-deoxy-2[18F]fluoro-D-glucose and positron emission tomography we selected 29 children (aged 5 days to 15.1 years) who had suffered transient neurological events not significantly affecting normal neurodevelopment. These 29 children were reasonably representative of normal children and provided an otherwise unobtainable population in which to study developmental changes in local cerebral metabolic rates for glucose (lCMRGlc). In infants less than 5 weeks old lCMRGlc was highest in sensorimotor cortex, thalamus, brainstem, and cerebellar vermis. By 3 months, lCMRGlc had increased in parietal, temporal, and occipital cortices; basal ganglia; and cerebellar cortex. Frontal and dorsolateral occipital cortical regions displayed a maturational rise in lCMRGlc by approximately 6 to 8 months. Absolute values of lCMRGlc for various grey matter regions were low at birth (13 to 25 mumol/min/100 gm), and rapidly rose to reach adult values (19 to 33 mumol/min/100 gm) by 2 years. lCMRGlc continued to rise until, by 3 to 4 years, it reached values of 49 to 65 mumol/min/100 gm in most regions. These high rates were maintained until approximately 9 years, when they began to decline, and reached adult rates again by the latter part of the second decade. The highest increases of lCMRGlc over adult values occurred in cerebral cortical structures; lesser increases were seen in subcortical structures and in the cerebellum. This time course of lCMRGlc changes matches that describing the process of initial overproduction and subsequent elimination of excessive neurons, synapses, and dendritic spines known to occur in the developing brain. The determination of changing metabolic patterns accompanying normal brain development is a necessary prelude to the study of abnormal brain development with positron emission tomography.

Positron emission tomography study of human brain functional development.

TO THE EDITOR: 

We read and re-read your outstanding supplement titled “A Tabulated Summary of the FDG PET Literature” ([1][1]). It helps take the world literature and put it in perspective. This has already helped us discuss the pros and cons of PET imaging in pancreatic carcinoma with a

https://jnm.snmjournals.org/content/jnumed/42/5_suppl/1S.full.pdf

A Tabulated Summary of the FDG PET Literature

Publisher Summary This chapter focuses on the effects of hypnotics and sedatives. Chlormethiazole is widely used as a hypnotic, particularly in older patients, where its rapid absorption and elimination suggest that it should be rapidly effective and have little hangover effect. It is also used in the treatment and prevention of delirium tremens when it is given orally or by intravenous infusion and should only be used for brief periods, e.g. up to one week. Abuse of sedatives only, as opposed to poly-drug abuse, may lead to neuropsychologic damage. Fifty-five patients with a history of exclusive dependence on sedatives were compared to matched controls on a battery of psychologic tests: scores on a synonyms test, which is believed to withstand intellectual impairment, were similar in the two groups but on tests of memory and verbal learning the experimental group's scores were significantly lower. Diazepam is used parenterally as a premedication and for minor surgical procedures such as dental treatment and endoscopies. Technical problems may arise at the site of injection. Triazolam is a short-acting benzodiazepine with a triazolo structure and thus rather different from the other benzodiazepines. It has been used mainly as a hypnotic, as which it has been shown to be effective both in the sleep laboratory and in patients.

Hypnotics and sedatives

s, 18th International Epilepsy Congress, p. 90, New Delhi, India, 1989a. KALVIAINEN, R., SIvENIUS, J., YLINEN, A., AND RIEKKINEN, P. J.: A doubleblind study of gabapentin in treatment of partial seizures. Epilepsia, 30: 661, l989b. KAMEI, C., OKA, M., MASUDA, Y., YOSHIDA, K., AND SHIMIZU, M.: Effects of 3-sulfamoylmethyl-1,2-benzisoxazole (AD-8l0) and some antiepileptics on the kindled seizures in the neocortex, hippocampus and amygdala in rats. Arch. Int. Pharmacodyn. Ther. 249: 164-176, 1981. KANEKO, S., HIRANO, T., KONDO, T., OTANI, K., FUKUSHIMA, Y., HISHIDA, R., AND MATSUNAGA, M.: Antiepileptic drug phenytoin potentiates GABA in the rat cuneate nucleus. Jpn. J. Psychiatry Neurol. 42: 643-645, 1988. KAPETANOVIC, I. M., AND KUPFERBERG, H. J.: Nafimidone, an imidazole anticonvulsant, and its metabolite as potent inhibitors of microsomal metabolism of phenytoin and carbamazepine. Drug Metab. Dispos. 12:

Antiepileptic drugs: pharmacological mechanisms and clinical efficacy with consideration of promising developmental stage compounds.

Experimental traumatic brain injury studies have shown that cerebral hyperglycolysis is a pathophysiological response to injury-induced ionic and neurochemical cascades. This finding has important implications regarding cellular viability, vulnerability to secondary insults, and the functional capability of affected regions. Prior to this study, posttraumatic hyperglycolysis had not been detected in humans. The characteristics and incidence of cerebral hyperglycolysis were determined in 28 severely head injured patients using [18F]fluorodeoxyglucose-positron emission tomography (FDG-PET). The local cerebral metabolic rate of glucose (CMRG) was calculated using a standard compartmental model. In six of the 28 patients, the global cerebral metabolic rate of oxygen (CMRO2) was determined by the simultaneous measurements of arteriovenous differences of oxygen and cerebral blood flow (xenon-133). Hyperglycolysis, defined as an increase in glucose utilization that measures two standard deviations above expected levels, was documented in all six patients in whom both FDG-PET and CMRO2 determinations were made within 8 days of injury. Five additional patients were found to have localized areas of hyperglycolysis adjacent to focal mass lesions. Within the 1st week following the injury, 56% of patients studied had presumptive evidence of hyperglycolysis. The results of this study indicate that the metabolic state of the traumatically injured brain should be defined differentially in terms of glucose and oxygen metabolism. The use of FDG-PET demonstrates that hyperglycolysis occurs both regionally and globally following severe head injury in humans. The results of this clinical study directly complement those previously reported in experimental brain-injury studies, indicating the capability of imaging a fundamental component of cellular pathophysiology characteristic of head injury.

Cerebral hyperglycolysis following severe traumatic brain injury in humans: a positron emission tomography study

Positron emission tomography with simultaneous electroencephalographic monitoring was performed with [18F]fluorodeoxyglucose in 20 patients with complex partial seizures who had normal computed tomographic scans. Seven patients had only unilateral epileptiform discharges on the electroencephalogram, 3 had predominantly unilateral discharges, and 10 had nonlocalized epileptiform abnormalities. Positron emission tomography showed a hypometabolic lesion in 16 of the 20 patients. Pathological changes in the hypometabolic region were found in postoperative specimens in 4 of 5 patients studied. Positron emission tomography was unaffected by the seizure frequency, state of alertness, or number of spike discharges during the scan. There was a tendency for patients to have higher overall metabolic rates when taking less medication. Seizures occurring during [18F]fluorodeoxyglucose uptake in 3 patients produced a hypermetabolic area at the interictal hypometabolic focus. Positron emission tomography sometimes showed more widespread hypometabolism than suspected on the basis of the scalp-recorded electroencephalogram. The frontal lobe showed a greater degree of hypometabolism than the temporal lobe in 3 patients. Focal lesions may be identified by positron emission tomography even if the electroencephalographic abnormality is not well localized.

[18F]fluorodeoxyglucose positron emission tomography in refractory complex partial seizures.

We compared the results of x-ray CT, magnetic resonance imaging (MRI), and positron emission tomography (PET) using 18F 2-deoxyglucose in 36 patients with partial seizures. Seventeen patients had localized epileptic discharges on surface EEG. MRI showed an abnormality in 9, CT in 4, and PET in 13 of 14 patients who had the test. Nineteen patients had nonlocalizing EEG discharges. MRI showed an abnormality in 11, CT in 10, and PET in 8 of 12. MRI is more sensitive than CT in detecting structural lesions underlying PET hypometabolism.

Neuroimaging in refractory partial seizures: comparison of PET, CT, and MRI.

We studied the effect of barbiturates on local cerebral glucose metabolism by performing positron emission scans before and after withdrawal of phenobarbital or primidone The postwithdrawal scan showed a significant increase (mean, 37%) in seven of eight cortical regions tested Patients who had serial scans without a drug change showed a nonsignificant tendency for metabolic rates to go down on the second scan (mean decrease, 7%) Addition or deletion of a single drug other than barbiturate did not change metabolic rates on repeat scans The depression in cerebral glucose metabolic rate due to phenobarbital, if confirmed, may have bearing on the adverse neuropsychological effects of the drug

Barbiturates reduce human cerebral glucose metabolism

The authors used /sup 18/F-fluorodeoxyglucose (FDG) positron emission tomography (PET) to study nine patients with clinical absence or generalized seizures. One patient had only absence seizures, two had only generalized tonic-clonic seizures, and six had both seizure types. Interictal scans in eight failed to reveal focal or lateralized hypometabolism. No apparent abnormalities were noted. Two patients had PET scans after isotope injection during hyperventilation-induced generalized spike-wave discharges. Diffusely increased metabolic rates were found in one compared with an interictal scan, and in another compared with control values. Another patient had FDG injected during absence status: EEG showed generalized spike-wave discharges (during which she was unresponsive) intermixed with slow activity accompanied by confusion. Metabolic rates were decreased, compared with the interictal scan, throughout both cortical and subcortical structures. Interictal PET did not detect specific anatomic regions responsible for absence seizure onset in any patient, but the results of the ictal scans did suggest that pathophysiologic differences exist between absence status and single absence attacks.

Positron emission tomography in generalized seizures.

We used serial positron emission tomography scans with [18F]2-deoxyglucose to study the effect of phenytoin on human cerebral glucose metabolism in 10 patients with seizure disorders. Local CMRglu ...

https://journals.sagepub.com/doi/pdf/10.1038/jcbfm.1986.54

Giovanni DiChiro

Papers

[18F]fluorodeoxyglucose positron emission tomography in refractory complex partial seizures.

Neuroimaging in refractory partial seizures: comparison of PET, CT, and MRI.

Barbiturates reduce human cerebral glucose metabolism

Positron emission tomography in generalized seizures.

Effect of phenytoin on human cerebral glucose metabolism.