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Biomedical subjects

W H Sweet

Publications and source records attributed to W H Sweet.

At least 19 recordsLinked to original sources
PubMed1991

Trigeminal facial pain: a model of peptides and monoamines in intracerebral cerebrospinal fluid.

A biochemical model of chronic trigeminal facial pain with elevated substance P (SP) and co-dysfunctional dopamine (DA), norepinephrine (NE) and purinergic systems is proposed. The serotonergic system is hypoactive as judged by low 5 hydroxyindoleacetic acid (5HIM). In distinction, intracerebral opioids may not be dysfunctional in facial pain as measured by normal levels of beta endorphin (BE). The neuropeptides somatostatin (SOM), cholecystokinin (CCK), met and leu-enkephalin (MENK, LENK) have very small picogram concentrations in these pain patients, but no definite conclusion can be reached on their role in trigeminal pain, alone or with monoamines, because of the small numbers, both sample size and concentrations. Interpretive obstacles to such human neurochemical studies suggest that future work might move to human clinical trials comodulating SP down, inhibitory peptides (SOM, CCK) up, and enhancing monoamine systems.

Biogenic Monoamines↗
PubMed1990

Entrapment of the C2 root and ganglion by the atlanto-epistrophic ligament: clinical syndrome and surgical anatomy.

Two cases of progressive, occipital lancinating pain and dysesthesias associated with a sensory deficit of the C2 dermatome are presented. Symptoms were relieved, and C2 sensory function restored by releasing a hypertrophied atlanto-epistrophic ligament entrapping the C2 root and ganglion. The normal anatomy and abnormal surgical findings are described. C2 entrapment by the atlanto-epistrophic ligament is discussed in reference to other C2 lesions causing occipital pain. We conclude that some patients whose progressive occipital pain is accompanied by a C2 sensory deficit are suffering from entrapment of the C2 root and ganglion amenable to surgical decompression.

Adolescent↗
PubMed1990

Pre-trigeminal neuralgia.

Eighteen patients who subsequently developed typical trigeminal neuralgia experienced a prodromal pain termed "pre-trigeminal neuralgia." These patients described their prodromal pain as a toothache or sinusitis-like pain lasting up to several hours, sometimes triggered by jaw movements or by drinking hot or cold liquids. Typical trigeminal neuralgia developed a few days to 12 years later, and in all cases affected the same division of the trigeminal nerve. Six additional patients experiencing what appeared to be pre-trigeminal neuralgia became pain-free when taking carbamazepine or baclofen. Recognition of pretrigeminal neuralgia makes it possible to relieve the pain with appropriate medications and avoid unnecessary irreversible dental procedures.

Adult↗
PubMed1989

Distribution of 10B after infusion of Na210B12H11SH into a patient with malignant astrocytoma: implications for boron neutron capture therapy.

If a sufficient concentration of the stable isotope 10B is introduced into a neoplasm, radiation therapy can be effected by short-range heavy charged particles from the disintegration of 10B by slow neutrons. Brain tumors were irradiated postoperatively by Hatanaka and co-workers in Japan using a 1 to 2 hour intraarterial infusion of 10B-enriched Na2B12H11SH (Na210B12H11SH) before exposure of the tumor-bearing area of the brain to slow neutrons from a 100 kilowatt nuclear reactor. The clinical outcome of such boron neutron capture therapy has been favorably impressive in some patients, but its efficacy in brain tumors needs improvement. In our study, a terminally ill patient with malignant astrocytoma was infused intravenously with Na210B12H11SH for 25 hours. The postmortem distribution of 10B in unfixed, frozen, tumor-bearing brain and spinal cord tissues was studied by comparing representative cryostat sections of these specimens with neutron-induced heavy charged particle radiographs of the same sections. Preferential accumulation of 10B was observed in the tumor, with relatively little accumulation of 10B in the parenchyma of the central nervous system.

Animals↗
PubMed1988

Percutaneous methods for the treatment of trigeminal neuralgia and other faciocephalic pain; comparison with microvascular decompression.

The treatment of trigeminal neuralgia by the minor percutaneous invasive procedures of selective thermal rhizotomy, glycerol injection, and balloon compression in the middle cranial fossa are compared with the open operations of compression in the middle fossa and MVD in the posterior fossa. A conservative end point for any one of the three percutaneous methods is recommended as the first invasive procedure in this disorder. The management of the facial pains in multiple sclerosis, cancer, posttraumatic and postherpetic pain, migrainous neuralgia (cluster headache), and vagoglossopharyngeal neuralgia is also discussed.

Denervation↗
PubMed1988

Deafferentation pain in man.

Pains of various etiologies are described in so many overlapping ways that verbal descriptions alone do not permit a valid distinction between those pains associated with neurological injury (with or without sensory loss) and those associated with neurological compression. Nor does the fact of some sensory loss plus pain constitute a useful classification to determine either the mechanism of the pain or its treatment. Progress is more likely to ensue if we seek to characterize in detail each type of painful lesion. Evidence for these conclusions is drawn from cases of brachial plexus injury, trigeminal rhizotomy and tractotomy, postcordotomy dysesthesia and central pain treated by regional guanethidine block. Examples of the value of totally innovative approaches are drawn from the physics of elementary particles.

Afferent Pathways↗
PubMed1979

Relative cerebral glucose metabolism evoked by dental-pulp stimulation in the rat.

Electrical stimulation of dental pulp is widely acknowledged to produce a sensation that is predominantly or exclusively noxious in character. The authors report the pattern of local cerebral glucose utilization evoked by dental-pulp stimulation in the barbiturate-anesthetized rat, using the [14C]2-deoxyglucose method of Sokoloff. Autoradiographs were prepared from cryostat-cut brain sections of animals given an intravenous pulse of [14C]2-deoxyglucose and sacrificed after 45 minutes of continuous bipolar stimulation of the incisor tooth pulp. Areas of high optical density on the autoradiographs identified brain regions where glucose consumption, and hence functional activity, was maximal. Stimulus-related increases in glucose utilization were seen ipsilaterally in an uninterrupted column from the lower levels of trigeminal nucleus caudalis to the rostral extent of the main sensory nucleus. Mandibular incisor pulp stimulation yielded increased deoxyglucose uptake in relatively restricted dorsal portions of the nuclei, while maxillary pulp stimulation produced a more extensive area of uptake ventrally. Elevated deoxyglucose uptake was also seen in the contralateral ventrobasal thalamus and sensory cortex with maxillary, but not mandibular, pulp stimulation. No changes in metabolic activity were detected in extralemniscal or limbic structures. These initial results suggest that the [14C]2-deoxyglucose method may be a useful means of mapping central structures involved in nociception.

Animals↗
PubMed1978

Brain death.

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Brain↗
PubMed1976

Control of pain by direct electrical stimulation of peripheral nerves.

Our results after implanting electrodes around peripheral nerves in 69 patients over a 10 year period are only fair with but 17 individuals maintaining relief until death or until the present time. Thirteen others had weeks or months of temporary relief. A continuing use of transcutaneous and better still of percutaneous electrodes to guide the decision regarding implantation is almost certainly advisable. Intensive efforts in laboratory animal studies with models of chronic pain are needed to improve our understanding of exactly what we should be doing. Empirical sustained work with the individual patient is likely to improve the figures we have presented, even in our present state of ignorance.

Aged↗
PubMed1976

Radical surgical treatment of craniopharyngioma.

There is evidence from this publication and those of Matson and colleagues that a determined effort at total excision of these tumors as the initial therapy is a tenable course of action. The main bases for this concept are: (1) that the dense gliosis characteristically intervening between these epithelial tumors and normal brain constitutes a margin of safety for the surgeon at least for the first several years such tumors are growing in the 3rd ventricle; (2) improved early diagnosis and better operative instruments, magnification, lighting, and technique are decreasing operative morbidity and mortality; and (3) new knowledge and new replacement therapy are reducing the burden of the metabolic and endocrine defects. Competing with this is the concept that rotationally delivered or even more precisely focused high energy photons and intracavitary beta-radiation have lower morbidity and mortality. The detailed and long term data on which to draw conclusions are not yet available. My medical colleagues and I are preparing case-by-case tables with all of the relevant facts to supply one component of the total picture.

Adolescent↗