Unusual neuroimaging in superficial siderosis.
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Adult↗
Biomedical subjects
D H Davis
Publications and source records attributed to D H Davis.
Multidirectional neck strength and electromyographic activity for normal controls.
OBJECTIVE: To assess the multidirectional force and indwelling electromyographic activity during maximal effort isometric actions of the neck. DESIGN: A descriptive study involving maximal effort isometric actions of the neck and bilateral electromyographic activity. BACKGROUND: This study extends previous efforts to assess the isometric strength of the neck, but with greater precision with respect to the intermediate angles between the frontal and sagittal planes. METHODOLOGY: Participants (n = 18) generated a maximal isometric force in twelve directions in the horizontal plane. All exertions were realized in neutral position. A load cell measured forces and intramuscular fine-wire electrodes were used to record the bilateral electromyographic activity of the sternocleidomastoid, scalenus medius, trapezius (middle fibers), semispinalis capitis, and splenius capitis. RESULTS: Strength in the anterolateral directions were similar, but exhibited right lateral dominance in extension. The sternocleidomastoid and trapezius (middle fibers) exhibited bilateral symmetry while the scalenus medius, semispinalis capitis, and splenius capitis did not. Furthermore, the agonist, synergist, and antagonist action of the individual muscles was clear. The direction of force that resulted in the greatest electromyographic activity was consistent with what has been shown in anatomy texts. This was not true for the scalenus medius. We showed that the scalenus medius contributes to extension, with synergistic activity in the lateral bending direction. CONCLUSIONS: The greater precision revealed novel information about the isometric strength of the neck and its musculature.
Adult↗
Outcome of trigeminal nerve section in the treatment of chronic cluster headache.
Chronic cluster headache accounts for 10 to 15% of all patients with cluster headache and is often resistant to medical management. The authors followed 17 patients with intractable chronic cluster headache who underwent trigeminal nerve section. They found that trigeminal nerve section is an effective treatment with acceptable morbidity for a carefully selected group of patients.
Aged↗
Observation of a (6)(LambdaLambda)He double hypernucleus.
A double-hyperfragment event has been found in a hybrid-emulsion experiment. It is identified uniquely as the sequential decay of ( 6)(LambdaLambda)He emitted from a Xi(-) hyperon nuclear capture at rest. The mass of ( 6)(LambdaLambda)He and the Lambda-Lambda interaction energy DeltaB(LambdaLambda) have been measured for the first time devoid of the ambiguities due to the possibilities of excited states. The value of DeltaB(LambdaLambda) is 1.01+/-0.20(+0.18)(-0.11) MeV. This demonstrates that the Lambda-Lambda interaction is weakly attractive.
Journal Article↗
Anesthetic management for two-stage computer-assisted, stereotactic thalamotomy in a child with Hallervorden-Spatz Disease.
We report the numerous management challenges surrounding the care of a child in whom bilateral thalamotomies were used to treat end-stage Hallervorden-Spatz Disease (HSD). The management of this patient was greatly facilitated by the use of modern anesthetic agents and a multidisciplinary team to care for the patient. The outcome was an improved life expectancy and quality of life.
Anesthesia↗
Distribution and regulation of proconvertases PC1 and PC2 in human pituitary adenomas.
Pituitary adenomas are members of the family of neuroendocrine cells and tumors which have secretory granules containing chromogranins/secretogranins and other proteins. Pituitary adenomas express the neuroendocrine specific proconvertases PC1 (also known as PC3) and PC2, which are important for the proteolytic processing of chromogranins/secretogranins molecules. We examined the distribution of PC1 and PC2 in primary cultures of 20 pituitary adenomas and analyzed the regulation of the proconvertase mRNAs and proteins by various secretagogues including hypothalamic hormones and phorbol ester to determine the role of PC1 and PC2 in CgA processing in pituitary adenomas. Although PC2 was present in all adenomas, there was a differential distribution of PC1 with PRL adenomas expressing lower levels of PC1 compared to other adenoma types by RT-PCR analysis, in situ hybridization and immunostaining. Treatment of primary cultures of pituitary adenomas with phorbol 12-myristrate 13-acetate (PMA) resulted in an increase in pancreastatin (PST) secretion in most pituitary adenomas and increased PC1 mRNA and protein expression in gonadotroph adenomas, but not in other types of adenomas. Analysis of a human pituitary adenoma cell line, immortalized by recombinant defective adenovirus (HP75), which expressed chromogranin A, FSH, PC1 and PC2 showed that PST was secreted by these immortalized cells. Treatment with TGF beta 1 resulted in an increase in PST secretion and in PC1 mRNA and protein. These results indicate that a) there is a differential distribution of PC1 in human pituitary adenomas with PRL adenomas expressing very little PC1 mRNA and protein and b) that PC1 expression in gonadotropin hormone-producing adenomas is regulated by PMA and TGF beta 1. These findings support the observation that chromogranin A is a substrate for the endoproteinase PC1 in human pituitary adenoma cells.
Adenoma↗
Herpes simplex encephalitis after brain surgery: case report and review of the literature.
Intracranial infection after neurosurgical intervention most often is caused by bacteria. A rare case of fatal herpes simplex encephalitis after removal of a meningioma is described and similar cases reported in the literature are reviewed. Recent diagnostic tools, including detection of herpes viral DNA sequences by polymerase chain reaction, complement clinical suspicion and facilitate mandatory early diagnosis, because herpes encephalitis, without rapid initiation of treatment, may lead to severe disability or death.
Aged↗
Associations of risk factors with segment-specific intimal-medial thickness of the extracranial carotid artery.
BACKGROUND AND PURPOSE: It is generally assumed that risk factors affect extracranial carotid intimal-medial thickness similarly among all arterial segments. This assumption underlies use of single segments or walls of segments as outcome variables for risk factor studies and clinical trials. However, if the impact of risk factors was unequal for various segments or circumferentially asymmetrical within segments, then inferences drawn from a single segment or wall might not be generalizable; furthermore, since individual segments and walls have unique histological characteristics and are differentially exposed to turbulent flow, risk factor relationships with a particular segment or wall may provide inferences regarding pathogenesis of atherosclerosis. METHODS: We evaluated associations of risk factors with intimal-medial thickness at the near and far walls of the common carotid artery, bifurcation, and internal carotid artery in 280 individuals older than 45 years equally divided between coronary artery disease cases and controls and between men and women. RESULTS: The patterns of differences in mean intimal-medial thickness among segments vary, depending on age, history of hypertension, body mass index in women, and coronary (case-control) status. The asymmetry of disease depended on blood glucose concentrations, prior history of diabetes, smoking, and coronary status. Sex, postmenopausal status, LDL cholesterol, systolic blood pressure, and history of myocardial infarction all had statistically significant relationships with intimal-medial thickness that were fairly homogeneous among arterial sites. CONCLUSIONS: Focus on an individual segments or walls of the extracranial carotid arteries may lead to overestimation or underestimation of associations of risk factors with extracranial carotid intimal-medial thickness.
Aged↗
Prolactinomas in male and female patients: a comparative clinicopathologic study.
OBJECTIVE: To explore the basis of the gender-based differences in endocrine and surgical findings in patients with prolactinoma (prolactin cell adenoma) as well as in their clinical outcome. MATERIAL AND METHODS: In young or reproductive-age female patients, older women (beyond 40 years of age), and male patients, we systematically studied the following factors: operative and endocrine features (tumor size, invasiveness, preoperative serum prolactin level, and biochemical outcome), specific biologic variables (mitotic index, MIB-1 labeling index, and p27 immunoreactivity), and hormone receptor status (estrogen and progesterone receptor proteins as well as dopamine D2 receptor messenger RNA). RESULTS: Of the various factors assessed, the preoperative prolactin level and MIB-1 labeling index were lower in young female patients in comparison with older female and particularly male patients. Hormone levels were also positively associated with mitotic activity as well as the MIB-1 labeling index. Although invasion was infrequent in microadenomas of young female patients, no statistically significant differences in tumor size or invasiveness were noted among the three patient groups. Absence of differences in invasiveness may, in part, be explained by artifacts of case selection. CONCLUSION: The basis for the observed differences in proliferative activities in tumors of the three study groups is not readily apparent but may reflect differences in the endocrine milieu or the effect of sex steroid hormone receptors, tumoral vascularity, or specific growth factors.
Adult↗
Peripheral nerve hemangioblastoma.
Capillary hemangioblastoma (HB) is a benign, highly vascular tumor limited almost exclusively to the central nervous system (CNS). It occurs primarily in the posterior fossa and less often in the spinal cord. We report three cases of HB occurring in peripheral nerve, two intradural tumors arising in a C4 and a cauda equina nerve root, respectively, and a third lesion in the sciatic nerve at mid thigh. The patients, 1 woman and 2 men, ranged in age from 25 to 49 years. Two had von Hippel-Lindau disease, an association usually found in one-third of CNS HBs, and one had a family history of pheochromocytoma. In every way, HBs of peripheral nerve were indistinguishable from their CNS counterpart. Ranging in size from 1.5 to 5.5 cm in diameter, the tumors were well circumscribed and contained a myriad of small caliber vessels lined by endothelial cells and surrounded by pericytes. Throughout, the lesions were rich in large, often vacuolated stromal cells. In all of the cases, these stained strongly for vimentin and neuron-specific enolase; only one showed focal S100 protein reactivity. Surgical therapy required excision of the affected nerve roots in the first two cases. In the third case, prominent extension of the tumor within epineurium permitted a microsurgical resection with sparing of sciatic nerve fascicles. No tumor recurred during a follow-up period of 5 to 20 months.
Adrenal Gland Neoplasms↗
Pituitary carcinoma: a clinicopathologic study of 15 cases.
BACKGROUND: Pituitary carcinomas are rare adenohypophysial neoplasms, the definition, diagnosis, therapy, and prognosis of which are controversial. METHODS: Pituitary carcinomas were defined as primary adenohypophysial neoplasms with documented craniospinal and/or systemic metastases. The authors report a clinicopathologic study of 15 examples examined by light microscopy, immunohistochemistry, and image analysis. Both proliferative activity and p53 tumor suppressor gene expression were studied. RESULTS: The study group consisted of 15 patients, including 8 males and 7 females ranging in age from 34-71 years (mean, 56 years). Of these patients, seven had adrenocorticotropic hormone (ACTH)-producing tumors (four in the context of Nelson's syndrome), seven had prolactin-producing tumors, and one had a nonfunctioning tumor. No evidence of diabetes insipidus was seen in any case. Fourteen tumors were initially considered macroadenomas. Of the ten cases for whom tumor extent was known, all had invasive tumors. The interval from the initial diagnosis of adenoma to that of carcinoma ranged from 0.3 to 18.0 years (mean, 6.6 years; median, 5.0 years); the longest mean interval (15.3 years) occurred for patients with Nelson's syndrome. The latency was twice as long for ACTH-producing tumors as for prolactin (PRL) cell tumors (9.5 vs. 4.7 years). All carcinomas showed a greater tendency toward systemic metastasis than craniospinal metastasis; the rate of systemic metastasis was 71% for PRL cell tumors and 57% for ACTH-producing tumors. Thirteen percent of tumors showed both patterns of metastasis. Fully 50% of primary tumors and the majority of metastases showed nuclear pleomorphism and/or hyperchromasia. The mean mitotic, MIB-1, and proliferating cell nuclear antigen indices for primary tumors and metastases were as follows: 2/10 high-power field (hpf), 2.6% and 11%, respectively; 6/10 hpf, 7.8% and 16%, respectively. Staining for p53 protein was noted in 57% of primary tumors and 88% of metastatic tumors; a relative increase in p53 expression in metastases was noted in 83%. All but one of the primary and metastatic tumors were aneuploid. The most common treatments were radiation therapy and, for PRL cell carcinomas, dopamine agonist administration. Both treatments provided only palliation. Eighty percent of the patients died of metastatic disease 7 days to 8 years after the diagnosis of carcinoma; of these, 66% died within 1 year. At last follow-up, 20% of patients were alive with metastases 9-18 months after diagnosis. CONCLUSIONS: Nearly all pituitary carcinomas present as functioning, microscopically atypical or mitotically active, invasive macroadenomas. By definition, after an interval related to their immunotype, all metastasize. The tumors show a greater tendency toward systemic metastasis than craniospinal metastasis and are associated with poor prognosis. Radiation and dopamine agonist therapy generally provide only palliation. Proliferation indices and p53 expression tend to be higher in metastases than in primary tumors. The current definition of pituitary carcinoma requires the demonstration of metastasis; however, high mitotic and MIB-1 labeling indices as well as p53 immunoreactivity suggest the diagnosis and appear to be of prognostic significance. A redefinition of aggressive pituitary tumors is proposed--one that facilitates the recognition of tumors prone to metastasis.
Adrenocorticotropic Hormone↗
Combat veterans with posttraumatic stress disorder exhibit decreased habituation of the P1 midlatency auditory evoked potential.
The current study used a paired stimulus paradigm to investigate the P1 midlatency auditory evoked potential in Vietnam combat veterans with posttraumatic stress disorder (PTSD) and three comparison groups: alcohol dependents, combat-exposed normals, and combat-unexposed normals. Compared to each comparison group, PTSD subjects exhibited significantly diminished habituation of the P1 potential. P1 potential habituation within the PTSD group, correlated significantly with intensity of PTSD reexperiencing symptoms, such as trauma-related nightmares and flashbacks. These findings are discussed as consistent with a sensory gating defect at the brainstem level in PTSD, and are further discussed in the context of other psychophysiological measures in PTSD and of P1 potential findings in psychiatric disorders other than PTSD.
Analysis of Variance↗
Prolactin receptor messenger ribonucleic acid in normal and neoplastic human pituitary tissues.
We examined the specific cell types in normal human pituitaries that expressed PRL receptor (PRL-R) messenger ribonucleic acid (mRNA) by combined in situ hybridization and immunohistochemistry. The distribution of PRL-R mRNA in 28 pituitary adenomas was examined by in situ hybridization and reverse transcription-PCR in 12 cases of adenomas. In another set of experiments, 34 PRL adenomas from men, women, and bromocriptine-treated patients were analyzed for PRL-R by in situ hybridization. In the normal pituitary, PRL- and LH-producing cells had significantly more mean grain counts per cell and higher percentages of cells positive for PRL-R than GH and TSH cells. PRL-R mRNA was present in all groups of adenomas by in situ hybridization and reverse transcription-PCR. PRL adenomas had a significantly higher density of labeling compared to other adenoma types. Although there was no difference in the levels of PRL-R mRNA in PRL adenomas from men and premenopausal and postmenopausal women, patients treated with bromocriptine before pituitary surgery had significantly lower levels of PRL-R compared to all other groups. These results indicate that in the normal pituitary, PRL and LH cells have the highest level of PRL-R mRNA, whereas PRL adenomas have significantly higher levels of PRL-R mRNA than other types of adenomas, and bromocriptine treatment decreases the levels of PRL-R mRNA in PRL adenomas.
Adenoma↗
Venous varix causing median neuropathy. Case illustration.
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Anatomy, Artistic↗
Gonadotroph adenoma of the pituitary gland: a clinicopathologic analysis of 100 cases.
OBJECTIVE: To determine the clinical and pathologic features in a large cohort of randomly selected patients with gonadotroph pituitary adenomas. DESIGN: We retrospectively reviewed clinical, surgical, and pathologic findings in 100 patients (79 men and 21 women, 30 to 82 years old) with this tumor. RESULTS: Diagnosis of a pituitary tumor was prompted by visual loss (43%), symptoms of hypopituitarism (22%), headache (8%), or a combination of these findings (10%); 17% of the patients were asymptomatic. Visual field defects were present in 68% of the study group, and complete or partial anterior pituitary failure was present in 77%. Serum prolactin concentrations were increased (maximum, 110 ng/mL) in 33% of patients. Hypersecretion of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) was documented in 11 and 5 patients, respectively. The serum level of alpha-subunit was increased in 1 of 29 patients in whom it was measured. All patients had pituitary macroadenomas, only 21% of which were grossly invasive. The surgical approach was transsphenoidal in all but two patients, who underwent transfrontal craniotomy; gross total tumor resection was achieved in 90%. By definition, all tumors had at least 10% immunoreactivity for LH, FSH, or both. All tumors were chromophobic. Ultrastructurally, the tumors were characterized as gonadotroph adenomas of "male" (45%) or "female" (9%) type as well as null-cell adenomas of the oncocytic (35%) or nononcocytic (11%) type. After a median follow-up of 4.3 years, 69% of the patients who had had visual field defects noted normalization or improvement. Persistent or clinically recurrent pituitary tumor tissue was present in 42%. A second pituitary surgical procedure was required in eight patients. CONCLUSION: Most patients with clinically evident gonadotroph pituitary tumors have loss of vision and hypopituitarism. Hypersecretion of FSH or LH is unusual, and no distinct hormone-dependent clinical phenotype is present. Transsphenoidal surgical treatment generally yields normalization or improvement of visual field defects.
Adenoma↗
Solitary fibrous tumor of the meninges: a lesion distinct from fibrous meningioma. A clinicopathologic and immunohistochemical study.
Seven solitary fibrous tumors (SFTs) of the meninges are presented and their clinicopathologic features are compared with those of 64 fibrous meningiomas (FM). Patients with SFT included 5 females and 2 males age 47 to 73 years. The dura-based tumors involved the parasagittal region (1), tentorium (2), cerebellopontine angle (2), and spinal region (2). One each showed invasion of brain and of a spinal nerve root. Of four SFTs with at least 1-year follow-up, one subtotally resected example recurred. No tumors metastasized. All consisted of spindle cells disposed in fascicles between prominent, eosinophilic bands of collagen. Whorls and storiform cell arrangements were lacking. Mitoses ranged from 1 to 7/10 400 x fields. MIB-1 labeling indices ranged from 1% to 18% (mean 4%). All were PAS negative and showed strong immunoreactivity for vimentin and CD34. Of cases studied, half were estrogen and all were progesterone receptor immunopositive. The majority (72%) of FMs occurred in females and most (72%) were supratentorial. Recurrence was noted in 15%. Mitotic activity varied from 0 to 3 mitoses per 10 400 x fields (mean < 1). MIB-1 labeling indices ranged from 1% to 5% (mean 1.5%). Unlike SFT, FMs were glycogen-containing and variously exhibited a storiform pattern (13 of 20), psammoma body formation (9 of 20), and calcification of collagen (4 of 20). Immunoreactivities included vimentin (100%), focal to patchy EMA (80%), S-100 protein (80%), collagen IV (25%), and patchy, mild-to-moderate CD34 staining (60%). Of cases studied, nearly half were estrogen and all were progesterone receptor staining positive. Meningeal SFTs represent a distinct morphologic entity, the morphologic and immunohistochemical features of which differ from those of FM and suggest a histogenetic relationship to pleural SFT. Although a minority histologically appear to be low grade malignant, our limited experience suggests that they behave in a benign fashion. The classification of mesenchymal tumors affecting the central nervous system must be expanded to include SFT.
Adult↗
Quantitative analysis of a noninvasive stereotactic image registration technique.
Our group has developed and tested a noninvasive image registration technique that does not require a special imaging study following the application of a head frame or radiological markers on the patient. This registration method involves performing automatic alignment between segmented scalp reconstructions from CT or MRI fitted with are surfaces traced with the Regulus Navigator. This paper will present a quantitative analysis of this technique compared to other stereotactic and image-guided registration techniques. This noninvasive surface alignment technique has been found to be a viable, quick and accurate method of performing image-guided registration.
Algorithms↗
Long-term outcome of iontophoresis treatment for torticollis.
In 1969, a patient with torticollis was successfully treated by a procedure called iontophoresis. Between 1958 and 1972 223 patients with torticollis were treated with this procedure. 88 of these patients (39%) were located and 56 (25% of the total, 64% of those located) returned a survey regarding their condition. 28 (13% of the total, 32% of those located, 50% of those responding) enjoyed an initial period of improvement. Of these, 16 patients (7% of the total, 18% of those located, 29% of those responding, 51% of those with initial improvement) reported sustained improvement through the time of the survey. However, 5 of these patients had additional treatment with botulinum toxin or selective denervation. We conclude that the long term effectiveness of iontophoresis treatment in the course of torticollis is minimal.
Adult↗