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PubMed1992

Laboratory automation systems. An introduction to concepts and terminology.

The concept of laboratory automation has existed for years; such automation has been used primarily in nonclinical and industrial settings. The next step is to implement automation systems in the clinical laboratory. A laboratory automation system consists of robots, conveyor systems, machine vision, and computer hardware and software. Specimen movement and result reporting are based on the identification of specimens using bar coded specimens and bar coded specimen carriers. The implementation of a laboratory automation system is dependent on the presence of a laboratory information system. An interface between the laboratory information system and the laboratory automation system provides the information required to move the specimen through the laboratory. The reporting of results is dependent on the laboratory information system or manual input, depending on the type of work cell in which the results are produced. The greatest hurdle to overcome in developing and implementing a laboratory automation system is the integration of systems, including commercial laboratory instrumentation and user-defined work cells. The barriers to implementation primarily are proprietary in nature: instrument software and instrument hardware. When the instrument manufacturers realize the necessity for development of electronic and physical integration, the proliferation of laboratory automation systems will occur. Several opportunities exist for the reduction in laboratory expenses and the development of new positions, such as "robotechnologist," a staff member who would function in a manner similar to the current laboratory information systems manager. This article describes the author's concepts of laboratory automation.

Automation↗
PubMed1992

An overview of head trauma for the primary care practitioner, Part I--Etiology, diagnosis, and consequences of head trauma.

At some point in their careers, most primary care providers will encounter patients who have sustained some degree of traumatic head or brain injury. This article presents an overview of the causative mechanisms responsible for this trauma, the nature of the injuries sustained, some relevant initial medical diagnostic procedures performed, and possible consequences encountered. An emphasis has been placed on familiarizing the primary care provider with specific terminology associated with head trauma incidents.

Brain Injuries↗
PubMed1992

Reflex blink to visual threat.

The requisite visual modalities for the reflex blink to visual threat have not been thoroughly studied. We identified five patients with different focal cerebral lesions documented on computerized tomography scan who had abnormal blink-to-threat reflexes. One had a homonymous hemianopia secondary to posterior cerebral artery occlusion; another had a unilateral parietal neglect; and a third had a frontal neglect. They did not blink in response to visual stimuli contralateral to their lesion. A cortically blind patient and one with Balint's syndrome did not have a blink response. Observation of these and other similar patients and animals previously reported suggests that the blink-to-threat reflex is cortically mediated and requires intact primary visual cortex as well as higher order mechanisms for visual attention mediated in the inferior parietal lobule and frontal eye fields.

Adult↗
PubMed1979

[Hypoplasia of the optic nerve head].

Optic nerve hypoplasia is not a rare eventuality in children. This report discusses the clinical features of 10 new cases on a multiple point of view including optic canal tomography, fluorescein angiography and cat's examination. Optic nerve hypoplasia is not always accompanied by decreased visual acuity: sector fields are often identified in these cases.

Adult↗
PubMed1992

Visual disturbances associated with primary empty sella syndrome in patients with chronic renal failure.

After describing the main clinical features of primary empty sella syndrome and the main hormonal alterations in chronic renal failure, the authors report the results obtained in a group of 33 patients undergoing dialysis three times a week. Each patient had a complete ophthalmologic examination, with electroretinography and visual-evoked potentials, a complete radiologic examination, including skull stratigraphy (particularly of the sellar and parasellar bony structures), and a computed tomographic scan. In the whole group, visual acuity, ocular and lid motility, and visual fields were normal. In two patients, a slight bilateral papilledema, associated with a P100 latency increase and normal morphology and visual-evoked potentials, was reported. Two patients had initial unilateral papillary pallor associated with P100 amplitude alterations. In all four of these patients, radiologic examination showed a markedly pathologic sellar widening with thickening and double contour image of the floor. The report of a primary empty sella was confirmed by computed tomography in all four cases. The authors discuss the possible etiopathogenic mechanisms of the neuroophthalmologic symptoms associated with this syndrome.

Adult↗
PubMed1992

Visual processing of motion-defined form: selective failure in patients with parietotemporal lesions.

The following psychophysical data were obtained from 13 patients with unilateral cerebral hemispheric lesions and 20 control subjects: speed thresholds for detecting and for recognizing motion-defined letters, speed thresholds for detecting coherent motion and for discriminating its direction, and visual acuity for recognizing letters of 96% and 11% contrast. Acuity was between 6/6 and 6/3 for all patients. Four patients showed a selective loss of ability to recognize motion-defined letters, while the ability to detect those same letters was spared, as was the ability to detect coherent motion and discriminate its direction (type I loss). Three patients showed a loss of ability both to recognize and to detect motion-defined letters, while the ability to detect coherent motion and discriminate its direction was spared (type II loss). All seven patients who failed to recognize motion-defined letters had extensive lesions in parietotemporal white matter underlying Brodmann cortical areas 18, 19, 37, 39, 21, and 22. The lesion was in the left hemisphere for three patients and in the right hemisphere for the remaining four. The region of overlap in these seven patients was not invaded by the lesion in any of the other six patients, and none of these six patients showed a loss of ability to recognize motion-defined letters. Three patients showed selective loss of acuity for low-contrast letters with normal Snellen acuity. The lesions in these three patients extended more posteriorly than in any other patient, and their region of overlap was in white matter underlying areas 18 and 19. We conclude that (1) the loss of ability to recognize letters in seven patients was specific to motion-defined letters rather than being a general loss of letter-recognition ability, (2) this visual loss was specific to motion-defined form rather than being a general failure of motion processing, and (3) the visual loss was not produced by lesions that did not involve the localized cerebral region specified above. To explain the existence of type I and of type II loss with sparing of the detection and discrimination of coherent motion, we propose that motion information is processed hierarchically. We further suggest that homologs of the socalled motion and color/form pathways (i.e., areas V1/MT/MST/7a and areas V1/V4/IT) are interconnected to form a distributed system that is important for the recognition of motion-defined form.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMedDate not supplied

[A sixty-eight-year-old man with giant intracranial arteriovenous malformation and right-sided hemicrania -- a case report].

Arteriovenous malformations (AVMs) are the most dangerous congenital vascular malformations. Intracranial AVMs occur in about 0.1 percent of the population and account for 1 to 2 percent of all strokes. The angioarchitecture of AVMs consists of direct arterial to venous connections without an intervening capillary network. The main symptom reported by half of all patients with arteriovenous malformations is an episodic headache. The headache is associated with nausea and vomiting and due to this resembles the hemicrania or cluster headache attacks. Although cerebral angiography is considered as the gold standard for the diagnosis, planned treatment and after treatment observation, AVMs are usually identified with advanced visual imaging techniques such as magnetic resonance imaging, computed tomography, and computed angiotomography. The treatment options consist of surgery, radiosurgery and endovascular embolization. We report a case of a 68-year-old man with giant intracranial arteriovenous malformation and right-sided hemicrania.

Aged↗
PubMed2005

[An elderly case of craniopharyngioma: treatment by limited surgery and radiation therapy].

Craniopharyngioma accounts for approximately 3.5% of all intracranial neoplasm and may occur at any age. However craniopharyngioma in the elderly was rare. We report a rare case of craniopharyngioma in an elderly patient, who was treated by radical surgery successfully. An 80-year-old male was admitted to our hospital with a history of visual disturbance and bitemporal hemianopsia. CT scan of the brain revealed a hypodense cystic mass with calcification in the suprasellar area. MRI demonstrated the optic chiasm was displaced superiorly. Her symptom deteriorated day short time of her hospitalized life. We decided to removal tumor radically because of saving her visual function. Subtotal removal of the suprasellar lesion was performed, followed by radiotherapy to the residual lesion. A visual impairment was improved after surgery. No recurrences had been detected on MRI eighteen months after the initial operation. Based on previous report and the clinical course of our case, radical surgery is sometimes needed for saving visual function in spite of elderly patient. However, in this case, sparing hypothalamic and pituitary function is essential for good prognosis.

Aged, 80 and over↗
PubMed2001

Cranioorbital fibrous dysplasia: with emphasis on visual impairment and current surgical management.

Fibrous dysplasia is a benign but slowly progressive disorder of bone in which normal cancellous bone is replaced by immature woven bone and fibrous tissue. Significant deformity and both acute and chronic visual impairment can result. A contemporary understanding of fibrous dysplasia, emphasizing the origins of visual impairment, indications for decompressive surgery, and the techniques for correction of the cosmetic deformity are presented. In their experience and review of the literature, the authors found the most frequent clinical presentations to be exophthalmos, displacement of the globe, abnormalities of extraocular motility, cosmetic deformity, and visual impairment. Although traditionally the cause of visual impairment has been ascribed to impingement of the optic canal on the optic nerve, the authors' experience is that the most common cause of visual loss is cystic degeneration of the tumor, particularly with those involving the anterior clinoid process. Exophthalmos and optic canal stenosis are less common causes of visual impairment. Indications for surgical intervention include acute and/or serially radiographically documented and relentless visual impairment and significant cosmetic deformity. Individualized management strategies are also discussed.

Adolescent↗
PubMed2006

[Sphenoid sinus mucocele of unusual aetiology and location].

UNLABELLED: Mucoceles of the sphenoid sinnus are rare. 140 cases have been reported in the literature. PURPOSES: We review a case and discuss: 1) pathophysiology and diagnosis of mucoceles; 2) etiologies, anatomical variants, clinical manifestations and treatment of sphenoidal mucoceles. MATERIAL AND METHOD: Case report and literature review. CASE REPORT: An 18-year-old female, with no past medical history was hospitalized for right fluctuating monocular blindness. MRI and CT scan facilitated the diagnosis of right clinoid mucocele with compression of the optic nerve. Imagery also revealed fibrous dysplasia of the anterior skull base which probably induced the mucocele formation. The mucocele was successfully decompressed during endoscopic sinus surgery. Postoperative course was unremarkable. At four months post surgery there was no recurrence of ophtalmological symptoms. DISCUSSION-CONCLUSION: The pathophysiology of mucoceles remains uncertain. Diagnosis is based on imagery (CT scan, RMI). Imagery allows accurate location of the mucocele, defines any concomitant pathology and oulines important anatomical structures necessary for safe endoscopic sinus surgery. The association of fibrous dysplasia and an anterior clinoidal mucocele is exceptional. To our knowledge this is the only report in the literature. Ophtalmologic symptoms with a risk of blindness require urgent surgical treatment. Surgery involves decompression, ideally endoscopically.

Adolescent↗
PubMedDate not supplied

[A follow-up of patients with anterior optic tract glioma concurrent with type 1 neurofibromatosis].

Fifty-nine patients with anterior optic tract (AOT) lesion concurrent with type neurofibromatosis (NF-1) were followed up for 1 to 36 years (median 5 years). Based on the study, the authors identified several grades of the disease: - stabilization without intervention; - stabilization after treatment; - insignificant negative changes as a slight tumor growth and a further stabilization of the process; - occasionally negative changes irrespective of treatment. The behavior of a tumor is unpredictable. The onset of progression in infancy is a poor predictor. Ophthalmological symptoms are not the criterion that can be used to make a prognosis. The prognosis is largely determined by neurovisualization techniques and primarily magnetic resonance imaging. A uniform slight thickening of AOT structures irrespective of the extent of the process along the AOT should be referred to as a good prognosis. There was no spontaneous tumor regression in any case. By taking into account the beneficial effect of radiotherapy, the authors consider it expedient to use it as monotherapy and in combination with surgery. Bypass surgery on the spinal fluid system frequently fails to entirely solve the problem intracranial hypertension.

Blindness↗
PubMed1991

Pituitary tumor volume as a predictor of postoperative visual field recovery. Quantitative analysis using automated static perimetry and computed tomography morphometry.

We attempted to define the relationship between the volume of pituitary adenomas and postoperative visual field recovery. Fourteen consecutive patients (27 eyes) were studied who presented with visual complaints and who were confirmed to have pituitary macroadenomas at the time of resection. For each eye, preoperative visual field loss in each quadrant as well as whole field loss were analyzed. Tumor volume was determined from computed tomography scans by summing serial axial sections. Statistically significant correlations (p less than 0.05) of preoperative superonasal and whole visual field loss with tumor volume were found. Postoperative visual field recovery was determined for each patient by subtracting the postoperative visual field loss from the preoperative field loss. Postoperative inferonasal field recovery was significantly correlated (p less than 0.01) with whole tumor volume, with markedly greater recovery in patients with tumor volumes of 5 cc or less. In general, tumor volume proved to be a poor predictor of postoperative visual field recovery.

Adenoma↗
PubMed1977

[Chiasmatic syndromes-diagnostic possibilities with computerized tomography (CT)].

The normal suprasellar subarachnoid space (so-called "suprasellar hexagon") and its content are fairly well demonstrated by CT. Abnormal appearance (obstruction, stenosis, asymmetry) of this space is always suspect of a suprasellar space occupying lesion. Enhancing (intravenous application of iodine containing contrast medium) helps to delineate the exact tumor extension. The point of origin--important for deciding on the nature of a lesion--is often difficult to determine. The CT-pattern itself is not specific for a certain kind of tumor. We have observed a typical chiasmatic syndrome with all meningiomas of the tuberculum sellae, with 75% of the chromophobe adenomas and with 50% of the craniopharyngiomas. Absence of this syndrome was due to high position of the tumor (craniopharyngiomas) or to parasellar extension of the lesion (chromophobe adenomas). Diagnosis of recurrent tumor is difficult; it must be based on the post-operative CT-examination. Chiasmatic syndromes not due to the pressure effect of a space occupying lesion (i.e. chiasmatic syndromes of vascular, toxic or degenerative origin) can not be assessed directly by CT.

Adenoma, Acidophil↗
PubMed1991

The neuroradiology of visual disturbances.

The neuroradiology of visual deficits has advanced dramatically in recent years. Plain film evaluation of the orbit and face remains useful in the emergency room for the evaluation of trauma. High-resolution coronal CT remains the method of choice in the assessment of serious injury to the orbit and in cases of penetrating metallic foreign body. The contrast-enhanced orbital CT provides useful information in cases of tumor and infection and when the bones of the face or skull are involved. MRI has largely replaced CT in the search for brain infarct, brain tumor, and cerebral inflammatory and demyelinating processes. MRI is the study of choice in all cases of sellar and parasellar disease. It offers high-resolution images in any plane. GTPA enhancement has provided additional information from MRI without significant risk. The final selection of an imaging modality should be based upon the clinical presentation and any physical limitations of the patient.

Brain Neoplasms↗
PubMed1990

[Cerebral aspergilloma. Review of the literature apropos of a case].

The incidence of mycotic infection of C.N.S. seems to have increased in the last few years and the diagnosis is being made more and more frequently. The authors are reporting a case of a 27 year old man, admitted with severe intracranial hypertension, very poor visual acuity and right motor weakness. The C.T. Scan showed a massive space occupying lesion in the left hemisphere. Only the biopsy, then the surgical removal of the lesion revealed the true histological nature. It turned out to be aspergilloma. The patient expired 13 hours later. Up to date, 25 cases of Aspergillus granulomas have been reported. This disease is included in the entity of neuromycosis. Its specificity compared to the other types of cerebral mycotic localization as for example abscess, meningitis, mycotic aneurysm, lies in the fact that it presents as granulomatous mass in the hemisphere, mimicking a brain tumor without any specific neuroradiological findings. In the light of so far published literature, the authors draw the attention to the fact of the difficulty of diagnosis of this dreadful benign disease due to the lack of specific clinical and radiological findings. They are stressing the necessity of early and vigorous diagnosis mainly in patients with a risk factor to try to reduce the high mortality that has been universally reported in almost all cases.

Adult↗
PubMedDate not supplied

[Description of an unusual clinical picture of visual hallucinations (polyopsia, erythropsia) as expression of right temporo-occipital ischemia (visual association cortex, Brodman area 37].

An unusual clinical picture (polypsia and erythropsia) as a consequence of an ischaemic lesion of the temporo-occipital junction, known as Brodman area 37 is reported. CT images showed that the lesion area was linked with the two particular function of visual association and memory peculiar to area 37 and, as is well known in the literature, predominant in right hemisphere damage.

Aged↗