Aplastic anaemia presenting with features of raised intracranial pressure.
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Adult↗
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Results for “Computer vision”
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
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Diagnostic strategies in the management of unexplained visual loss. A cost-benefit analysis.
In the investigation of visual loss from anterior visual pathway disease, it is imperative to differentiate the infrequent compressive from the much more common noncompressive lesions. To determine how relatively low-cost, risk-free, but error-prone visual field examination (VF) and high-cost, risk-prone, but accurate CT Scan (CT) and cerebral angiography (Angio) can be cost-effectively utilized to solve this diagnostic problem, the authors have developed a decision making model for the analysis of three management strategies. The visual field examination precedes and determines the use of neuroradiologic studies in Strategy A (VF-CT-Angio), whereas it follows the neuroradiologic studies in Strategies B (CT-VF-Angio) and C (CT-Angio-VF). The visual field-determined strategy (A) proved most cost-effective, based upon an estimated 6% or lower relative prevalence of chiasmal compressive lesions, a negligible risk in delaying their diagnosis, and a sensitive method of visual field examination. At a visual field sensitivity to chiasmal defects of 84% and a specificity of 88%, Strategy A annually saves $4 million over Strategy B and $27 million over Strategy C. At lower levels of perimetric accuracy, Strategy B is the most cost-effective approach. Strategy C is never cost-effective.
Cerebral Angiography↗
Alert for perioperative visual loss: an unusual presentation of an orbital haemangioma during spinal surgery.
A 62-year-old man with a history of non-insulin-dependent diabetes mellitus, hypertension and obesity, presented for elective lumbar laminectomy for spinal canal stenosis. Twenty minutes after placement in the prone position, he developed left orbital proptosis. The surgery was deferred and a subsequent CT scan showed an orbital haemangioma. This case highlights the importance of meticulous attention to eye-care for patients in the prone position.
Exophthalmos↗
Contrast sensitivity of patients with severe motor and intellectual disabilities and cerebral visual impairment.
We attempt to evaluate the residual visual capacities of nine patients (seven males and two females; age range 4 to 35 years, mean 13.8 +/- 9.98) with cerebral visual impairment coupled with severe motor and intellectual disabilities by their contrast sensitivities to sine-wave gratings. Two methods were used for detecting the occurrence of ocular responses to stimuli: (1) detection of optokinetic nystagmus to drifting sinusoidal gratings by naked-eye observation and electronystagmography and (2) detection of ocular pursuit for a drifting Gabor patch by naked-eye observation. We succeeded in measuring the sensitivities of eight cases. For the remaining one case, only the Gabor method could be applied. Most cases showed low contrast sensitivity in both higher (2 and 4 cycles/degree) and lower (0.125 and 0.25 cycles/degree) spatial frequencies and relatively high contrast sensitivity in the middle (0.5 and 1 cycle/degree) range of spatial frequencies. We conclude that the residual visual capacities of patients with severe motor and intellectual disabilities and cerebral visual impairment can be measured fairly accurately by these behavioral methods.
Adolescent↗
Optic pathway gliomas in children with and without neurofibromatosis 1.
Optic pathway gliomas represent 2 to 5% of brain tumors in children. Frequently asymptomatic, sometimes they demonstrate rapid growth, causing considerable visual dysfunction, neurologic deficits, and endocrine disturbances. Most optic pathway gliomas are diagnosed in patients with neurofibromatosis 1. Little is known about their natural course; therefore, there are no clear and widely accepted guidelines for their treatment. This study compared the clinical manifestations and natural history of sporadic and neurofibromatosis 1-associated optic pathway gliomas with regard to age at diagnosis, gender, and findings on neurologic, ophthalmologic, and neuroradiologic examinations in 83 children with optic pathway gliomas: 51 children with neurofibromatosis 1 and 32 children without any symptoms or signs of neurofibromatosis 1. A prospective study was performed in 21 patients with neurofibromatosis 1. In the rest of the patients with neurofibromatosis 1 and in 32 children with sporadic tumors, the analysis was carried out retrospectively. There was an increased incidence of females in the group of patients with neurofibromatosis 1 with optic pathway gliomas compared with the entire group of patients with neurofibromatosis 1 remaining for follow-up (P = .013). All optic pathway gliomas were found in children below 10 years of age, slightly earlier in the group without neurofibromatosis 1 (median age 4.6 vs 4.8 years). Children with optic pathway gliomas associated with neurofibromatosis 1 had predominantly multifocal lesions (P = .0001), whereas in the group without neurofibromatosis 1, isolated chiasmal involvement was more common (P = .002). Children with sporadic gliomas had significantly more frequently increased intracranial pressure, decreased visual acuity, and abnormalities of fundus of the eye at the time of diagnosis. The radiologic progression, visual deterioration, and endocrinologic complications were documented on follow-up more commonly in children with sporadic tumors. Our findings support the concept that there is an earlier and more severe clinical presentation of optic pathway gliomas in children with sporadic tumors than in those associated with neurofibromatosis 1.
Adolescent↗
Neuropsychiatric factors in the illusion of visitors among geriatric patients: a case series.
The 'illusion of visitors' is a common phenomenon among geriatric patients presenting for psychiatric or neurologic evaluation and treatment. Although these illusory beliefs are etiologically diverse, patients may commonly have visual impairment and functional and/or structural disruption of frontal and right-hemisphere-mediated cognitive functioning. This article outlines eight cases of illusory beliefs among elderly patients, presenting psychiatric, neurologic, neuroimaging, and neuropsychological findings among these patients. Commonalities and differences among these cases are discussed, and a framework is provided for multidisciplinary assessment and treatment of patients presenting with illusory beliefs.
Aged↗
Ophthalmologic aspects of pituitary apoplexy.
Pituitary apoplexy is an acute hemorragic or ischemic infarction in pituitary adenomas. The incidence in our series was 6.5%. Clinical diagnosis can often be difficult as the patient is frequently unaware of an existing adenoma (seven out of 11 patients). Therefore, the classic features of the syndrome must be known. They include sudden headaches, impairment of consciousness, endocrinological disturbances and sudden visual deterioration or oculomotor palsies. In this retrospective study from 1987 to 1994 of 14 patients presenting pituitary apoplexy there were 11 cases with visual abnormalities. Oculomotor palsies were more common (82%) than chiasmatic impairment (54.5%) and often revealed pituitary adenoma. CT-Scan and MRI examinations led to diagnosis, and emergency treatment (surgical removal by rhinoseptal approach or less often medical treatment) generally led to a regression of visual disturbances.
Adolescent↗
Neuroimaging, cognitive, and neurobehavioral outcomes following carbon monoxide poisoning.
Carbon monoxide is a colorless, odorless gas produced as a byproduct of combustion. Carbon monoxide is the leading cause of poisoning injury and death worldwide. Morbidity following CO poisoning includes neurologic sequelae, neuropathologic abnormalities on brain imaging, neurobehavioral changes, and cognitive impairments. It is estimated that as high as 50% of individuals with carbon monoxide poisoning will develop neurologic, neurobehavioral, or cognitive sequelae. Carbon monoxide related cognitive impairments included impaired memory, attention, executive function, motor, visual spatial, and slow mental processing speed. Given the high rate of brain related morbidity and the fact that the majority of carbon monoxide is avoidable, awareness and prevention of carbon monoxide poisoning is warranted.
Brain Injuries↗
Bioinformatics and medical informatics: collaborations on the road to genomic medicine?
In this report, the authors compare and contrast medical informatics (MI) and bioinformatics (BI) and provide a viewpoint on their complementarities and potential for collaboration in various subfields. The authors compare MI and BI along several dimensions, including: (1) historical development of the disciplines, (2) their scientific foundations, (3) data quality and analysis, (4) integration of knowledge and databases, (5) informatics tools to support practice, (6) informatics methods to support research (signal processing, imaging and vision, and computational modeling, (7) professional and patient continuing education, and (8) education and training. It is pointed out that, while the two disciplines differ in their histories, scientific foundations, and methodologic approaches to research in various areas, they nevertheless share methods and tools, which provides a basis for exchange of experience in their different applications. MI expertise in developing health care applications and the strength of BI in biological "discovery science" complement each other well. The new field of biomedical informatics (BMI) holds great promise for developing informatics methods that will be crucial in the development of genomic medicine. The future of BMI will be influenced strongly by whether significant advances in clinical practice and biomedical research come about from separate efforts in MI and BI, or from emerging, hybrid informatics subdisciplines at their interface.
Biomedical Research↗
Practice parameter: evaluation of the child with global developmental delay [RETIRED]: report of the Quality Standards Subcommittee of the American Academy of Neurology and The Practice Committee of the Child Neurology Society.
OBJECTIVE: To make evidence-based recommendations concerning the evaluation of the child with a nonprogressive global developmental delay. METHODS: Relevant literature was reviewed, abstracted, and classified. Recommendations were based on a four-tiered scheme of evidence classification. RESULTS: Global developmental delay is common and affects 1% to 3% of children. Given yields of about 1%, routine metabolic screening is not indicated in the initial evaluation of a child with global developmental delay. Because of the higher yield (3.5% to 10%), even in the absence of dysmorphic features or features suggestive of a specific syndrome, routine cytogenetic studies and molecular testing for the fragile X mutation are recommended. The diagnosis of Rett syndrome should be considered in girls with unexplained moderate to severe developmental delay. Additional genetic studies (e.g., subtelomeric chromosomal rearrangements) may also be considered in selected children. Evaluation of serum lead levels should be restricted to those children with identifiable risk factors for excessive lead exposure. Thyroid studies need not be undertaken (unless clinically indicated) if the child underwent newborn screening. An EEG is not recommended as part of the initial evaluation unless there are historical features suggestive of epilepsy or a specific epileptic syndrome. Routine neuroimaging, with MRI preferred to CT, is recommended particularly if abnormalities are found on physical examination. Because of the increased incidence of visual and auditory impairments, children with global developmental delay may undergo appropriate visual and audiometric assessment at the time of diagnosis. CONCLUSIONS: A specific etiology can be determined in the majority of children with global developmental delay. Certain routine screening tests are indicated and depending on history and examination findings, additional specific testing may be performed.
Algorithms↗
Spinal meningioma causing diffuse leptomeningeal enhancement.
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Adult↗
Diagnostic approaches to pituitary adenomas.
The utility of diagnostic tests for pituitary adenoma was compared in 12 patients. Endocrine and radiologic studies were always abnormal, even when neuro-ophthalmologic tests were normal. In most cases, both tomography of the sella turcica and CT scan revealed a mass in the region of the sella turcica. For more precise definition of suprasellar extension of the mass, metrizamide CT cisternography or tomographic pneumoencephalography with metrizamide provided similar details, although CT cisternography was much more easily done. Angiography provides a means to exclude an aneurysm or vascular malformation, a vascular tumor, or an aberrant course of the internal carotid artery.
Adenoma↗
Reversible alexia, mitochondrial myopathy, and lactic acidemia.
A 11-year-old boy of short stature had recurrent right temporal pounding headaches of 7 months' duration, and progressive visual loss for 3 days. There was a left hemianopia, alexia without agraphia, and diffuse muscle weakness. Investigation established the presence of a mitochondrial myopathy with pyruvate and lactic acidemia and increased serum content of sarcoplasmic enzymes. On treatment with prednisone, the patient's strength and reading skill improved, symptoms resolved, and muscle enzymes returned to normal. Three attempts to reduce steroids resulted in accentuation of symptoms, seizures, weakness, regression of reading skills, and elevation of serum enzymes. The alexia was also reversible.
Child↗
Occipital lobe infarctions: Perimetry and computed tomography.
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Adult↗
The anatomic basis of pure alexia.
The behavioral and anatomic correlates of pure alexia were analyzed in 16 patients. Right homonymous hemianopia failed to appear in three patients, who had right achromatopsia instead. Color anomia and unilateral optic ataxia were seen in six patients. Memory defects were found in two patients. Visual agnosia was noted in two. No patient had visual disorientation. The crucial anatomic correlate of alexia was a lesion of the paraventricular white matter of the left occipital lobe, capable of compromising both interhemispheric and intrahemispheric visual pathways. The lesion associated with color anomia was in the mesial occipitotemporal junction of the left hemisphere.
Adolescent↗
Percutaneous transvascular treatment of giant carotid aneurysms: neuro-ophthalmologic findings.
Twelve of 17 patients with cavernous carotid aneurysms had balloon embolization directed through a percutaneous double lumen catheter for progressive pain, ophthalmoplegia, or visual loss. Functional angiography was carried out with systemic heparinization and double-lumen balloon catheters to test tolerance to carotid occlusion. Eleven were successfully treated, though two patients with initial preservation of the ipsilateral carotid artery had unplanned deflation of the balloon, necessitating re-embolization. No serious permanent neurologic complications occurred. All patients had complete resolution of pain, and nine had improvement in the extraocular eye muscle and lid function. Balloon trapping of the cavernous carotid artery, rather than placing the balloon directly into the aneurysm, resulted in involution of the aneurysm and decompression of the involved cranial nerves.
Adult↗
Tomographic mapping of human cerebral metabolism: subcortical responses to auditory and visual stimulation.
We measured cerebral glucose metabolism with positron computed tomography during audio-visual stimulation in 42 studies of 21 subjects. Metabolic activations and stimulus-induced asymmetries were examined in subcortical structures (thalamus, caudate, lenticular nuclei). Bilateral activations of the thalamus occurred with verbal stimuli. The head of the left caudate was activated when subjects used visual imagery as a strategy to identify sequences of tones. These two types of stimuli produced dominant (left) hemisphere cortical activations in this same group of subjects. Clinical evidence has implicated the participation of subcortical (thalamus and basal ganglia) structures in the processing of language and auditory information. The present results demonstrate this functional role directly in normal subjects.
Acoustic Stimulation↗
Ischemic lesions of the occipital cortex and optic radiations: positron emission tomography.
We used 18-F-fluoro-2-deoxyglucose positron emission tomography (PET) and computed tomography (CT) to study eight patients with homonymous hemianopias or quadrantanopias due to ischemic lesions of the visual pathways. Four patients with ischemic damage to all or part of the occipital lobe had decreased glucose metabolism in the affected region. Three patients with ischemic damage limited to the optic radiations had decreased glucose metabolism in the portion of striate cortex appropriate for the visual field defect. Changes in glucose metabolism frequently occurred in the undamaged ipsilateral thalamus and visual association areas.
Adult↗