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At least 595 records · Page 33Linked to original sources
PubMed1989

Loss of spontaneous blinking in a patient with Balint's syndrome.

A patient with Balint's syndrome caused by bilateral parieto-occipital lesions lost spontaneous blinking, suggesting that humans, like nonhuman primates, have parietal lobe neurons that are important for blinking. Although the functions of spontaneous blinking are not known, they may help initiate some saccades and, like saccades, be involved in the cancellation of thalamic inhibitory postsynaptic potentials, thereby facilitating processing of new foveal targets. Spontaneous blinking may also facilitate sensory relay during sustained attention and, therefore, help prevent fading of a retinal image.

Adult↗
PubMed1999

Anatomy of sensory findings in patients with posterior cerebral artery territory infarction.

BACKGROUND: Posterior cerebral arteries (PCAs) supply the ventrolateral thalamic sensory nuclei and white matter sensory tracts to the somatosensory parietal cortex. Patients with PCA territory strokes often have visual, memory, cognitive, and sensory signs. Clinicoanatomic correlation of visual, cognitive, and memory functions are well defined but, to our knowledge, no systematic study has analyzed the anatomy of sensory abnormalities. OBJECTIVE: To assess the frequency and anatomic correlation of sensory symptoms and signs in patients with PCA territory infarction. PATIENTS AND METHODS: Sixty patients with hemispheral and hemispheral and deep PCA territory infarcts apparent on computed tomographic and magnetic resonance imaging scans were studied for the presence of sensory findings and location of infarcts. RESULTS: Sensory symptoms or signs were present in 15 (25%) of 60 patients. Among patients with sensory findings, 11 of 15 had infarcts in the ventrolateral thalamus in the territory of the thalamogeniculate or lateral posterior choroidal arteries. The other 4 patients had no ventrolateral thalamic or white matter infarction but had severe proximal vascular occlusive lesions that could have caused temporary thalamic ischemia. One of these 4 patients had a medial thalamic infarct and transient hemisensory symptoms. Twelve patients had thalamic infarcts and no recorded sensory findings. Seven patients with thalamic infarcts (6 medial and 1 ventrolateral) had no sensory findings, and sensory findings could not be accurately assessed in 4 patients with ventrolateral and 1 patient with medial thalamic infarcts. CONCLUSIONS: All patients with PCA territory infarcts and sensory findings either had thalamic infarcts in thalamogeniculate or lateral posterior choroidal artery territory or had thalamic ischemia. Sensory findings in PCA territory infarction indicate ventrolateral thalamic ischemia.

Cerebral Arterial Diseases↗
PubMed2006

Hypertropia associated with superolateral translation of the superior rectus muscle pulley in unilateral coronal synostosis.

OBJECTIVE: To explore the mechanisms underlying the hypertropia associated with unilateral coronal synostosis. METHODS: In 13 patients with unilateral coronal synostosis, we measured gaze-dependent binocular alignment before and after strabismus surgery, assessed the superior rectus muscle (SRM) pulley using computed tomography, and simulated posterior displacement of the trochlea and superolateral displacement of the SRM pulley. RESULTS: All the patients had an ipsilateral hypertropia in primary gaze (3-30 diopters) that increased in contralateral gaze and decreased in ipsilateral gaze and that simulated an inferior oblique muscle overaction. Strabismus surgery fully or partially corrected the hypertropia in only 7 of 11 patients. High-resolution computed tomography demonstrated that the pulley of the SRM relative to the inferior rectus muscle was translated 0 to 11.0 mm laterally and up to 2.7 mm vertically. Lateral translation (up to 10 mm) alone or combined with vertical translation (up to 5 mm) of the SRM pulley in the simulated model produced a hypertropia with lateral incomitance. Posterior translation (15 mm) of the trochlea did not induce a significant hypertropia. CONCLUSION: Superolateral translation of the SRM pulley creates an imbalance of muscle pulling forces that better accounts for the hypertropia than posterior displacement of the trochlea.

Child↗
PubMed1981

Transorbital approach to decompression in Graves' disease.

Patients with Graves' disease have an increased volume of orbital tissue that sometimes results in serious functional and cosmetic problems. Visual loss may result from optic nerve compression in the orbital apex. Surgical decompression provides space for expansion of orbital tissues and often results in dramatic improvement. A transorbital approach to decompression of the orbit, appropriate for the ophthalmologist with adequate orbital experience, is presented. A lower eyelid incision is used in the manner of exploring a blow-out fracture. The majority of the orbital floor and the entire ethmoidal complex are removed. Removal of bone to the orbital apex is emphasized in cases of optic neuropathy. A comparative study of the indications, results, and complications of this procedure vs other techniques of decompression for Graves' disease is presented in a companion article.

Ethmoid Bone↗
PubMed1983

Chiasmatic and hypothalamic extension of optic nerve glioma.

An 11-year-old boy was found to have a left optic nerve glioma confined to the orbit and optic canal by clinical examination and computed tomographic (CT) scanning. Repeated neuroradiologic examinations demonstrated intracranial extension of tumor to involve the hypothalamus and third ventricle. Following craniotomy and verification of the diagnosis of glioma by biopsy, the patient underwent a course of radiotherapy that resulted in marked tumor regression. The potential for growth of optic nerve gliomas mandates careful neuroradiologic follow-up regardless of whether there is ophthalmologic deterioration. The natural history of "optic gliomas" remains unknown.

Cerebral Ventricles↗
PubMed1985

Quantitative computed tomography of Graves' ophthalmopathy. Extraocular muscle and orbital fat in development of optic neuropathy.

Quantitative assessment of computed tomographic (CT) scans was performed on 98 orbits of 49 patients with Graves' ophthalmopathy. Extraocular muscle volume and orbital fat volume were determined, according to whether optic neuropathy was absent, had developed during follow-up, or was present at the time of scanning. No differences in muscle volume were found between the group already having optic neuropathy and the group in which optic neuropathy developed during follow-up. Both optic neuropathy groups, however, had significant increases in extraocular muscle volume compared with the group without optic neuropathy. The absolute amount of orbital fat was the same for all groups, but the relative amount of orbital fat tended to decrease as total orbital volume increased with development or presence of optic neuropathy. This study establishes a quantitative relationship between optic neuropathy and extraocular muscle enlargement in Graves' ophthalmopathy. Orbital fat, however, does not play an important role in the disease.

Adipose Tissue↗
PubMed1986

Intracranial extension and bone destruction in orbital pseudotumor.

Three cases of surgically proved pseudotumor of the orbital apex with intracranial extension occurred. All demonstrated bony destruction. Varying degrees of ophthalmoplegia and visual loss were present in all three. Previous computed tomographic descriptions of the patterns of orbital pseudotumor have not included bone destruction. Further, intracranial extension has been reported in only one patient. These three cases are reported to emphasize the fact that while these manifestations may be rare, it is appropriate to include orbital pseudotumor in the differential diagnosis of orbital apex lesions that are associated with both bone destruction and/or intracranial extension.

Aged↗
PubMed1987

Visual recovery from hypoxic cortical blindness during childhood. Computed tomographic and magnetic resonance imaging predictors.

We reviewed the clinical courses and computed tomographic (CT) and magnetic resonance imaging (MRI) scans of 30 infants and children with cortical blindness following hypoxic insults. The degree of injury to the striate and parastriate cortices and the area of the optic radiations were graded from 0 to 4 by a neuroradiologist. Only two children had normal scans of the posterior visual pathway and both had favorable visual outcomes. The visual recovery differed significantly with respect to the age at which the hypoxic insult occurred and CT and MRI abnormalities in the area of the optic radiations, but not with abnormalities in the striate or parastriate cortices. Our results suggest that CT and MRI scanning are helpful in prognosticating the visual potential of children with hypoxic cortical blindness.

Age Factors↗
PubMed1988

Optic nerve sheath decompression for pseudotumor cerebri.

We studied optic nerve sheath decompressions for pseudotumor cerebri performed at the Kresge Eye Institute, Detroit, over the past year. Six patients (ten eyes) were operated on. Visual function improved in all ten eyes. A decision to operate was based on progressive loss of visual acuity or visual field unresponsive to medical therapy, accompanied by echographic evidence of a distended optic nerve sheath (positive 30 degrees test). Follow-up ranged from four to 11 months. Four patients underwent subarachnoid iopamidol (Isovue) contrast injection followed by orbital computed tomography. The subarachnoid space totally filled in all patients. No evidence of fibrosis or obstruction of the optic nerve sheath existed; however, leakage of dye from the optic nerve sheath could not be demonstrated. Postoperative complications included transient diplopia and transient atonic pupil (one patient each). Our results indicate that optic nerve sheath decompression improves and protects visual function in patients with pseudotumor cerebri who demonstrate progressive visual field loss and fluid in the optic nerve sheath.

Adult↗
PubMed1985

X-linked progressive mixed deafness with perilymphatic gusher during stapes surgery.

Stapes gusher is a rare and usually unexpected complication of stapes surgery. This complication will inevitably be encountered during stapes surgery in all affected males with the X-linked, progressive mixed deafness syndrome. The opportunity of studying eight affected males in a large Dutch family with audiometry, vestibulometry, and polytomography was used to identify specific features. Awareness of these features will assist the otologist in recognizing new cases preoperatively.

Child↗
PubMed1999

D-2-Hydroxyglutaric aciduria: biochemical marker or clinical disease entity?

D-2-Hydroxyglutaric aciduria has been observed in patients with extremely variable clinical symptoms, creating doubt about the existence of a disease entity related to the biochemical finding. An international survey of patients with D-2-hydroxyglutaric aciduria was initiated to solve this issue. The clinical history, neuroimaging, and biochemical findings of 17 patients were studied. Ten of the patients had a severe early-infantile-onset encephalopathy characterized by epilepsy, hypotonia, cerebral visual failure, and little development. Five of these patients had a cardiomyopathy. In neuroimaging, all patients had a mild ventriculomegaly, often enlarged frontal subarachnoid spaces and subdural effusions, and always signs of delayed cerebral maturation. In all patients who underwent neuroimaging before 6 months, subependymal cysts over the head or corpus of the caudate nucleus were noted. Seven patients had a much milder and variable clinical picture, most often characterized by mental retardation, hypotonia, and macrocephaly, but sometimes no related clinical problems. Neuroimaging findings in 3 patients variably showed delayed cerebral maturation, ventriculomegaly, or subependymal cysts. Biochemical findings included elevations of D-2-hydroxyglutaric acid in urine, plasma, and cerebrospinal fluid in both groups. Cerebrospinal fluid gamma-aminobutyric acid was elevated in almost all patients investigated. Urinary citric acid cycle intermediates were variably elevated. The conclusion of the study is that D-2-hydroxyglutaric aciduria is a distinct neurometabolic disorder with at least two phenotypes.

Biomarkers↗
PubMed1999

(15)O water positron emission tomography in language localization: a study comparing positron emission tomography visual and computerized region of interest analysis with the Wada test.

We compared (15)O water positron emission tomography (PET) auditory and visual confrontational naming activation with an intracarotid amobarbital (Amytal) injection procedure (IAP) for language lateralization in 12 patients with intractable epilepsy. PET scans were evaluated by three raters experienced in functional imaging as well as by a region of interest (ROI) approach. Compared with IAP, raters' positive predictive value for language lateralization ranged from 88 to 91%. ROI analysis had a positive predictive value of 80%. Six patients had surgery; 1 with right-sided IAP language dominance but left-sided PET activation had dysphasia for 6 months after left temporal lobectomy.

Adolescent↗
PubMed1986

Signs of focal posterior cerebral abnormality in early subacute sclerosing panencephalitis.

In 16 cases of subacute sclerosing panencephalitis (SSPE), praxis and visual spatial capacities were more impaired early in the disease than were language functions. Together with the electroencephalographic findings, this suggests that the early lesions in SSPE are more pronounced in the parietooccipital area than in the classic language areas. Other reports also support such a localization. Detection of the disease in its early phase when dressing apraxia and visual impairment predominate is important in conducting clinical trials of different therapeutic agents.

Adolescent↗