Biomedical subjects

S H Wray

Publications and source records attributed to S H Wray.

At least 19 recordsLinked to original sources

PubMed1997

Pupil dilation to tropicamide is not specific for Alzheimer disease.

BACKGROUND: The extent of pupil dilation after instillation of a dilute tropicamide solution was proposed as a noninvasive neurobiological diagnostic test for Alzheimer disease (AD). Pupils in patients with AD dilated 23% vs only 5% in control subjects. OBJECTIVE: To determine whether pupil dilation in response to tropicamide distinguishes patients with AD from control subjects without dementia. METHODS: There were 50 patients with AD and 51 control subjects; no participant had primarily ocular pathological conditions or took drugs that affected cholinergic tone. All participants received 1 drop of 0.01% tropicamide in 1 eye and 1 drop of 0.9% saline solution in the other eye in random order. Pupil measurements were obtained using a pupil and corneal reflection tracking system (RK-426 PC system, ISCAN Inc, Burlington, Mass) that illuminated the eye with a low-level infrared source and measured pupil diameters, fixation, and light level every 16.7 milliseconds during each 30-second-measurement. Pupil measurements were obtained from each eye at baseline and 5, 10, 15, and 30 minutes after drop instillation. RESULTS: The increase in pupil size after tropicamide instillation was equal between patients with AD and control subjects. The mean (+/- SD) pupil diameter increased from 4.5 +/- 1.1 to 5.5 +/- 1.1 mm after 30 minutes in patients with AD and from 4.7 +/- 0.9 to 5.8 +/- 0.9 mm in control subjects. Anisocoria and the mean rate of dilation did not differ between patients with AD and control subjects. Eye color and corneal moisture did not affect these results. The extent of pupil dilation in patients with AD was not related to clinical estimates of dementia severity. CONCLUSION: Pupil dilation in response to instillation of 0.01% tropicamide is not useful as an antemortem diagnostic test for AD.

Aged↗

PubMed1995

Visual processing in migraineurs.

Twelve migraine subjects with aura and 12 matched control subjects performed four computerized visual tasks. Because chronic electroencephalographic and regional cerebral blood flow abnormalities in posterior brain functions have been documented during interictal periods, migraine subjects were tested between migraine attacks. Two tasks, orientation detection and temporal order judgement, were devised to examine 'low-level' visual processes. The results were compared with results from two tasks, picture naming and word priming, that were devised to examine 'high-level' visual processes. Regarding the response time data across all four tasks, the migraine group was faster in the two low-level tasks. There were no differences in error rate in any of the four tasks. The migraineur's apparent response time advantage in the low-level tasks provides a psychophysical corroboration of their assumed oversensitivity to visual stimuli. The remaining two tasks, picture naming and word priming, which involve the use of previously stored information, do not distinguish migraineurs from matched control subjects. These results suggest that migraineurs are better in low-level visual processing, in that the signals to the primary visual cortex (Area V1) are processed more rapidly, but this hypersensitivity does not carry over to the subsequent processing stages (beyond V1 to superior parietal and inferior temporal cortices), as evidenced by the absence of a response time advantage in the two higher-level vision tasks.

Adult↗

PubMed1995

Optic neuritis: guidelines.

A major breakthrough in the therapy of demyelinating disease has recently been disclosed by the Optic Neuritis Treatment Trial. Over the past 6 years the trial has accumulated evidence that a high dose of corticosteroids taken to treat patients with an isolated acute attack of optic neuritis reduces the rate at which multiple sclerosis develops over a 2-year period of follow-up. The findings of the trial have had an immediate impact on the neuro-ophthalmic and neurologic community in the USA; therefore, I have focused my review on this important topic.

Clinical Protocols↗

PubMed1995

MR of the brain in mitochondrial myopathy.

PURPOSE: To determine the spectrum of MR findings in patients with mitochondrial myopathy and correlate them with central nervous system symptoms and signs. METHODS: We performed a prospective evaluation of the MR findings of eight patients with mitochondrial myopathy (three with Kearns-Sayre syndrome and five with chronic progressive external ophthalmoplegia), six of whom had central nervous system symptoms or signs (ataxia, sensorineural hearing loss, or cognitive dysfunction). RESULTS: All six patients with neurologic symptoms or signs had multiple abnormal MR findings, whereas patients without neurologic symptoms had either normal MR findings (one patient) or the solitary finding of cortical atrophy (one patient). Abnormal MR findings consisted of cerebral cortical atrophy (seven patients), cerebellar atrophy (six patients), and hyperintense signal abnormalities on T2-weighted images within the cerebral white matter (three patients), cerebellar white matter (one patient), basal ganglia (three patients), brain stem (one patient), and thalamus (one patient). In two patients, the cerebral white matter signal abnormalities were primarily peripheral and involved the arcuate fibers. All patients with ataxia had abnormal cerebellar findings on MR imaging, but there was poor correlation between other neurologic features and MR findings. CONCLUSIONS: Cerebral and cerebellar atrophy are the most common MR findings in Kearns-Sayre syndrome and chronic progressive external ophthalmoplegia. White matter and deep gray nuclei abnormalities, presumed to result from the diffuse spongiform encephalopathy reported in these patients, can also be seen. Patients with abnormal neurologic findings typically have multiple abnormalities on MR imaging, which frequently do not correlate with specific symptoms.

Adult↗

PubMed1995

Functional MR of brain activity and perfusion in patients with chronic cortical stroke.

PURPOSE: (1) To determine whether functional MR can reliably map functional deficits in patients with stroke in the primary visual cortex; (2) to determine whether functional MR can reliably map perfusion deficits; and (3) to determine whether functional MR can give any additional diagnostic information beyond conventional MR. METHODS: Seven patients who had had a stroke in their primary visual system were examined using two functional MR techniques: (1) dynamic susceptibility contrast imaging, and (2) cortical activation mapping during full-field visual stimulation. Maps of relative cerebral blood volume and activation were created and compared with visual field examinations and conventional T2-weighted images on a quadrant-by-quadrant basis in five of these patients. RESULTS: Visual field mapping matched with both T2-weighted conventional images and activation mapping of 16 of 18 quadrants. In two quadrants, the activation maps detected abnormalities that were present on the visual field examination but not present on the T2-weighted images nor on the relative cerebral blood volume maps, which may indicate abnormal function without frank infarction. In addition, the activation maps demonstrated decreased activation in extrastriate cortex and had normal T2 signal and relative cerebral blood volume but was adjacent to infarcted primary cortex, mapping in vivo how stroke in one location can affect the function of distant tissue. CONCLUSION: Functional MR techniques can accurately map functional and perfusion deficits and thereby provide additional clinically useful information. Additional studies will be needed to determine the prognostic utility of functional MR in stroke patients.

Aged↗

PubMed1993

Neuropathic findings in oculopharyngeal muscular dystrophy. A report of seven cases and a review of the literature.

We describe seven patients with clinical evidence of oculopharyngeal muscular dystrophy. Four of these patients were members of the same Italian-American family. The age at onset was after the fourth decade in all patients. All seven patients had extraocular muscle involvement, and six of the seven patients had clinical, electrophysiological, and/or pathological evidence of neuropathy in addition to features that were suggestive of myopathy. An autopsy was performed on one patient. We discuss the significance of the concurrence of neuropathic features with oculopharyngeal muscular dystrophy in relation to these patients and previously reported cases.

Aged↗

PubMed1993

The management of acute visual failure.

This review of acute visual failure covers the clinical manifestations and management of ocular strokes CRA occlusion, BRA occlusion and AION. The diagnostic process for each patient requires meticulous attention to: 1. Blood pressure, heart rate and rhythm, palpation of the temporal arteries, and auscultation of the heart, neck, eyes and head. 2. Dilated funduscopic examination. 3. Immediate blood tests: complete blood count, PT, PTT, platelet count, ESR, fibrinogen level, fasting blood sugar, cholesterol, triglyceride and blood lipids. A test for antiphospholipid antibodies (ACLA and LA) is recommended in unexplained cases of CRA occlusion. Non-invasive investigations should utilise a battery of tests: 1. Carotid non-invasive studies; the useful tests give information about the presence of a haemodynamic lesion (Dopper ultrasonography and oculoplethysmography), analyse the bruit to determine the residual lumen diameter (phonoangiography), or image the artery with ultrasound (B-Scan ultrasonography). 2. Two-dimensional echocardiogram Invasive investigations are required in selected patients: 1. A temporal artery biopsy 2. A carotid arteriogram if the patient is a candidate for endarterectomy. The patient can be screened first with a non-invasive MRA of the neck and brain. 3. A timed FFA, particularly in cases of CRA occlusion when occlusion of the ophthalmic artery is suspected, in cases of AION of possible embolic origin or in AION to document the position of the watershed zone of the choroidal circulation and its relation to the optic nerve head. Emergency treatment in CRA occlusion is designed to lower intra-ocular pressure and dislodge the embolus. In impending CRA occlusion heparin is useful. Urgent systemic corticosteroids are needed when CRA occlusion, or AION are due to arteritis. In other situations treatment is directed towards preventing recurrence or involvement of the other eye by reducing or eliminating identified risk factors.

Blindness↗

PubMed1992

The pattern visual evoked potential and pattern electroretinogram in drusen-associated optic neuropathy.

Sixteen patients (29 eyes) with optic disc drusen were studied prospectively for clinical and electrophysiologic evidence of impaired optic nerve conduction. Abnormalities were detected in the following areas: visual acuity, eight (28%) of 29 eyes; kinetic visual field, 22 (76%) of 29 eyes; results of Farnsworth-Munsell 100-Hue test, 12 (41%) of 29 eyes; and flash visual evoked potential, 13 (54%) of 24 eyes. Simultaneous pattern visual evoked potentials and results of pattern electroretinograms were recorded. The P100 latency of the pattern visual evoked potential was prolonged in 41% of eyes. The P50 and N95 components of the pattern electroretinogram were also analyzed. The P50 amplitude was reduced in only four (17%) of 24 eyes. The most common abnormality was a reduction in amplitude or the absence of the N95 component in 19 (79%) of 24 eyes, reflecting ganglion cell dysfunction. The data support mounting evidence that the P50 and N95 components of the pattern electroretinogram have different retinal origins.

Adolescent↗

PubMed1991

Anti-Ri: an antibody associated with paraneoplastic opsoclonus and breast cancer.

The serum and cerebrospinal fluid (CSF) of 8 women with ataxia, 6 of whom also had eye movement abnormalities believed to be opsoclonus, were found to contain a highly specific antineuronal antibody we call anti-Ri. Seven of the 8 women also had or developed cancer: carcinoma of the breast in 5, adenocarcinoma in an axillary lymph node in 1, and carcinoma of the fallopian tube in 1. Four patients presented with the neurological disorder; the cancer was diagnosed first in the other 4. Immunohistochemical studies using serum or CSF from all 8 patients revealed a highly specific antibody interaction with central nervous system neuronal nuclei but not with glial or other cells; the titer ranged from 1:5,000 to 1:320,000 in serum and from 1:2,000 to 1:16,000 in CSF. Biotinylated IgG from the patients' serum reacted with the tumors of 3 of 4 patients with anti-Ri antibody but not with breast cancers from patients without anti-Ri antibody. Immunoblots against cerebral cortex neuronal extracts identified protein antigens of 55-kd and 80-kd relative molecular mass. Serum titers by immunoblot ranged from 1:500 to more than 1:40,000 and CSF titers, from 1:10 to 1:2,000. The relative amount of anti-Ri was always higher in CSF than in serum. The antibody was not present in sera from normal individuals; patients with breast cancer without opsoclonus; other patients with opsoclonus; or patients with other paraneoplastic syndromes related to breast, ovarian, or small-cell lung cancer. We conclude that the presence of anti-Ri antibody identifies a subset of patients with paraneoplastic ataxia and eye movement disorders (opsoclonus) who usually suffer from breast or other gynecological cancer; the antibody when present is a useful marker for an underlying malignancy.

Aged↗

PubMed1991

Uhthoff's symptom in optic neuritis: relationship to magnetic resonance imaging and development of multiple sclerosis.

Eighty-one patients with a first attack of isolated optic neuritis, 40 with Uhthoff's symptom (Group 1) and 41 without (Group 2), were studied. All had a neurovisual examination, 74 of 81 patients had the pattern visual evoked potential recorded at rest, and 43 had magnetic resonance imaging brain scans. The pattern visual evoked potential P100 latency was prolonged, Group 1 with a mean of 136 +/- 19 msec. Group 2 with a mean of 131 +/- 19 msec (control subjects, 102 +/- 5 msec; n = 84), and the P100 amplitude was reduced, without significant difference between the groups. Abnormal magnetic resonance imaging scans were present in significantly more patients in Group 1 (p less than 0.025). Treatment of optic neuritis with corticosteroids had no effect on the evolution or duration of Uhthoff's symptom. Overall, 35 of 81 (43%) patients, followed for a mean of 3.5 years, developed multiple sclerosis. The incidence was significantly greater in Group 1 (p less than 0.01). Uhthoff's symptom also correlated with a higher incidence of recurrent optic neuritis. We conclude that Uhthoff's symptom is a prognostic indicator for the early development of multiple sclerosis.

Acute Disease↗

PubMed1991

Bee sting optic neuritis. A case report with visual evoked potentials.

Simultaneous recordings of the pattern visual evoked potential and the pattern electroretinogram were recorded in a case of unilateral optic neuritis following a bee sting on the eye. The patient presented with severe eye pain, apoplectic visual loss, acute optic disc swelling and minimal signs of ocular inflammation and eyelid edema. The vision failed to recover. The electrophysiological recordings initially showed a delay in the P100 wave of the pattern visual evoked potential. On follow-up, a normal latency and amplitude of the P50 wave of the pattern electroretinogram was recorded with the flattening of the N95 component, but the pattern visual evoked potential was absent. The data suggests that the optic nerve was demyelinated acutely, and that subsequently axonal loss and degeneration of retinal ganglion cells occurred.

Adult↗

PubMed1988

An antineuronal autoantibody in paraneoplastic opsoclonus.

Sera from 7 patients with paraneoplastic opsoclonus were examined for antineuronal autoantibodies. An antibody against neuronal nuclei was found in serum from a patient with breast cancer, opsoclonus, and ataxia. This antibody recognized 53- to 61-kDa and 79- to 84-kDa antigens in immunoblots of neurons. Antineuronal antibodies were not found in other patients with paraneoplastic opsoclonus.

Adult↗

PubMed1988

The pattern electroretinogram: a long-term study in acute optic neuropathy.

We report a 2-year prospective study of the electroretinographic response to reversal of checkerboard patterns (P-ERG) obtained in 63 eyes with acute optic nerve lesions. The aim of the study was to document the value of P-ERG regarding diagnosis and prognosis of four types of optic neuropathy: optic neuritis, compressive or hereditary optic atrophy, and traumatic optic neuropathy. We documented visual loss by neuro-ophthalmologic examination and recorded pattern-reversal visual evoked potentials (P-VEP). The initial P-ERG was normal to large- and medium-sized checks in 89% and the P-VEP abnormal in 94% of eyes with acute optic nerve lesions. Forty-six eyes were followed for up to 2 years. Two groups emerged. Group A (n = 17) gradually and permanently had significant reduction of the P-ERG to three separate check sizes. All 17 had no improvement in acuity better than 20/100, retained centrocecal scotomas, and developed optic atrophy. In group B (n = 29) the P-ERG remained within normal limits to one or more check sizes. Twenty-two of these eyes recovered acuity to 20/25 or better and had resolution of the field defect. The data showed that P-VEP was superior to P-ERG in diagnosis of acute and chronic optic nerve lesions. However, significant reduction of the b-wave of the P-ERG to three separate check sizes correlated closely with failure of visual recovery and the eventual development of severe optic atrophy, suggesting a prognostic value for P-ERG in optic neuropathy.

Adolescent↗

PubMed1987

Contrast visual testing in neurovisual diagnosis.

Contrast visual testing (CVT) is a psychophysical visual test of undetermined diagnostic capability in many neurovisual disorders. CVT of 32 controls and 39 patients was compared with the pattern visual evoked response (PVER) from each group. CVT was more sensitive than PVER in detecting visual dysfunction in pseudotumor cerebri and subclinical optic neuritis and showed potential in distinguishing papilledema from pseudopapilledema. PVER was more sensitive than CVT in detecting subclinical visual dysfunction in MS and optic nerve compression. Neither was abnormal in asymptomatic Leber's optic neuropathy. In nonorganic visual loss, CVT data were variable and inconsistent, supporting this diagnosis; PVER was consistently normal. Although in certain disease conditions, each detected subclinical visual dysfunction, neither CVT nor PVER provided specific information leading to an etiologic diagnosis.

Adolescent↗

PubMed1985

Spatial vision in Alzheimer's disease. General findings and a case report.

Visual contrast sensitivity to sinusoidal gratings of five spatial frequencies was measured in 15 patients with Alzheimer's disease and in eight control subjects. Contrast sensitivity thresholds were elevated at all frequencies in 14 patients compared with control subjects. The 15th patient was unique: she had an impairment in object and face recognition so severe that she could not recognize her husband visually. Her sensitivity to low and intermediate frequencies was markedly reduced in relation to that of other patients, whereas her sensitivity to the highest frequency tested equaled theirs. These observations emphasize the importance of low spatial frequency information for visual object and face recognition.

Blood Physiological Phenomena↗

PubMed1983

Chronic progressive external ophthalmoplegia (CPEO): clinical, morphologic, and biochemical studies.

We studied skeletal muscles from eight chronic progressive external ophthalmoplegia patients with ragged-red fibers (group A), five CPEO patients without ragged-red fibers (group B), and five controls. The EM morphometric fraction of structurally abnormal mitochondria was increased in group A, and there was a similarly increased fraction of normal-appearing mitochondria in group B. State 3 respiration and uncoupled respiration were severely decreased in both groups. The morphometric mitochondrial fraction and respiratory functions were inversely related in all three groups. The cytochrome content in group A was normal; cytochromes b and cc1 were decreased in group B. These studies point to a central role of mitochondrial dysfunction in all types of CPEO, but the basic abnormalities remain to be elucidated.

Adult↗

PubMed1983

The one-and-a-half syndrome--a unilateral disorder of the pontine tegmentum: a study of 20 cases and review of the literature.

The one-and-a-half syndrome is a clinical disorder of extraocular movements characterized by a conjugate horizontal gaze palsy in one direction plus an internuclear ophthalmoplegia in the other. The syndrome is usually due to a single unilateral lesion of the paramedian pontine reticular formation or the abducens nucleus on one side (causing the conjugate gaze palsy), with interruption of internuclear fibers of the ipsilateral medial longitudinal fasciculus after it has crossed the midline from its site of origin in the contralateral abducens nucleus (causing failure of adduction of the ipsilateral eye). Twenty cases are reported; 14 had multiple sclerosis.

Abducens Nerve↗

PubMed1982

Quantitative histopathologic assessment of developing phenytoin-induced gingival overgrowth in the cat.

Phenytoin (Dilantin) induces gingival overgrowth characterized by an accumulation of connective tissue The cell-to-matrix ratio in the mature lesion is normal, yet there must be more fibroblasts per oral cavity if there is excessive tissue mass. Using a mongrel cat model system, we studied the early, developing phenytoin-induced lesion by quantitating fibroblasts per unit of tissue in papilla biopsies collected over a 3-month period of daily drug administration. At 6 and 8 weeks, the number of fibroblasts per unit of tissue increased dramatically. By 3 months, as the lesions matured, the fibroblast-to-matrix ratio returned to normal. We suggest that the drug interacts with resident gingival fibroblasts, causes them to proliferate and thus induces a true, but transient, hypercellularity. Cell division then appears to slow or cease, and rapid production of connective tissue matrix ensues, returning the cell-to-matrix ratio to normal.

Animals↗