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Biomedical subjects

V Purvin

Publications and source records attributed to V Purvin.

At least 19 recordsLinked to original sources
PubMed1998

Optic neuritis.

Advances in magnetic resonance (MR) orbital imaging using fat suppression techniques and contrast enhancement have increased our ability to visualize the area of inflammation in patients with optic neuritis. Our understanding of the natural history of optic neuritis continues to expand. The high risk of developing multiple sclerosis (MS) after an episode of optic neuritis has been confirmed with longitudinal studies. The most important predictive factor for the future development of MS continues to be an abnormal MR image at presentation. Treatment with intravenous steroids temporarily reduces this risk but has no effect on visual outcome. Although subjective visual complaints are common, objective measures of vision show only mild loss in most patients.

Diagnosis, Differential↗
PubMed1998

Unilateral optic disc edema following trabeculectomy.

Two cases of a benign form of optic disc edema after successful trabeculectomy are reported. In both patients, optic disc edema was noted 2 to 4 weeks after trabeculectomy. The edema occurred without loss of visual acuity or field. The absolute intraocular pressure and intracranial pressure were normal--that is, the edema was not a syndrome of hypotony or pseudotumor cerebri. However, both patients had intracranial pressure in the high-normal range. The decrease in intraocular pressure into the low normal range after trabeculectomy may have altered the intracranial pressure:intraocular pressure ratio at the lamina cribrosa enough to produce optic disc edema.

Adult↗
PubMed1996

Persistent palinopsia following ingestion of lysergic acid diethylamide (LSD).

OBJECTIVE: To identify a distinctive chronic visual complication of lysergic acid diethylamide (LSD) use. DESIGN: Description of the clinical findings in three patients with this disorder. SETTING: A neuro-ophthalmology referral center. RESULTS: All three patients experienced prolonged afterimages (palinopsia) during LSD intoxication and have continued to be symptomatic up to 3 years after they ceased to ingest the drug. Results of neuro-ophthalmologic and neurologic examinations and neuroimaging and electrophysiologic studies were normal. CONCLUSIONS: We have described three patients in whom persistent palinopsia developed following ingestion of LSD. Clinicians should inquire about past LSD use in all patients who initially have seemingly spontaneous, isolated palinopsia. Recognition of this distinctive clinical syndrome associated with LSD use might avoid unnecessary anxiety and excessive diagnostic tests for patients with this disorder.

Adolescent↗
PubMed1996

Migraine precipitated by head trauma in athletes.

PURPOSE: To present the clinical features of a case of migraine precipitated by head trauma. METHODS: Detailed history was obtained and ophthalmic and neurologic examinations were performed. RESULTS: This patient's history of transient loss of vision followed by severe headache precipitated by a direct blow to the top of the head is characteristic of this phenomenon. Normal neurologic and opthalmic examination findings, normal magnetic resonance imaging, and a history of similar episodes are all consistent with this diagnosis. CONCLUSION: Familiarity with this entity can obviate an expensive examination for patients with these classic symptoms.

Adult↗
PubMed1989

Palinopsia as a presenting manifestation of Creutzfeldt-Jakob disease.

A 70-year-old man developed a syndrome of progressive nondominant parietal and occipital dysfunction including palinopsia and a visual field defect. Despite the marked focality of his clinical findings, radiologic studies were normal. Myoclonus and ataxia began 6 weeks after onset of his illness at which time brain biopsy confirmed Creutzfeldt-Jakob disease (CJD). This is the first reported case of palinopsia due to CJD.

Aged↗
PubMed1988

Chiasmal neuritis as a complication of Epstein-Barr virus infection.

A 13-year-old boy developed visual loss in association with an upper respiratory tract infection. Neuro-ophthalmologic examination indicated a lesion at the junction of the right optic nerve and chiasm. Laboratory investigation and subsequent serologic studies demonstrated recent Epstein-Barr virus infection, suggesting an association of chiasmal optic neuritis with Epstein-Barr virus infection.

Adolescent↗
PubMed1988

Varicella optic neuritis.

A 14-year-old girl developed severe bilateral optic neuritis 1 week after the onset of chickenpox. Though previous case reports state that complete recovery is the rule, this child had a persistent decrease in visual acuity in the right eye and loss of color vision and defects in visual fields in both eyes.

Adolescent↗
PubMed1988

Dopamine in paragangliomas of the glomus jugulare.

Glomus jugulare tumors have the ability to synthesize, store, and secrete biogenic amines. Although the majority of these tumors remain endocrinologically silent, on rare occasions they present either as a pheochromocytoma or with a carcinoid syndrome. We report a 20-year-old male with two intracranial tumors: an intrasellar neoplasm and a glomus jugulare tumor. Catecholamine catabolites in the urine were not increased, and blood pressure was always normal. The pituitary tumor was an adenoma, immunostaining positive for prolactin. The second patient, a 29-year-old hypertensive male, with a glomus jugulare tumor, had increased vanillylmandelic-acid excretion. In both cases, the paraganglioma tumor cells contained numerous dense-core vesicles (125 to 380 nm in diameter) in electron microscopy, and showed intense fluorescence by the sucrose-potassium phosphate-glyoxylic acid method. Using high-performance liquid chromatography and microspectrofluorometry we were able to establish the presence of large amounts of dopamine in the cytoplasm of the tumor cells.

Adenoma↗
PubMed1988

Evidence of orbital deformation in indirect optic nerve injury. Weight lifter's optic neuropathy.

A 16-year-old boy developed monocular visual loss due to optic neuropathy following frontal head trauma. His trauma was unique in that it consisted of a static loading force to the brow, rather than the dynamic impact more commonly associated with blunt orbital injuries. This case demonstrates the role of isolated deformation of orbital bones in the pathogenesis of indirect optic nerve injury.

Adolescent↗
PubMed1988

Recurrent anterior ischemic optic neuropathy in young adults.

Anterior ischemic optic neuropathy (AION) is primarily a disease of middle and late life. When it affects the young patient, AION is often due to a specific underlying disease process predisposing to vasculopathy. Reported here are two patients with AION in whom no evidence of associated disease was found. The tendency for recurrent attacks of disc ischemia distinguishes this clinical entity from the more common idiopathic form of AION of older individuals. Hypotheses regarding possible etiology are discussed.

Adolescent↗
PubMed1987

Ischemic optic neuropathy secondary to intracarotid infusion of BCNU.

A 39-year-old man with a left parietal malignant glioma was treated with intracarotid infusion of 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU). Five weeks after a second infusion, he developed inferior altitudinal visual field loss and pallid optic disc edema ipsilateral to the injection. Retinal vasculitis is a well-recognized complication of intra-arterial BCNU infusion. It is believed that this patient suffered a similar vasculopathy in the posterior ciliary artery circulation.

Adult↗
PubMed1984

Primary reticulum cell sarcoma of the brain presenting as steroid-responsive optic neuropathy.

A 23-year-old woman presented with subacute monocular visual loss clinically resembling optic neuritis. CT scan revealed a cerebellar mass, biopsy of which led to the diagnosis of reticulum cell sarcoma (RCS). Corticosteroid therapy resulted in improvement of vision and a decrease in disc edema; this resolution was documented radiographically. While optic nerve involvement is sometimes seen in association with systemic lymphoproliferative disease, optic neuropathy as a manifestation of primary cerebral RCS is rare.

Adult↗
PubMed1975

Isorhodopsin II: artificial photosensitive pigment formed from 9,13-dicis retinal.

We have found that in addition to the 11-cis and 9-cis isomers of retinal which are known to couple with the visual pigment apoprotein opsin to form pigments, a third isomer 9,13-dicis retinal also will form a pigment. That this isomer is indeed bound to opsin has been shown unequivocally by removing the chromophore without isomerization and subsequent identification by high-speed liquid chromatography. Using similar techniques, we have shown that the product of bleaching by light of all three pigments in Trition X-100 is the all-trans isomer. This specificity in the product of bleaching, as with many other properties of visual pigments, is not shared by the free chromophore. Of particular interest is that when 9,13-dicis retinal is combined with opsin to form a pigment, a single photon can isomerize it about two double bonds, to the all-trans isomer.

Binding Sites↗
PubMedDate not supplied

MRI and cerebral venous thrombosis.

Difficulties in the diagnosis of cerebral thrombosis are due to the nonspecificity of symptoms and signs and the infrequent occurrence on computed tomography (CT) of direct signs of cerebral sinus thrombosis, i.e. the empty delta sign and cord sign. We present two patients, a 2 4/12-year-old girl with nephrotic syndrome, coma, papilledema, and hyperdensity along the sagittal sinus on CT; and a 34-year-old man with headaches, episodic visual loss, papilledema and a normal CT following posterior fossa craniotomy. On MRI, there was increased signal in sagittal and straight sinuses in the first patient, and in the lateral sinus in the second patient. The increased signal from clot, and the absence of signal from flowing blood, make MRI the procedure of choice for the initial diagnosis of cerebral sinus thrombosis.

Adult↗
PubMedDate not supplied

Unilateral headache and ptosis in a 30-year-old woman.

A 30-year-old woman developed left-sided headaches and ipsilateral oculosympathetic paresis (Horner's syndrome) secondary to carotid dissection. Although she initially denied preceding trauma, further questioning revealed a pattern of physical abuse by her boyfriend, including an attempted strangulation shortly before onset of symptoms. This case highlights the need for increased awareness of domestic violence among health care providers.

Adult↗
PubMedDate not supplied

Progressive visual loss and motility deficit.

A 63-year-old female with known stage III, low grade non-Hodgkin's lymphoma presented with progressive visual loss in the left eye and binocular diplopia in all positions of gaze. The left globe was almost immotile. Two MRI's of the orbit were interpreted as normal. Lumbar puncture did not reveal abnormal cytology. Although orbital apex involvement is uncommon in non-Hodgkin's lymphoma, the patient's clinical findings clearly indicated a lesion in this area, which was confirmed by a third MRI. Review of one of the initial films showed evidence of orbital apex involvement. To prevent diagnostic delay and unnecessary repeat imaging, the clinical diagnosis of orbital apex syndrome should be clearly communicated to the radiologist. Prompt recognition of orbital apex syndrome may improve visual outcome.

Disease Progression↗