Thomas M. Bosley

Alzheimer's Disease with Prominent Visual Symptoms: Clinical and Metabolic Evaluation

The authors examined eight patients with dementia of the Alzheimers type (DAT), five with prominent visual symptoms early in the illness (VS) and three with no visual symptoms (NVS). Results of neuro-ophthalmologic examinations on VS patients showed relatively consistent abnormalities in figure copying, color vision tested by isochromatic plates, and stereopsis. Cerebral glucose metabolism determined by 18F-fluoro-2-deoxyglucose positron emission tomography (PET) was unchanged in primary visual cortex of VS and NVS patients compared with 12 normal volunteers of similar age and sex. Glucose metabolism in VS patients was decreased by 45 and 34% in left and right visual association cortex (P less than 0.01 and P less than 0.05, respectively) and 34 and 37% in left and right inferior parietal cortex (P less than 0.05) compared with controls; NVS patients had no significant metabolic alteration in these areas. Symptoms, physical examination, and metabolic imaging imply that these patients are a heterogenous but distinct clinical subgroup of DAT often with mild dementia who have visual symptoms due primarily to visual agnosia.

Recognition of Gonadotroph Adenomas in Women

BACKGROUNDnPituitary adenomas that arise from the gonadotroph cells are being recognized with increasing frequency in men, but they are still rarely recognized in women. This rarity could be the result of an actual difference in occurrence or of greater difficulty in recognition. The tumors are usually recognized in men more than 50 years old, but elevated serum gonadotropin levels in women of that age could be produced by normal gonadotroph cells.nnnMETHODSnBecause the stimulation of follicle-stimulating hormone (FSH), luteinizing hormone (LH), and the beta subunit of LH (LH beta) by thyrotropin-releasing hormone (TRH) is a characteristic of gonadotroph adenomas in men, we administered TRH to 16 women with apparently nonsecreting pituitary macroadenomas and measured serum FSH, LH, LH beta, and the glycoprotein hormone alpha subunit every 15 minutes for 90 minutes before and 90 minutes after. The results were compared with the responses in 16 healthy women matched for age and in 10 women with macroadenomas secreting prolactin, growth hormone, or corticotropin. The tumors from 12 of the women with nonsecreting adenomas were cultured, and the secretion of FSH, LH, and LH beta in culture was determined.nnnRESULTSnEleven of the 16 women with apparently nonsecreting adenomas had significant increases in serum LH beta in response to TRH, 3 had FSH responses, and 4 had LH responses. None of the 16 healthy women and none of the 10 women with secreting macroadenomas had LH beta, FSH, or LH responses to TRH. Ten of the 12 adenomas that were cultured secreted readily detectable amounts of FSH, LH, and LH beta, and their secretion in vitro correlated with the patients responses to TRH in vivo.nnnCONCLUSIONSnMost apparently nonsecreting pituitary macroadenomas in women arise from gonadotroph cells. The majority of these can be recognized, even in postmenopausal women, by the serum LH beta responses to TRH, and some can be recognized by the responses of serum FSH and LH.

Color Doppler imaging of the ocular ischemic syndrome

PURPOSEnThis study describes hemodynamic characteristics of the ophthalmic, central retinal, and posterior ciliary arteries in 16 eyes of 11 patients with the ocular ischemic syndrome. Understanding the hemodynamic characteristics of the retrobulbar circulation may elucidate the natural history and pathophysiology of the ocular ischemic syndrome and perhaps form the basis for rational treatment of this condition.nnnMETHODSnColor Doppler imaging, a procedure that permits rapid noninvasive imaging of the ophthalmic, central retinal, and posterior ciliary arteries, was used to quantitate peak systolic blood flow velocities and vascular resistance (pulsatility index) within these vessels in study group eyes and in an age-matched control population.nnnRESULTSnWe demonstrated markedly reduced ocular ischemic syndrome central retinal and posterior ciliary artery peak systolic velocities compared with control group eyes. Central retinal and posterior ciliary artery vascular resistance (pulsatility index) was greater in ocular ischemic eyes versus control group eyes. Reversal of ophthalmic artery blood flow was detected in 12 of 16 ocular ischemic syndrome eyes. Study group eyes with poor vision had no detectable posterior ciliary arterial blood flow.nnnCONCLUSIONnColor Doppler imaging quantitates hemodynamic characteristics of the retrobulbar circulation in the ocular ischemic syndrome. There is markedly reduced peak systolic velocity and increased vascular resistance in ocular end arteries such as the central retinal and posterior ciliary arteries. Ophthalmic artery reversal of flow seems to represent collateral blood flow to lower resistance vascular beds. Posterior ciliary artery hypoperfusion may correlate with poor vision in the ocular ischemic syndrome.

The Syndrome of Paradoxical Worsening of Dural-Cavernous Sinus Arteriovenous Malformations

Three patients with dural arteriovenous malformations contiguous with the cavernous sinus had marked worsening of their neuro-ophthalmic symptoms. Such clinical deterioration has been attributed traditionally to increased blood flow through the malformations into the superior ophthalmic vein. However, arteriography in all three patients and magnetic resonance imaging (MR) in two patients demonstrated thrombosis of the entire superior ophthalmic vein. All patients subsequently underwent spontaneous, complete resolution of symptoms. This report describes a clinical syndrome of paradoxical worsening of cavernous sinus malformations and indicates that MR will aid in the management of these vascular malformations.

Delayed radiation injury to the retrobulbar optic nerves and chiasm : clinical syndrome and treatment with hyperbaric oxygen and corticosteroids

Thirteen patients with delayed radiation injury to the optic nerves and chiasm were treated with hyperbaric oxygen (HBO) and corticosteroids. These patients experienced painless, abrupt loss of vision in one (6 patients) or both (7 patients) eyes between 4 and 35 months after receiving radiation doses of at least 4500 cGy to the region of the chiasm. Diagnostic evaluation including neuro-imaging and lumbar puncture showed no recurrent tumor and no other cause for visual loss. No patients vision improved during treatment or follow-up lasting between 1 and 4 years. There were no serious complications of treatment.

Color Doppler imaging provides accurate assessment of orbital blood flow in occlusive carotid artery disease.

Color Doppler imaging was used to evaluate the hemodynamics of the ophthalmic vasculature in a case of complete internal carotid artery occlusion. This procedure, which allows rapid, noninvasive imaging, showed a partial ophthalmic artery obstruction with absent flow in the central retinal artery, central retinal vein, and nasal posterior ciliary arteries. Although altered perfusion of the retinal vessels may be evaluated clinically, assessment of blood flow in the ophthalmic and ciliary arteries previously could be evaluated only indirectly by intravenous fluorescein angiography. The color Doppler imaging findings were confirmed by intravenous fluorescein angiography and carotid arteriography. Color Doppler imaging represents a noninvasive method to diagnose abnormal blood flow of the ophthalmic artery and its branches and to evaluate serial changes of the circulation in a noninvasive manner.

Optic Nerve Sheath Decompression May Improve Blood Flow in Anterior Ischemic Optic Neuropathy

PURPOSEnThe purposes of this study are to evaluate the retrobulbar circulation in progressive nonarteritic ischemic optic neuropathy (NAION) and to assess changes in blood flow after optic nerve sheath decompression (ONSD).nnnMETHODSnTwenty-five patients with progressive NAION were studied using color Doppler imaging (CDI) before and after ONSD. Blood flow velocities and vascular resistance were calculated for the ophthalmic artery, central retinal artery, and posterior ciliary arteries in each eye. Contralateral eyes served as the control group.nnnRESULTSnPreoperatively, the study group demonstrated significantly lower blood flow velocities in the central retinal artery (P < 0.002) and posterior ciliary arteries (P < 0.02) when compared with the contralateral control group. Postoperatively, there was a significant increase in blood flow velocity in the ophthalmic artery (P < 0.04) and the central retinal artery (P < 0.05) as well as a significant decrease in vascular resistance in the posterior ciliary arteries (P < 0.02) in the study group. There were no significant changes in blood flow velocity or vascular resistance in the contralateral control group. Long-term follow-up on eight patients suggests a persistence of this trend. Seventeen of the 25 operated eyes demonstrated a postoperative improvement in visual function, defined as a gain of two lines or more in Snellen visual acuity or at least 20 degrees of visual field expansion.nnnCONCLUSIONSnThese data demonstrate that eyes with acute NAION have impaired blood flow when compared with the contralateral control group. Furthermore, they suggest that ONSD may improve blood flow to the ischemic optic nerve halting the progression of visual loss and in some cases improving visual function.

Modified Optic Nerve Decompression in Patients with Functioning Lumboperitoneal Shunts and Progressive Visual Loss

Chronic papilledema from pseudotumor cerebri can cause progressive visual loss despite functioning lumboperitoneal shunts. The authors performed modified optic nerve sheath decompression in 12 patients (16 operations) with functioning lumboperitoneal shunts and progressive visual loss. All of the patients demonstrated improvement in visual function. Optic nerve sheath decompression allows release of localized cerebrospinal fluid (CSF) pressure. By performing optic nerve sheath decompression, progressive visual loss secondary to chronic papilledema can be halted and reversed.

Rapidly progressive acute retinal necrosis secondary to herpes simplex virus, type 1

A systemically healthy 22-year-old man presented with unilateral acute retinal necrosis (ARN) that featured diffuse retinal whitening throughout the posterior retina, exudative retinal detachment, and a visual acuity of no light perception. Diagnostic vitrectomy revealed necrotic retinal cells containing intranuclear inclusions visible with light microscopy. On electron microscopy, viral particles consistent with a herpes family virus were detected. Culture of the vitrectomy specimen showed herpes simplex, type 1 (HSV 1) and rising convalescent serum ELISA titers to HSV 1 confirmed a recent infection. This case of ARN is unusual for its severity, early macular involvement, and development of exudative retinal detachment. In addition, it represents one of the few reported cases in which HSV 1 has been confirmed by both vitreous culture and serum titers as the etiologic agent. A review of the literature suggests that posterior segment inflammatory conditions secondary to HSV 1 can be associated with exudative retinal detachment, a clinical finding that may help differentiate such conditions from other infectious causes of chorioretinitis.

The results of radiotherapy for orbital pseudotumor

Between January 1982 and March 1987, 23 patients (26 orbits) were treated for orbital pseudotumor with radiation therapy at the Department of Radiation Oncology, Hospital of the University of Pennsylvania. The patients were referred for clinical relapse after steroid taper in 70%, no response to steroids in 17%, and no steroid treatment (refused or contraindicated) in 13%. Presenting symptoms/signs included soft tissue swelling in 92% of orbits, pain in 92%, proptosis in 85%, and extraocular muscle dysfunction or ptosis in 69%. Decreased visual acuity was seen in only 19% of orbits. Biopsy was performed in nine patients. Treatment consisted of 2000 cGy in 2 weeks in 10 fractions for all patients. Median follow-up was 41 months, with a mean of 53 months, and a range of 21-92 months. Complete response was documented in 87% of orbits with soft tissue swelling, 82% with proptosis, 78% with extraocular muscle dysfunction, and 75% with pain. Of the five patients with visual acuity defects, three experienced complete recovery. There was no difference in complete response in patients biopsied versus those not biopsied. Overall, 17 orbits have remained in complete orbital response with no further steroid requirement (66%). Three orbits suffered local relapse at some point following radiation therapy and were retreated with steroids. These three orbits had durable local control off steroids at last follow-up (11%). Therefore, 77% of orbits attained durable local control and were steroid independent with radiation therapy alone or radiation therapy followed by steroids for relapse. Only one patient developed systemic lymphoma with follow-up. No pretreatment clinical factor reached statistical significance with respect to prognosis following radiation therapy at the less than or equal to .05 level. There were no significant acute or chronic side effects secondary to treatment. Steroids should continue to be first line treatment for orbital pseudotumor, but radiation therapy has a well-defined role in cases of steroid failure or in patients unable to tolerate steroid therapy.