Role of vitamin A metabolism in IIH: Results from the idiopathic intracranial hypertension treatment trial

INTRODUCTION

Vitamin A and its metabolites (called retinoids) have been thought to play a role in the development of idiopathic intracranial hypertension (IIH). The IIH Treatment Trial (IIHTT) showed the efficacy of acetazolamide (ACZ) in improving visual field function, papilledema grade, quality of life and cerebrospinal fluid (CSF) pressure. We postulated that IIH patients would demonstrate elevated measures of vitamin A metabolites in the serum and CSF.

METHODS

Comprehensive measures of serum vitamin A and its metabolites were obtained from 96 IIHTT subjects, randomly assigned to treatment with ACZ or placebo, and 25 controls with similar gender, age and body mass index (BMI). These included retinol, retinol binding protein, all-trans retinoic acid (ATRA), alpha- and beta-carotenes, and beta-cryptoxanthin. The IIHTT subjects also had CSF and serum vitamin A and metabolite measurements obtained at study entry and at six months.

RESULTS

At study entry, of the vitamin A metabolites only serum ATRA was significantly different in IIHTT subjects (median 4.33nM) and controls (median 5.04nM, p=0.02). The BMI of IIHTT subjects showed mild significant negative correlations with serum ATRA, alpha- and beta-carotene, and beta-cryptoxanthin. In contrast, the control subject BMI correlated only with serum ATRA. At six months, the serum retinol, alpha-carotene, beta-carotene, and CSF retinol were increased from baseline in the ACZ treated group, but only increases in alpha-carotene (p=0.02) and CSF ATRA (p=0.04) were significantly greater in the ACZ group compared with the placebo group. No other vitamin A measures were significantly altered over the six months in either treatment group. Weight loss correlated with only with the change in serum beta-carotene (r=-0.44, p=0.006) and the change in CSF retinol (r=-0.61, p=0.02).

CONCLUSION

Vitamin A toxicity is unlikely a contributory factor in the causation of IIH. Our findings differ from those of prior reports in part because of our use of more accurate quantitative methods and measuring vitamin A metabolites in both serum and CSF. ACZ may alter retinoid metabolism in IIH patients.

Cortical blindness, transient and otherwise, associated with detachable coil embolization of intracranial aneurysms

BACKGROUND AND PURPOSE

Cortical visual loss is a rare complication of cerebral angiography without a definitive pathophysiology. Given the rapid increase in endovascular procedures used to treat cerebral aneurysms, we explored the prevalence of this complication and whether we could add to the understanding of this disorder.

MATERIALS AND METHODS

We performed a retrospective review of all procedures performed with the same contrast agent and detachable coils for treatment of posterior circulation aneurysms by 1 endovascular surgery service from 1996 to 2006. All patients were evaluated before and after each procedure by a team that included a neuro-ophthalmologist.

RESULTS

Of 137 intra-arterial treatment procedures performed for posterior circulation aneurysms, we identified 4 patients with cerebral vision loss complications. During the same time period, >500 aneurysms of the anterior cerebral circulation were treated without this complication. The visual field loss was unilateral in 2 and bilateral in 2 patients. Recovery was complete in 3 and almost normal in the fourth patient. The amount of contrast used and the duration of the procedure were similar among all patients. The 4 patients had no identified specific risk factors for developing procedure-associated occipital dysfunction, all 4 had undergone prior angiography, and 1 patient had undergone repeat coiling, without complication.

CONCLUSION

The 2.9% prevalence of cerebral visual loss with endovascular coil treatment of posterior circulation aneurysms is higher than that for angiography alone. Our patients recovered well with corticosteroid and intravenous hydration treatment. Recognizing the self-limiting nature of this problem might prevent an unneeded intervention.

Visual function at baseline and 1 month in acute optic neuritis: predictors of visual outcome

OBJECTIVE

To identify cutpoints for visual measures at baseline and 1 month predictive of abnormal 6-month vision that could be used as eligibility criteria in a clinical trial to test potential neuroprotection or myelin repair agents in patients with optic neuritis. To determine whether moderate-to-severe dysfunction in one or more visual measures at baseline or 1 month correlates with having major vision loss at 6 months.

METHODS

We used the Optic Neuritis Treatment Trial database to evaluate various cutpoints for baseline and 1-month vision levels that predicted abnormal 6-month vision. For selected cutpoints, we computed a 95% CI for positive predictive value and the required sample size if the cutpoint was to be used for clinical trial eligibility. We evaluated whether the degree of visual loss at baseline, 1 month, or change in visual function from baseline to 1 month correlated with 6-month visual acuity, contrast sensitivity, or threshold visual field.

RESULTS

The best cutpoints for baseline and 1 month were visual acuity <or= 20/50, contrast sensitivity < 1.0 log units, and visual field mean deviation <or= -15 dB. The same levels of visual dysfunction at 1 month, but not at baseline, correlated with having 6-month moderate-to-severe loss for each of these measures (p = 0.01). A trial could require as few as 100 subjects for an outcome variable of one or more abnormal measures. Cutpoints at 1 month were highly predictive of abnormal 6-month vision, but the proportion of patients who would be eligible for a trial would be small.

CONCLUSION

Provided data can be used either for the clinician to counsel patients on expected visual outcome or for designing studies to test therapies that might reduce the amount of permanent optic nerve damage due to optic neuritis in high-risk patients.

Treatment of cerebral aneurysms with hydrogel-coated platinum coils (HydroCoil): early single-center experience

PURPOSE

The authors report their experience using HydroCoils in the treatment of cerebral aneurysms.

METHODS

We performed a retrospective review of the first 100 nonrandomized patients (104 coiled saccular cerebral aneurysms) treated with HydroCoils during a 27-month period.

RESULTS

The average percentage of HydroCoil by length detached in treated aneurysms was 45.5% (range, 9.9-100%). Immediate postprocedure angiography demonstrated complete aneurysm occlusion in 34%, neck remnant in 35%, and incomplete occlusion in 32%. Immediate procedure-related morbidity and mortality rates were 5.8% and 0%, respectively. Angiographic follow-up was obtained in 51% (51/100 patients; 53/104 aneurysms; average, 10.3 months; range, 0-31 months). In these 53 angiographically followed aneurysms, the overall recanalization rate was 21%: no recanalization occurred in 23 aneurysms with small size (<10 mm)/small neck (<4 mm) (S/S); 4 recanalizations occurred in 7 aneurysms with small size/wide neck (>4 mm) (S/W); 6 recanalizations (27%) occurred in 22 large (L) aneurysms (>10-25 mm, 70% angiographic follow-up); and 1 giant (G) (>25 mm) aneurysm recanalized. A large proportion of aneurysms that were not initially completely occluded were completely occluded on follow-up (15/43 [35%]). Clinical follow-up was obtained in 73 patients (73%; average, 5.3 months; range, 0-24 months): 93% of these patients were neurologically improved or unchanged. Three patients rehemorrhaged and 3 patients with unruptured aneurysms developed delayed hydrocephalus.

CONCLUSIONS

The overall safety profile of HydroCoils appears acceptable. Preliminary midterm observations suggest less coil compaction/aneurysm recanalization in large aneurysms. However, HydroCoil-related delayed hydrocephalus is a concern.

Clinical profile of simultaneous bilateral optic neuritis in adults

AIM

To establish the clinical profile of simultaneous bilateral optic neuritis in adults, the efficacy of steroid therapy, extent of visual recovery, and neurological outcome.

METHODS

The authors performed a retrospective review of records of patients referred to a neuro-ophthalmology service with acute bilateral optic neuritis from 2000-4. Exclusion criteria included previous multiple sclerosis or myelopathy, known systemic disorders or medications associated with optic neuropathy, uveitis, or neoplasm. Patients received intravenous methylprednisolone followed by oral prednisone. Visual acuity (logMAR conversion), mean deviation (dB) for visual fields, percentage of Ishihara plates seen, ophthalmoscopy, and neurological evaluation were recorded at baseline and at 6 months or 12 months. Owing to strong correlation for visual loss between eyes, the results for the worse eye in each patient were analysed.

RESULTS

11 men and four women, with an age range of 18-64 years, had bilateral decreased vision, 12 with pain on eye movement. Except for one patient, no aetiology was found. All patients had normal neurological evaluations, average visual acuity 1.71 (SD 0.55), colour vision 2.7% (SD 9.9%), and mean deviation -25.35 dB (SD -7.95 dB). Both optic nerves showed abnormal signal on magnetic resonance imaging. 14 patients improved and their last average visual acuity, colour vision, and mean deviation were 0.36 (SD 0.54), 69% (SD 46%), and -7.05 dB (SD 8.40 dB), respectively. No patient developed a neurological problem during the follow up with a mean of 11 months.

CONCLUSION

Idiopathic acute bilateral optic neuritis without myelopathy occasionally occurs in adults. Vision recovers with corticosteroid therapy and during the first year neurological dysfunction will frequently not occur.

Ocular motor dysfunction and ptosis in ocular myasthenia gravis: effects of treatment

AIM

The optimal treatment of ocular myasthenia gravis (OMG) remains unknown. The authors evaluated the efficacy of prednisone and pyridostigmine in reducing diplopia, ocular motor dysfunction, and ptosis in patients with OMG.

METHODS

Review of records from a clinical database from one neuro-ophthalmology service of patients presenting with OMG between 1990 and 2002, excluding those who developed generalised MG within the first month after diagnosis. Institutional review board approval was obtained for this study.

PARTICIPANTS/INTERVENTIONS

Non-randomised, unmasked, therapy was given. 55 patients with diplopia in primary or downward gaze and clinically demonstrable extraocular muscle dysfunction received prednisone. 34 patients who had contraindications to steroids or who refused treatment with prednisone received pyridostigmine only. Over 5 days the daily prednisone dose was increased to 50-60 mg and then gradually reduced to 10 mg, followed by further reduction as tolerated. The pyridostigmine dose was begun at 180 mg daily and increased as tolerated.

MAIN OUTCOME MEASURES

Follow up evaluations, performed at 1, 3-6, 12, and 24 months, detailed the frequency of ptosis and diplopia and the amount of ocular motor deviation in primary and downward gaze.

RESULTS

The prednisone and pyridostigmine groups were similar for age, sex, acetylcholine receptor antibody level, prism cover test results for primary and downward gaze, diplopia in primary and downward gaze, and unilateral ptosis. Bilateral ptosis was present in 32.4% of the pyridostigmine group and 10.9% of the prednisone group (p = 0.02). The prednisone group showed resolution in primary gaze diplopia, downgaze diplopia, unilateral ptosis, and bilateral ptosis in 73.5%, 75.5%, 85.7%, and 98%, respectively at 1 month. The benefit persisted at 3-6, 12, and 24 months except for the bilateral ptosis. The pyridostigmine group showed resolution in primary gaze diplopia, downgaze diplopia, unilateral ptosis, and bilateral ptosis in 6.9%, 17.2%, 50%, and 76.7% of patients after 1 month of treatment. The prism cover results improved (p = 0.003) in the prednisone group only. In the prednisone group, four patients had no response to therapy. Among the 51 prednisone responsive patients, there were 33 recurrences in 26 patients. 12 patients, all prednisone treated, had remissions. Except for three patients who developed diabetes, no patient developed a clinically significant systemic corticosteroid complication.

CONCLUSION

These results suggest that 50-60 mg daily prednisone followed by lower doses (10 mg or less) has the benefit of resolving ptosis and diplopia that lasts for at least 2 years in approximately 70% of patients.

Idiopathic hypertrophic pachymeningitis

BACKGROUND

Hypertrophic pachymeningitis is an uncommon disorder that causes a localized or diffuse thickening of the dura mater and has been associated with rheumatoid arthritis, syphilis, Wegener's granulomatosis, tuberculosis, and cancer. Few series of the idiopathic variety have been described, particularly with respect to MRI correlation to clinical outcome and treatment.

OBJECTIVE

To investigate the clinical and laboratory evaluation, course, and treatment of patients with idiopathic hypertrophic pachymeningitis (IHP), to correlate the MRI findings with the clinical course, and to review the literature on IHP.

METHODS

Retrospective case series of 12 patients (9 men, 3 women), with a mean age of 55 years (range 39 to 88 years), who had IHP by imaging studies, meningeal or orbital biopsy, or both. The clinical features, laboratory evaluation, contrast-enhanced MRI, treatment, and clinical outcome were documented for each case. The mean duration of follow-up was 3.5 years (range 3 months to 16 years).

RESULTS

The main clinical features at presentation were headache (11 cases), loss of vision (7 cases), diplopia (4 cases), papilledema (2 cases), other cranial nerve involvement (3 cases), ataxia (2 cases), and seizures (1 case). On the initial MRI, the location of abnormal enhancement of the dura mater correlated with the clinical findings and the sphenoid wing area was affected in all patients. The sedimentation rate was elevated in five cases. The CSF had increased protein in six cases and lymphocytosis in four cases. Biopsy of the dura mater in five cases and the orbital soft tissue in one case showed infiltrates of small mature lymphocytes, plasma cells, and epithelioid histiocytes, but no neoplasia, vasculitis, or infectious agents. Cultures of the CSF and biopsy material remained sterile. Corticosteroid therapy improved the vision in 7 of 8 cases and controlled headache in 10 of 11 cases. Five cases had partial improvement of other neurologic symptoms and signs. Recurrence developed with steroid tapering in six cases. One case had progressive deterioration and died. In four cases methotrexate or azathioprine was added with reduction of the steroid dose. Follow-up MRI performed in 11 patients correlated 80% with the clinical state (p = 0.01).

CONCLUSION

IHP can be suspected on MRI and defined pathologically on biopsy. Untreated, the clinical course is usually marked by severe headache and progressive neurologic deterioration and vision loss. Although initially steroid-responsive, clinical manifestations frequently recur with corticosteroid taper, requiring the addition of immunosuppressive agents in some cases.

Bilateral orbital signs predict cortical venous drainage in cavernous sinus dural AVMs

BACKGROUND

Most cavernous sinus dural arteriovenous malformations (CSdAVM) have a benign clinical course. Those CSdAVM that drain into cortical veins have an increased risk for neurologic complications.

OBJECTIVE

To find whether a specific clinical sign predicts cortical venous drainage (CVD) in CSdAVM.

METHODS

The records of 118 patients with CSdAVM were evaluated for the clinical features of the disorder and tested for predictive value of CVD demonstrated angiographically or suggested by MRI using logistic regression and odds ratio (OR) analysis.

RESULTS

Clinical signs that predicted the presence of CVD included bilateral orbital signs (p = 0.004, OR = 23.84) and presence of a postauricular bruit (p = 0.035, OR = 23.8). No other clinical sign predicted the presence of CVD, including extraocular muscle dysfunction, abducens or oculomotor dysfunction, increased intraocular pressure, venous stasis retinopathy, choroidal effusion, optic neuropathy, subjective bruit, and objective orbital bruit.

CONCLUSION

Patients who present with or develop bilateral orbital congestion should be recognized as being at increased risk for CVD.

Visual function and quality of life among patients with giant cell (temporal) arteritis

OBJECTIVE

To investigate patient perception of visual and systemic disability associated with giant cell arteritis (GCA) and whether the perceived disability can be correlated with visual performance measures.

METHODS

We prospectively evaluated and compared the visual performance and quality of life survey for 20 patients with GCA after 4 to 5 weeks of corticosteroid therapy and after one year of therapy. We measured visual acuity, contrast sensitivity, and threshold perimetry and patients completed the Activities of Daily Vision Scale (ADVS) and the short-form of the Health Survey (SF-36). The results were grouped by GCA affected or unaffected eye or by better or worse eye and reported as a decimal and percent impairment for acuity, log units for contrast, mean deviation and the Advanced Glaucoma Intervention Study (AGIS) score for perimetry. The results for patients with and without visual loss were compared. Correlation analyses between ADVS categories and visual performance measures, SF-36 categories and the presence of visual loss, total corticosteroid dose, systemic symptoms, secondary hypertension or diabetes mellitus, the presence of vertebral fracture, and visual performance were performed.

RESULTS

Day driving was the only ADVS category significantly reduced at baseline in patients with visual loss (62.5) compared with those without visual loss (96.3, P = 0.04). Modest to moderate correlations between ADVS categories were most frequent for percent binocular acuity impairment with day driving (r = -0.62, P = 0.017), with distance vision (r = -0.5, P = 0.02), and with glare (r = -0.59, P = 0.006); and the AGIS score of the worse eye with day driving (r = -0.66, P = 0.01), with near vision (r = -0.49, P = 0.03), and with glare (r = -0.48, P = 0.04). The baseline SF-36 scores did not correlate with the presence of vision loss at baseline or systemic complications. The ADVS and SF-36 scores were similar at one year. The total dose of corticosteroids only had a modest correlation with the one-year mental health score (r = -0.45, P = 0.05), but there was no correlation between SF-36 scores and other systemic side effects of steroid therapy.

CONCLUSION

Except for the day driving score, the ADVS did not differ between patients with and without visual loss. The SF-36 did not distinguish between patients with and without visual loss and did not reveal significant trends. The ADVS and SF-36 did not reveal significant disability in GCA patients and there were no strong correlations with any visual performance or systemic measures.

Unilateral swollen disc due to increased intracranial pressure

Truly unilateral papilledema is rare and poses a diagnostic problem. The authors have prospectively looked for patients with truly unilateral papilledema and found 15 patients, 10 of whom had idiopathic intracranial hypertension. Neuroimaging did not indicate a reason for the lack of swelling in the other nerve. The visual deficits and outcomes were similar to those of patients with bilateral papilledema. Although monocular papilledema is uncommon, a lumbar puncture with opening pressure measurement should be considered.

Occlusion of the internal carotid artery based on a simple tolerance test

SUMMARY

In order to evaluate the safety of the internal carotid artery (ICA) occlusion based on our simple tolerance test, we reviewed 142 consecutive tolerance tests. Permanent endovascular ICA occlusion was performed on 99; a tolerance test only was performed on the remaining 43. Our assessment consisted of 1) angiographic evaluation of collateral circulations without and with ICA test occlusion, 2) evaluation of clinical tolerance to balloon ICA occlusion for 15-20 minutes. Complications of test and permanent ICA occlusion were retrospectively analyzed. Complications related to test occlusion occurred in 2 cases (1.4%) without causing permanent deficits. Complications related to permanent occlusion occurred in 16 cases (16%) including 2 technical, 10 temporary (10%) and 4 permanent (4%). Complications were significantly decreased after introduction of stringent postoperative care to prevent hypotension in 1987. Since 1988, we performed 47 permanent ICA occlusion and experienced no technical, 3 temporary (6%) and no permanent complications. Our method to evaluate tolerance to ICA occlusion is simple and safe. Reliability of the results is comparable to other more complicated methods of assessing ICA occlusion.

Natural history of brainstem cavernous malformations

OBJECTIVE

To review the natural history and determine the rates of intra- and extralesional hemorrhaging of brainstem cavernous malformations (cavernomas) monitored by one neuro-ophthalmology service.

METHODS

A record review of all patients with brainstem cavernomas who were evaluated by a neuroophthalmology service between 1987 and 1999 was performed. We recorded the clinical symptoms and Rankin disability grade at presentation, during the worst clinical episode, and at the last follow-up examination. Magnetic resonance imaging scans were reviewed for evidence of intralesional hemorrhage (a bleeding episode), edema, or venous anomalies, and the cavernoma size was assessed.

RESULTS

Thirty-seven patients (age range, 6-73 yr; mean age at presentation, 37.5 yr) underwent a mean of 4.9 years of follow-up monitoring. At presentation, there were 27 bleeding events and 8 nonhemorrhagic events; 2 patients did not exhibit symptoms. Patients who were at least 35 years of age exhibited a lower risk of bleeding episodes (odds ratio, 0.15; 95% confidence interval, 0.1-0.4). Cavernomas of at least 10 mm were associated with a higher risk of bleeding episodes (odds ratio, 3.48; 95% confidence interval, 1.3-9.4). Thirty-nine bleeding episodes occurred in 31 patients, yielding a bleeding rate of 2.46%/yr. There were eight rebleeding episodes, yielding a rebleeding rate of 5.1%/yr. Three patients experienced extralesional bleeding episodes; all of these patients experienced rebleeding. Of the 39 follow-up magnetic resonance imaging scans, the cavernoma size was unchanged in 66.7%, smaller in 18%, and larger in 15%. At the last follow-up examination, the mean Rankin grade was 1.0 for all patients, 0.6 for the 25 nonsurgically treated patients, and 1.4 for the 12 surgically treated patients.

CONCLUSION

Rebleeding is not more common among patients who first present with bleeding, and it often has little effect on the neurological status of patients. Significant morbidity attributable to a brainstem cavernoma occurred in 8% of patients during follow-up monitoring of medium duration.

Isolated sixth nerve palsy: an uncommon presenting sign of multiple sclerosis

We describe three patients in whom an isolated sixth nerve palsy was the only clinical symptom or sign of multiple sclerosis (MS). Data were collected prospectively over 6 years on these three patients, who showed no other signs of brainstem dysfunction or prior symptoms; in addition. Retrospective analysis of all patients with MS and all patients with sixth nerve palsy referred to a neuro-ophthalmology service between 1982 and 1998 showed isolated sixth nerve palsy to be the presenting sign of MS in only 0.5% of these patients. MS was the cause of isolated sixth nerve palsy in 0.8% of all patients and in 1.6% of those aged 18-50 years. Although it has been previously suggested that sixth nerve palsy is a not uncommon presenting sign of MS, our results suggest it is rare.

Orbital arteriovenous malformation mimicking cavernous sinus dural arteriovenous malformation

AIMS

Orbital arteriovenous malformations (OAVM) are rare, mostly described with high flow characteristics. Two cases are reported with an OAVM of distinct haemodynamic abnormality. The clinical, angiographic features, and the management considerations are discussed.

METHODS

Case review of two patients with dural AVM (DAVM) who presented to referral neuro-ophthalmology and endovascular services because of clinical symptoms and signs consistent with a cavernous sinus dural AVM.

RESULTS

In each patient, superselective angiography revealed a small slow flow intraorbital shunt supplied by the ophthalmic artery. The transarterial and transvenous endovascular approaches to treat the malformation were partially successful. Although, the abnormal flow was reduced, complete closure of the DAVM could not be accomplished without significant risk of iatrogenic injury. Neither patient's vision improved after intervention.

CONCLUSION

A DAVM in the orbit can cause similar clinical symptoms and signs to those associated with a cavernous sinus DAVM. Even with high resolution magnetic resonance imaging, only superselective angiography can identify this small intraorbital slow flow shunt. The location in the orbital apex and the small size precludes a surgical option for treatment. The transarterial and transvenous embolisation options are limited.

Visual loss from arterial steal in patients with maxillofacial arteriovenous malformation

OBJECTIVE

To determine whether an arterial "steal" from the ophthalmic artery accounts for the ocular manifestations associated with maxillofacial arteriovenous malformation (AVM) outside the orbit.

DESIGN

Retrospective noncomparative case series.

PARTICIPANTS

Seven patients with maxillofacial AVM who had been previously treated, unsuccessfully, with proximal ligation of the supplying external carotid artery branches were evaluated clinically and by superselective cerebral angiography. No cases had intraorbital arteriovenous shunting or abnormal venous drainage to the orbit.

INTERVENTION

Endovascular embolization.

MAIN OUTCOME MEASURES

Signs and symptoms of ocular ischemia were correlated with findings on cerebral/orbital angiography.

RESULTS

Four of seven patients had signs of ocular ischemia. By selective angiography, these four patients were found to have a significant ophthalmic artery supply to the AVM. In contrast, the three patients without signs of ocular ischemia had minimal or no ophthalmic artery supply to the AVM.

CONCLUSIONS

When the ophthalmic arterial blood supply is recruited, ophthalmic artery "steal" phenomenon occurs in patients with maxillofacial AVMs that do not directly involve the orbit. This mechanism appears to be the cause of ocular ischemia. It is possible that this "steal" is precipitated or worsened by previous surgical proximal ligation of external carotid arterial branches that are potential collaterals with the ophthalmic artery but fail to occlude the arteriovenous (AV) shunts.

Arachnoid cyst of the cavernous sinus resulting in third nerve palsy

A 67-year-old man exhibited long-standing left third nerve palsy. Magnetic resonance imaging revealed a cystic lesion in the left cavernous sinus with signal characteristics typical of arachnoid cyst. Intradural cavernous sinus arachnoid cyst has not reported previously. Pathogenetic mechanisms are discussed.

Infantile cerebral aneurysms with visual pathway compression

Intracranial aneurysms are rare in infancy. The commonest presentation is intracranial hemorrhage, but signs of mass effect are more frequent than in adults. We report 2 infants with cerebral aneurysms, one presenting with macrocephaly and another with strabismus. Both had visual loss and optic disc pallor; MRI revealed a suprasellar mass and anterior visual pathway compression. In both cases, the preoperative diagnosis was craniopharyngioma. It is essential to recognize that, although exceedingly uncommon, cerebral aneurysms do occur in infants and have features that differ from those in adults.

Visual performance in giant cell arteritis (temporal arteritis) after 1 year of therapy

AIMS

To determine if patients with giant cell arteritis (GCA) treated with corticosteroids develop delayed visual loss or drug related ocular complications.

METHODS

In a multicentre prospective study patients with GCA (using precise diagnostic criteria) had ophthalmic evaluations at predetermined intervals up to 1 year. The dose of corticosteroid was determined by treating physicians, often outside the study, with the daily dose reduced to the equivalent of 30-40 mg of prednisone within 5 weeks. Subsequently, treatment guidelines suggested that the dose be reduced as tolerated or the patient was withdrawn from steroids in a period not less than 6 months.

RESULTS

At presentation, of the 22 patients enrolled, seven patients had nine eyes with ischaemic injury. Four eyes had improved visual acuity by two lines or more within 1 month of starting corticosteroids. No patients developed late visual loss as the steroid dose was reduced. At 1 year the visual acuity, contrast sensitivity, colour vision, and threshold perimetry were not significantly different from the 4-5 week determinations. At 1 year, there were no significant cataractous or glaucomatous changes. At 2 months, there was no difference in systemic complications between patients who received conventional dose (60-80 mg per day) or very high doses (200-1000 mg per day) of corticosteroids at the start or early in the course.

CONCLUSIONS

Patients with GCA related visual loss can improve with treatment. Corticosteroids with starting doses of 60-1000 mg per day, with reduction to daily doses of 40-50 mg per day given for 4-6 weeks, and gradual dose reduction thereafter, as clinically permitted, did not result in delayed visual loss. There were no significant drug related ophthalmic complications.

Visual symptoms with dural arteriovenous malformations draining into occipital veins

OBJECTIVE

To determine the cause of the visual dysfunction and effect of treatment on dural arteriovenous malformations (DAVMs) that secondarily involve the occipital lobe.

BACKGROUND

DAVMs are an infrequent cause of visual dysfunction that should be amenable to treatment if diagnosed before permanent visual field loss.

METHODS

The records of seven patients with cerebral visual disturbances associated with DAVMs were analyzed with attention to visual symptoms, visual field testing, and vascular anatomy.

RESULTS

Sudden visual loss occurred in five patients, two with a hemorrhage and one with a venous infarct in the occipital lobe. Fortification images occurred in three patients, two of whom had palinopsia (one with de novo formed visual hallucinations). Homonymous quadrantic or hemianoptic field defects, some fluctuating, were found in six patients. Angiography revealed each DAVM was supplied solely by dural arteries and drained into occipital pial veins due to retrograde blood flow through the sites near or in the wall or lumen of the dural venous channels that normally drain the occipital lobe. Unlike DAVMs in other locations, only two patients had occlusion of an adjacent venous sinus. These patients, particularly the two with posterior fossa DAVMs remote to the occipital lobe, clearly demonstrate the visual and neurologic dysfunction resulting from venous hypertension. In six patients, intra-arterial embolization of the arterial feeders and nidus (one patient required additional surgery) resulted in resumption of normal occipital venous emptying. No further visual episodes occurred in five of these six patients. The visual fields normalized in three patients and improved in one with venous infarct but were unchanged in both patients with a hemorrhage.

CONCLUSIONS

DAVMs that drain into occipital veins cause field loss and other visual disturbances because of venous hypertension in the occipital lobe, which can be reversed by occluding the DAVM nidus. If a venous infarct or hemorrhage has not caused irreversible damage, visual recovery should be complete.

Monocular band optic atrophy

Band or "bow tie" optic atrophy is characterized by well-described ophthalmoscopic findings in the optic nerve and nerve fiber layer and homonymous hemianopia. It is typically associated with compressive lesions of the pregeniculate postchiasmal visual pathway or, less commonly, congenital malformations affecting the postgeniculate radiations or cortex. A unique case with band optic atrophy is described because of the unilateral visual defect. The optic atrophy is strictly unilateral and without an obvious structural lesion that could explain the optic disc damage. However, incidental cerebral gray matter cortical heterotopia may mark a congenital insult that contributed to both of these abnormal findings.

Effects of weight loss on the course of idiopathic intracranial hypertension in women

OBJECTIVE

To determine the role of weight loss in the treatment of idiopathic intracranial hypertension (IIH) in obese women.

METHODS

Chart review of 250 patients with suspected IIH revealed 58 women who met our criteria, did not undergo early surgical intervention, and had adequate documentation of visual status, papilledema, and weight at the baseline evaluation and at 6 months or longer. Patients were divided into two groups based on whether weight loss > or = 2.5 kg occurred during any 3-month interval. Papilledema grade, visual acuity, and visual field grade at 6 months or longer and the time to improve each were recorded.

RESULTS

Mean time in months to improve one grade for papilledema and visual field in one eye was 4.0 versus 6.7 (p = 0.013) and 4.6 versus 12.2 (p = 0.032), respectively, for the 38 patients with weight loss compared with the 20 patients with no weight loss. Papilledema resolved in 28/38 with weight loss (mean, 7.6 months) and 8/20 without weight loss (mean, 10.2 months; p = 0.352). There were no differences in final visual acuity or visual field between the two groups, but the papilledema grade was slightly better in the worst eye in each patient at baseline in the weight loss group (p = 0.03).

CONCLUSIONS

Weight reduction is associated with more rapid recovery of both papilledema and visual field dysfunction in patients with IIH compared with those who do not lose weight.

Aspirin reduces the incidence of second eye NAION: a retrospective study

The objective of this study was to determine if aspirin reduces the incidence of second eye involvement after nonarteritic anterior ischemic optic neuropathy (NAION) in one eye. Records were reviewed of 131 patients who sustained unilateral NAION. Of these, the 33 patients who sustained second eye NAION were compared to those followed for a minimum of 2 years without sustaining a second eye NAION (67). Thirty-one of the 131 patients were excluded because of inadequate follow-up. Except for diabetes (relative risk [RR] 1.43, p = 0.05), the incidence of second eye NAION was independent of gender, age, cup/disk, hypertension, anemia, and migraine. The degree of visual acuity or field dysfunction in the first eye correlated poorly with the acuity (r = 0.28) and field (r = 0.33) loss in the second eye. Aspirin (65-1,300 mg) taken two or more times per week decreased the incidence (17.5% vs. 53.5%) and relative risk (RR = 0.44, p = 0.0002) of second eye AION regardless of the usual risk factors. Even after eliminating those patients who had bilateral disease when first referred, ASA still reduced the incidence of second eye involvement (35% vs. 13%, RR = 0.74, p = 0.01). Aspirin may be an effective means of reducing second eye NAION.

Craniopharyngioma arising de novo in middle age. Case report

The authors report the case of a 55-year-old woman who developed a symptomatic craniopharyngioma within 2 years of obtaining a normal magnetic resonance image of her brain. Craniopharyngiomas are histologically benign tumors. They are thought to arise from embryonic remnants of Rathke's pouch and sac and to manifest themselves clinically after a steady growth that commences in fetal life. To the authors' knowledge, this is the first report that documents a tumor arising de novo in the sixth decade of life. This report appears to challenge the concept of the origin and natural history of craniopharyngiomas.

Beneficial effects of corticosteroids on ocular myasthenia gravis

OBJECTIVE

To determine if moderate-or low-dose corticosteroid therapy can reduce the diplopia and frequency of deterioration to generalized disease in ocular myasthenia gravis.

DESIGN

Retrospective record review.

SETTING

Two university-based neuro-ophthalmology services.

PATIENTS

All 32 patients with ocular myasthenia gravis, treated with prednisone, followed up for a minimum of 2 years were included. Patients were treated with 1 or more courses of daily prednisone (highest initial dose, 40-80 mg) gradually withdrawn over 4 to 6 weeks. Subsequently, in 6 patients, 2.5 to 20 mg of prednisone was given on alternate day.

OUTCOME MEASURES

Diplopia in the primary position or downgaze diplopia and generalized myasthenia gravis after 2 years of follow-up.

RESULTS

Diplopia, which was initially found in the primary position in 29 patients and in the downgaze position in 26 patients, was absent in 21 patients at 2 years. Generalized myasthenia gravis occurred in 3 patients at 2 years. Elevated serum acetylcholine receptor antibody levels and abnormal electromyography findings were not predictive of worsening. No patient experienced a major steroid complication.

CONCLUSIONS

Moderate-dose daily prednisone for 4 to 6 weeks, followed by low-dose alternate-day therapy as needed, can control the diplopia in patients with ocular myasthenia gravis. The frequency of deterioration to generalized myasthenia gravis at 2 years may be reduced; 9.4% in this study compared with more than 40% previously reported frequency. Corticosteroids may be useful even when ocular motor dysfunction is not normalized.

Occipital arteriovenous malformations: visual disturbances and presentation

BACKGROUND

Occipital arteriovenous malformations (AVMs) cause a variety of visual disturbances and headaches. Early diagnosis may lead to treatment that reduces the risk of hemorrhages, visual field loss and other neurologic deficits, and death.

METHODS

We reviewed the records of the 70 patients with occipital AVMs referred to New York University Medical Center to investigate the mode of presentation and the outcome of treatment.

RESULTS

Sixty-eight patients presented with one or more symptoms, including homonymous visual disturbances in 39, headache in 39, seizures in 20, and hemorrhage in twenty-six. Visual field loss was more common (p = 0.0007) and more severe (p = 0.0002) in patients who bled than in those with unruptured AVMs (16/44). The frequency of visual field loss was not associated with calcarine artery supply to the AVM. Prior to treatment, the fields improved in five patients with visual loss associated with a hemorrhage. Forty-six patients were treated with embolization, surgery, radiosurgery, or a combination of therapies. The AVM was eliminated in 19 of 20 patients (nine with preoperative partial embolization) treated with surgery versus in 4 of 27 patients treated only with embolization. There were two AVM-associated deaths, two subarachnoid hemorrhages, and four new neurologic deficits after treatment. Visual fields were worse in 15 patients, unchanged in 22, and improved in eight.

CONCLUSIONS

Whereas some features of headache and visual symptoms are similar for occipital AVMs and migraine, the two disorders are usually distinguishable. Visual field improvement can spontaneously occur in patients who have had loss secondary to an intracerebral bleed. Treatment with embolization or surgery, particularly with surgical excision of the AVM, can result in new or worse visual field loss.

Venous obstruction as the cause of retinal/choroidal dysfunction associated with arteriovenous shunts in the cavernous sinus

OBJECTIVE

To determine the hemodynamic abnormalities that result in visual acuity loss because of retinal or choroidal dysfunction associated with arteriovenous shunts (AVS) that involve the cavernous sinus.

METHODS

Retrospective study of the records of 250 patients with either a carotid cavernous fistula or dural arteriovenous malformation revealed a total of 10 patients with vision loss secondary to retinopathy (group I) or choroidal effusion (group II). The cerebral angiograms of these 10 patients and 10 additional patients with visual dysfunction due to elevated intraocular pressure (group III) were evaluated to determine whether the three groups could be distinguished by a specific vasculopathic pattern. Particular attention was given to the extent of thrombosis in the ophthalmic venous system and cavernous sinus.

RESULTS

There were angiographic signs of severe thrombosis in the ophthalmic vein in nine patients and in the cavernous sinus in seven patients ipsilateral to the retinal or choroidal lesion. In contrast, in group III, severe thrombosis in the ipsilateral ophthalmic vein and in the cavernous sinus occurred in one and two patients, respectively. Closure of the AVS improved the visual acuity in 1 of 4 patients in group I and in 4 of 5 patients in group II, and normalized the intraocular pressure in all patients.

CONCLUSIONS

Ophthalmic vein thrombosis, rather than arterialization of the venous system or an arterial "steal, " is the principal cause of retinal or choroidal dysfunction associated with AVS to the cavernous sinus. Following AVS closure, visual recovery is more frequent with choroidal effusion or detachment rather than with retinopathy.

Neuro-ophthalmologic presentations of functional visual disorders

Functional or nonorganic visual loss is a common problem that requires an active diagnosis. A complete neuro-ophthalmologic examination of the afferent and efferent visual system is essential to eliminate the possibility of organic causes of visual loss. With a sound knowledge of the anatomic, physiologic, and optical basis of the tests used to evaluate the visual pathway, the physician can detect the inconsistencies in visual performance that secure the diagnosis. The majority of patients will resolve their symptoms with time and reassurance.

Homonymous field defect as the first manifestation of Creutzfeldt-Jakob disease

PURPOSE

Although in the early stage of Creutzfeldt-Jakob disease most patients have obvious dementia, we found that the disease can be diagnosed in patients solely on the basis of a visual system disorder.

METHODS

We examined three patients who initially complained of a nonspecific, insidious visual disturbance.

RESULTS

The three patients were found to have Creutzfeldt-Jakob disease, confirmed by histopathologic analysis. Each patient had a homonymous hemianopsia on the first neuro-ophthalmologic examination. The initial neurologic, neuroimaging, and electrophysiologic examinations were not conclusive. The subsequent rapid deterioration in the neurologic status, including dementia and typical electroencephalographic changes, was suggestive of Creutzfeldt-Jakob disease.

CONCLUSION

At onset of Creutzfeldt-Jakob disease, patients may have a homonymous hemianopsia despite normal results of magnetic resonance imaging of the brain and neurologic examination.

Deep central arteriovenous malformations of the brain: the role of endovascular treatment

Cerebral deep central arteriovenous malformations (AVMs) are uncommon lesions associated with considerable difficulty in treatment. The authors report a series of 14 deep central AVMs treated by endovascular methods and examine the present role of endovascular treatment. This treatment used alone resulted in complete obliteration of AVMs in approximately 15% of case and reduction in 50% to a size permitting treatment by means of radiosurgery. Reversal of previous neurological signs and symptoms occurred in 35.7% of embolized patients. Overall, nearly 80% of patients had either complete obliteration of the lesion, reduction to a size allowing radiosurgical treatment, or reversal of previous neurological deficits. There were treatment complications in 14.3% of the cases. Endovascular treatment methods may make a significant contribution to the therapy of AVMs that have a particularly poor course and are difficult to treat by other means.

Comparison of visual evoked potential and psychophysical contrast sensitivity

We measured contrast processing as a function of spatial and temporal frequency using three measurement techniques: psychophysical thresholds, visual evoked potential (VEP) thresholds and VEP amplitudes. Measurements were made using the same stimulus parameters and on the same group of subjects. The agreement among these functions depended upon the particular spatio-temporal stimulus employed and in general, there were more differences than similarities among these measures. For example, VEP derived functions (both amplitude and threshold) peaked at 4 c/deg, whereas, the psychophysical functions peaked at 1 c/deg. VEP amplitude functions were maximum at > or = 3.5 Hz, whereas both psychophysical and VEP sensitivity were maximum at < or = 2.5 Hz. VEP thresholds were broad and low pass in shape and in contrast, the psychophysical and VEP amplitude functions were band pass. In summary, comparisons among these measures of contrast processing must be made with caution.

Craniopharyngiomas: a clinicopathological analysis of factors predictive of recurrence and functional outcome

Pathological and clinical data from 56 patients operated on for craniopharyngioma since 1981 were analyzed to determine the utility of dividing patients with this tumor into distinct clinical groups based on recognized pathological type and to determine the prognostic import of brain invasion. Of the tumors in the 30 adult patients, 66% were adamantinomatous, 28% were squamous papillary, and the remainder were mixed. However, of the tumors in the 26 children, 96% were adamantinomatous and none were pure squamous papillary (P < 0.01). Forty-six percent of the children compared with 17% of the adults had brain invasion (P < 0.01). Brain invasion was present in 37% of the adamantinomatous but in only 13% of the squamous papillary tumors. Seventy-seven percent of the children underwent gross total resection (GTR) compared with 27% of the adults (P < 0.01). Sixty-three percent of the squamous papillary tumors underwent GTR compared with 54% of the adamantinomatous and mixed tumors. Follow-up ranged from 7 to 187 months (mean, 49 mo). After subtotal resection, with or without radiation therapy, 58% of the tumors recurred compared with 17% recurrence after GTR (P < 0.01), with a mean time to recurrence of 34 months. In both tumor histological types, subtotal resection was associated with a higher rate of tumor recurrence compared with gross total resection. Among the subtotally resected craniopharyngiomas, 2 of the 3 (67%) squamous papillary and 11 of the 21 (52%) adamantinomatous and mixed tumors recurred. In contrast, among the totally resected tumors, none of the 5 squamous papillary and only 5 of the 25 (20%) adamantinomatous and mixed tumors recurred. There were no significant differences in Karnofsky performance status score, mortality rate, or visual and endocrine outcomes when comparing patients based on histological tumor type. When controlling for age and extent of resection, we found that brain invasion had no significant effect on recurrence rate in totally resected tumors. Based on the limited number of patients in this series, we conclude as follows. 1) Contrary to previous reports, squamous papillary craniopharyngiomas, like adamantinomatous tumors, may recur when subtotally resected. 2) For both tumor variants, the most significant factor associated with craniopharyngioma recurrence is the extent of surgical resection rather than histopathological subtype. 3) Contrary to prior hypotheses, brain invasion in totally resected tumors does not predict higher recurrence. 4) GTR is associated with a significantly lower recurrence rate and can be achieved without sacrificing functional outcome.

Visual evoked potentials following abrupt contrast changes

The timing of visual evoked potential (VEP) amplitude and phase changes following abrupt increases or decreases in contrast was examined. Gratings (1 c/deg) were presented at a low contrast for 8 sec, increased to a higher contrast for 8 sec, and then decreased to the initial lower contrast for another 8 sec. Second harmonic VEP amplitude and phase were recorded continuously and averaged in 1 sec epochs. Both amplitude and phase exhibited delays in reaching a stable level following the contrast change. For amplitude, the length of the delay was dependent on the magnitude and direction of the contrast step and on the spatial frequency of the stimulus. Time constants for the change in amplitude following step increases in contrast ranged from 0.2 sec for a 12% contrast step to 1.34 sec for a 37% contrast step. The timing of phase changes, however, was independent of the size of the contrast increases (tau = 0.7 sec). For step decreases in contrast, both amplitude and phase were relatively independent of the size of the change (tau = approx. 0.9 sec for amplitude and tau = 0.15 sec for phase). Amplitude time constants also increased with increasing spatial frequency (tau = 1.2 sec for 1 c/deg, tau = 1.6 sec for 4 c/deg and tau = 2.3 sec for 8 c/deg); phase time constants, however, did not change as a function of spatial frequency (tau = 0.7 for all spatial frequencies). These findings demonstrate that a unitary process may not always be tapped by signal averaging techniques. Additionally, swept stimulus VEP techniques may produce considerable errors in threshold estimation depending on the stimulus spatial frequency and on the slope and direction of the contrast change.

Visual loss in pregnant women with pituitary adenomas

OBJECTIVE

To investigate the potential risk for developing visual loss during single or multiple pregnancies in women with pituitary adenomas.

DESIGN

Cohort study.

SETTING

Referral center of a neuro-ophthalmology service.

PATIENTS

65 consecutive women with pituitary adenomas who had not been previously treated with surgery or radiation were monitored during 111 pregnancies. Sixty had increased levels of serum prolactin or growth hormone and 5 did not.

MAIN OUTCOME MEASURES

Visual field or acuity loss was compared with the baseline size of the adenoma measured on the coronal view of the computed tomographic or magnetic resonance image.

RESULTS

Computed tomography or magnetic resonance imaging showed a definitive tumor (> 0.3 cm, vertical height) in 57 patients, 8 of whom had macroadenomas (> or = 1.1 cm). Visual field loss occurred in 6 of 8 primiparous patients, all with adenomas greater than 1.1 cm (range, 1.2 to 2.5 cm). None of the 57 patients (95% CI, 0% to 6.3%) with a microadenoma or presumed microadenoma of 1 cm or smaller developed visual loss after as many as four full-term pregnancies.

CONCLUSIONS

The risk for developing visual loss during single or multiple pregnancies in patients with microadenomas was small. Six of eight pregnant women with macroadenomas, however, developed visual field loss during pregnancy.

Endovascular treatment of giant aneurysms which cause visual loss

BACKGROUND

Progressive visual loss that results when a giant cerebral aneurysm compresses the anterior visual pathway requires treatment. When surgical clipping is not safely feasible, percutaneous methods of embolization of the aneurysm can be visual or life saving.

METHODS

Endovascular techniques were used to treat 19 of 26 consecutive inoperable giant aneurysms in patients with visual loss, which included optic neuropathy (monocular in 13 patients and bilateral in 8) and optic tract dysfunction in five patients. Embolization of the aneurysm was performed with detachable balloons in 12 patients and with Guglielmi detachable electrocoils in 7.

RESULTS

After treatment, vision improved in 7 patients, was unchanged in 11, and worsened in 1. Neurologic complications with balloons were temporary in four patients and severe and permanent in three. In contrast, only one temporary complication occurred with Guglielmi detachable electrocoils. The treatment results are contrasted with the outcome in the seven patients who refused intervention: three hemorrhaged (1 death); monocular blindness with dementia developed in two; a complete homonymous hemianopia and dementia developed in one; and one became bilaterally blind.

CONCLUSION

Inoperable symptomatic giant aneurysms can be successfully treated with endovascular treatment.

The effects of dopamine blockade on the human flash electroretinogram

Single-cell electrophysiologic studies have shown that dopamine modulates retinal activity, but its role in human retinal processing is unclear. We investigated the effects of short-term oral administration of dopaminergic receptor blocking agents on the flash electroretinogram in humans. Both chlorpromazine (25 and 50 mg) and fluphenazine (1 and 2 mg) significantly reduced electroretinogram b-wave amplitudes and also selectively reduced the amplitude of the first oscillatory potential. Implicit times were not altered. Metoclopramide (10 and 20 mg) had no effect on any electroretinographic variable. Our study indicates that dopamine receptor blocking agents with both D-1 and D-2 receptor affinities reduce the amplitude of the electroretinogram in humans.

Optic tract atrophy with cerebral arteriovenous malformations: direct and transsynaptic degeneration

Three patients with postgeniculate cerebral arteriovenous malformations (AVM) had band atrophy of the contralateral optic nerve. One patient had homonymous hemioptic hypoplasia. These cases might have been construed as demonstrating transsynaptic degeneration across the lateral geniculate nucleus to the anterior visual pathway. However, neuroimaging studies revealed abnormal deep venous drainage remote from the AVM nidus that directly involved the lateral geniculate nucleus and posterior optic tract.

The effect of corticosteroids for acute optic neuritis on the subsequent development of multiple sclerosis. The Optic Neuritis Study Group

BACKGROUND

Optic neuritis is often the first clinical manifestation of multiple sclerosis, but little is known about the effect of corticosteroid treatment for optic neuritis on the subsequent risk of multiple sclerosis.

METHODS

We conducted a multicenter study in which 389 patients with acute optic neuritis (and without known multiple sclerosis) were randomly assigned to receive intravenous methylprednisolone (250 mg every six hours) for 3 days followed by oral prednisone (1 mg per kilogram of body weight) for 11 days, oral prednisone (1 mg per kilogram) alone for 14 days, or placebo for 14 days. Neurologic status was assessed over a period of two to four years. The patients in the first group were hospitalized for three days; the others were treated as outpatients.

RESULTS

Definite multiple sclerosis developed within the first two years in 7.5 percent of the intravenous-methyl-prednisolone group (134 patients), 14.7 percent of the oral-prednisone group (129 patients), and 16.7 percent of the placebo group (126 patients). The adjusted rate ratio for the development of definite multiple sclerosis within two years in the intravenous-methylprednisolone group was 0.34 (95 percent confidence interval, 0.16 to 0.74) as compared with the placebo group and 0.38 (95 percent confidence interval, 0.17 to 0.83) as compared with the oral-prednisone group. The beneficial effect of the intravenous-steroid regimen appeared to lessen after the first two years of follow-up. Signal abnormalities on magnetic resonance imaging (MRI) of the brain were a strong indication of risk for the development of definite multiple sclerosis (adjusted rate ratio in patients with three or more lesions, 5.53; 95 percent confidence interval, 2.41 to 12.66). The beneficial effect of treatment was most apparent in patients with abnormal MRI scans at entry.

CONCLUSIONS

In patients with acute optic neuritis, treatment with a three-day course of high-dose intravenous methylprednisolone (followed by a short course of prednisone) reduces the rate of development of multiple sclerosis over a two-year period.

Fellow eye abnormalities in acute unilateral optic neuritis. Experience of the optic neuritis treatment trial

BACKGROUND

Visual function in the fellow eye at the onset of unilateral optic neuritis has not been systematically evaluated. The authors prospectively determined the prevalence of abnormalities in the fellow eyes of the 448 eligible patients entered into the Optic Neuritis Treatment Trial.

METHODS

All patients underwent testing of visual acuity, contrast sensitivity, color vision, and visual field, as well as magnetic resonance imaging (MRI) of the brain and a neurologic examination.

RESULTS

Abnormalities in the fellow eye were found on measurement of visual acuity in 13.8%, contrast sensitivity in 15.4%, color vision in 21.7%, and visual field in 48.0% of patients. The majority of the fellow eye deficits resolved over several months. A higher prevalence of MRI changes consistent with demyelination of the brain was found in patients with a past history of optic neuritis in the fellow eye compared with patients without such a history (P = 0.004). Patients with abnormal fellow eyes but no history of previous optic neuritis were no more likely to have clinical (P = 0.658) or MRI evidence (P = 0.166) of multiple sclerosis than patients with normal fellow eyes.

CONCLUSIONS

The improvement of many of the visual deficits indicates that visual abnormalities detected in the fellow eye at the onset of symptomatically unilateral optic neuritis may not represent preexisting optic nerve demyelination. Whether the presence of these deficits is predictive of the development of clinical multiple sclerosis cannot be determined at this time.

The effect of embolization with N-butyl cyanoacrylate prior to surgical resection of cerebral arteriovenous malformations

Endovascular therapy of cerebral arteriovenous malformations (AVM's) is an accepted adjunct to surgical therapy. However, the literature has not characterized the benefits or the liabilities of preoperative embolization. This series compares two groups of patients who underwent surgical resection of a cerebral AVM; one group (20 patients) received preoperative transfemoral selective embolization with N-butyl cyanoacrylate (NBCA) and the other group (13 patients) did not. In the group with preoperative embolization, the AVM's were larger (3.9 vs. 2.3 cm) and of a higher Spetzler-Martin grade (3.2 vs. 2.5) as compared to the nonembolized group. The NBCA embolization facilitated surgical resection. Arteries supplying the vascular malformation were readily distinguished from those supplying the normal brain parenchyma. Embolized vessels were compressible and easily cut with microscissors. No bleeding occurred from transected vessels. Operative time and intraoperative blood loss for the two groups were not statistically different, despite the significant differences in lesion size and grade. Endovascular complications included immediate and delayed hemorrhage (15%) and transient ischemia (5%); there were no embolization-related deaths. Postoperative complications for both groups included hemorrhage (15%), residual AVM (6%), and cerebrospinal fluid leak (3%); the mortality rate was 3%. There was no statistically significant difference in surgical complications between the embolized and nonembolized groups. Most patients (91%) in both groups had an excellent or good late neurological outcome, with no significant difference between the groups. This study concludes that preoperative NBCA embolization of AVM's makes lesions of larger size and higher grade the surgical equivalent of lesions of smaller size and lower grade by reducing operative time and intraoperative blood loss, with no statistically significant difference in surgical complications or long-term neurological outcome.

Ophthalmoplegia as a presenting manifestation of internal carotid artery dissection

We present the case of a patient with an ipsilateral ophthalmoplegia as the presentation of a traumatic dissection of the internal carotid artery. We hypothesize that the cranial nerves dysfunction occurred because of interruption of the vascular supply to the nerves in the cavernous sinus from the inferolateral trunk of the cavernous carotid artery.

The benign course of cavernous carotid artery aneurysms

Recently, the benign nature of aneurysms of the cavernous carotid artery has been questioned. In a review of cases evaluated from 1980 to 1990 with this developmental aneurysm, the authors found 70 patients with 79 cavernous carotid artery aneurysms. As expected, the great majority (59 patients) had ophthalmoplegia as the initial problem. Retro-orbital pain (three cases) and a carotid-cavernous fistula (five cases) were infrequently the sole manifestation. Mirror-image asymptomatic aneurysms were found in nine patients and asymptomatic cavernous aneurysms were found in three additional patients. Thirty-four patients not surgically treated were followed for a mean of 2.8 years, and 36 surgical patients were followed for a mean of 4.1 years prior to treatment. Of the 79 aneurysms, one (1.3%) ruptured into the subarachnoid space during this period. Other than optic neuropathy or cranial neuropathy, no patient had a permanent neurological deficit; the 12 asymptomatic aneurysms remained asymptomatic. It is concluded that an aneurysm of the cavernous carotid artery is rarely associated with life-threatening complications, and treatment should be considered principally for patients with intolerable pain or problems related to vision.