Performance measures in Friedreich ataxia: Potential utility as clinical outcome tools

Although several neuroprotective agents have been proposed as potential therapies in Friedreich ataxia (FA), clinical trials of their efficacy are limited by a lack of sensitive outcome measures. We assessed whether performance measures (nine-hole peg test, the timed 25-foot walk, and low-contrast letter acuity) provide valid measures of disease status in FA. Scores for each measure correlated significantly with neurologic disability and disease duration. Rank correlations between scores for performance measures were moderate in magnitude, suggesting that the each test captures separate yet related dimensions of neurological function in FA. Linear regression models demonstrated that scores from the nine-hole peg test and the timed 25-foot walk (after reciprocal transformation) were predicted by age and triplet repeat length in patients with FA. In addition, comparison of the temporal courses of change for each performance measure demonstrated that scores from the timed 25-foot walk change early in the course of FA, nine-hole peg test scores change slowly over the full course of the disorder, and low-contrast letter acuity scores change in the later stages of the disease. Thus, a composite scale derived from these performance measures may provide the best overall measure for assessing disease progression throughout the illness.

Endocrine and metabolic deficiency

Endocrine and metabolic disorders that cause neuro-ophthalmologic manifestations are frequently encountered by ophthalmologists in clinical practice. This review focuses on three of the most common entities for which neuro-ophthalmologic signs and symptoms are a prominent feature. These entities include pituitary disorders (adenoma, apoplexy, and hypophysitis), thyroid-associated ophthalmopathy, and neuro-ophthalmologic complications of diabetes mellitus, such as ischemic ocular motor mononeuropathies and diabetic papillopathy.

Acute ocular motor mononeuropathies: prospective study of the roles of neuroimaging and clinical assessment

The role for immediate neuroimaging in patients 50 years of age or older with acute isolated third, fourth, and sixth nerve palsies is controversial. We prospectively evaluated 66 patients, aged 50 years and older (median 67 years, range 50-85), with acute isolated ocular motor mononeuropathies. Our purpose was to evaluate both the role of neuroimaging and the role of clinical assessment in determining etiology. We found that clinical features, including time to maximal diplopic symptoms, were not predictive of etiology (median 2 days to maximal diplopic symptoms for both peripheral microvascular and other etiologies). The presence of any common vascular risk factor, including diabetes mellitus, hypertension, hypercholesterolemia, or coronary artery disease, was significantly associated with peripheral microvascular etiology in this cohort (p=0.0004, Fisher's exact test). Despite the high prevalence of peripheral microvascular ischemia as an etiology in this age group, other causes were identified by magnetic resonance imaging (MRI) or computed tomography (CT) scanning in 14% of patients. Diagnoses included brainstem and skull base neoplasms, brainstem infarcts, aneurysms, demyelinating disease, and pituitary apoplexy. Neuroimaging procedures may have a role in the initial evaluation of patients 50 years of age or older with acute ocular motor mononeuropathies.

Giant cell arteritis

Patients with a suspected diagnosis of giant cell arteritis (GCA) should be started on high-dose corticosteroid therapy without delay. A temporal artery biopsy should be performed after initiation of therapy to confirm the diagnosis. Patients with acute visual or neurologic symptoms present a neuro-ophthalmic emergency. Therapy should be initiated immediately with high-dose intravenous methylprednisolone sodium succinate and followed by high-dose oral prednisone. Treatment may begin with high-dose oral prednisone in patients without visual or neurologic symptoms. Calcium, vitamin D, and peptic ulcer prophylaxis should accompany steroid therapy, as indicated. The following treatments should be considered for patients with suspected GCA and acute visual or neurologic signs or symptoms: intravenous methylprednisolone sodium succinate (250 mg intravenously every 6 hours) should be given for 3 days, followed by oral prednisone (80 mg per day or 1 mg/kg) for 4 to 6 weeks. Prednisone should then be tapered by 10 mg per day every month. Most patients require 1 year of therapy to avoid relapse. Taper and duration should be modified according to erythrocyte sedimentation rate, C-reactive protein, and signs and symptoms of GCA. Rheumatologic consultation and follow-up is often helpful for these patients. For patients with suspected GCA and no acute visual or neurologic signs or symptoms, therapy may begin directly with oral prednisone (80 mg per day or 1 mg/kg) with same taper and duration based on laboratory values and clinical signs and symptoms.

Laser Pointer Visual Field Screening

BACKGROUND

Sensitivity of confrontation visual field (CVF) screening is low unless defects are significant. We compared the sensitivity of laser pointer visual field screening (LVF) with conventional CVF for identifying eyes with abnormal automated perimetry.

METHODS

Ninety consecutive patients presenting for HVF prospectively underwent a masked comparison of CVF and LVF testing (175 eyes) from April to May 2000. LVF was performed using a laser pointer target projected onto a tangent screen. Points were tested in random fashion on either side of the vertical and horizontal meridians, near central fixation, around the blind spot, and in each quadrant. Single and double simultaneous finger counting was used to test CVF.

RESULTS

LVF demonstrated significantly greater sensitivity as compared with CVF (73% versus 31%, P = 0.001) in identifying field defects found on HVF. Specificities for LVF and CVF were 82% and 99%, respectively. The average testing times per eye were 0.5 minute for CVF, 1.5 minutes for LVF, and 8.0 minutes for HVF.

CONCLUSIONS

In this cohort, laser visual field testing was significantly more sensitive than confrontation testing. It may represent an effective, time-efficient tool for visual field screening.

Contrast letter acuity as a visual component for the Multiple Sclerosis Functional Composite

BACKGROUND

Visual dysfunction is one of the most common causes of disability in multiple sclerosis (MS). The Multiple Sclerosis Functional Composite (MSFC), a new clinical trial outcome measure, does not currently include a test of visual function.

OBJECTIVE

To examine contrast letter acuity as a candidate visual function test for the MSFC.

METHODS

Binocular contrast letter acuity testing (Sloan charts) was performed in a subgroup of participants from the International Multiple Sclerosis Secondary Progressive Avonex Controlled Trial (IMPACT Substudy) and in MS patients and disease-free control subjects from a cross-sectional study of visual outcome measures (Multiple Sclerosis Vision Prospective cohort [MVP cohort]). High-contrast visual acuity was measured in both studies; MVP cohort participants underwent additional binocular testing for contrast sensitivity (Pelli-Robson chart), color vision (D-15 desaturated test), and visual field (Esterman test, Humphrey Field Analyzer II).

RESULTS

Contrast letter acuity (Sloan charts, p < 0.0001, receiver operating characteristic curve analysis) and contrast sensitivity (Pelli-Robson chart, p = 0.003) best distinguished MS patients from disease-free control subjects in the MVP cohort. Correlations of Sloan chart scores with MSFC and Expanded Disability Statue Scale (EDSS) scores in both studies were significant and moderate in magnitude, demonstrating that Sloan chart scores reflect visual and neurologic dysfunction not entirely captured by the EDSS or MSFC.

CONCLUSIONS

Among clinical measures, contrast letter acuity (Sloan charts) and contrast sensitivity (Pelli-Robson chart) demonstrate the greatest capacity to identify binocular visual dysfunction in MS. Sloan chart testing also captures unique aspects of neurologic dysfunction not captured by current EDSS or MSFC components, making it a strong candidate visual function test for the MSFC.

Pituitary Apoplexy Causing Optic Neuropathy and Horner Syndrome Without Ophthalmoplegia

A 47-year-old woman presented with headache, acute monocular vision loss, and ipsilateral Horner syndrome. Apart from the optic neuropathy, all cranial nerve function was intact. Magnetic resonance imaging revealed an enlarged pituitary gland with compression of the orbital apex. The surgical specimen was consistent with pituitary apoplexy. The combination of headache, acute visual loss, and ipsilateral Horner syndrome without ophthalmoplegia, which may suggest carotid artery dissection, is evidently an unusual manifestation of pituitary apoplexy.

Lack of effect of polymorphisms in dopamine metabolism related genes on imaging of TRODAT-1 in striatum of asymptomatic volunteers and patients with Parkinson's disease

SPECT scanning using (99)Tc-TRODAT-1, a ligand that binds to dopamine transporters, may be useful for detection of early Parkinson's disease (PD), diagnosis of presymptomatic individuals, and monitoring disease progression. Understanding whether genetic factors contribute to inter-individual variability is crucial for interpreting imaging results in the context of disease pathophysiology. We tested whether polymorphisms in the genes for catechol-O-methyltransferase (COMT), monoamine-oxidase B (MAO-B), and the dopamine transporter (DAT) influence dopamine uptake parameters in the striatum in vivo in asymptomatic volunteers and patients with PD as measured with (99)Tc-TRODAT-1. (99)Tc-TRODAT-1 binding declined with age in both asymptomatic volunteers and PD patients, and depended on disease duration in PD patients. We found no significant association between COMT, MAO-B, and DAT polymorphisms and results of (99)Tc-TRODAT-1 testing in asymptomatic volunteers or patients with PD. In PD patients, the age of disease onset and speed of progression did not differ based on these polymorphisms. These results demonstrate that these specific genetic variations do not alter the fidelity of (99)Tc-TRODAT-1 as a measure of dopaminergic function in asymptomatic volunteer individuals or patients with PD.

Supranuclear gaze palsy and opsoclonus after Diazinon poisoning

A 52 year old man developed a supranuclear gaze palsy and opsoclonus after Diazinon poisoning. The diagnosis was confirmed by low plasma and red blood cell cholinesterase activity and urine mass spectroscopy. Saccadic control may be mediated in part by acetylcholine. Opsoclonus in the setting of organophosphate intoxication may occur as a result of cholinergic excess which overactivates the fastigial nuclei.

The role of unilateral temporal artery biopsy

PURPOSE

To examine the role of unilateral temporal artery biopsy (TAB) in suspected giant cell arteritis (GCA).

DESIGN

Retrospective interventional case series.

PARTICIPANTS

We identified 181 subjects from pathology and diagnostic code databases at the University of Pennsylvania Medical Center who underwent TAB between January 1990 and January 2001.

METHODS

The medical records for all subjects who underwent TAB were reviewed. Follow-up information was obtained by telephone or record review for those patients who had negative unilateral TAB.

MAIN OUTCOME MEASURES

Follow-up information for patients with unilateral negative TAB was reviewed for potential adverse outcomes caused by missed or delayed diagnoses of GCA. Presenting signs and symptoms and laboratory values were recorded for all subjects. Comparisons of clinical profiles between subsets of subjects were performed using Fisher's exact test, significance level alpha = 0.01.

RESULTS

Follow-up information was available for 88 (86%) of 102 subjects who had unilateral negative biopsy samples. One (1%) subjects of 88 had a subsequent positive contralateral TAB; no adverse outcomes occurred for this subject or for any other subjects with unilateral negative TAB. Compared with subjects who had unilateral positive or who underwent bilateral TAB (n = 74), those who had unilateral negative TAB (n = 88) had a significantly lower prevalence of jaw claudication (P = 0.007). Compared with subjects diagnosed with GCA (n = 39), those with unilateral negative TAB (n = 88) had significantly lower frequencies of jaw claudication (P = 0.001), "chalky white" optic disc edema (P = 0.002), and fever (P < 0.0001). Compared with subjects with positive TAB (n = 33), subjects with negative TAB (n = 148) had significantly lower prevalence of jaw claudication (P < 0.0001), "chalky white" disc edema (P = 0.0002), pale disc edema (P = 0.006), or any systemic symptom other than headache (P = 0.0002). ("Chalky white" denotes notably extreme disc pallor). The most common indications for biopsy in subjects with unilateral negative TAB were elevated erythrocyte sedimentation rate (ESR) (74%), headache (69%), visual complaints (58%), and ophthalmic signs (52%). Although ESR was a significant predictor of positive TAB overall (unilateral and bilateral TAB) in logistic regression models accounting simultaneously for subject age (P = 0.04), ESR did not significantly predict unilateral negative status in our patients (P = 0.13).

CONCLUSIONS

In this cohort of patients, unilateral TAB was associated with an extremely low frequency (1%) of subsequent positive contralateral TAB and was not associated with adverse visual or neurologic outcomes for any subject. We conclude that in the hands of experienced physicians, a unilateral TAB is sufficient to exclude a diagnosis of GCA in populations for which clinical suspicion is low. Jaw claudication, pale optic disc edema, particularly "chalky white" disc edema, fever, or any systemic symptom other than headache should raise suspicion for a diagnosis of GCA.

Contrast letter acuity as a measure of visual dysfunction in patients with Friedreich ataxia

BACKGROUND

Friedreich ataxia is a progressive neurodegenerative disorder affecting afferent cerebellar pathways and other neuronal systems, including afferent visual pathways. A systematic clinical outcome measure for examination of visual dysfunction in Friedreich ataxia has not been identified. We sought to identify a simple, reliable method for assessing clinical and subclinical visual dysfunction in patients with Friedreich ataxia.

METHODS

Contrast letter acuity was measured binocularly in Friedreich ataxia patients and age-matched visually asymptomatic volunteers (control group) using the Low-contrast Sloan Letter Charts at three different low-contrast levels (5.0%, 1.25%, and 0.6%). Binocular high-contrast visual acuity (100% level) was also determined for each participant.

RESULTS

Despite equal median binocular high-contrast visual acuities between the two groups, patients with Friedreich ataxia had significantly lower (worse) Low-contrast Sloan Letter Chart scores compared with controls, particularly at the lowest contrast levels (1.25% and 0.6%). Ambulation status significantly predicted Low-contrast Sloan Letter Charts scores in linear regression models accounting for patient age, suggesting a potential complementary role for Low-contrast Sloan Letter Chart testing in the assessment of disease status as well as visual function in Friedreich ataxia.

CONCLUSIONS

This study demonstrates that Low-contrast Sloan Letter Chart testing may provide a useful clinical outcome measure for Friedreich ataxia and other neuro-ophthalmologic disorders.

Idiopathic Intracranial Hypertension

Idiopathic intracranial hypertension (IIH), also known as pseudotumor cerebri, can be a serious vision-threatening disease. Visual acuity, visual fields, and ocular fundus appearance should be followed closely in all patients with IIH. Obese patients with IIH should be encouraged to lose weight. Medications that might cause or exacerbate IIH should be identified and discontinued if possible. Mild headaches can be treated with nonsteroidal anti-inflammatory drugs (NSAIDs) or migraine prophylactic agents. Some patients may not require additional treatment if they are otherwise asymptomatic and have no evidence of vision loss. Symptomatic patients (significant headache, visual complaints, tinnitus) or patients with visual field or acuity loss should be treated initially with acetazolamide. Furosemide may be a useful second-line agent. If vision loss is progressive despite maximal medical therapy or severe at the time of diagnosis, surgical intervention may be required. Optic nerve sheath fenestration is effective and safe, and may be repeated if initially unsuccessful. Lumboperitoneal shunting is also an option, especially if symptoms of headache are prominent and refractory to medical therapy, but it has significant complication and failure rates. Bariatric surgery can be an effective treatment for IIH in severely obese patients, but is not a useful acute intervention. Special issues must be considered when treating IIH in children or pregnant women.

Self-reported visual dysfunction in multiple sclerosis: new data from the VFQ-25 and development of an MS-specific vision questionnaire

PURPOSE

To examine vision-specific health-related quality of life in a cohort of patients with multiple sclerosis (MS) using the 25-Item National Eye Institute Visual Function Questionnaire (VFQ-25), and to identify content areas for a brief MS-specific vision questionnaire.

DESIGN

Cross-sectional survey.

METHODS

The VFQ-25 and a modified version of the Optic Neuritis Treatment Trial (ONTT) Patient Questionnaire were administered by in-person interview to 80 patients at the University of Pennsylvania MS Center. Binocular visual acuities were obtained following a standard protocol using retroilluminated Early Treatment Diabetic Retinopathy Study charts.

RESULTS

Despite a median binocular visual acuity of 20/16 (20/12.5-20/250), VFQ-25 subscale scores in the MS cohort were significantly lower (worse) compared with those of a published reference group of eye disease-free patients (P =.0001-0.009, two-tailed t tests). Rank-correlations of VFQ-25 composite (overall) scores with visual acuity were modest, but significant (r(s) = 0.33, P =.003), supporting construct validity for VFQ-25 scores in MS populations. Seven additional aspects of self-reported visual dysfunction in MS were also identified.

CONCLUSIONS

Patients with MS have a high degree of self-reported visual dysfunction that is not entirely captured by visual acuity. The VFQ-25 is an effective measure of self-reported visual loss in MS. A brief MS-specific vision questionnaire may provide additional useful information when administered concurrently with the VFQ-25 in future investigations of MS and other neuroophthalmologic disorders.

Friedreich ataxia: effects of genetic understanding on clinical evaluation and therapy

The discovery of the genetic cause of Friedreich ataxia has significantly affected our understanding of the disorder at both the clinical and basic science levels. Friedreich ataxia results from a deficiency of functional frataxin, a protein that appears to be involved in mitochondrial iron homeostasis. This leads to iron accumulation and mitochondrial abnormalities with consequent oxidant damage. The clinical spectrum of Friedreich ataxia has also expanded with the recognition of broader phenotypic features, including the absence of classical Friedreich ataxia features, later age at onset, and spasticity instead of ataxia. Although no proven therapy is yet available, antioxidants are a potential method for therapeutic intervention.

Near infrared muscle spectroscopy in patients with Friedreich's ataxia

Friedreich's ataxia is a progressive neurodegenerative disorder of the afferent cerebellar pathways associated with mitochondrial dysfunction at the cellular level. We have used noninvasive continuous near infrared muscle spectroscopy (NIRS) to investigate the delivery and utilization of oxygen in response to exercise in this disorder. Patients performed an incremental treadmill walking protocol in which levels of muscle deoxygenation or oxygenation were continuously measured in the medial calf muscle. The kinetics of recovery from exercise-induced deoxygenation, called the half-time of recovery (t(1/2)) were determined. The t(1/2) was prolonged in patients with Friedreich's ataxia compared with controls, and the degree of prolongation correlated with the length of the shorter GAA repeat, a genetic measure that correlates with the age of onset of disease. The t(1/2) also correlated inversely with patient age and with the maximum treadmill speed attained. Several patients also displayed features consistent with inadequate oxygen utilization by muscle. These results suggest that NIRS may be an effective tool for monitoring the biochemical and functional features of Friedreich's ataxia in parallel.

Clinical outcome measures for research in multiple sclerosis

The development of new and more sensitive clinical outcome measures for research in multiple sclerosis (MS) has been fueled by the development of effective therapies. As such, active arm comparison studies that require more sensitive clinical outcome measures are now commonplace. The Kurtzke Expanded Disability Status Scale (EDSS), the most widely used measure of neurologic impairment in MS, is particularly designed for classifying patients with respect to disease severity but has been criticized for its noninterval scaling, emphasis on ambulation status, relatively reduced sensitivity in the mid and upper ranges of scores, and absence of adequate cognitive and visual components. In response to perceived difficulties with the EDSS, the National Multiple Sclerosis Society Clinical Outcomes Assessment Task Force has developed the Multiple Sclerosis Functional Composite (MSFC). The MSFC includes three components that yield objective and quantitative results: 1) the timed 25-ft walk, 2) the nine-hole peg test, and 3) the 3-second paced auditory serial addition test. This scale has the advantages of continuous scoring with a composite Z score, standardized protocols, and high degrees of reliability and validity. Candidate visual function outcome measures for the MSFC, including the low-contrast Sloan letter chart, are currently under investigation. In addition to measures of neurologic impairment, health-related quality of life (HRQOL) measures have gained increasing importance as clinical trial outcome measures. The MS Quality of Life Inventory, a disease-specific HRQOL measure, has been developed to capture self-reported neurologic dysfunction and the impact of MS upon activities of daily living. MS clinical trials of the future, particularly active-arm comparison studies, will require more sensitive clinical outcome measures such as the MSFC. Measures of visual function and HRQOL should also be incorporated to capture the broad scope of neurologic impairment and disability in MS populations.

Evidence-based neuro-ophthalmology: advances in treatment

This review presents highlights and updates from of the most significant clinical trials in neuro-ophthalmology to date, the Optic Neuritis Treatment Trial, the Controlled High-Risk Avonex Multiple Sclerosis Prevention Study, and the Ischemic Optic Neuropathy Decompression Trial. The quality of evidence for treatment efficacy from these trials and other recent investigations of giant cell arteritis and idiopathic intracranial hypertension is classified herein according to published criteria based on sample size and study design.

New developments in idiopathic intracranial hypertension

This review highlights recent additions to the literature regarding the diagnosis, evaluation, and management of idiopathic intracranial hypertension (pseudotumor cerebri). Unique features of pediatric pseudotumor cerebri are addressed as well.

Optic Neuritis

Patients with signs and symptoms consistent with acute monosymptomatic optic neuritis should undergo evaluation with gadolinium-enhanced MRI of the brain and orbits to determine whether or not they are at high risk for the development of clinically definite multiple sclerosis (CDMS). The presence of two or more white matter lesions (3 mm or larger in diameter, at least one lesion periventricular or ovoid) suggests high risk for CDMS, and should prompt immediate treatment as follows: Intravenous methylprednisolone sodium succinate (1 g intravenously per day for 3 days) followed by oral prednisone (1 mg/kg per day for 11 days) with a 4-day taper (20 mg on day 1, 10 mg on days 2 and 4). Interferon beta 1-a, which has been demonstrated to significantly reduce the 3-year probability of the development of CDMS and the development of clinically silent MRI lesions in high-risk patients with acute optic neuritis, should be considered following IV methylprednisolone treatment (30 &mgr;g intramuscularly weekly). In monosymptomatic patients with fewer than two white matter lesions by MRI, and in patients for whom a diagnosis of CDMS has been established, treatment with IV methylprednisolone followed by oral prednisone (as outlined), should be considered on an individual basis and may hasten visual recovery, but has not been demonstrated to affect long-term visual outcome. In all cases of typical acute monosymptomatic demyelinating optic neuritis, oral prednisone alone at a dose of 1 mg/kg per day, without prior treatment with IV methylprednisolone (1 g per day for 3 days), may increase the risk for recurrent optic neuritis, and should be avoided.

The Heidenhain variant of Creutzfeldt-Jakob disease: clinical, pathologic, and neuroimaging findings

We report two patients who developed isolated visual symptoms and signs as initial manifestations of Creutzfeldt-Jakob disease (CJD). Both patients had normal conventional T1- and T2-weighted brain magnetic resonance (MR) images; in one patient, early cortical abnormalities were detected by diffusion-weighted and fluid attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI). Results from the cerebrospinal fluid assay for the 14-3-3 brain protein were also negative in one patient, despite pathologic confirmation of CJD at autopsy. The Heidenhain variant of CJD should be considered in all patients who present with isolated visual manifestations, including homonymous hemianopsia and normal conventional brain MRI. Diffusion-weighted and FLAIR MRI may demonstrate early cortical abnormalities in patients with CJD. The CSF assay for the 14-3-3 protein may be normal, even in pathologically confirmed cases.

Visual loss in children with neurofibromatosis type 1 and optic pathway gliomas: relation to tumor location by magnetic resonance imaging

PURPOSE

To examine the potential for visual acuity loss, and its relation to extent and location of optic pathway gliomas in a cohort of children with neurofibromatosis type 1 studied with magnetic resonance imaging.

METHODS

We reviewed the neuro-ophthalmologic records and brain/orbital magnetic resonance imaging scans for 43 consecutive pediatric patients with neurofibromatosis type 1 and optic pathway gliomas who were followed at the Children's Hospital of Philadelphia. The presence of visual loss, defined as abnormal visual acuity for age in one or both eyes, was determined. Optic pathway gliomas were classified by tumor extent and location according to involvement of the optic nerves, chiasm, and postchiasmal structures by magnetic resonance imaging.

RESULTS

Involvement of the optic tracts and other postchiasmal structures at tumor diagnosis was associated with a significantly higher probability of visual acuity loss (P =.048, chi-square test). Visual loss was noted in 20 of 43 patients (47%) at a median age of 4 years; however, three patients developed visual acuity loss for the first time during adolescence.

CONCLUSIONS

In pediatric patients with neurofibromatosis type 1 and optic pathway gliomas, the likelihood of visual loss is dependent on the extent and location of the tumor by magnetic resonance imaging and is particularly associated with involvement of postchiasmal structures. Furthermore, older age during childhood (adolescence) does not preclude the occurrence of visual loss. Close follow-up beyond the early childhood years, particularly for those with postchiasmal tumor, is recommended.

Anatomic review and topographic diagnosis

Neuro-ophthalmologic disorders, affecting the afferent and efferent visual systems, are frequently encountered by ophthalmologists in clinical practice. This article focuses on aspects of ocular, orbital, and neuroanatomy that are most important to the diagnosis of afferent and efferent visual pathway lesions. The use of optic disc and fundus appearance, visual fields, and ocular motility and pupillary findings are emphasized in the discussions of topographical diagnosis.

Retinal findings in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (cadasil)

We describe a 45-year-old man with biopsy proven cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). This patient demonstrated unique retinal findings, including arteriole narrowing and sheathing, irregular choroidal filling on fluorescein angiography, and patchy visual field loss. CADASIL is a hereditary, nonamyloid, nonathersclerotic microangiopathy. This disorder has been mapped to chromosome 19 with mutations in the Notch 3 gene. Deposits of granular osmiophilic material in the basal lamina of the smooth muscle cells of small vessels are considered pathognomonic for CADASIL and are typically seen only on electron microscopy. Although CADASIL is a systemic vascular disease affecting the entire arteriole tree, we are unaware of other reports describing the retinal findings observed in our patient.

Sixth nerve palsy as a presenting sign of intracranial plasmacytoma and multiple myeloma

Multiple myeloma and plasmacytoma are rare causes of mass lesions at the skull base and cavernous sinus. Sixth nerve palsy, in isolation or in combination with other cranial neuropathies, may occur rarely as the initial presenting feature of multiple myeloma. We report the neuro-ophthalmologic, radiologic, and pathologic findings for two patients who developed sixth nerve palsies as an initial manifestation of intracranial plasmacytoma and multiple myeloma. One patient presented with an isolated sixth nerve palsy in the setting of multiple vasculopathic risk factors. Treatable skull base lesions, including plasmacytoma and multiple myeloma, must be considered in patients with sixth nerve palsies, especially among those who demonstrate a progressive course or multiple cranial neuropathies.

Current neuro-ophthalmic therapies

The clinical characteristics, differential diagnosis, and treatment options are presented for five different categories of neuro-ophthalmic disease. Nystagmus, optic neuritis, diplopia, pseudotumor cerebri, and temporal arteritis, are frequently encountered in neuro-ophthalmic practice. This article focuses on current therapies for these neuro-ophthalmic disorders. Potential differences in approach to pediatric versus adult patients are emphasized.

Self-reported visual dysfunction in multiple sclerosis: results from the 25-Item National Eye Institute Visual Function Questionnaire (VFQ-25)

Visual impairment is one of the most common clinical manifestations of Multiple Sclerosis (MS), and is strongly related to overall health-related quality of life (HRQOL) in MS and other disorders. However, the assessment of vision-specific HRQOL in patients with MS has been limited. The purpose of this study was to examine self-reported visual dysfunction in a clinically heterogeneous MS cohort using the 25-Item National Eye Institute Visual Function Questionnaire (VFQ-25). The VFQ-25 was administered by telephone interview to a subset of participants in a follow-up study to a phase III trial of interferon beta-1a for relapsing-remitting MS. Mean VFQ-25 composite scores and selected sub-scale scores were significantly lower (worse) among patients in our MS cohort (n=35) compared with a published reference group of patients with no history of chronic eye disease (n= 118). These differences were observed despite a relatively younger age and tighter distribution of binocular visual acuities in the MS cohort Patients with MS in this study thus demonstrated a greater degree of self-reported visual dysfunction, as measured by the VFQ-25, compared with an eye disease-free reference group. The VFQ-25 is a potentially useful measure of vision-specific HRQOL in patients with MS.

Sixth nerve palsy as a presenting sign of intracranial plasmacytoma and multiple myeloma

Multiple myeloma and plasmacytoma are rare causes of mass lesions at the skull base and cavernous sinus. Sixth nerve palsy, in isolation or in combination with other cranial neuropathies, may occur rarely as the initial presenting feature of multiple myeloma. We report the neuro-ophthalmologic, radiologic, and pathologic findings for two patients who developed sixth nerve palsies as an initial manifestation of intracranial plasmacytoma and multiple myeloma. One patient presented with an isolated sixth nerve palsy in the setting of multiple vasculopathic risk factors. Treatable skull base lesions, including plasmacytoma and multiple myeloma, must be considered in patients with sixth nerve palsies, especially among those who demonstrate a progressive course or multiple cranial neuropathies.

Use of a portable head mounted perimetry system to assess bedside visual fields

AIM

This study was designed to test the ability of a portable computer driven, head mounted visual field testing system to perform automated perimetry on patients at their bedside and to compare these results with the "gold standard" for bedside examinations, confrontation visual fields.

METHODS

The Kasha visual field system is a portable automated perimeter which utilises a virtual reality headset. 37 neurosurgery patients were examined at their bedside with a central 24 degree suprathreshold testing strategy after confrontation visual field testing. The patterns of visual field defects were categorised and compared with the results of confrontation testing.

RESULTS

A total of 42 field examinations were completed on 37 patients, and the average testing time for both eyes was 4.8 minutes with the perimetry system. Each of the 11 fields (100%) classified with defects on confrontation testing was similarly categorised on head mounted perimetry. 26 out of 31 (84%) visual fields were normal on both confrontation and perimetry testing, while five out of the 31 fields (16%) which were full on confrontation had visual field defects identified by head mounted perimetry.

CONCLUSION

The head mounted, automated perimetry system proved easily portable and convenient for examining neurosurgical patients at their bedside in the perioperative period. The device demonstrated equal sensitivity to confrontation visual field testing methods in detecting field defects and offers the advantage of standardised, quantifiable testing with graphic results for follow up examinations.

New low-contrast vision charts: reliability and test characteristics in patients with multiple sclerosis

The quantitative assessment of visual function in multiple sclerosis (MS) clinical trials has been limited to Snellen visual acuity. The purpose of this study was to examine the inter-rater reliability and test characteristics of a new visual outcome measure, the Low-Contrast Sloan Letter Charts, in patients with MS and visually-asymptomatic volunteers. Contrast letter acuity scores (letter scores) were measured at each of four contrast levels (100, 5, 1.25 and 0.6%) by two independent raters. Inter-rater agreement was described with the intraclass correlation coefficient (ICC) and comparison of mean scores. Excellent inter-rater agreement (ICC=0.86 - 0.95) was demonstrated at each contrast level among MS patients (n=100) and visually-asymptomatic volunteers (n=33). Average letter scores at the lowest contrast level (0.6%) were highly variable in the MS group, even among patients with visual acuities of 20/20 or better, and among those who required no assistance for ambulation. Low-Contrast Sloan Letter Chart testing is a highly reliable method of visual assessment, and provides information on an aspect of neurologic impairment in MS which is not captured by Snellen visual acuity or ambulation status. This new method demonstrates excellent potential as a visual function outcome measure for future MS clinical trials.

Anatomic review and topographic diagnosis

Neuro-ophthalmologic disorders affecting the afferent and efferent visual systems are frequently encountered by neurosurgeons in clinical practice. This article focuses on aspects of neuroanatomy that are most important to the diagnosis of afferent and efferent visual pathway lesions. The use of optic disc and fundus appearance, visual fields, and ocular motility and pupillary findings are emphasized in the discussions of topographic diagnosis.

Idiopathic intracranial hypertension: relation of age and obesity in children

The relation between obesity and age in children with idiopathic intracranial hypertension (pseudotumor cerebri) has remained uncertain. The authors reviewed the records of 45 consecutive children with newly diagnosed idiopathic intracranial hypertension seen at two medical centers. Forty-three percent of patients aged 3 to 11 years were obese, whereas 81% of those in the 12- to 14-year age group and 91% of those in the 15- to 17-year age group met criteria for obesity (p = 0.01). Younger children with idiopathic intracranial hypertension are less likely to be obese than are older children or adults.

Neuro-ophthalmologic manifestations of Maffucci's syndrome and Ollier's disease

Patients with Ollier's disease (multiple skeletal enchondromas) and Maffucci's syndrome (multiple enchondromas associated with subcutaneous hemangiomas) may develop skull base chondrosarcomas or low-grade astrocytomas as a delayed consequence of these disorders. We report three patients with Ollier's disease and Maffucci's syndrome who had diplopia as the initial manifestation of intracranial tumors. Since patients with Maffucci's syndrome and Ollier's disease are at risk for the delayed development of brain and systemic neoplasms, neuroophthalmologists must be aware of the need for long-term surveillance in patients affected by these conditions.

Visual impairment associated with mutism after posterior fossa surgery in children

OBJECTIVE

To report four children with visual impairment associated with mutism after posterior fossa surgery. Mutism after posterior fossa surgery is a well-described phenomena, but to our knowledge, visual impairment has not been reported in association with it.

METHODS

Record review of four children (age range, 3-7 yr) who underwent posterior fossa surgery (via suboccipital craniotomies) for removal of a medulloblastoma (three patients) or ependymoma (one patient). Each presented with headache, ataxia, or nausea and vomiting, but none had preoperative visual complaints other than diplopia. Postoperatively, all patients were mute, and because of apparent visual loss, neuro-ophthalmic consultation was requested. Postoperative scans and examinations were also reviewed.

RESULTS

Each child was awake but appeared withdrawn without verbal output. No child blinked to threat or fixed or followed. In each case, pupillary reactivity was normal, and funduscopic examinations revealed only papilledema. One child reached for money. Within weeks or months postoperatively, the mutism spontaneously resolved, and visual behavior in general improved, roughly in parallel. During the follow-up period, papilledema resolved and the disc color was normal in each case. Magnetic resonance images obtained postoperatively revealed nothing remarkable, except surgical defects, without lesions in the retrogeniculate pathway.

CONCLUSION

Impaired visual behavior, mimicking cortical visual loss, may be associated with mutism after posterior fossa surgery in children. The prognosis for recovery is excellent and parallels the return of normal speech. The mechanism is unclear.

Optic nerve disorders

This review highlights recent advances related to diagnosis, clinical course, and management of nonglaucomatous optic neuropathies. Optic nerve disorders of particular interest and importance are emphasized, including ischemic optic neuropathy, optic neuritis, HIV-related infection, neoplastic disease, and pseudotumor cerebri.

Refractory giant cell arteritis with spinal cord infarction

We report an elderly patient with aggressive steroid-refractory giant cell arteritis manifesting as myelopathy and bilateral visual loss while on treatment. Pathologically, spinal cord infarction was observed and was due to extensive necrotizing granulomatous arteritis of spinal arteries. Spinal cord damage in giant cell arteritis is rare. One prior autopsy report of spinal cord infarction in giant cell arteritis did not identify vasculitic changes in the spinal arteries.

Giant cell arteritis with unusual flow-related neuro-ophthalmologic manifestations

We report two patients with giant cell arteritis and unusual neuro-ophthalmic findings. One patient developed a horizontal one and a half syndrome associated with upright posture. The responsible lesion was dorsal pontine infarction. The other patient had bright light-induced amaurosis fugax in the absence of extracranial carotid occlusive disease. Both patients continued to have symptoms despite the use of high-dose intravenous corticosteroids. The manifestations of both patients occurred early in the course of giant cell arteritis and were flow related.