Serous retinal detachment in hypertensive posterior reversible encephalopathy syndrome.

In accelerated hypertension, vasogenic brain edema associated with PRES may represent either autoregulatory breakthrough leading to vasodilation or excessive autoregulation leading to vasoconstriction. We describe 2 patients with PRES in accelerated hypertension who had serous retinal detachments, a vasoconstrictive phenomenon. The concurrence of serous retinal detachment and PRES offers intriguing support for the idea that vasoconstriction rather than vasodilation is the mechanism of vasogenic edema in PRES.

Spastic paraplegia, ataxia, mental retardation (SPAR): a novel genetic disorder.

OBJECTIVE: To describe a kindred with a dominantly inherited neurologic disorder manifested either as uncomplicated spastic paraplegia or ataxia, spastic paraplegia, and mental retardation. METHODS: Neurologic examinations and molecular genetic analysis (exclusion of known SCA and HSP genes and loci; and trinucleotide repeat expansion detection [RED]) were performed in six affected and four unaffected subjects in this family. MRI, electromyography (EMG), and nerve conduction studies were performed in three affected subjects. RESULTS: The phenotype of this dominantly inherited syndrome varied in succeeding generations. Pure spastic paraplegia was present in the earliest generation; subsequent generations had ataxia and mental retardation. MRI showed marked atrophy of the spinal cord in all patients and cerebellar atrophy in those with ataxia. Laboratory analysis showed that the disorder was not caused by mutations in genes that cause SCA-1, SCA-2, SCA-3, SCA-6, SCA-7, SCA-8, and SCA-12; not linked to other known loci for autosomal dominant ataxia (SCA-4, SCA-5, SCA-10, SCA-11, SCA-13, SCA-14, and SCA-16); and not linked to known loci for autosomal dominant hereditary spastic paraplegia (HSP) (SPG-3, SPG-4, SPG-6, SPG-8, SPG-9, SPG-10, SPG-12, and SPG-13) or autosomal recessive HSP SPG-7. Analysis of intergenerational differences in age at onset of symptoms suggests genetic anticipation. Using RED, the authors did not detect expanded CAG, CCT, TGG, or CGT repeats that segregate with the disease. CONCLUSIONS: The authors describe an unusual, dominantly inherited neurologic disorder in which the phenotype (pure spastic paraplegia or spastic ataxia with variable mental retardation) differed in subsequent generations. The molecular explanation for apparent genetic anticipation does not appear to involve trinucleotide repeat expansion.

Common errors in the use of magnetic resonance imaging for neuro-ophthalmic diagnosis.

The optimal utilization of magnetic resonance imaging in neuro-ophthalmic diagnosis is limited by errors in prescribing and interpreting scans. In a review of case material, we discovered four common prescriptive errors: 1) failure to apply a dedicated study, 2) inappropriate use of a dedicated study, 3) omission of intravenous contrast, and 4) omission of specialized sequences. The four common interpretive errors were the following: 1) failure to detect the lesion because of misleading clinical information, 2) rejection of a clinical diagnosis because an expected imaging abnormality was absent, 3) assumption that a striking imaging abnormality accounted for the clinical abnormality, and 4) failure to consider the lack of clinical specificity of imaging abnormalities. Many of these errors could be avoided by improved communication between clinicians and radiologists.

Syndrome simulating pseudotumor cerebri caused by partial transverse venous sinus obstruction in metastatic prostate cancer.

PURPOSE: To report a case of partial transverse venous sinus obstruction causing a syndrome resembling pseudotumor cerebri. METHOD: Case report. A 61-year-old man developed decreased vision, bilateral papilledema, and a highly increased cerebrospinal fluid opening pressure. Brain magnetic resonance imaging (MRI) disclosed a small, extra-axial mass near the torcula, which was dismissed as an incidental meningioma because cerebral angiography showed sinus patency. RESULTS: The patient's vision worsened. Biopsy of the enlarging mass disclosed metastatic prostate cancer. After radiation therapy, the mass shrank, magnetic resonance angiography disclosed reopening of the transverse sinuses, and papilledema resolved, but visual fields remained severely compromised. CONCLUSION: Partial blockage of the dural venous sinus by a small mass near the torcula can cause a sufficient increase in intracranial pressure to produce vision-threatening papilledema.

Akinetopsia from nefazodone toxicity.

PURPOSE: To investigate two cases of selective impairment of motion perception (akinetopsia) induced by toxicity from the antidepressant nefazodone, a new drug that blocks serotonin reuptake and antagonizes 5-HT2 receptors. METHODS: Case reports. RESULTS: A 47-year-old man receiving nefazodone (Serzone; Bristol-Meyers Squibb, New York, N.Y.) (100 mg twice daily), reported a bizarre derangement of motion perception. Moving objects were followed by a trail of multiple "freeze-frame" images, which dissipated promptly when motion ceased. A 48-year-old woman receiving nefazodone (400 mg daily at bedtime) reported a similar phenomenon, with visual trails following moving objects. In both patients, vision returned to normal after the dosage of nefazodone was reduced or eliminated. CONCLUSIONS: Nefazodone toxicity can result in akinetopsia, characterized by the inability to perceive motion in a normal, smooth fashion; persistence of multiple, strobelike images; and visual trails behind moving objects. In this rare syndrome, stationary elements are perceived normally, indicating that nefazodone causes selective impairment of pathways involved in motion processing in the visual system.

The impact of the optic neuritis treatment trial on the practices of ophthalmologists and neurologists.

OBJECTIVE: To determine whether the Optic Neuritis Treatment Trial (ONTT) results have altered the practice patterns of ophthalmologists and neurologists. DESIGN: Mail survey. PARTICIPANTS: A random sample of 987 ophthalmologists and 900 neurologists practicing in the United States were mailed a questionnaire that inquired into decision-making with regard to management of optic neuritis before and after the publication of the ONTT results. MAIN OUTCOME MEASURES: Responses received from 202 ophthalmologists and 244 neurologists, a response rate of 47%. RESULTS: Following the ONTT reports, nearly all ophthalmologists and neurologists have reduced their use of oral prednisone alone, substituting a regimen that includes intravenous methylprednisolone. A large proportion of practitioners in both specialties mistakenly believe that intravenous methylprednisolone treatment improves final visual outcome. Only 7% of neurologists and 36% of ophthalmologists (P = 0.0001) are adhering to the ONTT suggestion to use magnetic resonance imaging as a basis for initiating treatment. CONCLUSIONS: The ONTT has led to a dramatic reduction in the use of oral prednisone without a preceding course of intravenous methylprednisolone in the treatment of acute optic neuritis. Ophthalmologists and neurologists have changed some of their practices without fully understanding the results of the ONTT.

The emerging role of magnetic resonance angiography in the management of patients with third cranial nerve palsy.

PURPOSE: To discuss the sensitivity of three-dimensional time-of-flight (3D TOF) magnetic resonance angiography (MRA) for detecting aneurysms causing third cranial nerve palsy and to propose guidelines for the use of MRA in the evaluation of patients with different clinical presentations of oculomotor nerve palsy. METHODS: From a review of the scientific literature, we determined the proportion of aneurysms of various size that cause third nerve palsy, the sensitivity of MRA in detecting aneurysms of these size classes, and the relationship of aneurysmal size to rupture. RESULTS: The data disclose that properly performed and interpreted 3D TOF MRA will overlook only 1.5% of aneurysms producing third cranial nerve palsy that will, if untreated, rupture during the subsequent 8 years. CONCLUSIONS: Magnetic resonance angiography plays an important diagnostic role in the evaluation of patients with isolated third cranial nerve palsy. However, because of the potentially drastic consequences of overlooking an aneurysm, MRA should be the definitive screening test only among patients with a relatively low likelihood of harboring an aneurysm or a relatively high likelihood of suffering a complication from catheter angiography.

Brain biopsy in primary angiitis of the central nervous system.

To determine the yield of brain biopsy and the predictive value of clinical features and ancillary studies, we retrospectively analyzed hospital chart data from 61 consecutive patients suspected of having primary angiitis of the CNS (PACNS). Biopsies disclosed PACNS in 22 (36%), alternative diagnoses in 24 (39%), and no diagnosis in 15 (25%). Clinical indicators and angiography were not useful predictors of PACNS. Brain biopsy should be the primary diagnostic tool in this setting because of the poor reliability of other indicators and because of the high yield of alternative diagnoses requiring different management.

Minocycline treatment and pseudotumor cerebri syndrome.

PURPOSE: To demonstrate the association between minocycline treatment and development of the pseudotumor cerebri syndrome. METHODS: A retrospective study was conducted of 12 patients from five neuro-ophthalmic referral centers who developed pseudotumor cerebri syndrome after being treated with standard doses of minocycline for refractory acne vulgaris. The main outcome measures included resolution of headaches, transient visual obscurations, diplopia, papilledema, and visual fields static thresholds after withdrawal of minocycline and treatment for increased intracranial pressure. RESULTS: Nine (75%) of the 12 patients developed symptoms of the pseudotumor cerebri syndrome syndrome within 8 weeks of starting minocycline therapy; six were not obese. Two patients developed symptoms only after a year had elapsed because of commencement of treatment with minocycline. One patient was asymptomatic, and pseudotumor cerebri syndrome was diagnosed by finding papilledema on routine examination 1 year after minocycline was started. None of the patients developed recurrences for at least 1 year after the discontinuation of minocycline and treatment for increased intracranial pressure, but three (25%) of the 12 patients had substantial residual visual field loss. CONCLUSION: Minocycline is a cause or precipitating factor in pseudotumor cerebri syndrome. Although most patients have prominent symptoms and are diagnosed promptly, others are asymptomatic and may have optic disk edema for a long period of time before diagnosis. Withdrawal of minocycline and treatment for increased intracranial pressure lead to resolution of the pseudotumor cerebri syndrome, but visual field loss may persist.

Two types of oscillopsia in a patient with idiopathic vestibulopathy.

A patient with an idiopathic bilateral vestibulopathy described two types of oscillopsia, one induced by head movement, the other induced by changing pressure in the right external auditory canal. This is the first report of both types of oscillopsia occurring in the same individual and illustrates their different mechanisms and symptomatology.

Visual-spatial deficits expalin visual symptoms in Alzheimer's disease.

PURPOSE: To determine whether the visual symptoms of patients with Alzheimer's disease are related to visual-spatial dysfunction. METHODS: We administered a test battery modified from existing neuropsychometric materials that taxed visual-spatial skills, form identification, color vision, and visual memory. We tested 14 patients with Alzheimer's disease who had visual symptoms prominent enough to prompt ophthalmologic consultation, 11 patients with Alzheimer's disease who lacked such visual symptoms, and a control group of 53 subjects without Alzheimer's disease. The groups with Alzheimer's disease were matched for Wechsler Adult Intelligence Scale-Revised scores. RESULTS: Patients with Alzheimer's disease who had prominent visual symptoms differed significantly from those without prominent visual symptoms only in their relatively poor visual-spatial test scores. CONCLUSIONS: Visual symptoms in Alzheimer's disease are related primarily to visual-spatial deficits. These findings are consistent with previous evidence that patients with Alzheimer's disease who have prominent visual symptoms have accentuated histologic and metabolic abnormalities in the parieto-occipital regions known to process visual-spatial information. The findings support the view that pathways mediating visual-spatial and form identification are at least partially segregated in the brain, and emphasize that tests used to screen visually symptomatic patients with Alzheimer's disease will be more effective if they prominently assess visual-spatial skills.

Crashes and violations among drivers with Alzheimer disease.

BACKGROUND: Several small studies have found a high automobile crash rate for drivers with Alzheimer disease (AD) compared with unaffected elderly drivers, prompting the suggestion that the diagnosis of AD mandate cessation of driving. OBJECTIVES: To compare automobile crash and violation rates of a large number of patients with AD with appropriately matched elderly subjects. To determine if neuropsychological test scores predict these adverse driving events. To determine if intervention by physicians or family members influences driving cessation. DESIGN: Review of crashes and violations from 1986 to 1993 in police-filed Michigan State driving records of 143 licensed patients with AD and 715 licensed comparison subjects matched 5 to 1 in age (+/- 6 years), sex, and county of residence. We correlated crashes and violations with neuropsychological test scores. A questionnaire-based inquiry on the influence of physician, family, and state interventions on driving cessation was administered. RESULTS: The crash and violation rates of patients with AD were not significantly different from those of comparison subjects. However, patients with AD probably drove fewer kilometers than did comparison subjects. Neuropsychological test scores did not predict future crashes or violations. CONCLUSIONS: This study, the largest to our knowledge involving state driving records of patients with AD, does not confirm the previously reported excessive crash rate among drivers with AD relative to an appropriate comparison population. Reduced driving exposure of patients with AD probably kept their crash adverse equal to that of comparison subjects. Intervention by physicians and family members was major factor in reducing driving exposure. These findings affirm that the mere diagnosis of AD does not justify license revocation.

Contrast sensitivity and other vision tests in the optic neuritis treatment trial.

PURPOSE: To determine the intercorrelation, prevalence of abnormality, and incremental detection value of vision tests in optic neuritis. METHODS: We calculated the linear correlation of paired vision tests and prevalence of abnormal test values from baseline and six-month measurements of Snellen visual acuity, Pelli-Robson contrast sensitivity, Humphrey Field Analyzer mean deviation, and Farnsworth-Munsell 100-hue color vision in 438 patients entered in the Optic Neuritis Treatment Trial from 1988 to 1991. The incremental detection value of nonvisual acuity tests was defined as their frequency of abnormality when visual acuity was 20/20 or better. RESULTS: All four vision-test results were highly intercorrelated at baseline and at six months. At baseline, contrast sensitivity had the highest prevalence of abnormality, but all vision tests were so often abnormal that differences were not clinically relevant. At six months, when visual recovery had occurred, contrast sensitivity was most often abnormal (2.2 X visual acuity; 1.8 X mean deviation; 1.5 X Farnsworth-Munsell 100-hue color vision test); when contrast sensitivity, mean deviation, or Farnsworth-Munsell 100-hue color vision was normal, visual acuity was 20/25 or better in 98% of patients. CONCLUSIONS: The high intercorrelation of four vision tests suggests that optic neuritis affects a broad range of visual functions. Among non-visual acuity tests, Pelli-Robson contrast sensitivity proved to be a particularly practical and sensitive indicator of visual dysfunction in optic neuritis.