Val rie Biousse

Natural history of homonymous hemianopia.

Objective: To describe the characteristics of spontaneous recovery of homonymous hemianopia (HH). Methods: The authors reviewed medical records of all patients with HH confirmed by formal visual field testing and seen in follow-up in their service between 1989 and 2004. Clinical characteristics, causes, neuroradiologic definition of lesion location, final outcome, and evolution of the visual field defects were recorded. The associations among final visual field defect outcome, time from injury, and clinical features were analyzed. Results: A total of 254 patients with 263 HH were included in this study. Spontaneous visual field defect recovery was observed in 101 HH (38.4%). The likelihood of spontaneous recovery decreased with increasing time from injury to initial visual field testing (p = 0.0003). The probability of improvement was related to the time since injury (p = 0.0003) with a 50 to 60% chance of improvement for cases tested within 1 month after injury that decreased to about 20% for cases tested at 6 months after surgery. No other factor was found to correlate with the final outcome of the visual field defects. Improvement after 6 months from injury was mild and usually related to improvement of the underlying disease. Conclusion: Spontaneous improvement of homonymous hemianopia is seen in at least 50% of patients first seen within 1 month of injury. In most cases, the improvement occurs within the first 3 months from injury. Spontaneous improvement after 6 months postinjury should be interpreted with caution as it is most likely related to improvement of the underlying disease or to improvement in the patient’s ability to perform visual field testing reliably.

Homonymous hemianopias Clinical–anatomic correlations in 904 cases

Objective: To describe the clinical characteristics and clinical-anatomic correlations of homonymous hemianopia (HH). Background: Homonymous hemianopia impairs visual function and frequently precludes driving. Most knowledge of HH is based on relatively few cases with clinical-anatomic correlations. Methods: The authors reviewed medical records of all patients with HH seen in their service between 1989 and 2004. Demographic characteristics, characteristics of visual field defects, causes of visual field defects, neuroradiologic definition of lesion location, and associated neurologic deficits were recorded. Results: A total of 904 HH were found in 852 patients. A total of 340 HH (37.6%) were complete and 564 HH (62.4%) were incomplete. Homonymous quadrantanopia (264 HH, 29%) was the most common type of incomplete HH, followed by homonymous scotomatous defects (116 HH, 13.5%), partial HH (114 HH, 13%), and HH with macular sparing (66 HH, 7%). A total of 407 HH (45.0%) were isolated. Causes of HH included stroke (629 HH, 69.6%), trauma (123, 13.6%), tumor (102, 11.3%), brain surgery (22, 2.4%), demyelination (13, 1.4%), other rare causes (13, 1.4%), and unknown etiology (2, 0.2%). The lesions were most commonly located in the occipital lobes (45%) and the optic radiations (32.2%). Every type of HH, except for unilateral loss of temporal crescent and homonymous sectoranopia, was found in all lesion locations along the retrochiasmal visual pathways. Conclusion: Homonymous hemianopia is usually secondary to stroke, head trauma, and tumors. Although the characteristics of visual field defects can be helpful in lesion location, specific visual field defects do not always indicate specific brain locations.

Ischemic optic neuropathies

Purpose of reviewTo review recent clinical data on ischemic optic neuropathies, which are some of the most frequently encountered optic neuropathies. These disorders include nonarteritic anterior ischemic optic neuropathy, arteritic anterior ischemic optic neuropathy, and posterior ischemic optic neuropathy. Recent findingsRecent studies have facilitated our understanding of the natural history of visual loss, recovery, and recurrence in these disorders. Additionally, the value of various diagnostic techniques and treatment options, particularly for arteritic anterior ischemic neuropathy, has been clarified. SummaryApplication of the studies described in this paper should allow the clinician to more accurately diagnose ischemic optic neuropathies and counsel the patient with regard to appropriate management, prognosis for visual recovery and future risk of recurrence.

Most cases labeled as "Retinal Migraine" are not migraine

Background: Monocular visual loss has often been labeled “retinal migraine.” Yet there is reason to believe that many such cases do not meet the criteria set out by the International Headache Society (IHS), which defines “retinal migraine” as attacks of fully reversible monocular visual disturbance associated with migraine headache and a normal neuro-ophthalmic examination between attacks. Methods: We performed a literature search of articles mentioning “retinal migraine,” “anterior visual pathway migraine,” “monocular migraine,” “ocular migraine,” “retinal vasospasm,” “transient monocular visual loss,” and “retinal spreading depression” using Medline and older textbooks. We applied the IHS criteria for retinal migraine to all cases so labeled. To be included as definite retinal migraine, patients were required to have had at least two episodes of transient monocular visual loss associated with, or followed by, a headache with migrainous features. Results: Only 16 patients with transient monocular visual loss had clinical manifestations consistent with retinal migraine. Only 5 of these patients met the IHS criteria for definite retinal migraine. No patient with permanent visual loss met the IHS criteria for retinal migraine. Conclusions: Definite retinal migraine, as defined by the IHS criteria, is an exceedingly rare cause of transient monocular visual loss. There are no convincing reports of permanent monocular visual loss associated with migraine. Most cases of transient monocular visual loss diagnosed as retinal migraine would more properly be diagnosed as “presumed retinal vasospasm.”

Atypical idiopathic intracranial hypertension Normal BMI and older patients

Background: Idiopathic intracranial hypertension (IIH) typically affects young, obese women. We examined 2 groups of atypical patients with IIH: those with a normal body mass index (BMI) and those at least 50 years of age. Methods: A retrospective cohort study of 407 consecutive adult patients with IIH with known BMI from 3 centers was undertaken. Demographics, associated factors, visual acuity, and visual fields were collected at presentation and follow-up. Results: We identified 18 IIH patients (4%) with normal BMI and 19 (5%) aged 50 years or older at the time of diagnosis who were compared with the remainder of the cohort. Medication-induced IIH was more frequent in patients with IIH with normal BMI (28 vs 7%, p = 0.008). No patient with IIH with a normal BMI had severe visual loss in either eye (0 vs 17%, p = 0.09). Older patients with IIH had a lower BMI, but were still generally obese (33 vs 38, p = 0.04). Older patients were less likely to report headache as initial symptom (37 vs 76%, p < 0.001) and more likely to complain of visual changes (42 vs 21%, p = 0.03). Treatment of any type was less likely in older patients (significant for medications: 74 vs 91%, p = 0.004), and they were more likely to have persistent disc edema at last follow-up (median Frisén grade: 1 vs 0, p = 0.002), but had similar, if not better, visual outcomes compared with younger patients. A case-control study did not identify any new medication or risk factor associations. Conclusions: Patients with normal body mass index and those 50 years or older make up a small proportion of patients with idiopathic intracranial hypertension (IIH), but appear to have better visual outcomes than more typical patients with IIH.

Neuro-ophthalmic manifestations of head trauma.

Objective To describe the neuro-ophthalmic findings in a group of patients with head trauma. Materials and Methods A retrospective chart review of all patients given a diagnosis code of head trauma in the neuro-ophthalmology unit at Emory University between 1991 and 1999. Results A total of 326 consecutive patients were reviewed (203 [63%] men and 123 [37.0%] women). Age ranged from 2 to 86 years, with a mean of 30 years. Motor vehicle accident was the most common cause of head trauma, occurring in 195 (59.8%) patients. An abnormal neuro-ophthalmic examination was noted in 185 of 326 patients (56.7%). Loss of consciousness was not associated with any outcome, but the presence of a neuroimaging abnormality, particularly intracranial hemorrhage, was significantly associated with specific neuro-ophthalmic deficits. Conclusions Head trauma causes a number of neuro-ophthalmic manifestations. The afferent and efferent pathways are vulnerable to traumatic injury, although the efferent system is more commonly affected. Loss of consciousness may not be a reliable predictor of specific neuro-ophthalmic outcomes, but neuroimaging abnormalities may.

The “sunglasses sign” predicts nonorganic visual loss in neuro-ophthalmologic practice

Objective: The aim of our study was to evaluate whether wearing sunglasses (the “sunglasses sign”) can be used by neuro-ophthalmologists to predict nonorganic visual loss (NOVL) in their patients. Methods: We prospectively collected information on all new patients seen by us over 13 months. We included all patients who ultimately received a diagnosis of NOVL, and all patients wearing sunglasses in our clinic. We recorded demographics, iris color, number of positive review of systems, ocular examination, precipitating event or trauma, workers’ compensation claims, disability and lawsuit related to the visual loss, and the reason for wearing sunglasses. Results: Among the 1,377 consecutive new patients seen in our clinic during the study, 34 patients wore sunglasses, among whom 7 (20.6%) had organic visual loss. During the study period, 59 patients were diagnosed with NOVL, among whom 27 (45.8%) wore sunglasses. The sensitivity of wearing sunglasses for NOVL was 0.46 (95% CI 0.33 to 0.59). The probability that a patient walking into our clinic had NOVL was 0.043 (95% CI 0.033 to 0.055); it increased to 0.79 (95% CI 0.62 to 0.91) in sunglasses patients. The specificity of sunglasses for the diagnosis of NOVL was 0.995 (95% CI 0.989 to 0.998). At least one of the following characteristics (highly positive review of systems, workers’ compensation claim, disability, and lawsuit) was found in 26 of 27 (96.3%) of NOVL patients wearing sunglasses and in none of the sunglasses patients with organic neuro-ophthalmic disorders. All 7 sunglasses patients with organic neuro-ophthalmic disorders had reasonable ophthalmic explanations for wearing sunglasses. Conclusion: The “sunglasses sign” in a patient without an obvious ophthalmic reason to wear sunglasses is highly suggestive of nonorganic visual loss.

Small vessel vasculopathies affecting the central nervous system.

Small vessel diseases affecting the central nervous system are common causes of ischemic and hemorrhagic stroke. Diseases affecting the small vessels are due either to abnormalities in the content of the vessel or to abnormalities in the vessel wall. Causes include atherosclerosis, inflammatory vasculitides, and noninflammatory vasculopathies such as postpartum angiopathy, cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), Susac syndrome, and Sneddon syndrome.

Leptomeningeal enhancement and venous abnormalities in granulomatous angiitis of the central nervous system.

A 68-year-old woman with a relatively acute onset of right homonymous hemianopia, Gerstmann syndrome, and global cognitive failure was found to have a lymphocytic pleocytosis and elevated protein on spinal fluid examination and displayed marked meningeal enhancement on magnetic resonance imaging and dilated cortical venules on cerebral angiography. Brain and meningeal biopsy disclosed a necrotizing granulomatous inflammation of small and medium-sized subarachnoid vessels. The brain parenchyma was normal. The angiographic presence of venous abnormalities, the lack of observable angiographic arterial involvement, and the lack of parenchymal pathology are distinctly unusual in granulomatous angiitis of the central nervous system. This case, therefore, extends the pathologic and imaging spectrum of this disorder.

Functional and simulated visual loss

Nonorganic visual loss (NOVL) is the cause of a large number of referrals to neurologists and ophthalmologists and is a frequent area of overlap between neurologists, ophthalmologists, and psychiatrists. NOVL is the presence of visual impairment without an organic cause for disease despite a thorough and comprehensive investigation. A diagnosis of NOVL requires both the absence of any findings on examination and proof of the integrity and functioning of the visual system. Although sometimes a challenging diagnosis to make, there are a number of techniques and maneuvers which can be utilized fairly easily, either at the bedside or in the clinic, to help determine if a patient has NOVL. In some instances specialized testing, such as formal visual field testing, optical coherence tomography, visual evoked responses, electroretinogram, and various imaging modalities (magnetic resonance imaging) are performed to help determine if the cause of visual loss is organic or nonorganic. Once a diagnosis of NOVL is made, treatment centers around reassurance of the patient, close follow-up, and, if necessary, referral to a psychiatrist, as these patients may have underlying psychiatric disorders and a preceding strong emotional event leading to the current symptoms, and may be more likely to develop depression and anxiety.