Bilateral optic neuritis as a first presentation of lymph node tuberculosis.

Tuberculosis (TB) may affect the nervous system in many ways. We describe an immunocompetent teenage girl with lymph node TB who had first presented with bilateral optic neuritis. Detailed history identified features inconsistent with immune-mediated optic neuritis. Several unusual features prompted further investigation, including transient visual obscurations without raised intracranial pressure, prominent disc swelling and absence of laboratory findings to support an immune-mediated cause. Whole body PET/MR imaging identified widespread mediastinal and supraclavicular lymphadenopathy. Despite no known TB contacts, a negative interferon gamma release assay and a normal chest X-ray, a targeted lymph node biopsy confirmed TB.

Patterns of peripapillary retinal nerve fiber layer thinning in vigabatrin-exposed individuals.

PURPOSE: To explore the relationship of peripapillary retinal nerve fiber layer (ppRNFL) thinning in individuals exposed to the antiepileptic drug vigabatrin with respect to 2 separate variables: cumulative vigabatrin exposure and severity of vigabatrin-associated visual field loss (VAVFL). DESIGN: Cross-sectional observational study. PARTICIPANTS: Subjects were older than 18 years, 129 with vigabatrin-treated epilepsy (vigabatrin-exposed group) and 87 individuals with epilepsy never treated with vigabatrin (nonexposed group). METHODS: All subjects underwent ppRNFL imaging using spectral-domain optical coherence tomography. Eighty-four vigabatrin-exposed individuals underwent Goldmann kinetic perimetry. The visual field examined from the right eye was categorized as normal (n = 47), mildly abnormal (n = 18), or moderately to severely abnormal (n = 19). In 91 vigabatrin-exposed individuals, the cumulative vigabatrin exposure could be ascertained: 41 subjects received 1000 g or less, 23 subjects received more than 1000 g but equal to or less than 2500 g, 16 subjects received more than 2500 g but equal to or less than 5000 g or less, and 11 subjects received more than 5000 g. MAIN OUTCOME MEASURES: Differences in ppRNFL thickness across the twelve 30° sectors: (1) among all nonexposed individuals and all vigabatrin-exposed individuals, (2) between each vigabatrin-exposed group, according to cumulative vigabatrin exposure, and the nonexposed group, (3) among different vigabatrin-exposed subjects grouped according to cumulative vigabatrin exposure, and (4) among vigabatrin-exposed subjects grouped according to severity of VAVFL. RESULTS: The ppRNFL was significantly thinner in vigabatrin-exposed compared with nonexposed individuals in most 30° sectors (P<0.004). The temporal, temporal superior, and temporal inferior 30° sectors, as well as the nasal 30° sector, were not affected. There was a trend for increasing ppRNFL thinning with increasing cumulative vigabatrin exposure. The nasal-superior 30° sector was significantly thinner in group 1 (≤1000 g) compared with nonexposed individuals (P<0.05) and in vigabatrin-exposed individuals with normal visual fields compared with nonexposed individuals (P<0.05). CONCLUSIONS: After vigabatrin exposure in individuals receiving cumulative doses of 1000 g or less or in the presence of normal visual fields, ppRNFL thinning in the nasal superior 30° sector may occur. With higher cumulative doses of vigabatrin exposure, additional ppRNFL thinning was observed. The temporal aspects of the ppRNFL are spared, even in individuals with large cumulative vigabatrin exposures and moderate or severe VAVFL.

Electrodiagnostic assessment in optic nerve disease.

PURPOSE OF REVIEW: Complementary electrophysiological techniques can be useful in detecting and localizing dysfunction within the visual pathway. Recent developments are outlined in the context of neuro-ophthalmology. RECENT FINDINGS: The relationship between nerve fibre layer anatomy and the pattern visual evoked potential has been addressed, correlating axonal loss with visual pathway dysfunction. Longitudinal assessment of multiple sclerosis patients has defined parameters affecting the utility of the pattern visual evoked potential as an outcome measure in potential treatment trials. In optic nerve tumours, the pattern visual evoked potential may help identify and monitor the disorder. The pattern electroretinogram assesses retinal ganglion cell function and can identify macular dysfunction, possibly mimicking optic nerve disease clinically. The spatial extent of macular dysfunction can be assessed using the multifocal electroretinogram. Objective visual evoked potential assessment of visual acuity can be important in the management of nonorganic visual loss. The multifocal visual evoked potential is a relatively new technique that is attracting increasing research interest, particularly as a measure of visual field loss, but has yet to be established as a reliable diagnostic tool. SUMMARY: Electrophysiology, combined with clinical and imaging investigations, is a powerful diagnostic and monitoring tool. Macular dysfunction can mimic optic nerve disease in the absence of fundus abnormality.

A pharmacogenetic exploration of vigabatrin-induced visual field constriction.

INTRODUCTION: Use of the antiepileptic drug (AED) vigabatrin is severely limited by irreversible visual field constriction, an adverse reaction to the drug reported in approximately 40% of patients. Given the evidence suggesting an idiosyncratic drug response, we set out to detect genetic variation of strong, clinically relevant effect that might guide clinicians in the safe, controlled prescribing of this otherwise usefuldrug. METHODS: Patients with a history of at least 1-year exposure to vigabatrin were enrolled at two independent referral centers. Using Goldmann perimetry, visual fields and the extent of constriction were calculated for each patient. We examined the correlation between the extent of vigabatrin induced visual field constriction and genetic variation across six candidate genes (SLC6A1, SLC6A13, SCL6A11, ABAT, GABRR1 and GABRR2). We availed of HapMap data and used a tagging SNP technique in an effort to efficiently capture all common variation within these genes. We attempted to replicate any positive associations before drawing conclusions from our results. RESULTS: The degree of visual field constriction correlated with three SNPs and one haplotype in a cohort of 73 patients. However we were unable to replicate these findings in a second independent cohort consisting of 58 patients, suggesting the initial results were possibly false positives, or variants of weak effect. CONCLUSION: Common variants of strong, clinically relevant effect do not appear to reside in the candidate genes studied here. This does not rule out the presence of genetic variants of weak effect in these genes, nor of variants of strong effect in other genes.

Idiopathic intracranial hypertension and visual function.

BACKGROUND: Idiopathic intracranial hypertension is a relatively common condition (incidence up to 19/100 000/year in the high-risk group of obese women in reproductive age range) causing headaches with papilloedema. Detailed investigations are required to exclude other causes of raised intracranial pressure. The condition may be self-limiting or enter a chronic phase with significant morbidity because of headache and visual loss. METHODS AND RESULTS: This includes an overview of literature and internal audit date. DISCUSSION AND CONCLUSIONS: Management of hypertension is initially medical, utilizing a combination of managed weight reduction and diuretic therapy. Cerebrospinal fluid (CSF) diversion surgery may be required to stabilize vision. Options include neurosurgical shunting by lumbar-peritoneal of ventriculo-peritoneal routes or by optic nerve sheath fenestration or both. High category evidence from randomized trials to guide management decisions is lacking. This article sets out to guide current best practice.

Familial Bell's palsy in females: a phenotype with a predilection for eyelids and lacrimal gland.

The authors report a family with familial Bell's palsy affecting seven individuals, six of whom are females. This is a distinct subtype of Bell's palsy with a predilection for juvenile females, previously reported only very rarely. In conjunction with a review of the literature, this case suggests that this phenotype carries with it a greater risk of serious complications affecting the eyelids and lacrimal gland. These carry significant functional and cosmetic implications owing to aberrant regeneration of the seventh, sixth and possibly third cranial nerves, chronicity and relapses. Clinical features include synkinesis of the eyelids with the orbicularis oris causing synkinetic ptosis, recurrent paralytic ectropion, paralysis of facial muscles of expression with dry eye, hyperlacrimation (crocodile tears), and transient strabismus. Clinically, the decision to offer surgery in place of conservative treatment should consider the natural history of chronicity and relapses often seen with this subtype of familial Bell's palsy. Botulinum toxin injections are especially versatile in managing the complications associated with this phenotype.

Twin and triple peaks papilledema.

PURPOSE: To describe 2 adult patients who presented with papilledema after band atrophy (i.e., twin and triple peaks papilledema). DESIGN: Retrospective small case series. PARTICIPANTS: Two outpatients. METHODS: Observations made on 2 patients whose cases were reviewed in the neuro-ophthalmology clinic. RESULTS: The first patient had a pituitary tumor presenting with papilledema, causing a triple peaks clinical sign. Color photographs, optical coherence tomograms, and magnetic resonance images are shown. The second patient developed twin peaks papilledema due to a chiasmal glioma causing secondary raised intracranial pressure. CONCLUSION: Twin peaks papilledema is a rare clinical sign that may develop in adults as well as in children. The first report and optical coherence tomography features of triple peaks papilledema illustrate a new clinical sign.

Changes in intraocular pressure in anesthetized prone patients.

BACKGROUND: Postoperative visual loss occurs more commonly in patients placed prone. The mechanism may be raised intraocular pressure (IOP) causing an ischemic oculopathy. METHODS: IOP was measured in 20 patients undergoing spinal surgery. The IOP was measured prior to intubation, immediately after pronation, and at the end of surgery before the patient was returned to the supine position. Duration of surgery, method of head stabilization and standard physiological parameters were recorded. RESULTS: Both measurements of median IOP in the prone position were significantly higher than that in the supine position (P < 0.001). There was no evidence of a relationship between rise in IOP and duration of surgery, age, or body mass index. There was weak evidence of a tendency for patients whose heads were on pillows to have higher values of IOP at the end of surgery than patients whose heads were supported in pins. CONCLUSION: IOP increases when anesthetized patients are placed in the prone position.