Little Rock Eye Clinic

Neuro-Ophthalmology Newsletter- November 2011
Neuro-Ophthalmology Newsletter Andrew Lawton, M.D. November 2011 - Volume VIII, Number 11 Treatment of dystonia and hemifacial spasm can be very effective. For treatment to occur, however, a physician must establish the diagnosis first. Jog, et al (Can J Neurol Sci 2011; 38:704-711) surveyed 866 patients in 14 Canadian treatment centers to better understand how they came to be diagnosed and treated. 64 percent of the patients were women with an average age of 58 years. On average, patients were examined by 3.2 physicians and went 5.4 years prior to receiving the correct diagnosis. 34 percent received an incorrect diagnosis first, most commonly “stress” in 42.7 percent. Even after diagnosis, patients had a delay of over 3 months before receiving appropriate treatment with Botulinum toxin. The authors concluded that an educational program for primary care physicians would be of significant value to better inform these providers about the presentation of dystonias. Pediatric patients with benign intracranial hypertension may be hard to diagnose since their presentation may appear very different from that in adults. Kang and Kim (Korean J Ophthalmol 2011; 25:289-293) described an 11-year-old girl who presented with a 20 diopter esotropia at distance that disappeared at near. A neurologic evaluation and extraocular motility were normal. Six months later, the deviation had increased to 35 diopters. An MRI and MRV were negative. A lumbar puncture demonstrated an elevated opening pressure with normal CSF composition. Three months after initiation of Acetazolamide therapy, the esotropia at distance was down to 10 diopters. The final diagnosis was a divergence insufficiency without sixth cranial nerve palsy due to benign intracranial hypertension. The authors concluded that ophthalmologist must be aware of the possibility of an atypical presentation of benign intracranial hypertension in children so they can perform an adequate evaluation. Susac’s syndrome is a rare condition characterized by encephalopathy, recurrent and multifocal branch retinal artery occlusion, and sensorineural hearing loss. Francis, et al (Otol Neurootol 2011; 32:1198-1204), had the opportunity to histologically examine the inner ear of a patient with Susac’s syndrome. The patient had died one month following the onset of symptoms as a result of a pulmonary embolus. Sections of the apical cochleae revealed atrophy of all the tissues of the cochlear duct plus evidence of occlusion of capillaries. The vestibular tissues were intact. No evidence of endolymphatic hydrops was identified. The authors concluded that the damage from Susac’s syndrome results from capillary obliteration. Neuro-Ophthalmology Newsletter Volume VIII, Number 11 - November 2011 Case Study Patient VIII11 is a 64-year-old woman, who noticed changes in the appearance of her left eye following thyroid surgery on August 25, 2011. She has noticed that the upper eyelid appears droopy and that the pupil is smaller on that side than on the right. She does not perspire on the left side of her face following exertion. She does have a history of Post-Polio syndrome affecting the musculature on the right side of her body. Since surgery, her vision has become more blurred. Her medical history is significant for Post-Polio syndrome, arthritis, migraines, environmental allergies, and pain in her left shoulder and arm. Her ocular history is significant for the problems listed above. Her review of systems is otherwise noncontributory. Her family history is significant for glaucoma in her father, macular degeneration in her father, diabetes in a brother, cancer in her mother, arthritis in her mother, heart disease in her maternal grandmother, and hypertension in her mother. Current medications include Climara, Synthroid, Fiorinal, and Calcium. Her social history is significant for smoking three packs of cigarettes per week for the last 37 years and social alcohol consumption. She reported an allergy to Ibuprofen. On examination, her visual acuity at distance, without correction, was 20/20 in each eye. Vertical lid fissures were 11 mm on the right and 9 mm on the left. Orbicularis activity was normal. Her orbits were free of masses. Her right pupil measured 4 mm in the dark and 3 mm in the light. Her left pupil measured 3 mm in the dark and 2.5 mm in the light. Both pupils constricted at similar rates but the left pupil dilated more slowly than the right. No relative afferent pupillary defect was noted. Confrontation visual fields were full in both eyes. Both eyes moved fully in all directions. Both eyes were properly aligned. Slit lamp examination revealed a quiet conjunctiva, clear cornea, deep anterior chamber, normal iris, and clear lens in both eyes. Following dilation, examination of the posterior segment showed a cup to disc ratio of 0.2 in both eyes. Both optic discs were pink and flat. There was a normal appearance of the macula, retinal blood vessels, and peripheral retina in both eyes. A mental status examination revealed her to be alert and oriented x4. What testing is usually performed under these circumstances? . Discussion of Case VIII10 from October 2011 Newsletter Patient VIII10 has all of the features of benign intracranial pressure. She had a negative MRI indicating no intracranial mass. A reliable lumbar puncture, however, yielded an opening pressure of only 17 cm water, well within the normal range. The key here is the precipitating factor for her situation, obstructive sleep apnea. Whenever presented with a patient with any kind of optic disc edema (since this complex is responsible for many cases of anterior ischemic neuropathy), it is critical to inquire into the symptoms and findings related to obstructive sleep apnea. These include: 1. Snoring 2. Tossing and turning during the night 3. Gasping for air or ceasing to breathe entirely 4. Frequent awakenings 5. Fatigue on awakening in the morning 6. Insomnia 7. Falling asleep during the day at inappropriate times (driving prohibited!) 8. Obesity 9. Increased neck circumference 10. Older age The key metabolic abnormality is decreased oxygen saturation of the blood while asleep caused by periods of hypopnea and apnea. Since patients with sleep apnea have normal respiration during the day, intracranial pressure may be normal during waking hours. The rise of intracranial pressure while asleep, therefore, may be missed since lumbar punctures are done during waking hours. Appropriate diagnosis is critical. Patients with sleep apnea have high inflammatory mediators in the bloodstream. The inflammation results in significant joint and muscle pain that may mimic fibromyalgia. More importantly, the mediators cause a hypercoaguable state with a significantly increased risk of myocardial infarction and stroke. If the diagnosis is suspected, a referral for a sleep study with titration for treatment is imperative. Treatment is effective and most often consists of a weight loss program and nighttime use of a positive pressure device (a CPAP mask or nasal apparatus) to force the breathing passages open.. Your patients will thank you afterwards.

Neuro-Ophthalmology Newsletter- Sept./Oct. 2011
Neuro-Ophthalmology Newsletter Andrew Lawton, M.D. October 2011 - Volume VIII, Number 10 Neuromyelitis optica is a potentially debilitating syndrome characterized by demyelinating, necrotizing lesions of the thoracic spinal cord and optic chiasm. The isolation of aquaporin 4 (NMO) antibodies has allowed differentiation between patients with neuromyelitis optica and classical multiple sclerosis. Are NMO antibodies, however, necessary for the diagnosis of neuromyelitis optica? Nakamura, et al (Intern Med 2011; epublished August 1, 2001), presented the case study of a 15-year-old girl who developed a viral syndrome due to influenza type A. Three days after onset, she developed dysuria and decreased sensation in her legs. Nine days after onset, she lost vision drastically in both eyes (counting fingers only in right eye, 20/100 in left eye). Both optic discs were swollen. Despite the clinical picture, the patient demonstrated no aquaporin 4 antibodies. MRI showed longitudinal demyelinating lesion of the thoracic spinal cord and multiple cerebral white matter lesions. She responded well to intravenous and oral corticosteroids with no recurrences. The authors emphasized that multiple types of viral infections have been associated with neurological disease meeting the classical definition of NMO without aquaporin 4 antibodies detected. Patients with high myopia may develop significant visual field defects that may mimic bitemporal hemianopia. Ohno-Matsui, et al (AJO 2011; 152:256-265), looked at 492 eyes in 308 patients with high myopia defined as a refractive error of greater than -8 diopters or and axial length of greater than or equal to 26.5 mm. Minimum follow up was 5 years. Patients underwent Goldmann kinetic perimetry with the field divided into 100 sectors. A loss of 10% of the sectors was considered clinically significant and loss of an additional 10% or more of sectors evidence of visual field progression. Patients were excluded if they had some type of visible myopic macular or peripheral retinal lesion. 13.2% of patients developed new visual field defects over a mean follow up period of 11.6 years. Oval optic discs were more commonly associated with visual field loss than round optic discs. The authors noted a prevalence for temporal defects that progressed in 73.8% of eyes over a mean 10.2 year period. Progression of the visual field defects was associated with an abrupt change in sclera curvature in a staphylomatous pattern. The authors recommended annual visual field testing in patients fitting their definition of high myopia. They hypothesized that the changes in sclera curvature resulted in damage to the retinal nerve fiber layer. Temporal artery biopsy is a relatively low risk surgical procedure. One potential complication, however, is an injury to the facial nerve. Yoon, et al (AJO 2011; 152:251-255) reviewed four patients referred to them with the above problem. All of the incisions were within 3 cm of the lateral canthal angle either in the preauricular region or in front of the hairline. Two patients had partial return of function while the remaining two never improved. Because of the risk for this complication, the authors recommended biopsying the parietal branch of the superficial temporal artery rather than the frontal branch. Neuro-Ophthalmology Newsletter Volume VIII, Number 10 - October 2011 Case Study Patient VIII10 is a woman in her 30s who presented with headaches. She notes dimming of her vision on changing posture. An MRI revealed no significant abnormalities. Her medical history was significant for the problems listed above and obesity. Her ocular history was as above. A review of systems was otherwise noncontributory. She does snore. Her family history and social history were non-contributory. She was on over-the-counter medications for her headaches. She reported no allergies to medications. At exam, her visual acuity was 20/20 in each eye. Both eyes moved fully in all directions. Her eyes were appropriately aligned. An external examination showed a normal appearance of her eyelids, orbits, lacrimal glands, lacrimal drainage system, and regional lymph nodes on both sides. She had a large neck circumference. Both pupils measured 5 mm in the dark and 3 mm in the light. No relative afferent pupillary defect was present. Humphrey perimetry demonstrated nasal defects peripherally in both eyes. A slit lam examination showed normal conjunctiva, corneas, anterior chambers, irises, and lenses in both eyes. Intraocular pressures were 15 mm Hg in each eye. Following dilation, examination of her posterior segments revealed 1+ edema of both optic discs. Her maculae, retinal blood vessels, vitreous, and peripheral retinas were intact otherwise. A mental status exam indicated she was alert and oriented times four. An MRI demonstrated no abnormalities of the brain or orbits. A lumbar puncture revealed an opening pressure of 17 cm water. How can this be possible? . Discussion of Case VIII9 from September 2011 Newsletter Patient VIII9, as mentioned, carries the diagnosis of Maroteaux-Lamy syndrome. This condition is a mucopolysaccharidosis caused by a deficiency of N-acetylgalactosamine 4-sulfatase. Systemic problems include short stature due to a shortened upper body, a crouched stance, and joint stiffness. The individual’s abdomen may be distended due to a reversal of the normal curvature of the lower spine. Umbilical and inguinal hernias are common. Patients commonly have heart disease with valve deformities. Neurological and ophthalmological complications are important and may be permanently vision threatening. The dura becomes thickened with the development of obstructive hydrocephalus. The resultant elevation of intracranial pressure results in headaches and papilledema. Unfortunately, many of these patients develop permanent visual field loss due to a delay in diagnosis of their papilledema. Cataracts are common in these individuals and vision loss from optic nerve injury may be attributed incorrectly to the lens changes. An interesting sideline to this condition relates to treatment. An enzyme replacement is available in the form of the medication galsulfase (Naglazyme). This medication does improve height and joint development. The kicker is the price tag: one year’s supply of Naglazyme costs approximately $350,000, and there is not much demand for it. Our patient underwent two critical tests. First, he had an MRI which demonstrated expansion of the ventricular system and cervical stenosis. The MRI was followed by a lumbar puncture which confirmed an elevated intracranial pressure. He currently is under evaluation by a neurosurgeon to see if a shunt procedure or cervical spine surgery is indicated.

Neuro-Ophthalmology Newsletter- November 2011

Neuro-Ophthalmology Newsletter- Sept./Oct. 2011