Bettina Sadowski

Visual field constriction and electrophysiological changes associated with vigabatrin

Purpose: We investigated functional, morphological and electrophysiological changes in patients under anti-epileptic therapy with vigabatrin (VGB), a GABA aminotransferase inhibitor. Methods: 20 epileptic patients treated with vigabatrin (age range 25–66 years) were enrolled in this study. The referrals were made by the treating neurologist, based on suspected or known visual field changes in these patients. Two patients had vigabatrin monotherapy, 18 patients were treated with vigabatrin in combination with other antiepileptic drugs. None of the patients reported visual complaints. Patients were examined with psychophysical tests including colour vision (Farnsworth D15), dark adaptation threshold, Goldmann visual fields and Tuebingen Automated Perimetry (90°). A Ganzfeld ERG and an EOG following the ISCEV standard protocol were also obtained. Additionally, all patients were examined with the VERIS multifocal ERG including recordings of multifocal oscillatory potentials. Results: Visual acuity, anterior and posterior segments, colour vision and dark adaptation thresholds were normal in all patients. Of 20 patients, 18 presented visual field constriction. All patients with visual field defects revealed altered oscillatory potentials waveforms in the ERG, especially in those patients with marked visual field defects. Multifocal oscillatory potentials were also delayed in those patients. In some patients a delayed cone single flash response (6/20), a reduced mERG amplitude (12/20) and a reduced Arden ratio (9/20) were found. Conclusions: The present data indicate an effect of vigabatrin on the inner retinal layers. Since abnormalities of the oscillatory potentials were seen in all patients with visual field defects a dysfunction of GABA-ergic retinal cell transmission might be assumed.

Parietal somatosensory association cortex mediates affective blindsight

To investigate the neural substrates underlying emotional feelings in the absence of a conscious stimulus percept, we presented a visual stimulus in the blind field of partially cortically blind patients and measured cortical activity (by functional magnetic resonance imaging, fMRI) before and after the stimulus had been paired with an aversive event. After pairing, self-reported negative emotional valence and blood oxygen level–dependent (BOLD) responses in somatosensory association areas were enhanced, whereby somatosensory activity predicted highly corresponding reported feelings and startle reflex amplitudes across subjects. Our data provide direct evidence that cortical activity representing physical emotional states governs emotional feelings.

Visual Loss without Headache in Children with Pseudotumor Cerebri and Growth Hormone Treatment

We report on two prepubescent girls with visual loss due to idiopathic intracranial hypertension (IIH), or pseudotumor cerebri, both treated with recombinant human growth hormone for growth failure. The interval from starting hormone therapy to diagnosis of IIH was 3 and 18 months, respectively. Both girls did not complain of headache and nausea. They were neither obese nor did they suffer from renal insufficiency. In both patients, we observed bilateral optic disc edema with visual loss and elevated cerebrospinal fluid (CSF) pressures. Other causes of IIH were excluded with neuroimaging and CSF examination. Cessation of drug administration is often sufficient for symptom resolution in cases of hormone therapy-associated IIH. However, visual field defects in one girl remained unchanged during follow-up of 8 months. In children with IIH, the spectrum of neurologic and visual manifestations might be variable and unspecific. Diagnosis and management of IIH can be difficult in the absence of headache. Blurred or double vision due to cranial nerve palsy might be the only symptom rather than complaints about reduced visual acuity. Therefore, regular clinical monitoring of visual function and fundus appearance is essential for early diagnosis, efficient management, and improvement of visual outcome in children receiving recombinant human growth hormone.

Oligocone trichromasy – a rare form of incomplete monochromatism

SummaryOligocone trichromasy is a rare form of congenital incomplete monochromatism. Patients and methods: An 11-year-old girl presented because of reduced visual acuity while color vision was almost normal. Besides a general ophthalmological examination, special psychophysical tests, such as perimetry, color vision tests using pseudoisochromatic plates, arrangement tests, the Nagel anomaloscope and spectral sensitivity measurement, and electrophysiological tests (electroretinogram and electrooculogram) were conducted. Results: The tests yielded the following: congenital nystagm, normal results at ophthalmoscopy, best visual acuity of 0.1 monocular and 0.2 binocular. Perimetry revealed a relatively central scotoma. All color vision tests showed only mild dysfunction of the blue-sensitive cones. Findings at photopic electroretinogram were almost completely lacking. There was no sign of progression in the last 6 years. Conclusion: Differential diagnosis includes all diseases associated with congenital nystagm, such as aniridia, diseases of the optic nerve, albinism and all forms of hereditary cone dysfunction, cone dystrophies and complete and incomplete congenital stationary monochromatism. In the present case the findings are most congruent with oligocone trichromasy.ZusammenfassungDie „Oligocone“-Trichromasie (OCT) ist eine seltene Form der angeborenen inkompletten Achromatopsie. Eine Fallbeschreibung soll dieses Krankheitsbild erläutern: Patient und Methode: Ein 11-jähriges Mädchen fiel durch ein reduziertes Sehvermögen bei fast normalem Farbunterscheidungsvermögen auf. Neben allgemeinophthalmologischen Untersuchungen wurden spezielle psychophysische Untersuchungen (Gesichtsfeld, Pseudoisochromatische Tafeln, Farbanordnungstests, Anomaloskop und Analyse der spektralen Empfindlichkeit) sowie elektrophysiologische Untersuchungen angewendet. Ergebnisse: Die folgenden Befunde konnten bei kongenitalem Nystagmus und unauffälligem Fundusbefund erhoben werden: monokularer Visus bei bestmöglicher Korrektur beidseits 0,1; binokular 0,2; im Gesichtsfeld eine relatives Zentralskotom, in allen Farbsinnprüfungen geringe Störungen im Blaubereich, im photopischen ERG lediglich Restantworten. Diese Befunde waren in den letzten 6 Jahren stationär. Schlußfolgerung: Die Diagnose einer Sonderform der inkompletten Achromatopsie, der „Oligocone“-Trichromasie nach van Lith (1972) wurde gestellt. Differentialdiagnostisch sollten alle Krankheiten in Betracht gezogen werden, die mit einem kongenitalen Nystagmus einhergehen, z. B. Optikuserkrankungen, Albinismus oculi, hereditäre Zapfendysfunktionen und Zapfendystrophien sowie die kompletten und inkompletten Formen der angeborenen stationären Achromatopsie.

Electrophysiological and psychophysical examination in patients with optic nerve compression

Compression of the optic nerve causes a descending degeneration of optic nerve fibers. Additionally to the clinical symptoms (loss of visual acuity, scotomas), electrophysiological methods can be used to evaluate the function of the optic nerve (VEP) and the retinal ganglion cell layer (pattern ERG, PERG).In order to investigate the prognostic significance of electrophysiological methods for postoperative recovery of visual function, 11 patients (22 eyes) suffering from compression of the optic nerve or chiasm due to pituitary tumors or meningiomas were investigated prior to and after surgical decompression. Visual acuity and perimetry were compared to preoperatively performed transient pattern VEP and transient PERG (N-95 amplitude).Prior to surgery, the patients suffered from impairment of visual acuity and scotomas. After surgical decompression, visual acuity improved in seven eyes, remained unchanged in 11 eyes and deteriorated in four eyes. Visual field defects improved in 13 eyes, one visual field d...

Detecting color vision in a malingerer

A patient describing himself as totally color blind was ordered by the judicial system to have his color vision investigated in order to establish his suitability for military service. Basic clinical (Farnsworth Panel D-15, Moreland and Rayleigh anomaloscope equations), electroretinographic (ERG) and psychophysical techniques (spectral sensitivities) were applied to determine the extent of his color discrimination performance and cone function. These standard procedures were complemented by a test for cone interaction (transient tritanopia) and by newly developed cone-isolating flicker large-field ERG recordings. The patients data consistently indicate the function as well as the functional interaction of the middle-wavelength-sensitive (M-) and the short-wavelength-sensitive (S-) cones. But the function of the long-wavelength-sensitive (L-) cones was completely absent. Hence the patient was correctly demonstrated to be a protanope. This study establishes that standard classical procedures, in combination with newly developed and easy to apply psychophysical and ERG ones, which can be reliably used to assess true color discrimination performance, in difficult cases of malingering.

An optical device for patients with downgaze problems shown in a patient suffering from Steele-Richardson-Olszewski syndrome

Progressive supranuclear palsy (PSP) or Steele-Richardson-Olszewski syndrome is a degenerative disorder which includes vertical gaze paralysis, nuchal dystonia, parkinsonism, and dementia. Consequently, since patients suffering from this disorder tend to fall, sedentary occupations and interests predominate. Because of the relatively early appearing gaze palsy, patients are unable to read or to eat on their own. Personal dependence increases and the quality of life decreases. In this report, a patient suffering from PSP in an initial stage with an impairment of vertical ocular pursuit movements and consequent difficulties in reading and eating is described. With the help of a new device, where refraction and movable prism glasses in front of the eyes are integrated, the patient could be rehabilitated. Patients suffering from vertical ophthalmoplegia of other causes can also take advantage of this new optical device.

Reversibility of Tamoxifen® Retinopathy—A Ten-Year Follow-Up

High doses of the non-steroidal oral antiestrogen tamoxifen (60 mg/m2/day or more for at least 1 year) may cause decreased visual acuity due to retinal crystalline deposits and other ocular side-effects. A 56-year-old female patient suffering from pulmonary lymphangioleiomyomatosis (BML) with paraneoplastic estradiol production was presented with deterioration of visual acuity because of bilateral macular degeneration after an intake of 190–250 mg/day Tamoxpuren for five years. After discontinuing tamoxifen, ocular side-effects disappeared, perimetric and electrophysiological alterations almost normalized while visual acuity increased internal medical findings remained stable.

Intracranial Arachnoid Cyst: Symptoms, Diagnosis, and Therapy

Intracranial arachnoid cysts are common findings on routine cross sectional imaging, which may cause neurological problems depending on their extension and location, leading to neurosurgical intervention. An 11-year-old boy presented with symptoms of increased intracranial pressure. A neurosurgical fenestration of an arachnoid cyst detected in the MRT was performed because of a slight relative afferent pupillary deficiency, a papillary edema, and an elevated optic nerve sheath diameter (ONSD). In the follow-up of 2 years the patient was free of symptoms with normalization of the ophthalmologic findings, reduced size of the cyst, and decreasing ONSD.