Case update on cranial osteopetrosis: which is the role of the neurosurgeon?

PURPOSE: Osteopetrosis (OP) is a rare skeletal disease, which can affect the skull base and calvaria. A multidisciplinary approach is mandatory and patient may need neurosurgical care. Few observations have been published, and optimal management of OP is not established yet. METHOD: We report a case of an infant with OP diagnosed at 5 months, who presented signs of intracranial hypertension associated with unilateral blindness. Bone marrow allograft was performed at 6 months of age. At neurosurgical first examination at 11 months, the child was hypotonic, with severe amblyopia; features of bicoronal synostosis were appreciated, with tense anterior fontanel bulging indicating synostotic oxycephaly. Head circumference had decreased from +3 SD to +1SD. Cerebral CT scan showed reduction of intracranial volume, inward thickening of the calvaria, bilateral stenosis of optic canal, ventricular dilatation, enlarged arachnoid spaces, and tonsillar herniation. We performed cranial vault expansion with frontal advancement and bi parietal decompression, thinning of the inner table, unroofing of the left orbit and optic canal in order to obtain optic nerve decompression. RESULTS: Postoperative course was uneventful, and the patient was discharged on day 8. Vision was unchanged but rapid improvement of axial tonus was noted. The CT scan showed satisfactory calvarial expansion with regression of tonsillar herniation. CONCLUSIONS: Neurosurgical evaluation and care are necessary in the context of a multidisciplinary approach to the patient affected by osteopetrosis. Cranial vault remodeling and expansion should be considered in patients with sign of intracranial hypertension. Timing of optic canal decompression is to be defined.

Long-term follow-up of two patients with oligocone trichromacy.

INTRODUCTION: Oligocone trichromacy (OT) is an uncommon cone dysfunction disorder, the mechanism of which remains poorly understood. OT has been thought to be non-progressive, but its long-term visual outcome has been seldom reported in the literature. Our aim was to present two OT patients followed at our institution over 18 years. MATERIALS AND METHODS: Complete ocular examination, color vision, visual fields, and full-field electroretinography (ERG) were performed at initial presentation and follow-up. Spectral-domain optical coherence tomography (OCT) was performed during follow-up when available at our institution. RESULTS: Initial ocular examination showed satisfactory visual acuities with normal fundus examination and near-to-normal color vision. However, computerized perimetry demonstrated a ring-shaped scotoma around fixation, and ERG showed a profound cone dysfunction. The discrepancy between preserved color vision and profound cone dysfunction leads to the diagnosis of OT. Subsequent follow-ups over 18 years showed subtle degradation of visual acuities along with progression of the myopia in both patients and slight worsening of color vision in one patient. Initial OCT revealed a focal interruption of the ellipsoid line along with decreased thickness of the perifoveal macula. Subsequent OCT imaging performed 2 years later did not show any macular changes. CONCLUSION: Although OT is known to be a non-progressive cone dysfunction, our results suggest that subtle degradation of the visual function might happen over time.

Optical coherence tomography in clinically isolated syndrome: no evidence of subclinical retinal axonal loss.

BACKGROUND: Optical coherence tomography has emerged as a new tool for quantifying axonal loss in multiple sclerosis (MS). A reduction in retinal nerve fiber layer (RNFL) thickness is correlated with Expanded Disability Status Scale score and brain atrophy. OBJECTIVE: To investigate RNFL and macular volume measurements using optical coherence tomography in the clinically isolated syndrome population. DESIGN: Prospective case series. Settings Neurologic clinics at the university hospitals of Lille and Strasbourg (France). PARTICIPANTS: Fifty-six consecutive patients with clinically isolated syndrome (18 with optic neuritis and 38 without optic neuritis) and 32 control subjects. MAIN OUTCOME MEASURES: Macular volume and RNFL thickness. RESULTS: Mean (SD) overall RNFL thickness (98.98 [10.26] microm) and macular volume (6.86 [0.32] microm(3)) in the clinically isolated syndrome population were not significantly different compared with the controls (98.71 [9.08] mum and 6.92 [0.38] microm(3), respectively). No link was noted between atrophy of the RNFL or macula and conversion to MS at 6 months. CONCLUSIONS: Optical coherence tomography does not reveal retinal axonal loss at the earliest clinical stage of MS and does not predict conversion to MS at 6 months.

Craniopharyngioma: ophthalmological aspects at diagnosis.

AIM: We studied ophthalmological signs at diagnosis in children with craniopharyngioma. PATIENTS AND METHODS: Twenty-nine children aged from 3 to 16 years (mean 9.1 years) were retrospectively studied. All of them had visual acuity measurement, oculomotor examination, fundoscopy and, whenever possible, visual field testing. RESULTS: Visual signs were present at diagnosis in 96% of patients in our series, but were the circumstances of diagnosis of craniopharyngioma in only 34.5%. Loss of visual acuity was present at diagnosis in 15 patients (51.7%), strabismus in eight (27.6%), papilloedema in ten (34.4%), and optic nerve atrophy in 11 patients (37.9%). A visual field defect was present at diagnosis in all 18 children who were able to perform an instrumental visual field and in three of the children who were tested by attraction visual field. CONCLUSIONS: In children, ophthalmological signs are not the main circumstance of diagnosis of craniopharyngioma because children do not complain of a mild or unilateral reduction in visual acuity. The central visual field is more often affected than the peripheral visual field; computerized static automated perimetry, which allows precise study of the central visual field, is difficult to perform in children. Because of the infiltrating nature of craniopharyngiomas, visual field defects are sometimes atypical and do not indicate a chiasmal problem.