Lai Kuan-chi,  Martinez-agosto Julian,  Chawla Soni,  Zipser Brian

Final Pr. ID: Poster #: CR-064

Optic nerve aplasia (ONA) is a very rare developmental anomaly characterized by absence of optic nerve, retinal ganglion, and optic nerve vessels. The majority of reported ONA cases are unilateral. The rarer cases of bilateral ONA are often associated with additional brain anomalies. ONA is considered distinct from optic nerve hypoplasia. Both environmental and genetic factors have been hypothesized to contribute to ONA, and several genetic mutations have been identified, including PAX6, OTX2, CYP26A1, or CYP26C1. We report a case of bilateral ONA in an otherwise healthy infant with mild hypoplasia of the corpus callosum without dysplasia, and macrocephaly.
A 13-month-old male presented for evaluation of macrocephaly and global developmental delay that was attributed to cortical blindness. He was born full-term without complications, however mother felt no fetal movement for one week prior to delivery. Abnormal roving eye movements were noted since the early neonatal period. There was no family history of any congenital diseases. Examination revealed conjugate non-purposeful rapid eye movements without nystagmus, bilateral lens opacification, and absence of the pupillary light response, startle reflex, and red reflex. The remainder of the physical exam was normal.
MRI of the brain and obits demonstrated absence of the bilateral optic nerves, optic chiasm, and the optic tracts. The globes were normal in size and appearance, although with the right minimally larger than the left. The corpus callosum was relatively thin, but intact, suggesting mild hypoplasia without dysplasia. In contrast to the majority of reported bilateral ONA cases that have associated CNS anomalies (polymicrogyria, corpus callosum agenesis, hypopituitarism, hydrocephalus, microphthalmus), our patient was only noted to have macrocephaly and mild hypoplasia of the corpus callosum. No other brain structural abnormalities were present. Initial genetics evaluation with a microarray was normal, therefore further testing with exome sequencing is planned. We report an extremely rare case of bilateral ONA in an otherwise healthy infant and review the literature for the associated radiologic and genetic findings. Read More

Authors:  Lai Kuan-chi , Martinez-agosto Julian , Chawla Soni , Zipser Brian

Keywords:  Optic nerve, aplasia, congenital

Kaloianova Maria,  Naidoo Jaishree,  Thomson Heather,  Bhengu Louisa

Final Pr. ID: Poster #: CR-002

Krabbe disease is an autosomal recessive leukodystrophy that presents clinically with regression of milestones, excessive irritability and inconsolable crying. The pathologic basis of the disease is due to abnormal myelin metabolism resulting from a deficiency in the galactocerebrosidase enzyme with subsequent white matter destruction.
Although optic atrophy is a classic presentation of Krabbe disease, we report two patients who are biological brothers presenting with optic nerve enlargement in addition to other typical MR imaging features of Krabbe disease, thereby confounding the initial diagnosis.

Krabbe disease, also known as globoid cell leukodystrophy, is a lysosomal function disorder which ultimately results in demyelination and dysmyelination of white matter.
Worldwide incidence of Krabbe disease has been shown to be 1 in 100 000-200 000, with 1 in 150 000 live births reported in Europe (1, 2). The incidence in the South African population has not been well established.

Case Report 1:
Patient 1 presented in February 2012 to the paediatric neurodevelopmental clinic at 7 months of age with excessive inconsolable crying, regression of milestones, numerous café au lait macules and large eyes. Birth history was non-contributory.
MRI of the brain was done, demonstrating hypertrophy of the optic nerves and multiple other cranial nerves bilaterally (see figure 1).
High signal intensities were noted within the white matter of the brachium pontis, cerebellar dentate nuclei and corona radiata with a significant background of cortical and white matter atrophy (see figure 2).

Patient 1 died at one year of age with a provisional diagnosis of Neurofibromatosis I (NFI). No specific tests for Krabbe disease were performed prior to his death.

Case Report 2:
Patient 2 presented in November 2014 at 5 months of age with regression of milestones, excessive crying which was difficult to soothe, numerous café au lait macules, large eyes and a relative macrocephaly. Birth history was non-contributory and the child developed normally up until 3 months of age.
Blood tests for amino acids and organic acids, as well as liver and renal functions were normal. CSF lactate and glycine levels were also normal.

Specific enzyme testing for Krabbe disease was performed for patient 2 in Philadelphia, United States. Results revealed the galactocerebrosidase enzyme value to be very low (0.07). This is in the range of patients affected with Krabbe disease.
Patient 2 died shortly after the diagnosis of Krabbe disease was confirmed.

MRI brain scan of patient 2 demonstrated markedly hypertrophied optic nerves (see figures 3 and 4). Increased T2 and T2 Flair signal intensities of the white matter of the brachium pontis and the cerebellar dentate nuclei (see figure 5). The midbrain, pons and cerebellum also demonstrated increased T2 and T2 Flair signal intensities with a significant background of cortical and white matter atrophy (see figure 6).

PLEASE NOTE: the discussion related to Krabbe disease in this case review has not been included here due to charachter limitations. In addition, 6 images in total will be included should this case report be accepted for presentaton. Read More

Authors:  Kaloianova Maria , Naidoo Jaishree , Thomson Heather , Bhengu Louisa

Keywords:  Krabbe disease, leukodystrophy, globoid cell leukodystrophy, optic nerve enlargement

Ramírez Tamara,  Abdeen Nishard

Final Pr. ID: Poster #: SCI-027

The optic nerve sheath diameter (ONSD) has been noted to distend in patients with increased intracranial pressure. There is relatively little data on the sensitivity of dilated optic nerve sheath on initial CT or MRI as a sign of raised Intracranial pressure (ICP) in children with ventriculoperitoneal (VP) shunt malfunction. This pilot study aims to establish if there is a significant difference in ONSD pre- and postshunt revision surgery. Read More

Authors:  Ramírez Tamara , Abdeen Nishard

Keywords:  Optic nerve sheath diameter, Intracranial pressure, Ventriculoperitoneal shunt