Imaging Casebook &&&&&&&&&&&&&& Aicardi Syndrome with Probable Intraorbital Cystic Encephalocele

Imaging Casebook &&&&&&&&&&&&&& Aicardi Syndrome With Probable Intraorbital Cystic Encephalocele

Thomas E. Herman, MD approximately two thirds of patients2 and consist of block vertebrae, Marilyn J. Siegel, MD hemivertebrae, butterfly vertebrae, and abnormal costovertebral articulations. An interesting abnormality is the cysts seen in the orbit posterior CASE PRESENTATION to the microphthalmic globe in this patient. In one similar case, this A 41 weeks’ gestation infant girl was born vaginally with Pitocin lesion was pathologically confirmed and seen to be a cystic induction. The finding of fetal hydrocephalus on a screening intraorbital encephalocele. Because of the MRI similar to our 4 sonogram had complicated the pregnancy. The infant was limp at patient’s orbital cyst, we believe this also represents the same lesion. delivery, but had Apgar scores of 6 at 1 minute and 8 at 5 minutes. Aicardi syndrome is believed to be due to interstitial deletions in 6 The child had a seizure shortly after delivery. An electroencephalo- the region of X p22.3. The disease is thought to be an X-linked gram demonstrated a seizure focus and a disordered background. dominant lesion lethal in males, except in one report case of a Physical examination in the nursery demonstrated right micro- patient with Klinefelter’s syndrome. Rett syndrome, incontinentia phthalmia. A cranial magnetic resonance imaging (MRI) was pigmenti, and Goltz focal–dermal hypoplasia syndrome are other X- obtained (Figures 1 and 2) and ophthalmologic consult was linked dominant conditions. It is believed that Aicardi syndrome and obtained. A skeletal survey was normal. Goltz focal–dermal hypoplasia syndrome may be contiguous gene

DENOUEMENT AND DISCUSSION The ophthalmologic examination demonstrated a chorioretinopathy thought to be characteristic of Aicardi syndrome. The cranial findings of midline cyst with agenesis of the corpus callosum and the electroencephalographic findings all supported this diagnosis. The cystic lesion in the orbit was felt to be a cystic encephalocele. Aicardi syndrome is an X-linked dominant condition consisting of the triad of agenesis of the corpus callosum, infantile spasms with characteristic EEG findings, and chorioretinal lacunae of hypo- pigmentation.1 Infantile spasms have their onset most frequently in the neonatal period, but always by 24 weeks of age.2 They are associated with multifocal epileptiform abnormality on a severely disordered background. Although seizure frequency may decrease with time, the seizures may also be intractable. The chorioretinal atrophy is pathognomonic with hypopigmented or apigmented retinal epithelium in lacunae most marked around the papilla.3 Other characteristic findings in patients with Aicardi syndrome include cortical heterotopia, polymicrogyria, orbital colobomas, choroid plexus cysts, choroid plexus papillomas,1 intraorbital and pineal cysts,4,5 Dandy Walker posterior fossa cyst, costovertebral anomalies, and cleft palate. Vertebral anomalies are seen in

Figure 1. MRI (T1-weighted) coronal image through third ventricle. Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 South Kingshighway Boulevard, St. Louis, MO, USA. Agenesis of the corpus callosum is appreciated with widely separated lateral ventricles, much larger on the right (RLV) than the left (L). In the midline Address correspondence and reprint requests to Thomas E. Herman, MD, Mallinckrodt Institute of Radiology, Washington University School of Medicine, 510 South Kingshighway Boulevard, are cysts of a slightly higher signal than the cerebrospinal fluid (CSF) of the St. Louis, MO 63110, USA. ventricles (MC). The third ventricle (3V) is located caudal to these cysts.

Figure 2. MRI (T2-weighted) axially at the level of the body of the lateral ventricles (A) and through the orbits and brainstem (B). The midline cysts have a signal higher than CSF on these T2-weighted sequences. Again the right lateral ventricle (RLV) is seen to be much larger than the left lateral ventricle (L). A retrobulbar cystic is seen in the right orbit (C). syndromes because they have been found in the same patient6 who 2. Phillips HE, Carter AP, Kennedy JL, Rosman NP, O’Connor JF. Aicardi syndrome; had deletions of the short arm of the X-chromosome. radiologic manifestations. Radiology 1978;217:453–5. The prognosis is exceedingly guarded in this severe condition in 3. Ohtsuki H, Haebara H, Takahashi K, Midorikawa O. Aicardi syndrome: report of which severe mental retardation and high mortality are common. an autopsy case. Neuropediatrics 1981;12:279–85. Only one reported patient with Aicardi syndrome has developed 4. Mehta RC, Marks MP, Levin PS. Aicardi syndrome: MR appearance of speech.7 Treatment is supportive and usually requires anticonvulsant unusual orbital and ventricular cystic lesions. AJR, Am J Roentgenol 1993; 160:601–3. therapy. 5. Besenski N, Bosnjak V, Ligutic I, Della Marina BM. Cortical heterotopia in Aicardi syndrome: CT findings. Pediatr Radiol 1988;18:391–3. 6. Naritomi K, Izumikawa Y, Hagataki S, et al. Combined Goltz and References Aicardi syndromes in a terminal Xp deletion. Am J Med Genet 1992;43: 1. Brondum Nielson K, Anvert M, Flodmark O, Furuskog P, Bohman-Valis K. 839–43. Aicardi syndrome: early neuroradiological manifestations and results of DNA 7. Constad WH, Wagner RS, Caputa AR. Aicardi syndrome in one dizygotic twin. studies in one patient. Am J Med Genet 1991;38:65–8. Pediatrics 1985;76:450–3.

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