content:aicardi_syndrome

This is an old revision of the document!


Aicardi syndrome

This page is being edited and might be incomplete. (LIST)

~~AUTHORS:off~~

A rare neurodevelopmental disorder characterized by the classic triad of agenesis of the corpus callosum (total or partial), central chorioretinal lacunae and infantile spasms that affects almost exclusively females & rarely in 47 XXY males. However Aicardi syndrome is now recognized as a more complex, pleiotropic disorder with an expanded spectrum of phenotypical features. The syndrome is named after Jean Aicardi[1]

  • Agenesis of the corpus callosum
  • Infantile spasms
  • Chorioretinal lacunae
  • Microcephaly, heterotopias
  • polymicrogyria
  • Cerebellar dysgenesis
  • Microphthalmia , coloboma
  • Costovertebral defects
  • Facial asymmetry
  • Intellectual disability
  • developmental delay
  • hypotonia
  • Focal seizures

Seizures

Infantile spasms are the most characteristic seizure type in Aicardi syndrome[2]. Most seizures appear early, at 3–4 months of age, and are often asymmetric or even unilateral. With increasing age, the seizure pattern evolves and focal seizures become more frequent[3]. EEG features include asynchronous multifocal epileptiform abnormalities with burst suppression and dissociation between the two hemispheres[4].

Chorioretinal lacunae

Retcam photo of right eye shows optic disc coloboma (black arrow) and dome shaped loci of pale areas with sharp borders nasal to the optic disc suggestive of chorio retinal lacunae (white arrows).

Central Chorioretinal lacunae (CRL) represent a defect of the pigment epithelium and choroid. CRL are pathognomonic for Aicardi syndrome and are seen in all patients (see figure[5]).They are well-defined, multifocal pale areas with minimally pigmented borders, and are usually found in the peripapillary area of the posterior pole. They do not change or evolve over time. CRL do not affect vision unless the central foveal area is involved.

Optic nerve anomalies are present in the majority of affected individuals, with coloboma being the most common. Other abnormalities include asymmetric microphthalmia, morning glory discs, abnormal retinal vessels and cysts and often result in significant visual impairment.

Aicardi syndrome is associated with distinctive facial features including prominent premaxilla, upturned nasal tip, decreased angle of the nasal bridge, and sparse lateral eyebrows.

Other abnormalities reported include hemivertebrae, block vertebrae, fused vertebrae, and missing, malformed or fused ribs[6] hand abnormalities including camptodactyly, proximal placement of the thumb, and hypoplasia of the fifth finger[7][8].

Sutton et al. (2005) proposed the following modified diagnostic criteria[8]:

  • The presence of all three classical features (classic triad) is diagnostic for Aicardi syndrome
  • The presence of two classical features in addition to at least two major or supporting features is strongly suggestive of a diagnosis of Aicardi syndrome

Nearly all reported cases of Aicardi syndrome are sporadic and in females. The disorder is believed to result from new gene mutations. Aicardi syndrome is classified as an X-linked dominant condition[Credit:U.S National Library of Medicine. In 2015 mutation in gene TEAD1 was found to be associated with Aicardi syndrome[9]. This was the first genetic mutation associated with Aicardi syndrome to be reported. This study also found that TEAD1 mutations may be present in males.

Neuroimaging

Abnormalities identified on MRI are characteristically[10]

  • polymicrogyria that was predominantly frontal and perisylvian and often associated with underopercularization
  • Periventricular nodular heterotopias
  • single or multiple intracranial cysts
  • Cerebellar abnormalities
  • tectal enlargement

Differential Diagnosis

Treatment

  • seizure management. Seizures are often refractory
  • physical, occupational, speech therapy
  • vision
  • management of vertebral abnormalities including scoliosis

Prognosis

  • majority of children are unable to sit independently, walk or talk
  • The 5-, 10- and 20-year survival rates are 90%, 80% and 50%, respectively[11]

History

This disorder was first recognized as a distinct syndrome in 1965 by Jean Aicardi, a French pediatric neurologist and epileptologist.


1. a Aicardi J, Lefebvre J, Lerique-Koechlin A. A new syndrome: spasms in flexion, callosal agenesis, ocular abnormalities. Electroencephalogr Clin Neurophysiol 1965;19:609-610
2. a long:15737696
3. a long:17621479
4. a long:16967367
5. a long:19384023
6. a long:4314028
7. a long:2773986
8. a, b long:16158440
9. a long:26091538
10. a long:18925666
11. a RESERVED, I. (2020). Orphanet: Aicardi syndrome. [online] Orpha.net. Available at: https://www.orpha.net/consor/cgi-bin/OC_Exp.php?Lng=EN&Expert=50 [Accessed 13 Feb. 2020].
 Hopkins B, Sutton VR, Lewis RA, Van den Veyver I, Clark G. Neuroimaging aspects of Aicardi  syndrome. Am J Med Genet A 2008 Nov 15;146A(22):2871–2878.      
Enter your comment. Wiki syntax is allowed:
O N W J V
 
  • content/aicardi_syndrome.1581598919.txt.gz
  • Last modified: 2020/02/13 13:01
  • by icna