NEURORADIOLOGY


 
Case 9 :  


A 13-year-old male presents with seizure disorder. CT scan was performed. 
What is the diagnosis?

Click here for Bigger Picture

Click here for Bigger Picture

Click here for Bigger Picture



__________SCROLL FOR ANSWER__________


 

 

 

 

 

 



Imaging Findings
Study shows a cleft in the temporal lobe, communicating with a prominent extra-axial space with temporal lobe atrophy.

Diagnosis
Schizencephaly (open type)

 

Discussion
Clinical Findings
Patients may present with seizure disorders, mild to moderate developmental delay and mental retardation.

Etiology/Pathophysiology
Failure of the normal migration of neurons from the germinal matrix zone at 1-5 months of gestation. A gray matter lined parenchymal cleft develops which extends from the subarachnoid space to the subependyma of the lateral ventricles. Schizencephaly occurs when there is a failure of the normal migration of neurons from the germinal matrix zone at 1-5 months of gestation. Some theories suggest that possible causes of this are in-utero stroke, early gestational viral infections, and recent Italian research has linked Schizencephaly with a mutated gene called the Homeobox gene EMX-2. If the gene EMX-2 is missing or defective, nerve cell growth and migration will not occur normally and this 
will lead to the formation of the 'clefts' associated with Schizencephaly.

The cleft may be narrow or closed (type 1) or wide and open (type 2). It is frequently associated with complete or partial absence of the cavum septum pellucidum in approximately 80-90% of cases. the cleft is usually located near the pre- or postcentral gyri. The clefts can be unilateral or bilateral. Polymicrogyria, microcephaly, and gray matter heterotopia have also been noted. Optic nerve hypoplasia has been noted in 33% of cases, with possibility of blindness.

 

Differential Diagnosis

Pseudoporencephaly due to trauma, vascular, or infectious insults, which are almost always unilateral.
Cystic tumor
Arachnoid cyst

 

References
1. Behrman RE, Kliegman R. Nelson Essentials of Pediatrics. Philadelphia, W.B. Sander, 1990 pg. 651-652.
2. Blickman J.G. Pediatric Radiology, The Requisites. ST Louis, Mosby, 1994. pg 210.
 

Site For Parents of Kids with schizencephaly:
http://www.geocities.com/Heartland/Meadows/7384/

Contribution
Dr. Sanjeev Mani, Mumbai