A ten-year girl presented at Sultan Qaboos University Hospital with poor school performance and generalised tonic 
clonic seizures in the previous three months. Her 
birth history and antenatal history were normal. 
She also had poor school performance. Her 
other siblings were normal. Her general physical 
examination and neurological examination was 
unremarkable. There were no neurocutaneous 
lesions. An assessment revealed an IQ of 57, which 

is very low. The routine blood work up was normal. 
An electroencephalogram showed left temporal 
region seizure discharges with generalisation. A 
magnetic resonance imaging scan of the brain 
revealed complete band heterotopias in both 
hemispheres (double cortex) [Figures 1 and 2].

Neuronal migration disorders (NMD), are 
seen in children with psychomotor developmental 
delay, epilepsy and mental retardation. Physical 
examination is usually normal in these children 

SQU Med J, April 2010, Vol. 10, Iss. 1, pp. 136-137, Epub. 17th Apr 10
Submitted 12th Oct 09
Revision Req. 9th Dec 09, Revision Recd. 16th Jan 09
Accepted 20th Jan 09

Departments of 1Child Health, and 2Radiology, Sultan Qaboos University Hospital, Muscat, Oman; Department of 3Radiology, 
College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Oman.
*To whom correspondence should be addressed. Email: koul@squ.edu.om

ع ُمغايِر شريطي أو قشرة مزدوجة   طفلة عمرها عشر سنوات بَتَوٍضُ
)دماغني(

رو�شان ك�ل، اآمنة الفطي�شي، قي�شل العزري، راجيف جني

A Ten year-old Girl with Band Heterotopia or 
Double Cortex (two brains)

*Roshan Koul,1 Amna Alfutaisi,1 Faisal Alazri,2 Rajeev Jain3 

interesting medical image

Figure 1: Magnetic resonance imaging T1 weighted 
axial image of the brain shows double cortex. Arrows 
indicate two layers of grey matter separated by bright 
looking white matter.

Figure 2: Magnetic resonance imaging T1 weighted 
axial image (inversion recovery), shows bilateral band 
heterotopia (double cortex). Large arrows denote grey 
matter and small arrows white matter.



Roshan Koul,Amna Alfutaisi,Faisal Alazri and Rajeev Jain

Interesting Medical Image | 137

except neurocutaneous disorders. Minor forms 
of NMD are picked up only when imaging is 
done. The normal human brain goes through 
three major phases of morphogenesis which are 
neuronal production, neuronal migration and 
differentiation. This mechanism is complex and 
chemical signals and guides control this.1 Neuronal 
production and migration starts at six weeks of 
gestation and proceeds until twenty-six weeks. 
After this phase, differentiation and maturation 
continue until the age of 15 years.1 Heterotopias 
are one of the NMDs, where in ectopic grey 
matter cells get arrested in inappropriate sites in 
the brain. The cells may be arrested between the 
leptomeninges and periventricular region. The 
cells arrested in the subependymal region are called 
subependymal nodular heterotopias. The cells 
arrested below the proper cortex and separated 
from the cortex by a thin band of white matter, are 
called subcortical band heterotopias (SBH). When 
this band is circumferential beneath the cortex, it 
is called a double cortex as was seen in our child. 
This condition is very rare with only about 120 
cases reported in the world medical literature.2 
The syndrome is usually associated with mutations 

in the doublecortin (DCX) (Xq22.3-q23) gene, and 
much less frequently in the LIS1 (17p13.3) gene. The 
majority of patients with SBH are sporadic, most 

patients are females and few patients with familial 
X-linked inheritance have been seen.2 Heterotopias 
may be isolated or part of a syndrome. The exact 
incidence of heterotopias in the general population 
is unknown; however, heterotopias formed 11.6% 
of cases of NMD in our series.3 Only one of them 
had SBH, forming about one percent of NMD. 

a c k n o w l e d g m e n t

This case was presented on 12th November 2008 in 
the SQU Clinical-Pathological Conference Series 
(SCRAPS) as: “Are two brains better than one?”

1.  Caviness VS Jr, Goto T, Tarui T, Takahashi T, 
Bhide PG, Nowakowski RS. Cell output, cell 
cycle duration and neuronal specification: 
a model of integrated mechanisms of the 
neocortical proliferative process. Cerebral 
Cortex 2003; 13:592–8.

2.  D’Agostino MD, Bernasconi A, Das S, Bastos 
A, Valerio RM, Palmini A, et al. Subcortical 
band heterotopia (SBH) in males: clinical, 
imaging and genetic findings in comparison 
with females. Brain 2002; 125:2507–22.

3.  Koul RL, Alfutaisi A, Sankhala DK, Javad H, 
William RR. Pattern of childhood neuronal 
migration disorders in Oman. Neurosciences 
2009; 14:158–62.