cerebral palsy ( cp ) is the most common cause of motor disability in children , with incidence of 2 - 2.5 per 1000 live birth ( 1 ) . cerebral palsy is a group of permanent disorders of the development of movement and posture , causing activity limitation , that are attributed to non - progressive disturbance that occurred in the developing fetal and infant brain . the motor disorders of cerebral palsy are often accompanied by disturbance of sensation , perception , cognition , communication , behavior , epilepsy and by secondary musculoskeletal problems ( 2 ) . the surveillance of cerebral palsy in europe study group ( scpe ) has proposed three cp type groups : spastic , dyskinetic and ataxic cp . the subtypes of spastic cerebral palsy are unilateral spastic cp ( instead of previous term hemiplegia ) and bilateral spastic cp ( instead of previous terms diplegia and quadriplegia)(3 ) . unilateral spastic cerebral palsy ( us cp ) is the unilateral motor impairment , congenital or early acquired , isolated or associated with additional impairments . it is the second most common cp subtype , that is reported in around 25% of children with cp ( 4 ) . neuroimaging , especially magnetic resonance imaging ( mri ) is very useful diagnostic procedure that is commonly used in clinical evaluation of children with cp ( 5 , 6 ) . the brain mri may help to identify the type and timing of lesions that cause cp and may help to provide early prognosis of motor outcome , but also occurrence and severity of associated disabilities . the aim of the study was to investigate neuroimaging findings in children with unilateral spastic cerebral palsy and compare them between term and preterm ( gestation age<37wks ) born children . the study was hospital based , which has included 106 patients with us cp ( 82 term/24 preterm ) . patients with us cp have been followed up at pediatric hospital , clinical center of university sarajevo , bosnia and herzegovina in outpatient and inpatient settings , during the study period of 20 years ( 1996 - 2015 ) . the inclusion criteria have been : confirmed diagnosis of uc cp by child neurologist at minimal age of three years . neuroimaging studies have included computed tomography ( ct ) and mri with t1 and t2-weighted images and fluid - attenuated inversion recovery ( flair ) . neuroimaging findings were classified into 5 groups : a ) maldevelopment ; b ) predominant white matter injury ; c ) predominant gray matter injury ; d ) non specific findings ; and e ) normal findings ( table 1 ) . classification of neuroimaging findings non specific findings group included abnormal mri patterns , which did not meet criteria mentioned above . during the study period 106 patients with us cp has been followed up . among the participants there were 72/106 ( 67.9% ) males and 34/106 ( 32.1% ) females , 82/106 ( 77.36% ) term born and 24/106 ( 22.64% ) preterm born . neuroimaging studies have been performed in 105/106 cases ( 99.05% ) of the total cohort . in one case ( 1/106 , 0.94% ) , parents refused neuroimaging study to be done for their child . only brain ct has been done in 18/106 ( 17%)cases , only brain mri has been done in 27/106 ( 27% ) cases , while 60/106 ( 60%)patients had both ct and mri neuroimaging studies ( table 2 ) . distribution of neuroimaging modalities neuroimaging studies have been abnormal in 92/106 patients ( 85.85% ) . the normal neuroimaging finding were present in 14 out of 106 cases ( 13.21 % ) , among them 3/14 have done only ct , while 11/14 had normal brain mri . predominant white matter lesions where the most frequent ( 48/106,45.28% ) , term 35/preterm 13 , without statistically significant difference between term and preterm born children ( x=0.4357 ; p=0.490517 ) . gray matter lesions had 32/106 , 30.19% participants ( term 25/preterm 7 ) , without statistically significant difference between term and preterm born children ( x=0.902 ; p=0.9862 ) . there was only one case with deep gray matter lesions , all other cases where cortical - subcortical lesions . brain malformations had 10/106 ( 9.43% ) participants and all of them were term born . other finding had 2/106 ( 18.9% ) participants and both of them were term born ( figure 1 ) . different agents affecting the developing brain during the 1 and 2 trimester of pregnancy may cause various maldevelopment ( 7 ) . by the end of 2 trimester the  gross architecture  of the brain is established . during the early 3rd trimester and in the preterm if some agents , especially inflammation , affect developing brain during in this period , then the brain lesions may appear . by the end of 3 trimester and in the term born cortical and deep gray matter ( basal ganglia and thalamus ) may be affected ( 7 ) . in our study these results are similar to the results of d. romeo et co - workers , where with 61% males and 39% females were reported . sex differences in the immature brain injuries have been explained with greater biological vulnerability of male children . the incidence of cerebral palsy is significantly higher in males than females , due to different resistance to hypoxia an higher incidence of preterm births in males . there is larger number of connections and better dendritic arborization in females than males , so the better post - lesional reorganization is possible the neuroprotective role of estrogen and progesterone has been explained with their antioxidant effect and their membrane stabilizing effect ( 8) . information on brain ct or mri imaging were available in 105/106 cases ( 99.05% ) of the total cohort . in the quebec cerebral palsy registry neuroimaging information was available for 88% of the total cohort of patients with cerebral palsy ( 9 ) . abnormal brain mri imaging was present in 92/106 patients ( 85.85% ) , which is similar to other studies . found brain abnormalities on mri in 89% of 644 children with cp ( 9 ) . in krageloh - mann study 52 out of 58 patients ( 90%)with us normal imaging results were found in 14 out of 106 cases ( 13.21 % ) . these children may have cerebral lesions or abnormalities which are so subtle to be detected by neuroimaging modalities which have been used ( 6 ) . ct scans are inferior to mri scans for detecting periventricular white matter lesions ( 6 ) . predominant white matter lesions where the most frequent ( 48/106 , 45.28% ) , without statistically significant difference between term and preterm born children ( x=0.4357 ; p=0.490517 ) ( figure 2 ) . in krageloh - mann s study periventricular white matter lesions ( pwm lesions ) were present in 36% patients with us cp , but significantly more often in preterm us cp ( 7 ) . an axial t2 tirm dark fluid mri scan in a 6 year old boy with right sides us cp due to preterm birth and perinatal asphyxia : periventricular white matter lesions predominant gray matter lesions have been visualized in 32/106 participants ( 30.19% ) , without statistically significant difference between term and preterm born children ( x=0.902 ; p=0.9862 ) . this result is almost identical to krageloh- mann , where gray matter lesions have been found in 31% us cp patients ( 7 ) . but , in our study there were no statistically significant difference between preterm and term us cp patients , while other studies have confirmed that gray matter lesions appear significantly less often in preterm us cp patients ( figure 3 ) . an axial t2 tirm dark fluid mri scan in a 11 year old girl with right sided ucp due to perinatal stroke : cortical / subcortical lesion white and gray matter lesions are the most prevalent type of injury detected by neuroimaging studies in children with us cp ( 10 ) . gray matter lesions are less common and they may be presented as diffuse or more selective cortical / subcortical lesions and basal ganglia or thalami lesions . those lesions may lead to more severe impairments of several functions , in particular motor function ( 10 ) . brain malformations have been identified in 10/106 ( 9.43% ) children and that is less in comparison to other studies , where brain malformations were present in 16% of us cp cases ( 7 ) . there were no statistically significant difference between term and preterm born children with brain maldevelopment . the spectrum of brain malformations in our study was : isolated corpus callosum agenesis ( acc ) 2 cases ; acc+ schizencephaly1 case;pachygiria 3 cases ; pachygiria+arnold - chiarimalformation type i ( ac type i)1 case ; hemimegalencephaly ( hmeg ) 1 case ; schizencephaly + septo - optic dysplasia ( sod ) + heterotopia + polymicrogyria1 case and focal cortical dysplasia 1 case ( table 3 ) . acc = agenesis of corpus callosum , ac type i = arnold - chiari type i , hmeg = hemimegalencephaly , pmg = polymicrogyria , sod = septo - optc dysplasia , fcd = focal corticl dysplasia acc could be isolated or combined with other central nervous system ( cns ) or systemic malformations . epilepsies are reported in up to two thirds of patients with complete or partial acc . acc is not indicative for seizure disorder , more often additional malformations of cortical development are causal . microstructural cc abnormalities are detected by advanced imaging techniques and they constitute a part of diffuse white matter disturbance ( 12 - 14 ) . in our study , there were 3 patients with acc , two of them had epilepsy and all three of them were intellectually disabled . the first one had acc associated with eye malformations ( ipsilesional coloboma iridis and micro cornea ) and epilepsy . schizencephaly may be presented as unilateral or bilateral cleft , that is extending from the subarachnoid spaces to the ventricles . in our patient with acc and schizencephaly , three of them had pachygiria only , while one patient had pachygiria , ac type i malformation and epilepsy .. three of them were intellectually disabled , one of them had epilepsy and autism ( figure 4 ) . an axial t1 weighted inversion recovery mri scan in a girl with right sided us cp due to brain maldevelopment ( pachygiria and arnold - chiari type i malformation ) hemimegalencephaly was present in one case . it was type one of hemimegalencephaly , without hemicorporal hypertrophy and cutaneous or systemic involvement ( 15 ) . there were one case with multiple brain malformations : schizencephaly+sod + heterotopia + polymicrogyria and another one with isolated focal cortical dysplasia . the diagnosis of sod is defined by the presence of two , out of three characteristics ( optic nerve hypoplasia , pituitary dysfunction and midline brain defects , such as absent septum pellucidum or agenesis of the corpus callosum ) . sod generally occurs sporadically but environmental , epigenetic and genetic factors are implicated in its etiology ( 17 , 18 ) . heterotopia is migration disorder with abnormal location of neurons at any place between the subependymal region of the lateral ventricles and cerebral cortex , due to arrest of radial migration ( 15 ) . polymicrogyria ( pmg ) is caused by an interruption in normal cerebral cortical development in the late neuronal migration or early postmigrational development periods . clefts ( schizencephaly ) and cortical  bumps ( polymicrogyria ) are malformations which are frequently encountered together ( 15 ) . focal cortical dysplasia ( fcd ) is a malformation of cortical development , which is the most common cause of medically refractory epilepsy in the pediatric population . both genetic and acquired factors are involved in the pathogenesis of cortical dysplasia ( 15 ) . malformations of cerebral cortical development include a wide range of developmental disorders that are common causes of neurodevelopmental delay and epilepsy . many genes regulate cortical development and their mutation may cause malformation of cortical development ( 19 - 21 ) . the group of nonspecific neuroimaging findings included 2 cases : hypomyelinisation and enlarged subaracnidal spaces . brain neuroimaging studies may help to identify the timing of brain lesion and also may help to predict the motor outcome in children with us cp .
introduction : unilateral spastic cerebral palsy ( us cp ) is the second most common subtype of cerebral palsy.aim:the aim of the study was to analyze neuroimaging findings in children with unilateral spastic cerebral palsy.material and methods : the study was hospital based , which has included 106 patients with us cp ( boys 72/girls 34 , term 82/preterm 24 ) . 
 neuroimaging findings were classified into 5 groups : brain maldevelopment , predominant white matter injury , predominant gray matter injury , non specific findings and normal neuroimaging findings.results:predominant white matter lesions where the most frequent ( 48/106,45.28% ; term 35/preterm 13 ) , without statistically significant difference between term and preterm born children ( x2=0.4357 ; p=0.490517 ) . 
 predominant gray matter lesions had 32/106 children , 30.19% ; ( term 25/preterm 7 , without statistically significant difference between term and preterm born children ( x2=0.902 ; p=0.9862 ) . 
 brain malformations had 10/106 children , 9.43% , and all of them were term born . 
 other finding had 2/106 children , 1.89% , both of them were term born . 
 normal neuroimaging findings were present in14/106 patients ( 13.21%).conclusion : neuroimaging may help to understand morphological background of motor impairment in children with us cp . 
 periventricular white matter lesions were the most frequent , then gray matter lesions .