cPACNS is a primary immune mediated inflammatory disorder of CNS although it is hypothesized that reactivated Varicella Zoster virus (VZV) and other neurotropic viruses can induce a post infectious type of CNS vasculitis and it has been proposed that viral infections such as Parvovirus B19 has been reported to trigger CNS vasculitis among immune-suppressed pediatric patients;  however, these patients usually have a long prodromal period, with few patients presenting so far and constitutional symptoms are uncommon. 
Signs and symptoms of systemic vasculitis such as peripheral neuropathy, fever, weight loss or rash are usually absent.  In our study Systemic symptoms such as fever, decreased energy level and weakness were common findings 54%, 45%, 31% respectively. The main complaints of patients in this study were headache (68%) then fever (54%) and seizure with mental disorder in (45%). CNS vasculitis is usually suspected when recurrent vascular events occur in young patients with no identifiable risk factors, or in the setting of chronic and progressive unexplained CNS disorder . In one study focal neurologic deficits were the most frequent clinical symptom, including acute hemiparesis (80%), hemi-sensory deficit (79%), and fine motor deficits (73%). Headaches were present in 56% of patients and seizures in 15%. Diffuse neurologic deficits included mood/personality changes in 26%, cognitive dysfunction in 37%, and concentration difficulties in 29% of patients. Concentration difficulties and cognitive dysfunction resulted in decline in school performance and participation. .
A study conducted by Benseler et al on children with initial diagnosis of cerebral vasculitis (the proof was based on the findings of angiography and MRA) 62 children (38 male, 27 female, mean age 2/7 years) with a diagnosis of primary CNS vasculitis were divided into two groups with progressive disease (20 patients) and non-progressive disease (42 patients). Neurologic symptoms such as cognitive impairment, attention and mood disorders in patients with progressive disease were significantly higher than other groups. (p<001/0) [7, 27].
The spectrum of cPACNS includes three distinct disease entities: progressive angiography-positive cPACNS (P-cPACNS); non-progressive angiography-positive cPACNS (NP-cPACNS); and angiography-negative, small-vessel cPACNS (SV-cPACNS). .
Proximal, large-vessel inflammation with subsequent focal stenosis is the hallmark of NP-cPACNS. NP-cPACNS patients often present with unilateral MRI lesions predominantly focal deficits, and proximal vessel stenosis on angiography. These patients have a monophasic inflammatory large-vessel disease, which does not progress beyond 3 months. The majority of NP-cPACNS patients present with strokes.
In contrast, Patients with angiography-positive, P-cPACNS frequently present with multifocal MRI lesions and evidence of both proximal and distal vessel stenosis on angiography and both focal and diffuse neurological findings. Untreated patients progress beyond 3 months .
P-cPACNS patients have both large- and small-vessel inflammation and will therefore present with overlapping clinical features. Distal vessel inflammation is commonly seen in P-cPACNS and SV-cPACNS and is frequently associated with features of adjacent parenchymal inflammation. Children with SV-cPACNS present with distal vessels stenosis and multifocal MRI lesions with significant diffuse neurological deficits including cognitive decline, behavior changes, school difficulties, and mood/personality changes. Angiography remains normal and brain biopsies confirm the diagnosis of SV-cPACNS. [32-35]
Laboratory results although in different reports did not show specific findings, systemic inflammatory markers are frequently normal in children with cPACNS. Some children may have positive antinuclear antibodies (ANA) [11, 29].
However, as the inflammation progresses, some children may develop mildly elevated systemic inflammatory markers. [27,29] A normal erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), white blood cell count (WBC), C3 complement, or immunoglobulin levels by no means exclude an active vasculitis process in the CNS. In our series anemia (63%) and leukocytosis (45%) were common abnormalities. ESR and CRP were in high amounts in (40%) patients .ANA was positive in (31%) patients although not in significant and high titers. Pathological and imaging studies (MRI, MRA, CT-SCAN and CA) are valuable tools for the diagnosis of cerebral vasculitis. [36-40]
In this study CT-SCAN showed nonspecific abnormalities in three patients only, however in MRA study small vessels involvements were in 14 (63%) patients, which could be in favor of P-cPACNS. Four patients had large vessels involvement and in the rest (4 patients) both vessels were involved.14 patients (63 %) showed abnormality in both middle cerebral artery (MCA) and anterior cerebral artery (ACA), whereas posterior cerebral artery (PCA) showed this abnormity in 36% (8) patients. In six patients MRI showed some pathologic results and their simultaneous MRA had particular findings. Comparisons of the MRI and MRA findings of these patients have been shown in table 2.
There is not clear findings about EEG in this disorder, most patients 86 %(19) in our group had normal EEG results. In children, the choice of treatment depends on the cPACNS classification.
 Intravenous (IV) monthly cyclophosphamide plus high-dose corticosteroids are the current method in patients with P-cPACNS and SV-cPACNS. (25, 29) Induction therapy consists of seven IV cyclophosphamide pulses (500–1000 mg/m2/month) plus corticosteroids (2 mg/kg/day). Maintenance course follow with oral drugs such as azathioprine or mycophenolate mofetil plus a tapering low dose of corticosteroids for 2 years.  Approach of therapy was on a case by- case basis, diseases severity, neurologic handicap, drug tolerance and availability were additional parameter that we considered in therapy. Prednisolone (90%) Cyclophosmide (50%), MMF (50%), Azathioprne (45%), Methotrexate (9%) have been used. In spite of full course therapy, five patients (22%) had sever and permanent neurological sequel such as seizure, mental regress and personality disorders. At recent decade in all refractory cases our first choice of biologic therapy was infliximab, most of them in view of subsiding clinical symptoms showed favorable response to this treatment.
There are some limitation in this study such as lack of biopsy proven and tissue pathology that are not available in our country, on the other hand long term period of study 25 years made we could not follow accurately our patients because of changing of their follow up clinic by adult one.