however , it has a higher frequency among patients younger than 40 years , patients with thrombophilia and patients that have foreign body such as catheter in their veins or arterial system . in this case report , we described the clinical and radiological findings of a patient who developed cerebral vein thrombosis post coronary artery bypass grafting secondary undiagnosed protein c and s deficiency which was precipitated by malposition of subclavian central catheter into internal jugular vein . we emphasis the importance of radiological veiw of central vein catheter position just after or at the time of cannulation of central vein , not at some hours later as in our case . central venous catheterization ( cvc ) via subclavian approach is a very common practice in cardiac surgery , in the view of simplicity , monitoring of blood volume , monitoring of cardiac status , vasomotor tone , management of prolonged surgery and rapid compensation of blood loss intra operatively or in post operative courses . ( 1 ) found that the most common malposition related to subclavian vein catheterization is entrance into the internal jugular vein . malposition of a cvp line in the jugular vein automatically has not any complication in the absence of hypercoagulable state . family histories or history of thromboembolism and an unusual site of thrombosis are emphasized for accurate diagnosis of thrombophilia in the post surgery state . however , the post surgical state could be considered as a hypercoagulable state in the absence of reduced serum level of protein c - s . although , there are some reports of jvt with extension to a subclavein vein or the right atrium and subsequent pulmonary artery emboli , but retrograde progression of thrombus from catheter site in jugular vein to cerebral venous system has not been reported in the medical literature ( 2,3,4 ) . herein , we report a patient who developed cerebral vein thrombosis in post cabg secondary to undiagnosed protein c and s deficiency which was precipitated by malposition of subclavian central catheter into ijv . a 38 years old , 80 kg male patient with history of thrombophelebitis presented with left main coronary artery disease on angiocardiography . neurological examination was be normal and the patient did not have any signs and symptoms such as headache , lethargy , motor or sensory deficits , seizures , neck stiffness and fever . cervical murmur was noted with carotid auscultation , and the remainder of the physical examination was normal.there was no evidence suggestive of thrombus in the left ventricle.the patient was scheduled for off - pump coronary artery bypass grafting ( opcab ) with general anesthesia , central venous pressure ( cvp ) line and arterial monitoring . a ( cvp ) line was inserted via the right subclavian vein by seldinger technique ( 3 ) under aseptic precautions by the anesthesia registrar in the operating room . there was a good cvp waveform and good back flow of blood on aspiration from all the three lumens . anesthesia protocol included a combination of fentanyl and pancronium bromide supplemented with isoflurane to permit early extubation . stabilization of target arteries was accomplished with octopus stabilizer ( medtronic , ts 300 ) . intravenous heparin ( 1 mg / kg ) was given to maintain activated clotting time ( act ) between 200 and 300 seconds . cvp readings were taken 30 min apart and each time a good back flow was noted . as part of routine protocol , a portable chest x - ray was performed next morning ( 12 hours ) and , the cvp catheter was found to be internally rotated inside the right proximal internal jugular vein in the direction to cavernous sinus . however , blood could be aspirated from all the three lumen ports , cvp was measured with a normal cvp wave form and iv fluids / drugs could be infused via the same catheter ; we intended to pullout the line and re route it to right atrium . in icu , , he did not have the normal extremity movement or related awakening of the cerebral functions or spontaneous eye opening . the anti - brains edema therapy with steroid was started but the cerebral pathology was seen to persist at the fifth day of post operation . despite neurologist recommendation , the respiratory instability did not permit to transfer the patient for brain imaging safely . however early extubation failed on the eight postoperative day , but the patient was able to move his limbs although he was drowsy . on the twelve postoperative day , he opened his eyes and was able to obey commands ; however , he was not able to move his left arm . history of thrombophelebitis , young age , sub - acute presentation , focal neurologic sign and its rapid recovery urged to reconsider a mri venography and thrombophilia test for detection of cerebral veins pathology . complete blood count and blood biochemistry were within normal limits , except for prolonged erythrocyte sedimentation and areduced protein c and s level . the protein c level was 35% ( normal : > 70 ) , and protein s level was 55 % ( normal : 65% ) . there were no abnormal values of antithrombin iii , lupus anticoagulant , and anticardiolipin antibodies . the other tests such as hla - b5 , hla - b27 , anti - nuclear antibody and rheumatoid factor were also negative . mri venoghraphy on the 18 day of hospital stay revealed thrombosis of cerebral dural vein with typical delta sign , effacement of brains sulcui and edema , but infarction or hemorrhage was not observed ( figures 2 , 3 ) . central vein cathter going up to cerebral vein magneticresonance imaging showing duralvein thrombosis magnetic resonance imaging revealing empty delta sign protein c - s is a vitamin k - dependent , serine protease that is found in the blood plasma and synthesized in the liver . the active form of protein c - s can inhibit blood coagulation and stimulate fibrinolysis ( 1 ) . svt has been often a multi factorial disease , i.e the identification of a risk factor or even of a cause should not deter a search for other causes ( 5,6 ) . several studies , have described some of the well - established risk factors for svt that include inherited thrombophilia such as factor v leiden mutation , protein c and s deficiency , acquired prothrombotic state ( pregnancy , purperium and postsurgical period ) , hepatic dysfunction , autoimmune disease ( behet syndrome , systemic lupus erythematosus ) , malignancy ( lung cancer , blood dyscrasia , systemic carcinoma ) , systemic infectious disease , local infection of the skull ( e.g. otitis , mastoiditis ) and use of oral contraceptives . other rare conditions predisposed to svt include , inflammatory bowel disease , spontaneous intracranial hypotension , demyelinating disease , down 's syndrome , idiopathic hypereosinophilic syndrome , evans syndrome ( immune thrombocytopenia and autoimmune hemolytic anemia ) , bone marrow transplantation , high altitude , trivial trauma , jumping from a rock , surgical procedures , head trauma , brain tumors and arterial infarcts ( 714 ) . nagesh kumar reported a case of a 35 years old male who presented to the emergency center with drowsiness and focal seizures leading to grand seizures and loss of consciousness . significantly low protein s ( 7% ; normal 54137% ) and c ( 41% ; normal 72147% ) levels were detected . the author concluded that advanced aids might be considered as an acquired hypercoagulable state ( 16 ) . kuwahara described a 47 years old male who , despite anticoagulant therapy for thrombophlebitis for long time period , presented with mild left hemiparesis and ipsilateral hypesthesia . magnetic resonance ( mr ) imaging showed subacute thrombosis of both svt and a cortical vein in the right cerebral hemisphere . the diagnosis was svt and cerebral cortical venous thrombosis caused by congenital protein c deficiency . the patient was treated conservatively , and his clinical course was uneventful ( 17 ) . singhal reported a case of hepatic failure caused thrombophilia by severe deficiency of protein c , protein s and antithrombin iii . lefebvre presented the combined occurrence of protein c and protein s deficiencies in a 32 years old woman who presented by focal neurological sign and symptom and manifested by extensive cerebral venous thrombosis ( 19 ) . roos described a case of intracranial dural sinus thrombosis in the postpartum period related to the hypercoagulable state of pregnancy . the author report a patient who developed a superior sagittal sinus thrombosis in the second week postpartum , associated with a dysfunctional protein c and a decreased free protein s concentration ( 20 ) . massons reported a 32 years old patient with protein c deficiency who presented with the endocranial hypertension syndrome and multiple hemorrhagic cerebral infarction . the author demonstrated the importance of considering protein c deficiency in the diagnosis of cerebral venous thrombosis in young adults ( 21 ) . chung evaluated central venous catheter ( cvc ) blockage as a complication in pediatric oncology patients . this author investigated inherited thrombophilic states as a predisposing factors for cvc blockage in chinese children with cancer . the author concluded that inherited thrombophilic factors alone were not associated with cvc blockage in their , s pediatric cancer patient population ( 22 ) . barker reviewed his cytic fibrosis center 's history of catheter - related events over 13 years and found five thrombotic events in four patients , two of whom carried the factor v leiden mutation . the author concluded that thrombophilic state was detected in 53% patients , and two out of four subjects with catheter related thrombosis carried a genetic defect . the author concluded that genetic risk factors for familial thrombophilia play an important role in the manifestation of catheter - related thromboembolism in children ( 24 ) . wermes evaluated the clinical relevance of genetic risk factors of thrombosis in 137 paediatric patients with malignancy . all patients had central venous lines . no patient received heparin or any other anticoagulant . ten patients ( 7.3% ) , six with leukemia and four with solid tumors developed thrombosis . four of the six patients with leukemia and thrombosis ( 67% ) but only 21% of leukemia patients without thrombosis had a genetic risk factor ( p < 0.013 , chi2 ) . no genetic defect was found in the four patients with other solid malignancies and thrombosis ( 25 ) . a prothrombotic risk factor or a direct cause often , a precipitating factor such as foreign body in venous system like cvp line , head injury or even surgical immobility causes sinus thrombosis in a person with a genetically increased risk such as thrombophilia state . our case had predisposing risk factors for svt such as history of dvt , post surgical period and mal position of cvp line , but cabg was performed by beating heart and without use of cpb or fibrinolytic drugs as predisposing factors to thrombosis . post - surgical state automatically did not predispose to svt in the absence of thrombophilia . some cases of svt in the pregnancy related surgical procedures were associated with hyper coagulable state and hormonal change of pregnancy . in our patient , central line was exactly malpositioned into the internal jugular vein . in non - thrombophilic patients , risk of thromboembolic sequels in temporary cvp malposition is probably very low , but in thrombophilic disorders such as protein c - s deficiency , this risk severely increased . ferro fund that at least one risk factor such as internal jugular vein cathterizem can be identified in more than 85% of patients with cerebral venous thrombosis and an aquired thrombophilia and inherited thrombophilia was noted in 34% , 22% of patients subsequently ( 26 ) . inherited thrombophilias associated with cerebral venous thrombosis with or without foreign body include deficiencies of antithrombin , protein c - s deficency , factor v leiden mutation and the prothrombin gene mutation 20210 ( 27 ) . the most probable explanation of svt in our patient with unusual course of cvp line in the jugular vein in proximity to cerebral veins was the presence of a background of protein c - s deficiency . angiography , magnetic resonance ( mr ) imaging , un - enhanced computed tomography ( ct ) , mr venography and ct venography are particularly useful techniques for detecting cerebral venous and brain parenchymal changes that may be related to thrombosis . cvt may cause obstruction of venous drainage with increasing venous pressure in the affected region of the brain and causes parenchyma changes , secondary to cytotoxic edema , vasogenic edema , or intracranial hemorrhage . in contrast with arterial ischemic states , many parenchymal abnormalities secondary to venous occlusion are reversible . the direct signs of svt include demonstration of the thrombus on imaging or indirect , as when there are ischemic or vascular changes related to the venous outflow disturbance . indirect signs are not specific , such as parenchyma change by brain swelling , white matter edema , cortical sulci narrowing , loss of gray - white matter differentiation and hemorrhagic infarction as hemorrhagic spot in white matter edema ( 27.28 ) . in conclusion , this case report aims to bring to attention the possibility of sagittal vein thrombosis associated with malposition and internal rotation of cvp line inside vessels in thrombophilic patient . careful literature search revealed that our case is the only reported case of thrombophilia induced svt predisposed by cvp line . we reiterate the importance of radiological verification of cvp catheter position just after or at the time of cannulation of central line , not at 12 hour later as in our case .