Cerebral venous sinus thrombosis is a specific type of low incidence cerebrovascular disease in which cerebral venous blood flow is blocked when the thrombus completely occludes the venous sinus, brain tissue edema occurs, punctate hemorrhage or hemorrhagic infarction occurs in the cerebral cortex or subcortex, and intracranial pressure increases. Venous sinus thrombosis has a complex etiology, different forms of initiation, a variable natural course, and a variety of clinical manifestations. Severe cerebral venous sinus thrombosis with increased intracranial pressure, persistent epilepsy, mental disorder or coma has a poor prognosis with a mortality rate of 10% to 20% if not treated actively and appropriately. With the common application of antibiotics, infection-induced cerebral venous sinus thrombosis has become less common. In this paper, we summarize 10 cases of ICVST diagnosed in recent years in the Department of Neurosurgery of Xuanwu Hospital of Capital Medical University with complete clinical and imaging data, analyze their clinical manifestations, imaging features and treatment and prognosis, and explore the pathogenesis of ICVST and the relationship between early diagnosis treatment and prognosis.
Materials and methods.
The cases were inpatients admitted to our hospital from May 2000 to October 2006, including 6 males and 4 females, aged 2 to 52 years, with an average age of 22.6 years.
Course of disease and cause of infection.
The time interval between the appearance of first symptoms and admission to the hospital was used as a criterion for determining the form of onset [1], with 2 cases of acute onset (within 1 week), 4 cases of subacute onset (1 week-1 month), and 4 cases of chronic onset (more than 1 month). Causes of infection: 4 cases secondary to mastoid infection, 2 cases secondary to head and facial boil infection, 3 cases secondary to otitis media, and 1 case caused by viral encephalitis .
Clinical manifestations.
There were 10 cases of fever, 10 cases of headache, 7 cases of nausea and vomiting, 6 cases of optic papilloedema, 6 cases of decreased visual acuity, 4 cases of ocular motility disorders, 2 cases of dilated pupils, 2 cases of loss of light reflex, 3 cases of impaired consciousness, 4 cases of limb paralysis (2 cases of quadriplegia, 1 case of bilateral lower limb paralysis, 1 case of mild hemiplegia), 3 cases of mental disorders, and 3 cases of tinnitus and hearing loss.
Imaging examination
CT: CT scan was performed in 10 cases.
MRI examination: All the cases in this group underwent MRI examination, and the phenomenon of empty blood flow in the superior sagittal sinus disappeared and was replaced by high signal on T2WI, equal to high signal on T1WI in 2 cases, symmetrical abnormal signal in the frontal and parietal lobes bilaterally in 1 case, involving the right and left transverse sinuses in 2 cases, involving the sigmoid sinus in 3 cases and the cavernous sinus in 4 cases, showing cerebral edema changes in 3 cases and cerebral infarction in 3 cases.
DSA: Six patients underwent this examination, and one case showed uneven visualization of the superior sagittal sinus, four cases showed no visualization of the right and left transverse sinuses, four cases showed filling defects or uneven visualization, and one case showed abnormal signal of the sigmoid sinus.
Laboratory tests
Cerebrospinal fluid examination: 8 out of 10 patients had increased intracranial pressure, with the pressure ranging from 240 mmH2O-350 mmH2O; 4 cases had a mild increase in protein, 2 cases had red blood cells in the cerebrospinal fluid, and 5 cases had increased white blood cells.
Routine blood examination: 9 cases with increased leukocytes and 1 case with normal.
Treatment
All patients in this group were given anti-infection, dehydration and cranial pressure lowering treatment. 6 cases were given heparin anticoagulation treatment and 4 cases were given urokinase local thrombolytic treatment.
Results
Seven patients in this group were cured after treatment, and upon review, CT showed that cerebral edema disappeared, MRV showed venous sinus recanalization, and patients’ clinical symptoms disappeared; all four patients treated with urokinase local thrombolysis were cured, while only three of the seven patients treated with anticoagulation were cured; two patients improved, and patients’ symptoms were significantly reduced, and imaging showed venous sinus recanalization, but infarct foci remained in brain tissue; one patient died due to complication of severe One patient died due to severe intracranial infection. Six of these patients were followed up for 2 years, and their status was stable without recurrence.
Discussion
Cerebral venous sinus thrombosis is a specific type of cerebrovascular disease with a high mortality and disability rate [1]. The former refers to venous and venous sinus thrombosis caused by systemic and localized septic infections, commonly seen in middle ear mastoid sinusitis, paranasal sinus and orbital area with foci of infection spreading to the dura and venous sinuses via the conduit and platysmal veins, represented by cavernous and ethmoid sinus thrombosis [2]; the latter is often secondary to a variety of diseases, such as severe head trauma, wasting diseases (e.g. tuberculosis), anemia, dehydration, pregnancy, congestive heart failure, cachexia, meningioma, hypercoagulable states and use of contraceptives [3]. The cases in this group were inpatients admitted to our hospital from May 2000 to October 2006, and their CVST etiology was caused by infection, including four cases secondary to mastoid infection, two cases secondary to infection of boils on the head and face, three cases secondary to otitis media, and one case caused by viral encephalitis. After analysis, the causes of cerebral venous sinus thrombosis caused by infection can be summarized as follows: ① Infection in the head and face, especially in the danger triangle, can easily spread to the skull due to the lack of venous valves in the nearby veins, forming intracranial secondary infection, especially in the cavernous sinus. (2) Increased leukocyte exudation and release of inflammatory factors when inflammation occurs cause changes in blood composition and coagulation status, making it easy for thrombosis to occur. ③ Inflammatory factors damage the vascular wall, causing endothelial damage and activating the coagulation system to further promote thrombosis. ④ Intracranial venous blood flow depression and change of blood flow status when intracranial infection occurs is another cause of thrombosis.
The clinical signs and symptoms of CVST are variable, making the diagnosis more difficult and leading to serious consequences due to delayed diagnosis and treatment, but patients with inflammation-induced CVST mostly have signs of infection that are not easily misdiagnosed [4-5]. In our case, due to the spread of infection from the facial boil to the intracranial cavernous sinus, the patient showed obvious symptoms of systemic infection, obstruction of intraorbital venous return, protrusion of the eyeball, congestion and edema of the eyelid, periorbital area and conjunctiva, stasis of the fundus venosus, and involvement of the sinus penetrating the ophthalmic, talipes, spreading and ophthalmic branches of the trigeminal nerve. The symptoms include limited eye movement in all directions, pupil dilation, loss of light response, loss of sensation in the distribution area of trigeminal nerve branches, and loss of corneal reflex. In these patients, the symptoms and signs are obvious and the diagnosis is clear and timely. The literature reports that otitis media and mastoiditis mostly involve the transverse and sigmoid sinuses, and thrombosis of the superior sagittal sinus caused by infection is less common [6-7], which occurred in two patients in our group and should not be ignored in clinical diagnosis. With the development of imaging and the popularization of neuroimaging, the occlusion of intracranial veins and the damage of brain tissue can be clearly observed, which is very helpful for the diagnosis of ICVST, and the imaging examinations of this group of patients were all timely, which is an important reason for the faster diagnosis.
The treatment of cerebral venous sinus and cerebral vein thrombosis includes treatment of the primary disease, anti-infective treatment and anticoagulation and thrombolytic therapy for thrombosis [8]. In our group of cases with increased intracranial pressure, dehydration therapy such as mannitol and adrenocorticosteroid therapy were given to prevent the occurrence of brain herniation. Patients with septic primary lesions such as mastoiditis were given surgery and antimicrobial therapy. Based on cerebrospinal fluid smear, bacterial culture and blood culture, sensitive antibiotics are selected for the pathogenic bacteria. Penicillin 10-20 million U daily, intravenous; aminobenzyl penicillin 6-12 g daily, intravenous; chloramphenicol 2 g daily, intravenous. In addition, medication is needed for 2 weeks after the fever subsides to prevent recurrence. For the treatment of intracranial venous sinus thrombosis, heparin anticoagulation was given in 6 cases and urokinase thrombolysis was given in 4 cases in this group of patients, and positive results were achieved.
The prognosis of cerebral venous sinus thrombosis is better in non-infectious cases and worse in infectious cases, which are prone to complications such as sepsis, meningitis and brain abscess. Cerebral venous thrombosis generally has a good prognosis, but if it extends to the large cerebral veins, the condition can deteriorate and lead to death [9]. In our group, one case of death occurred due to uncorrectable intracranial infection, while the rest of the patients had a good prognosis due to timely diagnosis and positive results after treatment. Therefore, early diagnosis and timely and effective treatment can significantly increase the cure rate, reduce the mortality rate, and improve the prognosis of patients.