|Year : 2014 | Volume
| Issue : 1 | Page : 30-36
Lateral sinus thrombosis in children: Case series
Mohamed H Alshehabi1, Munahi M Alqahtani1, Abdulrahman A Alsanosi2, Khalid A Almazrou3
1 Otorhinolaryngology Departments, Riyadh Military Hospital, Riyadh, Kingdom of Saudi Arabia
2 College of Medicine, King Abdulaziz University Hospital, King Saud University, Riyadh, Kingdom of Saudi Arabia
3 College of Medicine, National Guard Hospital, Riyadh, Kingdom of Saudi Arabia
|Date of Web Publication||7-Mar-2014|
Mohamed H Alshehabi
King Abdulaziz Medical City, Otorhinolaryngology and Head and Neck Surgery Department, King Abdulaziz Medical City, P.O. Box 22490, Riyadh 11426, Kingdom of Saudi Arabia
Lateral sinus thrombosis is rare but potentially fatal condition. The consequences of misdiagnosis of this condition are detrimental.
Aims: To review our experience in lateral sinus thrombosis secondary to otogenic disease in pediatric population.
Settings and Design: Retrospective study of case series treated in two teaching hospitals over five years.
Materials and Methods: Clinically and radiologically diagnosed cases of lateral sinus thrombosis were identified through database search.
Results: Lateral sinus thrombosis was the result of chronic suppurative otitis media in 7 cases, with 3 patients (42.85%) having cholesteatoma. There were no associated intracranial complications in any of the patients. Two patients (28.57%) underwent medical treatment, and 5 patients (71.43%) had surgical treatment. Aggressive and early surgical intervention treatment was initiated according to evaluation of preoperative findings. The sigmoid sinus was aspirated in three patients. Complete re-canalization or lysis of the thrombus was achieved. Anticoagulant agent was used in 1 patient (14.28%). Six patients (85.82%) presented with the typical lateral sinus thrombosis clinical features, and 1 patient (14.28%) presented with otorrhea solely. Mastoidectomy was undertaken in 5 patients (71.42%) with canal wall up in 2 patients (28.57%) and canal wall down in 2 patients (28.57%). Myringotomy, ventilation tube insertion, and cortical mastoidectomy were done in 1 patient (14.28%).
Conclusions: Early and aggressive surgical intervention of lateral sinus thrombosis otogenic complication can minimize mortality, hospitalization period, and length of medical treatment. High index of suspicion is important.
ملخص البحث :
تعنى هذه الدراسة الإسترجاعية باستعراض تخثر الجيب الجانبي في الدماغ والناتج عن أمراض الأذن لدى الأطفال. إعتمدت الدراسة على مراجعة حالات هذا المرض سريرياً وشعاعياً باستخدام قائمة المعلومات المتوفرة.
أظهر البحث أن معظم سبب تخثر الجيوب الجانبية في الدماغ ناتج عن التهاب الأذن الوسطى دون مضاعفات داخل الجمجمة. عولج أثنان دوائياً, أما الخمس حالات الأخرى فقد خضعت لعمليات جراحية. بينت هذه الدراسة أن التدخل الجراحي المبكر يؤدي إلى خفض فترة العلاج والبقاء في المستشفى وكذلك نسبة الوفاة.
Keywords: Chronic suppurative otitis media, lateral sinus thrombosis
Key messages: High index of suspicion, early and aggressive interference of lateral sinus thrombosis otogenic complication can minimize mortality, morbidity
|How to cite this article:|
Alshehabi MH, Alqahtani MM, Alsanosi AA, Almazrou KA. Lateral sinus thrombosis in children: Case series. Saudi J Med Med Sci 2014;2:30-6
|How to cite this URL:|
Alshehabi MH, Alqahtani MM, Alsanosi AA, Almazrou KA. Lateral sinus thrombosis in children: Case series. Saudi J Med Med Sci [serial online] 2014 [cited 2019 May 25];2:30-6. Available from: http://www.sjmms.net/text.asp?2014/2/1/30/128450
| Introduction|| |
Cerebral venous system is divided into a superficial and a deep system. The superficial system involves the sagittal sinuses and cortical veins and these drain superficial surfaces of both cerebral hemispheres. Both these systems mostly drain into internal jugular veins. The veins draining the brain do not go along the path as the arteries that supply it. With the exception of wide variations of basal vein, the deep system is invariable in comparison to the superficial venous system. Hence, their thrombosis is easy to distinguish. 
The sigmoid sinus is the inferior extension of the transverse sinus. It lies close to mastoid cells in a well-pneumatized temporal bone. Knowledge of venous connections of the transverse and sigmoid sinuses is obligatory for understanding the spread and possible origin of venous thrombosis. 
Before the antibiotic era, lateral sinus thrombosis was the most common complication of otitis media.  The introduction of antibiotics in the 1930s and 1940s has led to a decline in the incidence of otitis media complications. ,
However, otitis media and its complications continued to progress due to the emergence of antibiotic resistance and the introduction of pneumococcal vaccines.  Intracranial complications of otitis media still signify a challenging situation owing to its high mortality rate (36%).  Thus, a retrospective review of the experience at our institutions with lateral sinus thrombosis was undertaken to determine the current assessment of the symptoms and signs, diagnostic studies, management, and outcomes of patients with lateral sinus thrombosis.
| Materials and Methods|| |
A retrospective chart review of all patients diagnosed with otogenic lateral sinus thrombosis in tertiary hospitals from 2005 to 2010 was done. The chart review included signs, symptoms, radiological findings, surgical findings, surgical treatment, antibiotic treatment, complications, and the use of anticoagulation.
Patient outcomes were assessed by review of otolaryngology clinic notes.
| Results|| |
Nine patients were identified, but only 7 patients' records were available for review. All were males, and the age of the patients ranged from 9 to 18 years. The mean follow-up time was 18 months (range 12-24 months). Patient signs and symptoms are summarized in [Table 1] with headache, fever, and otalgia being present in most patients.
|Table 1: Shows the clinical features, microbiology, presence of cholesteatoma, and the radiological findings among the patients diagnosed with lateral sinus thrombosis|
Click here to view
Thrombosis was assessed by computed tomography scan, computed tomography venogram, magnetic resonance imaging, or magnetic resonance venography. All patients had radiographic evidence of lateral sinus thrombosis. None of the patients had extension to the proximal jugular vein, or cavernous sinus [Table 1].
Surgical treatment consisted of tympanostomy tubes in 2 patients [28.57%%], cortical mastoidectomy in 2 cases [28.57%], canal wall down mastoidectomy in 3 cases [42.85%] [Table 2].
|Table 2: Demonstrates the surgical intervention, anticoagulants use, and the mastoid culture results of the lateral sinus thrombosis patients|
Click here to view
Surgical findings included mucoid effusion in 1 case [14.28%], granulation tissue in 5 cases [71.42%] [Table 2].
Needle aspiration of the sigmoid sinus was performed in 3 cases (42.85%), and none underwent incision [Table 2].
One case (14.28%) received anticoagulation, dose was 1 mg/kg low-molecular-weight heparin once-daily for a month [Table 2].
[Table 3] highlights the duration of hospitalization, intravenous and oral antibiotics, and the post-treatment sequelae.
Patients' outcome as assessed by clinical examination and history at 6-month follow-up revealed headache in 3 cases (42.85%), otalgia in 1 case (14.28%), otorrhea in 3 cases (42.85%), and imbalance in 1 case (14.28%).
One patient who received anticoagulation reported persistent headaches and otorrhea [Table 3].
|Table 3: Shows the management course in the lateral sinus thrombosis patients|
Click here to view
Four patients had follow-up imaging, but none had evidence of thrombus progression.
| Discussion|| |
Since the introduction of antibiotics, the incidence of complications after otitis media has fallen from 3 to 0.15 percent. 
In the pre-antibiotic era, most sigmoid sinus thrombosis was attributable to acute otitis, whereas in most of the recent published reports, chronic otitis outweighs. Lateral sinus thrombosis is the second most frequent complication of otitis media after meningitis. 
Although the occurrence of this disease has decreased noticeably since the introduction of antibiotics, mortality from septic lateral sinus thrombosis continues to be a problem.  Lateral sinus thrombosis is a rare live-threatening complication of otitis media with a mortality rate of around 10 percent.  Most of the patients with lateral sinus thrombosis are under 15 years. 
Susceptibility of pathogenic organisms to antibiotics may have contributed to a sense of infrequency of intracranial complications in the early antibiotic era.  With the emergence of significant resistance to antibiotics, an increase in complications is being noted.  Streptococcal infections are reemerging as a threat in the United States.  This bacterium has been linked with lateral sinus thrombosis. 
In addition, the improved diagnostic capacity of modern non-invasive radiographic investigations such as contrast-enhanced computed tomography and magnetic resonance imaging may be causative to an increase in the incidence of radiographically diagnosed sigmoid/lateral sinus thrombosis.
Samuel and Fernandes  reported 21 cases of otogenic complications with an intact tympanic membrane. Besides its rarity, non-specificity of the signs and symptoms and the masking effect of antibiotic therapy make the diagnosis of lateral sinus thrombosis not easy. 
Cerebral venous sinus thrombosis is not often reported in the pediatric literature. Its incidence is evaluated to be 0.67 case per 100,000 children per year. 
The causes of cerebral venous sinus thrombosis are numerous, but can be classified, according to Virchow, into 3 main groups. The first group consists of all hyper-congealable states. The second group consists of conditions causing blood flow disturbance. The third group comprises all causes of inflammation, infection, or damage to the sinus wall. 
The classic presentation of cerebral venous sinus thrombosis is severe illness associated with typically high and swinging fever. As the clot proliferates along the sinus, it is accompanied by peri-venous inflammation, tenderness, and jugular lymphadenopathy. The increased intracranial pressure is usually suggested by papilledema and visual loss. Septic emboli dissemination to the lungs, large joints, and subcutaneous tissues usually follows. 
Four signs are present in more than 40% of patients with acute mastoiditis: Post-auricular erythema, edema, tenderness, and protrusion of the ear.  Changes in tympanic membrane and fever are seen in less than 35% of the cases. 
Four of the 7 cases in our study presented with otitis media that led to mastoiditis. Headache was the only symptom seen in all 7 cases described, and its intensity was usually severe.
Headache is the most common neurologic symptom in patients with cerebral venous thrombosis. The precise mechanism of headache in such patients who have no intracranial involvement remains unknown.
A local inflammatory reaction is a possibility with dilatation of vessels in the sinus walls as suggested by the frequent contrast enhancement surrounding the clot, known for thrombosis as the "empty delta sign," but also present in lateral sinus thrombosis. 
The pain might also be due to the irritation or stretching of nerve fibers in the walls of the affected sinus. 
Occlusion of the transverse sinus produces pain over the ear and mastoid, and may cause edema over the mastoid (Griesinger΄s sign).
Previous reports suggest that lateral sinus thrombosis can manifest as isolated or multiple cranial nerve palsy.  Loss of hearing may be due to the extension of thrombosis to cochlear veins, which drain into the lateral sinus or through the inferior petrosal vein. When present, they should not be mistaken for mastoiditis. They may also help to differentiate lateral sinus thrombosis from lateral sinus hypoplasia.
Samuel, et al.  stated that transverse sinus thrombosis and abscess formation can result from either direct spread of the infection from the mastoid or from thrombophlebitis of small veins of the middle ear that communicate with the transverse sinus. In due course, it can extend through an intact bone to the sigmoid sinus.
Because there is no bacterial growth in many cultures, the frequency of each bacterial pathogen in mastoiditis is uncertain. However, S. pneumoniae, S. pyogenes, H. influenzae, and anaerobes are the most frequently isolated pathogens. 
Investigations such as neutrophil leukocytosis of greater than 20.000 mm 3 and progressive anemia are of limited help. A lumbar puncture can be dangerous because of the risk of brain herniation, and the Tobey Ayer test is unreliable. 
Radiologic investigations are the cornerstone of correct diagnosis. Computerized tomography (CT) is useful for signifying osteitis or bone destruction, and is indicated when intracranial complications are suspected. 
CT with contrast media infusion is often regarded as the radiologic study of choice for such diagnostic purposes. CT alone can often identify extradural, subdural, and cerebral abscess, and more provides supportive evidence of sigmoid sinus thrombosis and cerebritis. 
However, an MRI has proven more sensitive in detecting this complication. 
Precise orientation of thin cuts, concentrated contrast medium, multiplanar reconstruction, and special window settings are all needed. 
MR may show abnormal signal from the sinus and high signal intensity on T1- and T2- weighted images. Godolinium enhancement of MR images may also show a "delta sign" comparable to that seen on CT scanning. 
MR angiography is quite sensitive to blood flow and differentiates thrombosis from slow flow. It has several advantages; it is a non-invasive technique and does not require the use of intravenous contrast agent, it can be performed rapidly and does not use ionizing radiation. 
The two main diagnostic pitfalls of lateral sinus thrombosis, i.e., lateral sinus hypoplasia and arachnoid granulation, have thus been carefully ruled out. Lateral sinus hypoplasia can be mistaken for lateral sinus thrombosis (LST) if the diagnosis is based purely on the absence of flow on angiography but not if the positive image of the thrombus is detected in the non-visualized vessel. 
Similarly, arachnoid granulations, predominantly when they are large, can be misdiagnosed as a focal thrombosis if the diagnosis is based purely on the presence of a "positive" image within the sinus but not if there is an absence of flow in the entire lateral sinus or its sigmoid part. 
In our study, different modalities of radiological screening were useful in the diagnosis.
Vascular exams are the most informative and accurate studies in verifying a venous occlusion, but they may have the potential to dislodge the thrombus. 
For this reason, the role of conventional angiography in the diagnosis of venous thrombosis is moving back. 
The treatment of superficial venous sinus thrombosis of infectious origin consists of intravenous antibiotic therapy and surgical drainage of the infected site, with possible removal of the obstructing clot. 
Care should be taken to the choice of the antibiotic regimen, not to only ease symptoms, while helping emergence of resistant strains. 
There is no agreement about the best antibiotic to use. Because mixed flora is often present, broad spectrum, some authors support multiple antibiotic therapies. The choice of initial antibiotic treatment varies and must be culture-directed. An antibiotic with good blood-brain barrier penetration should be used if there is a clinical suspicion that an intracranial complication exists. In the background of a prolonged course of treatment or repeated changes in antibiotic regimens, a resistant organism must be suspected. 
Our 7 patients we treated empirically with metronidazole plus ceftriaxone, and no microorganism was isolated.
Although surgical intervention is necessary in lateral sinus thrombosis of otogenic infectious origin, the extent of the surgical procedure has not been examined as a factor in resolving lateral sinus thrombosis. 
Approximately 57% to 87% of the children with this clinical condition responded well to intravenous antibiotics and myringotomy. 
The need for mastoidectomy should be reassessed in children who fail to respond in 24 to 48 hours. 
Intraoperative needle aspiration of the sinus confirms the patency or obstruction of blood flow. Absence of free blood indicates thrombus and needs longitudinal incision of the sinus and removal of the thrombus. The importance of ligating the internal jugular vein remains controversial.
It has been reported that the jugular vein should be ligated in the course of the surgery if thrombosis is discovered at operation.  However, some believe that the prognosis does not improve by exploring the sinus and removing the clot. 
The sigmoid sinus was aspirated in 3 of our patient. Complete re-canalization or lysis of the thrombus was achieved.
Wong et al.  proposed an algorithm for the treatment of lateral sinus thrombosis and concluded that if the patient remains unresponsive or deteriorates under this regimen, a mastoidectomy should be performed, and the perisinus area should be examined.
Mastoidectomy was undertaken in 5 patients of series (71.42%).
Mortality in cases of transverse venous sinus thrombosis was close to 100%.
Surgical intervention reduced mortality rate by about 50%.
Use of both antibiotics (introduced between 1932 and 1940) and surgery decreased the mortality rates to less than 25%, and recent articles report absence of deaths. 
The use of anticoagulation therapy in an attempt to prevent thrombus propagation and embolic dissemination is still controversial.  Its concomitant use with antibiotics is not favored because this can lead to the release of septic emboli.
Nevertheless, low-dose anticoagulant therapy supposedly can be used as a prophylactic measure to prevent thrombus formation and for cases in which the thrombus extends into internal jugular vein and transverse sinus. 
In 1991, Bousser  stated that the benefit of anticoagulants was well established and should be used unless there was an important contraindication. There are reports indicating that anticoagulants may noticeably improve some cases.  In 1994, Grafstein, et al.  stated that anticoagulant therapy was not recommended because it could lead to septic emboli liberation after clot breakdown or even to a hemorrhagic process if it occurred in the mastoid. 
Bienfait et al.  stated that no conclusions could be made about the effects of anticoagulant therapy.
Anticoagulant agent was used in 1 patient of our series (14.28%).
| Conclusions|| |
Early and aggressive surgical intervention of lateral sinus thrombosis otogenic complication can minimize mortality, hospitalization period, and length of medical treatment. High index of suspicion is important.
| References|| |
|1.||Uddin MA, Haq TU, Rafique MZ, Cerebral venous system anatomy. J Pak Med Assoc 2006;56:516-9. |
|2.||Weon YC, Marsot-Dupuch K, Ducreux D, Lasjaunias P. Septic thrombosis of the transverse and sigmoid sinuses: Imaging findings. Neuroradiology 2005;47:197-203. |
|3.||Unsal EE, Ensari S, Koç C. A rare and serious complication of chronic otitis media: Lateral sinus. Thrombosis AurisNasus Larynx 2003;30:279-82. |
|4.||Agrawal S, Husein M, MacRae D. Complications of otitis media: An evolving state. J Otolaryngol 2005;34Suppl 1:S33-9. |
|5.||Kuczkowski J. Thrombophlebitis of venous sinuses in otitis media.Otolaryngol Pol 2007;61:769-73. |
|6.||Miura MS, Krumennauer RC, LubiancaNeto JF, Intracranial complications of chronic suppurative otitis media in children.Braz J Otorhinolaryngol 2005;71:639-43. |
|7.||Kelly KE, Jackler RK, Dillon WP. Diagnosis of septic sigmoid sinus thrombosis with magnetic resonance imaging. Otolaryngol HeadNeck Surg 1991;105:617-24. |
|8.||Wolfowitz BL. Otogenic intracranial complications. Arch Otolaryngol 1972;96:220-2. |
|9.||Kangsanarak J, Fooanant S, Ruckphaopunt K, Navacharoen N, Teotrakul S. Extracranial and intracranial complications of suppurative otitis media: Report of 102 cases. J LaryngolOtol 1993;107:999-1004. |
|10.||Teichgraeber JF, Per-Lee JH, Turner JS Jr. Lateral sinus thrombosis: A modern perspective. Laryngoscope 1982;92:744-51. |
|11.||Samuel J, Fernandes CM. Lateral sinus thrombosis (a review of 45 cases). J LaryngolOtol 1987;101:1227-9. |
|12.||Goldenberg RA. Lateral sinus thrombosis: Medical or surgical treatment? Arch Otolaryngol 1985;111:56-8. |
|13.||Antonelli PJ, Dhanani N, Giannoni CM, Kubilis PS. Impact of resistant pneumococcus on rates of acute mastoiditis. Otolaryngol Head Neck Surg 1999;121:190-4. |
|14.||Whitney CG, Farley MM, Hadler J, Harrison LH, Lexau C, Reingold A, et al. Increasing prevalence of multidrug-resistant Streptococcus pneumoniae in the United States. N Engl J Med 2000;343:1917-24. |
|15.||Syms MJ, Tsai PD, Holtel MR. Management of lateral sinus thrombosis. Laryngoscope 1999;109:1616-20. |
|16.||Samuel J, Fernandes CM. Otogenic complications with an intact tympanic membrane. Laryngoscope 1985;95:1387-90. |
|17.||Tovi F, Hirsch M. Computed tomographic diagnosis of septic lateral sinus thrombosis. Ann Otol Rhinol Laryngol 1991;100:79-81. |
|18.||De Veber G, Andrew M, Adams C, Bjornson B, Booth F, Buckley DJ, et al. Cerebral sinovenous thrombosis in children. N Engl J Med 2001;345:417-23. |
|19.||Jose J, Coatesworth AP, Anthony R, Reilly PG. Life threatening complications after partially treated mastoiditis. BMJ 2003;327:41-2 |
|20.||Hoppe JE, Köster S, Bootz F, Niethammer D. Acute mastoiditis-relevant once again. Infection 1994;22:178-82. |
|21.||Nadal D, Herrmann P, Baumann A, Fanconi A. Acute mastoiditis: Clinical, microbiological, and therapeutic aspects. Eur J Pediatr 1990;149:560-4. |
|22.||Cumurciuc R, Crassard I, Sarov M, Valade D, Bousser MG. Headache as the only neurological sign of cerebral venous thrombosis: A series of 17 cases. J Neurol Neurosurg Psychiatry 2005;76:1084-7. |
|23.||Boukobza M, Crassard I, Bousser MG. When the 'dense triangle' in dural sinus thrombosis is round. Neurology 2007;69:808 |
|24.||Kuehnen J, Schwartz A, Neff W, Hennerici M. Cranial nerve syndrome in thrombosis of the transverse/sigmoid sinuses. Brain 1998;121:381-8. |
|25.||Samuel J, Fernandes CM, Steinberg JL. Intracranial otogenic complications: A persisting problem. Laryngoscope 1986;96:272-8. |
|26.||Ogle JW, Lauer BA. Acute mastoiditis: Diagnosis and complications. Am J Dis Child 1986;140:1178-82. |
|27.||Manolidis S, Kutz JW. Diagnosis and management of lateral sinus thrombosis. Otol Neurotol 2005;26:1045-51. |
|28.||Irving RM, Jones NS, Hall-Craggs MA, Kendall B. CT and MR imaging in lateral sinus thrombosis. J Laryngol Otol 1991;105:693-5. |
|29.||Daniels DL, Czervionke LF, Bonnerille JF,Cattin F, Mark LP, Pech P, et al. MR of the cavernous sinus: Valve of spin echo and gradient recalled echo images. AJR Am J Roentgenol 1988;151:1009-14. |
|30.||Mas JL, Meder JF, Meary E, Bousser MG. Magnetic resonance imaging in lateral sinus hypoplasia and thrombosis. Stroke 1990;21:1350-6. |
|31.||Leach JL, Jones BV, Tomsick TA, Stewart CA, Balko MG. Normal appearance of arachnoid granulations on contrast-enhanced CT and MR of the brain: Differentiation from dural sinus disease. AJNR Am J Neuroradiol 1996;17:1523-32. |
|32.||Venezio FR, Naidich TP, Shulman ST. Complications of mastoiditis with special emphasis on venous sinus thrombosis. J Pediatr 1982;101:509-13. |
|33.||Perkins GD. Cerebral Venous Thrombosis: Developments in imaging and treatment. J Neurol Neurosurg Psychiatry 1995;59:1-3 |
|34.||Zanetti D, Nassif N. Indications for surgery in acute mastoiditis and their complications in children. Int J Pediatr Otorhinolaryngol 2006;70:1175-82. |
|35.||Samaha M, Prudencio JA, Tewfik TL, Schloss MD. Bilateral lateral sinus thrombosis associated with otitis media and mastoiditis. J Otolaryngol 2001;30:250-3. |
|36.||Cohen-Kerem R, Uri N, Rennert H, Peled N, Greenberg E, Efrat M. Acute mastoiditis in children: Is surgical treatment necessary? J Laryngol Otol 1999;113:1081-5. |
|37.||Kimmick H, Myers D. Lateral sinus thrombosis. Arch Otolaryngol 1958;62:156-9. |
|38.||Singh B. The management of lateral sinus thrombosis. J Laryngol Otol 1993;107:803-8. |
|39.||Wong I, Kozak FK, Poskitt K, Ludemann JP, Harriman M. Pediatric lateral sinus thrombosis: Retrospective case series and literature review. J Otolaryngol 2005;34:79-85. |
|40.||O'Connell JE. Lateral sinus thrombosis: A problem still with us. J Laryngol Otol 1990;104:949-51. |
|41.||Bradley D, Hashisaki G, Mason J. Otogenic sigmoid sinus thrombosis: What is the role of anticoagulation? Laryngoscope 2002;112:1726-9. |
|42.||Kaplan DM, Kraus M, Puterman M, Niv A, Leiberman A, Fliss DM. Otogenic lateral sinus thrombosis in children. Int J Pediatr Otorhinolaryngol 1999;49:177-83. |
|43.||Bousser MG.Cerebral Venous Thrombosis: Report of 76 cases.J Mal Vasc 1991;16:249-54. |
|44.||Ameri A, Bousser MG. Cerebral venous thrombosis. Neurol Clin 1992;10:87-111. |
|45.||Grafstein E, Fernandes CM, Samoyloff S. Lateral sinus thrombosis complicating mastoiditis. Ann Emerg Med 1995;25:420-3. |
|46.||Bienfait HP, Stam J, Lensing AW, Van Hilten JJ. Thrombosis of the cerebral veins and sinuses in 62 patients. Ned Tijdschr Geneeskd 1995;139:1286-91. |
[Table 1], [Table 2], [Table 3]