时间：2022-05-24 05:24:56
BACKGROUND： Cerebral venous thrombosis （CVT） is a rare disease and it has different etiologies. Inherited or acquired prothrombotic state plays a key role in the development of CVT.
METHODS： A 28-year-old man who presented to our emergency department with persistent headache and accompanied by complaints of nausea and vomiting over a week. Neurologic examination revealed bilateral papilledema. Brain computed tomography showed a hyperdense area on the posterior part of the occipital lobe. Brain magnetic resonance imaging and magnetic resonance venography revealed thrombosis of CVT. Homozygous mutations were found for methylenetetrahydrofolate reductase （MTHFR）. MTHFR CG677T gene mutation and blood tests showed elevated homocysteine levels on the etiological screening. There was no other etiology for CVT.
RESULTS： Headache and other complaints were improved after treatment of heparin， warfarin， and vitamin B12. No recurrence of symptoms was observed upon outpatient follow-up.
CONCLUSION： Since CVT is an important cause of headache， we recommend etiology screening for patients who present with CVT for MTHFR gene mutations and family counseling should be provided.
KEY WORDS： Cerebral venous thrombosis； Headache； Methylenetetrahydrofolate reductase gene mutation
World J Emerg Med 2013；4（1）：69–72
DOI： 10.5847/ wjem.j.1920–8642.2013.01.013
INTRODUCTION
Cerebral venous thrombosis （CVT） is a relatively uncommon condition afflicting mostly young adults. Many clinical conditions have been described as risk factors for CVT， including hereditary thrombophilia， pregnancy and puerperium， postoperative state， intracranial or local infections and use of oral contraceptives. CVT is often misdiagnosed and rarely compared with stroke that has an arterial cause.
Homocysteinemia is a significantly independent， usually heritable， prothrombotic risk factor for atherothrombotic cardiovascular， cerebrovascular， and peripheral vascular diseases. The patients with methylene tetrahydrofolate reductase （MTHFR） gene mutation usually have high levels of serum homocysteine.[1] The common homozygous mutation in the MTHFR gene is associated with a significant risk factor for ischemic stroke and it is related to the increased level of total homocysteine.[2] We report a case of a 28-year-old man with CVT in whom we recognized of MTHFR gene mutation and hyperhomocysteinemia.
CASE REPORT
A 28-year-old right handed man was admitted to our emergency department because of severe posterior headache persisted over a week. The headache was mostly severe， tightening in quality and progressive in nature. Occasionally， headache was accompanied by nausea and vomiting. On admission， he was conscious， his blood pressure and temperature were within normal range. Physical examination revealed that he was an alert patient with bilateral papilledema. His visual acuity was reduced. Neurological examination was normal. Brain computed tomography showed a hyperdense area on the posterior part of the occipital lobe （Figure 1）. Hereupon， magnetic resonance venography was obtained. Because of absence of signal on the location of bilateral transverse sinus， sinus rectus and superior sagittal sinus on magnetic resonance venography （Figure 2）， the patient was admitted to the neurology clinic with the diagnosis of venous sinus thrombosis. Familial and personal history did not reveal any previous cerebrovascular diseases as vascular risk factors. He did not smoke nor drink alcohol. But there was a family history of miscarriage （his cousin 14 times）. His differential blood cell count， biochemical results （including， C-reactive protein， prothrombin and partial thromboplastin times， serum glucose， electrolytes， liver enzymes， urea， creatinine， protein， calcium， magnesium） and urinalysis were normal. The results of thrombophilic screening tests involving antinuclear antibodies， anti–single-stranded DNA and anti–double-stranded DNA antibodies， anticardiolipin IgG and IgM antibodies， anti–SS-A and anti–SS-B were all negative. No mutations were found for factor V Leiden， factor V H1299R， factor VIII， factor XIII， prothrombin G20210A， b-fibrinogen， plasminogen activator inhibitor type 1， angiotensin-converting enzyme， apolipoprotein BR3500Q， or apolipoprotein E. But the level of serum homocysteine was elevated （21 μmol/L； normally 5.00–12.00 μmol/L） and there was homozygous CG677T polymorphism of the MTHFR gene （genotype 677TT）. The levels of serum vitamin B12 and folate were
MTHFR gene scanning of the patient's family was performed； his father， mother and elder brother had heterozygote CG677T polymorphism of MTHFR gene mutation， one of his brothers had homozygote CG677T polymorphism of MTHFR gene mutation. But， no clinical manifestations were observed in his 16-year-old brother so far.
Heparin， warfarin， vitamin B12 and folic acid were prescribed. After four days， patient's complaints subsided， and he was discharged without any sequelae. Neither recurrence of headache nor neurological complication was found during follow-up.
DISCUSSION
Thrombosis of the cranial venous sinuses and the cerebral cortical veins can lead to a distinct cerebrovascular disorder， which unlike arterial stroke， most often affects even young adults and children. Symptoms and clinical course are highly variable， etiological factors are even more heterogeneous making cerebral cortical vein thrombosis a unique clinical entity. The disorder can occur de novo as the first manifestation or can overlap with another existing clinical problem. Each component of the Virchow's triad （endothelial damage， stasis and hypercoagulability of blood） may in turn have several contributory factors/causes to produce the final manifestation of CVT.[3]
CVT presents with a wide spectrum of manifestations. The most common presenting symptom is headache， and other associated symptoms and signs are seizures， focal neurological deficits， papilloedema and impaired consciousness. The clinical picture is determined by the age of patient， site of CVT and the presence or absence of parenchymal lesions.[4] Our patient had only headache and papilloedema. Isolated headache， as the only presentation of CVT， has been described but it is rare.[5]
Because of the heterogeneity in clinical presentation and etiology， the diagnosis of CVT is often missed， and even if a diagnosis is made， the contributory factors are often subclinical and are also missed or overlooked. Most often only one of the etiological factors is prominent enough to be picked up and it is a universal practice to look for rarer causes and some inherited causes of venous thrombosis. Diagnosis is often missed unless clinicians maintain a high index of suspicion and be aware of varied clinical presentations.[3]
Venous thrombosis in the body results from exaggerated activity of one or more mechanisms of hemostasis or reduced activity of one or more natural antithrombotic mechanisms or a combination of both.[3]