Cerebral venous thrombosis manifesting as hypertonic intracerebral hematoma

Dear Editor,

We present a case report of a patient with thrombosis of the sinus transversus and sinus sigmoideus on the right, which first manifested as a unilateral intracerebral hematoma in a typical localization for hypertonic hemorrhage (in the area of the capsule externa on the right). The correct diagnosis eventually led to a change in the therapeutic approach.

Cerebral venous sinus thrombosis (CVST) accounts for approximately 0.5% of all strokes [1]. The incidence is estimated to be approximately 3/100,000 population per year [2]. It predominantly affects young people, especially females (up to 70%). The basic division of intracranial venous thromboses is into infectious (septic) and non-infectious (aseptic). Risk factors for aseptic thromboses can be divided into predisposing, e.g. Leiden mutations, and provoking conditions, e.g. use of hormonal contraceptives. Diagnosis is often difficult, with an average time to diagnosis of 7 days [3]. It manifests itself most often with intracranial hypertension syndrome, subacute encephalopathy, focal neurological deficit or epileptic seizure, rarely with sinus cavernosus syndrome. One of the basic methods for diagnosis is MR venography, preferably with contrast medium. The black-blood sequence is a promising sequence that could be equal to contrast in specificity and sensitivity [4]. The main therapeutic approach is anticoagulation therapy; rarely, endovascular treatment or decompressive craniectomy can be resorted to. The mortality rate is reported to be 2-4% in the acute phase. Complete recovery occurs in up to 79% of cases [5]. Patients with bleeding have a worse prognosis.

Our patient was admitted to the ictal intensive care unit of the Neurology Clinic for a week of symptoms of fluctuating severity (left-sided limb weakness, dysarthria and headache). So far, he had not been treated for anything, was not taking medication, and smoked 10 cigarettes a day. An initial CT scan of the brain revealed an intracerebral hematoma measuring 29 × 14 × 24 mm in the capsule externa on the right, with an intracranial hemorrhage score of 0. Due to the typical localization and initial decompensated blood pressure, a hypertonic etiology of the cerebral hemorrhage was considered. Neurosurgical evacuation of the hematoma was not indicated. There was no evidence of congestion on the ocular background. However, an atypical hypodense course of the right-sided sinus transversus and sinus sigmoideus was also described on the initial brain CT scan, and intracranial venous thrombosis was suspected (Figure 1). Subsequently, MRI of the brain with venogram was performed and verified subacute intracranial venous thrombosis of the sinus transversus and sigmoideus on the right (T1 and T2 hyperintense), thrombosis of the vein of Trolard, and dilated venous collaterals and dilated superficial collateral cortical veins were found around the thrombosed sinus transversus, and the hematoma image was stationary. Since the capsula externa is located at the border of the drainage of the superficial and deep venous system, one possible explanation for the cause of the hemorrhage is the rupture of dilated collateral veins or postcapillaries. Low-molecular-weight heparin was first administered, with the dose targeted at the lower therapeutic limit (antiXa 0.5-0.6 kUI/l). On follow-up brain CT at 12 days, the volume of intracerebral hematoma in the capsulor externa region was significantly reduced to 19.9 × 12.9 × 17 mm. Anticoagulation therapy with dabigatran (2×150 mg) was started 20 days after the onset of clinical symptoms. Clinically, the patient completely recovered, and blood pressure was successfully compensated with oral antihypertensive drugs. Basic oncological screening was negative (chest X-ray, abdominal and pelvic ultrasound and oncomarkers). The sampling for thrombophilic disposition was without pathological findings. The patient was discharged home with no focal neurological deficit and no subjective complaints. Follow-up MRI at 16 weeks interval showed partial recanalization of the right-sided sinus transversus (Figure 2).

Intracerebral haemorrhage is present in approximately 1/3 of all intracranial venous thromboses [6]. Bleeding in CVST is typically localized cortico-subcortically in the form of peripheral lobar hematomas. Irregular lobar hematomas are typically present parasagittally frontally or parietally in sinus sagitalis superior thrombosis, and temporally or occipitally in sinus transversus and sigmoideus thrombosis [7]. Less frequently, subarachnoid hemorrhage (about 20%) and subdural hemorrhage (about 5%) are encountered [8]. A rare complication that we present in our case is intracerebral hematoma in an area that is typical of hypertonic hemorrhages.

When intracerebral hematoma or hemorrhagically transformed ischemia is considered in practice, the suspicion of a secondary origin of the hemorrhage is usually aroused by an atypical localization of the hemorrhage that does not correspond to any arterial watershed or is not clearly delineated. It is also atypical if the haemorrhages are multiple. The presence of bilateral haemorrhage, e.g. bilateral thalamic haemorrhage or bilateral basal ganglia haemorrhage, is highly suspicious for thrombosis of (especially deep) cerebral veins. In these atypical cases, we investigate the etiology of the hemorrhage further (CTA, MRA, DSA). However, if the bleeding is in a typical hypertonic localization (as in our case), the patient has a history of arterial hypertension and is older than 60 years, we usually conclude the etiology as hypertonic bleeding and do not perform further investigation [6]. This may lead to misdiagnosis and thus harm the patient because we do not provide adequate therapy (in our case, anticoagulation). In this case, we were led to the correct diagnosis by both the suspicious findings on the native CT scan and a history that was not entirely typical of hypertonic bleeding (mild fluctuating neurological deficit with headache lasting a week before admission).

The case report shows the importance of early and especially correct diagnosis of the etiology of cerebral hemorrhage. The mere fact that the bleeding occurs in a typical hypertonic localization and that the patient has risk factors suggestive of a hypertonic cause (arterial hypertension, age over 60 years) should not lead us astray. We should always look for atypical manifestations or signs of secondary etiology (hyperdense or rarely hypodense run-off on native CT) [9]. Only after careful exclusion of a secondary etiology can we conclude the diagnosis as hypertonic hemorrhage. This uncomplicated process may ultimately result in a change in therapeutic management, thus avoiding harm to the patient (failure to order anticoagulation therapy when it is fully indicated).

Conflict of interest

The authors declare that they have no conflict of interest in relation to the subject of the paper.

This is an unauthorised machine translation into English made using the DeepL Translate Pro translator. The editors do not guarantee that the content of the article corresponds fully to the original language version.