Cerebral Venous Thrombosis Presenting as Cortical Subarachnoid Haemorrhage- A Case Report and Review
Correspondence Address :
Dr. Parag Rameshrao Aradhey,
JNMC SAWANGI DMIMS (DU) Wardha, Nagpur, Maharashtra, India.
In the presence of Subarachnoid Haemorrhage (SAH), diagnosis of underlying Cerebral Venous Thrombosis (CVT) is challenging as there is no difference in clinical presentation and therapeutically it is important because CVT need to be treated with anticoagulant unlike SAH. This article is about a 50-year-old male presenting with headache, right hemiparesis, and recurrent seizures. The Computed Tomography (CT) head was suggestive of SAH in right posterior parietal region. But Magnetic Resonance Imaging (MRI) venogram showed cerebral venous sinus thrombosis. Hence, he was treated with anticoagulants. The patient showed significant clinical improvement. SAH secondary to underlying CVT is relatively rare entity. After reviewing medical literature of such cases, 42 case reports and case series forming 95 cases of SAH secondary to CVT were found.
Anticoagulation, Cerebral venous infarction, Non aneurysmal subarachnoid haemorrhage
A 50-year-old male presented with complains of headache and giddiness for two days, followed by generalised tonic clonic seizures for 2-3 minutes and post ictal drowsiness, which lasted for 20 minutes. Same day in the afternoon, he had second episode of convulsion after which, his relatives brought him to the hospital. There was no history of seizures, diabetes, hypertension. Patient was non alcoholic.
On clinical examination, the patient was afebrile, his pulse 72/minutes regular, Blood Pressure (BP) 140/80 and Oxygen Saturation (SpO2) was 98% on room air. He was drowsy, pupils were normal in size, reacting to light. Motor examination showed right sided hemiplegia. Planters were bilaterally extensor. Fundus examination showed bilateral papilledema. His non contrast Computed Tomography (NCCT) head was suggestive of SAH in right posterior parietal region (Table/Fig 1).
The patient was admitted to Intensive Care Unit (ICU), and was started on intravenous levetiracetam 1 gm twice daily and phenytoin 100 mg three times daily; but he continued to have recurrent right focal clonic seizures on second day too. So, intravenous lacosamide 200 mg, twice daily, was added and further he was put on midazolam infusion for two days. Finally, on the fourth day of admission, the seizures were controlled. In view of recurrent seizures and presence of SAH on CT head, MRI Brain with MR angiogram and MR venography was done, which was suggestive of severe attenuation of superior sagittal sinus and bilateral transverse sinuses (Table/Fig 2). The cerebral angiogram was normal. In view of venous sinus thrombosis with SAH, the patient was started on injection enoxaparin 0.6 mL subcutaneous once daily, on the fourth day of admission.
After three days of once daily enoxaparin doses, repeat NCCT head was done which showed organised parasagittal parieto-occipital bleed with no evidence of SAH. The patient was continued on subcutaneous injection enoxaparin 0.6 mL twice a day for further one week. He showed significant improvement at the end of two weeks, as his level of consciousness improved, there was no headache and right-side motor power improved from grade 1/5 to 3/5. He had no seizures since day 4 of admission. The patient was discharged on antiepileptics and anticoagulant drugs. He was reassessed on follow-up after 15 days of discharge when his right-side motor power was 4-5/5, and he was completely seizure-free.
Rupture of an intracranial aneurysm is usually the most common cause of spontaneous SAH causing SAH in 85% cases. But in almost 15% of patients of spontaneous SAH, bleeding source of subarachnoid bleed cannot be identified despite of repeated neuroimaging (1).
The CVT is one of the causes of spontaneous non aneurysmal SAH though considered rare (2). (Table/Fig 3) shows some of the causes of SAH. The reported cases SAH secondary to CVT, seems to be increasing over the years. Panda S et al., reported 10 (4.3%) of 233 patients of CVT having SAH (3). In a retrospective review, Oda S et al., found 3% of CVT cases with SAH (4). Boukobza M et al., reported 22 cases (6.63%; 22/332) of CVT presenting as SAH without haemorrhagic brain lesion (5). The most likely reason for increasing number of cases appears to be the technological advances in radiological diagnosis and widespread availability in the last few years (6). This entity is diagnostically and therapeutically distinct because of better prognosis and needs treatment with anticoagulants unlike aneurysmal SAH.
Literature review for SAH, secondary to CVT, was conducted on PubMed, MedLine, Google Scholar. The keywords were subarachnoid hemorrhaged, cerebral venous thrombosis, cortical SAH, and non aneurysmal SAH. There were 51 articles where these terms were present in abstract/ title published from 1995 to 2021. These articles were screened, and the reference lists were also checked to find out relevant articles. Finally, 41 journal articles including case reports and reviews were compiled, which included a total of 95 cases. These cases were reviewed for their available demographic data, clinical and neuroimaging findings.
Diagnosis of CVT in presence of SAH poses diagnostic and therapeutic challenge (1). CVT should be considered in the differential diagnosis of patients presenting with SAH without evidence of an aneurysm.
Approximately 80% of cases of SAH occur in people aged 40-65 years of age (2), and though CVT in male has uniform age distribution, females suffer from CVT at younger age of 20-35 years (6). The present review included total 95 cases of CVT complicated with SAH at presentation. Mean age of patients was 43.6 years (range 14-83 years). There were 54 females (54/95) with a mean age of 43 years, and 41 males with a mean age of 44 years. Thus there was no significant age difference. CVT is seen in females routinely (F:M 1.29:1) (6) and a female dominance is also found in cases of aneurysmal SAH (F:M 3:2) (2). In the present review, the F:M ratio was 1.31: 1 in cases of SAH secondary to CVT, which is not different from that observed in the cases of aneurysmal SAH or CVT.
Aneurysmal SAH presents with seizure in 10-25% of cases in the acute phase (7). On the other hand, seizures are more common and recurrent in CVT at presentation, occurring in about 40% of patients (8). Ferro JM et al., found that about 39.2% (245/624) patients had seizures and 58 patients (9.3%) had focal seizures (9). In the present review of 95 cases of SAH secondary to CVT, 36 (37.9%) patients had seizures which included generalized tonic clonic seizures or focal seizures (Table/Fig 4). Focal neurological deficit was reported in 10.3% of 213 patients of SAH in a case series (10). While in case of CVT, focal deficit was seen in upto 44% of patients which include motor weakness, aphasia, ataxia (8). Aphasia is also a common neurological defect, that is observed in 19-24% of CVT patients. (6). In the present case review as well, focal neurological deficit was reported in 35.8% (34/95) which included hemiparesis, monoparesis, sensory deficit, aphasia, dysarthria. Signs of meningism like Kernig’s Sign, Brudzinski sign or neck stiffness was reported in 19/95 cases (20%). Small number of patients had dysarthria, aphasia or visual symptoms like blurring or aura (Table/Fig 4).
The SAH commonly presents as thunderclap headache, “the worst headache of life”- striking suddenly like a clap of thunder (7). But thunderclap headaches have been reported in 5-13% of CVT cases too (8). It is difficult to distinguish a thunderclap headache in CVT from that of subarachnoid hemorrhage. In this review, the most common presenting symptom was moderate to severe headache (76.8%), of which, 20% patients presented with thunderclap headache, which continued as mild to moderate ache. CVT presents with altered consciousness in 20-30.6% of patients (8). SAH patients also present with loss of consciousness in 45% of cases, due to increased intracranial tension and 10% patients may remain comatose for several days (2). In the present review, 24.2% (23/95) cases had altered level of consciousness in the form of reduced level of vigilance, drowsiness, or disorientation. Papilledema is a common manifestation of CVT that was observed in 28-67.5% of CVT patients (8). In cases of SAH, papilledema and sub-hyaloid hemorrhage may be evident in 20-30% of patients (2). In the present review, 13.7% patients with SAH secondary to CVT had papilledema. Though papilledema was reported in these cases of SAH secondary to CVT, it is difficult on clinical grounds solely to suspect that SAH visible on neuroimaging is secondary to CVT.
Smoking and heavy alcohol consumption are strong risk factor for SAH (2). Risk of SAH also increases during pregnancy (1). Though there are very few case reports showing smoking as risk factor for CVT by causing significant polycythemia, a case-control study showed no relationship (12). Though alcohol consumption has not been mentioned as independent risk factor for CVT (6), some studies had suggested associated dehydration and hyperviscocity related to alcoholism as predisposing factor for CVT (13),(14). Oral Contraceptive Pills (OCP), hyper-homocystenemia, hyper coagulable states are not risk factors for subarachnoid haemorrhage (2). In the present case review, 9 (9.5%) patients had history of alcoholism and two patients were smoker. The most common predisposing condition for CVT was OCP (21.05%) in females, and alcoholism was most common predisposing factor in male patients (9.5%). In majority of the patients, no predisposing factor was found (38.95%). Thus, the present review of cases of SAH secondary to CVT revealed risk factor profile which are similar to risk profile of CVT cases as compared to SAH. This may raise suspicion of underlying CVT in case of non-aneurysmal SAH (Table/Fig 5).
Spontaneous SAH is caused by ruptured cerebral aneurysm in 85% of patients and non aneurysmal peri mesencephalic hemorrhage accounts for 10% of cases (1). In these cases, SAH is mainly involving the skull base (2). In the present case review, the most common location of SAH was cortical involving convexity of cerebral hemisphere in 87 patients (91.58%), while 5 patients (5.26) had peri mesencephalic SAH. Typical aneurysmal distribution was also reported in 3 cases (3.16%) (Table/Fig 4). Therefore, when SAH is localised at the cerebral convexity, CVT should be ruled out as underlying cause.
In majority of these reported cases most commonly superior sagittal sinus was thrombosed with variable involvement of other major venous sinuses (84/95) while seven cases had only isolated cortical vein thrombosis. There were four cases in which venography was not available (Table/Fig 4). In patients presenting with non aneurysmal SAH, the diagnosis of CVT is relatively straight when there was a major sinus thrombosis. By contrast, the diagnosis was challenging when there is an isolated cortical vein thrombosis (4),(15). Even in the absence of SAH, CVT is difficult to diagnose, because of the variable number and location (1). The largest veins are detectable on MRV or CT venography (6). When there is a SAH localised at the convexity T2 MR sequences are crucial. It shows thrombosed cortical vein as an hypointense tubular structure while SAH appears as a slight hemosiderin deposit (5) So, review of neuroimaging findings of these cases shows that SAH localised at the cortical convexity area should raise possibility of thrombosis cerebral venous sinuses or cortical vein and should be evaluated. Thus, the localisation of cortical SAH appears to be a good indicator of the involved venous structure. The diagnosis of CVT in a patient with SAH is crucial, because it needs to be treated with heparin, but it is contraindicated in all other causes of SAH (11). Most of the reviewed cases were treated with either conventional heparin or low molecular weight heparin followed by oral anticoagulant. One case report by Arevalo-Lorido JC and Carretero-Gomez J mentioned that patient was initially treated with once daily dose of LMWH and after 3 days dose was increased to two times daily (16). No other case report mentioned the dose of heparin used. Hegazi MO et al., reported a case of SAH secondary to CVT where they started anticoagulation after 3-4 days on evidence of reduced SAH component on repeat neuroimaging (17). But none of these cases included in present review showed worsening of SAH after starting anticoagulant therapy. (Table/Fig 6) shows a total of 95 cases which were reviewed for their available demographic data, clinical and neuroimaging findings (3),(4),(5),(13),(15),(16),(17),(18),(19),(20),(21),(22),(23),(24),(25),(26),(27),(28),(29),(30),(31),(32),(33),(34),(35),(36),(37),(38),(39),(40),(41),(42),(43),(44),(45),(46),(47),(48),(49),(50).
The review had significant limitations because of variability of information reported in each case, and lack of clinical data in some papers or insufficient neuroimaging data in others. There is also a chance of selection bias, but this was not a statistical problem as present data collected yields information on clinic-radiological features, and it is not intended to compare outcome morbidity or mortality.
In patients with non aneurysmal SAH, MRI/ CT venography should be done to rule out cerebral venous sinus thrombosis. Presence of cortical pattern of SAH and risk factors for CVT should raise suspicion of underlying venous thrombosis. Diagnosing CVT in these cases is therapeutically important in view of starting anticoagulant treatment.
Date of Submission: Oct 11, 2021
Date of Peer Review: Jan 12, 2022
Date of Acceptance: Apr 12, 2022
Date of Publishing: Jun 01, 2022
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