ABSTRACT

Corresponding Author:
Dr. E. Premakumari,
K-2, Paras Apartments,
Shanthi Colony, Jeevarathinam Nagar,
Adyar, Chennai-600020, Tamilnadu, India.
E-mail: drprema2016@gmail.com

ABSTRACT

BACKGROUND

Cerebral venous thrombosis (CVT) is a neurological emergency caused due to thrombus formation in the cerebral veins or sinuses. CVT has a varied presentation and its ability to mimic other conditions makes diagnosis of CVT difficult.

Aims and Objectives:

1. To analyse pregnant and puerperal patients with cerebral venous thrombosis.
2. Identifying the possible risk factors, clinical presentations and prognosis of CVT in pregnant and puerperal women.

MATERIALS AND METHODS

Demographic and obstetric history, clinical features, management and prognostic details were retrospectively collected and recorded in a proforma. Results were expressed in terms of frequency. Chi-square test was used as the test of significance.

RESULTS

The observational study showed mean age to be 23.6 ± 3.90 years. Higher proportions of cases were from rural areas (60%), low socioeconomic status (66.7%), multipara (56.7%) and presented within 10 days postpartum (53.5%). Headache was present in all patients. Other symptoms included seizures (60%), altered level of consciousness (20%), visual disturbances (26.7%), papilloedema (53.3%), focal neurological deficits (10%) and cranial nerve palsy (3.3%). Superior sagittal sinus (63.3%) and transverse sinus (70%) were the most commonly involved sinuses. CT was normal in 26.7% of the cases, but magnetic resonance venogram showed positive signs even in CT negative cases. Recovery was good in 86.7% of the cases and ended in mortality in 13.3% of the cases.

CONCLUSION

Pregnant and puerperal women of 21 - 25 years of age were most commonly affected. Most of the cases presented within 10 days postpartum. Headache was the most frequently encountered symptom. Altered consciousness, cranial nerve involvement and headache of more than 24 hours of duration were associated with poor prognosis. CT was normal in 26.7% of the cases, but MRV was conclusive of CVT in these cases. Superior sagittal sinus and transverse sinus were the commonly affected venous channels. Involvement of superior sagittal sinus showed good prognosis, whereas involvement of deeper cortical veins showed poor prognosis. If adequate treatment is initiated before patient progresses to altered level of consciousness, almost complete recovery is possible.

KEY WORDS

Cerebral Venous Thrombosis (CVT), Pregnancy, Puerperium, Headache, Venous Sinus, CT, MRV, Heparin.

BACKGROUND

Cerebral venous thrombosis (CVT) is a neurological emergency due to thrombus formation in the cerebral veins or sinuses. The incidence of CVT in pregnancy is significantly higher in developing countries (450 per 100,000 deliveries) as compared to developed countries (11.6 per 100,000 deliveries).¹ CVT may be due to septic or aseptic thrombi. In the current antibiotic era, increased number of cases with aseptic thrombus is seen. The cause of this aseptic thrombotic activity is primarily attributed to the hypercoagulable state of pregnancy.

Radiological imaging by CT and CECT showed a normal film in 26.7% of the patients. 50% of the patients showed venous infarcts which showed statistically significant good prognosis, p=0.032. 30% of the CT reports were positive for empty delta sign which did not show significant association with the prognosis, p=0.160. A combination of both delta sign and infarcts were also observed in some cases.

Imaging by MRV showed involvement of superior sagittal sinus in 21 (70%) of the cases, transverse sinus in 19 (63.3%) of the cases, sigmoid sinus in 16 (53.3%) of the cases and deeper veins in 1 (3.3%) of the case including cases with multiple sinus involvement. Chi-square analysis shows a statistically significant good prognosis associated with involvement of superior sagittal sinus p= 0.035 and sigmoid sinus p= 0.022 in contrast to involvement of deeper cortical veins which were indicative of a statistically significant poor prognosis p=0.010 (Table 6).

DISCUSSION

Cerebral venous thrombosis is a pathological condition due to clot formation in the vascular lumen resulting from an imbalance in the Virchow’s triad. The blood clot formed in the vascular channel obstructs the normal blood flow to the organs causing ischaemia.⁴ The brain is an organ with elaborate network of vascular channels that provide collateral supply in the very initial stage of vessel block. The clinical picture of CVT becomes evident when the alternative pathway becomes insufficient to meet the demands.⁵ A high degree of suspicion is required to identify this neurological emergency, failing which the chance of recovery falls.

CVT in pregnancy and puerperium can be septic or aseptic. Aseptic CVT can be a direct result of hypercoagulability caused by increased clotting factors (I, VII, VIII, X), decreased levels of protein C and S, decreased fibrinolysis or a combination of multiple factors.⁶ The physiological state of pregnancy and puerperium in addition to factors such as intake of hormonal contraceptive pills,⁷ immobilisation after delivery, inadequate intake of water make women at a higher risk of developing CVT. The hypercoagulable state of pregnancy behaves as a double-edged sword with a protective role against post-partum haemorrhage as well as a negative role in the causation of CVT.⁸ Furthermore, the uterine contractions facilitate dislodgement of the formed clot and its movement along a retrograde route via vertebral veins.⁹

In the current study, majority of the cases were in the post-partum period as against the study conducted by Liang Z (2017) in China, where more number of cases were in the antenatal period as to puerperium (122/100,000 versus 80/100,000 cases).¹ However, the results were consistent with the study conducted in India by Saroja AO (3 antenatal versus 66 postnatal cases of CVT).¹⁰ This could be suggestive of a possible geographical variation. In the location of the present study the tropic climate, excessive sweating and inadequate intake of water (superstitious beliefs) result in dehydration. Immobilisation worsens the situation. Moreover, there is a gross under-reporting of cases in developing countries and delay in the seeking of health care due to lack of awareness.

In our study, more number of cases with CVT were seen in the group delivered vaginally. This may be due to the perineal and pelvic structure injury sustained during labour. Secondly, Valsalva manoeuvre that occurs in patients with labour raises the intra-abdominal and intra-thoracic pressure. The large and bulky uterus compresses the abdominal veins. Both these factors result in increased intravenous pressure. Valsalva retinopathy is a condition where the Valsalva manoeuvre causes intraocular haemorrhage.¹¹ Similarly, the raised intravenous pressure in the cerebral veins during the Valsalva manoeuvre of labour could probably injure the cerebral veins also and cause thrombus formation (arising de novo). However, more clinical and analytical studies are required to give a definite conclusion.

In the present study, 33.3% cases of CVT had anaemia. The association between anaemia and CVT was explained by Coutinho J et al (2015) who suggested that iron deficiency anaemia could result in thrombocytosis as a causal relationship.¹² 53.3% of the patients among those studied were diagnosed to have PIH. Exaggerated hypercoagulable state of pregnancy, intravascular volume depletion due to oedema, generalised endothelial injury and dysfunction favour thrombus formation.^13,14 33.3% of the cases had GDM.

The clinical presentation recorded in the current study was restricted to headache, grand mal and partial seizures, blurring of vision, diplopia, photophobia, altered level of consciousness, hemiparesis, papilloedema and facial nerve involvement. However, only headache showed statistical significance. Cranial nerve involvement and disturbed consciousness showed a statistically significant association with the prognosis of the disease. This limited number of symptoms encountered is most likely due to the smaller number of cases analysed. In an observational study conducted by Bansal, Gupta and Prakash (1980) with 138 cases of CVT, a spectrum of additional symptoms including fever, paraesthesia, vertigo, limb pain, excessive salivation, motor aphasia and 6^th cranial nerve involvement was also noted. These findings were attributed to raised intracranial tension, haemorrhagic meningeal irritation and active thrombotic process.¹⁵ In the current study, the superior sagittal sinus and transverse sinus were the two commonly involved venous channels which is consistent with the reports of Liang Z.¹

In the 30 patients studied, the treatment given was targeted at thrombolysis using unfractionated heparin (UFH) which showed good outcome. However, the treatment protocol has undergone improvisation and low molecular weight heparin (LMWH) is preferred over UFH. Though both unfractionated and low molecular weight heparin do not cross the placental barrier, LMWH is preferred in acute episodes. In patients with previous episodes of CVT, LMWH is recommended prophylactically in pregnancy and puerperium. Symptomatic treatment with antiepileptic has been recommended to prevent recurrence. Recent advances are being directed towards surgical management such as decompressive surgeries in acute cases and supratentorial lesions.¹⁶ Further studies are required to analyse the efficacy of the current treatment.

CONCLUSION

Pregnant and puerperal women of 21-25 years of age were most commonly affected. Most of the cases presented within 10 days postpartum. Headache was the most frequently encountered symptom. Altered consciousness, cranial nerve involvement and headache of more than 24 hours of duration were associated with poor prognosis. CT was normal in 26.7% of the cases, but MRV was conclusive of CVT in these cases. Superior sagittal sinus and transverse sinus were the commonly affected venous channels. Involvement of superior sagittal sinus showed good prognosis, whereas involvement of deeper cortical veins showed poor prognosis. If adequate treatment is initiated before patient progresses to altered level of consciousness, almost complete recovery is possible.

Limitations of the Study

The current study was a pilot study with less number of cases. More studies with large number of participants are required for conclusive results. Also, the coagulation profile could not be assessed to rule out thrombophilia.

Recommendations

• Prophylactic anticoagulant therapy should be given in all the puerperal women with anaemia, PIH, diabetes mellitus and previous thromboembolic episodes.
• The efficacy of the current treatment methods over the conventional unfractionated heparin should be evaluated.