Park Ji Hyun, Yoon Soo Han
Department of Neurosurgery, Ajou University School of Medicine, Suwon 443-721, Republic of Korea.
Med Hypotheses. 2008;70(1):143-7. doi: 10.1016/j.mehy.2007.03.036. Epub 2007 Jun 13.
Cerebral venous sinus thrombosis develops as a consequence of sinus obstruction, leading to hindering of venous drainage, gradual edema and increased intracranial pressure (ICP). Intracerebral hemorrhage occurs, of which the symptoms may be alleviated by cerebrospinal fluid (CSF) drainage. Clinical brain function improvement may be directly attributed to the effect of the decreased ICP, or to the decreased pressure on the venous sinus which alleviates venous blood flow and sinus thrombosis. However, worsening, rather than improvement of symptoms are occasionally observed in patients after CSF drainage, and therefore it is as yet difficult to determine the precise indications for CSF drainage. The authors of this study suggest that external CSF drainage of sagittal sinus thrombosis may accelerate the sinus thrombosis and aggravate symptoms in such a patient. In other words, the sagittal sinus differs from other sinuses in that when sinus thrombosis develops, CSF absorption is impeded from the early stages, leading to a higher likelihood of ventricular dilatation, because most of the CSF are normally absorbed through the arachnoid villi and drain into the sagittal sinus. External CSF drainage and subsequently decreased ICP will improve sinus thrombosis after implementation of CSF drainage of the sagittal sinus thrombosis, but on the other hand, this decreased CSF drainage leads to decreased venous sinus blood flow, both of which may result in aggravation of the sinus thrombosis. However, it is also suggested that CSF drainage may be accomplished safely on the unilateral lateral sinus thrombosis because CSF drainage may alleviate venous sinus obstruction, and does not influence the sinus blood flow. We, authors of this study suggest that caution should be taken when external CSF drainage of the sagittal sinus thrombosis is performed to prevent further aggravation of intracranial pressure elevation.
脑静脉窦血栓形成是由于窦道阻塞，导致静脉引流受阻、逐渐出现水肿和颅内压（ICP）升高。继而发生脑出血，其症状可通过脑脊液（CSF）引流得到缓解。临床脑功能改善可能直接归因于颅内压降低的作用，或者归因于静脉窦压力降低，从而缓解静脉血流和窦血栓形成。然而，在脑脊液引流后的患者中，偶尔会观察到症状恶化而非改善的情况，因此目前仍难以确定脑脊液引流的确切指征。本研究的作者表明，矢状窦血栓形成的外部脑脊液引流可能会加速该患者的窦血栓形成并加重症状。换句话说，矢状窦与其他窦不同，当窦血栓形成时，脑脊液吸收从早期就受到阻碍，导致脑室扩张的可能性更高，因为大多数脑脊液通常通过蛛网膜绒毛吸收并排入矢状窦。矢状窦血栓形成进行脑脊液引流后，外部脑脊液引流及随后颅内压降低会改善窦血栓形成，但另一方面，脑脊液引流减少会导致静脉窦血流减少，这两者都可能导致窦血栓形成加重。然而，也有人认为，单侧外侧窦血栓形成时脑脊液引流可以安全进行，因为脑脊液引流可缓解静脉窦阻塞，且不影响窦血流。本研究的作者建议，在进行矢状窦血栓形成的外部脑脊液引流时应谨慎，以防止颅内压升高进一步加重。
