An overlooked cause of subdural effusions
Related Experiment Video
Updated: Feb 25, 2026

Double Direct Injection of Blood into the Cisterna Magna as a Model of Subarachnoid Hemorrhage
Published on: August 30, 2020
Yan-Lin Li1,2, Chi Sum Tsang2
1Department of Radiology, Queen Mary Hospital, University of Hong Kong, Pokfulam, Hong Kong.
Abstract:
A middle-aged man presented with progressive confusion. Initial brain CT was misinterpreted to have 'cerebral atrophy and bilateral subdural effusions' by the emergency physician, and the patient was admitted to a medical ward for further investigation. Two days later, the patient experienced acute neurological deterioration, and burr hole drainage was performed to relieve the effusions. It was later confirmed that the effusions were caused by intracranial hypotension secondary to spinal cerebrospinal fluid leakage. The patient improved on conservative treatment with no lasting neurological sequela.
Related Concept Videos
Pleural Effusion I: Introduction
There are two main types of pleural effusion: transudative and exudative. They are differentiated using Light's...
Pleural Effusion II: Symptoms and Management
A pleural effusion is the abnormal collection of fluid between the parietal and visceral pleura layers of tissue that form the lining of the lungs and chest cavity. It can occur independently or due to surrounding parenchymal diseases, such as infection, malignancy, or inflammatory conditions.
Clinical Manifestations:
Cranial and Spinal Meninges
Cranial Meninges
These meningeal layers cover the cranium. The dura mater is the outermost layer of cranial meninges. It is a thick and durable membrane of dense...
Veins of Head and Neck
On the other hand, the vertebral veins, unlike their arterial counterparts, are not primarily responsible for brain drainage. Instead, they drain the cervical vertebrae, spinal cord, and some small...
Venous Thrombosis II: Clinical Manifestations and Diagnostic Studies
Venous Thrombosis I: Introduction

