CASE 1305 Published on 30.12.2001

Spontaneous intracranial hypotension

Section

Neuroradiology

Case Type

Clinical Cases

Authors

N. Sadeghi, J. Garbuzinski, C. Neugroschl, Ph. David, D. Balériaux

Patient

46 years, female

Categories
No Area of Interest ; Imaging Technique CT, MR
Clinical History
The patient presented with orthostatic headaches. CSF pressure was low. MR of the brain showed bilateral subdural collections and diffuse pachymeningeal enhancement.
Imaging Findings
The patient presented with persistent headaches, not relieved by nonsteroidal antiinflammatory drugs, and associated with nausea and vomiting. She stated that her headaches were alleviated by lying flat. She had a history of minor thalassemia.

The neurological examination was unremarkable apart from mild cervical stiffness. The patient also had a mild inflammatory syndrome with a white cell count of 11.3x10³/mm³(N:4-10.5x10³/mm³)and CRP of 1.3 mg/dl(N:<0.5mg/dl). Lumbar puncture revealed an initial low pressure of 3 cm H2O. The CSF analysis yielded evidence of blood contamination and a white cell count of 12/mm³(predominantly composed of lymphocytes), 150 mg/dl protein (N:30-60mg/dl), 65 mg/dl glucose(blood glucose of 101mg/dl), 123 mEq/L chlorine(N:118-132mEq/L) and 2.1 mEq/L lactate(N:0-2.4mEq/L). CSF cytology revealed no evidence of malignant cells; smears and cultures for bacteria, fungi or viruses were negative.

CT of the brain showed bilateral hemispheric subdural effusions with diffuse flattening of the cortical sulci over both cerebral hemispheres and a focal area of enhanced meningeal thickening in the right pontocerebellar angle. MR of the brain after contrast injection revealed, in addition, diffuse thickening and enhancement of the dura which was not visible on post-contrast CT.

Discussion
Spontaneous intracranial hypotension (SIH) was first described by Schaltenbrand in 1938 and is characterised by postural headache associated with low CSF pressure. The similarity of SIH to the post-dural puncture headache syndrome supports the notion that a CSF leak may be the cause. Most commonly there is CSF leakage from a spinal meningeal defect. However in many cases the aetiology may remain obscure.

Since 1991, the frequency of reported cases has increased because of the very sensitive and relatively specific changes found on brain and spinal MRI. The main MRI findings within the brain are diffuse pachymeningeal gadolinium enhancement, subdural fluid collections, descent of cerebellar tonsils, decrease in the size of prepontine and perichiasmatic cisterns, decrease in the size of the ventricles and sulcus, engorgement of the cerebral venous sinuses and enlargement of the pituitary gland. Spine MRI may show extra-arachnoid fluid, meningeal diverticula, meningeal enhancement and engorgement of the epidural venous plexus (1,2,3).

Radioisotope cisternography, CT myelography or MR myelography may be used in order to find the site of the CSF leak in those patient who do not improve spontaneously or after epidural blood patch. Surgical repair of the leak should be considered in these cases (4,5).

Differential Diagnosis List
Spontaneous intracranial hypotension
Final Diagnosis
Spontaneous intracranial hypotension
Case information
URL: https://www.eurorad.org/case/1305
DOI: 10.1594/EURORAD/CASE.1305
ISSN: 1563-4086