Evaluation of patients with headache due to spontaneous intracranial hypotension by RN cisternography

Spontaneous intracranial hypotension (SIH) typically occurs without an obvious cause. However, it can be seen following the lumbar puncture, craniotomy, or spinal surgery. Also listed are contributing factors such as sneezing, coughing, intercourse or minor fall. Spontaneous spinal CSF leaks are not common, but are now increasingly recognized as a cause of postural headache associated with intracranial hypotension. The purpose of our study was to evaluate the role of RN cisternography in the diagnosis of SIH cuased by spinal CSF leakage. Four patients with clinical suspicion of SIH (Group I) and six patients as normal control (Group II) underwent RN cisternography. RN cisternography in Group II was done for various reasons, such as hydrocephalus, syringomyelia and memory loss. Group I consisted of the patients who presented with postural headache, as well as additional symptoms, such as nausea, vomiting, dizziness, tinnitus and eyeball pain. The age range of these patients was 27 - 67 years. Lumbar puncture and CSF examinations were performed in Group I more than once and showed typical findings of low CSF pressure and slightly elevated protein level. Brain MRI (4/4), Cervico-thoracic spine MRI (3/4) were also performed. On gadolinium-enhanced brain MRI, enhancement of the meninges which is the most characteristic radiographic finding in intracranial hypotension was found in all patients of Group I. But, cervico-thoracic spin MRI was nonspecific. None of Group I had contrast myelography because of the patient's refusal. Group I and Group II underwent radionuclide cisternography following lumbar subarachnoid injection of 99mTc-DTPA (1-2mCi). The scans were taken in 2, 5, 24 hours later using single head gamma camera equipped with LEAP. Entire spinal region in posterior view and head in frontal and lateral views were obtained. The cisternography of Group I showed the CSF leakage or diverticulum at the level of cervico-thoracic junction(3/4) and mid-thoracic level (1/4). Also, other findings, such as early accumulation of the tracer in the bladder, slow ascent along the spinal subarachnoid space, were seen. These patterns were different from the Group II. We conclude that the CSF leakage causing headache due to SIH was easily detected by radionuclide cisternography in four patients whereas other radiographic methods such as cranial and spinal MRI were nonspecific