Spontaneous Spinal Cerebrospinal Fluid Leaks: A Review

, Cedars-Sinai Neurosurgical Institute, Los Angeles, and Department of Neurosurgery, University of California, Irvine, California

Neurosurg Focus. 2000;9(1) 

In This Article

Clinical Presentation

The clinical hallmark of intracranial hypotension is the presence of an orthostatic headache that, according to the criteria of the International Headache Society,[27] should "occur or worsen less than 15 minutes after assuming the upright position, and disappear or improve less than 30 minutes after resuming the recumbent position." The onset of the individual's headache generally is gradual or subacute and often is first noted upon arising in the morning. However, in some patients the onset is acute ("thunderclap" headache), and such patients often will have undergone cranial CT scanning and cerebral angiography to rule out an aneurysmal subarachnoid hemorrhage. The severity of the headache varies widely, and many mild cases undoubtedly are never diagnosed. On the other hand, the headaches may become quite incapacitating, preventing the patient from engaging in any useful activity while in the upright position. Such patients will characteristically present in a recumbent position to their physicians' offices. The headache may be generalized or it may be localized to the frontal or (sub)occipital regions. The headache most likely is a direct result of the decrease in CSF volume and the downward displacement of the brain, which causes traction on pain-sensitive structures, particularly the intracranial dura that is supplied by the trigeminal, glossopharyngeal, and vagal nerves, as well as the upper cervical nerve roots.[19,33]

Although all patients in all major series have presented with orthostatic headaches it is well known that this posture-related component often becomes less prominent or even disappears over time when the intracranial hypotension is left untreated and becomes chronic.[49,70] Rarely, patients with spontaneous intracranial hypotension have been described in whom there is no posture-related component to their headaches from the onset.[2,74]

A wide variety of symptoms may be associated with spontaneous intracranial hypotension. Nausea, vomiting, phonophobia, photophobia, and neck pain or stiffness are common symptoms and suggest meningeal irritation. Many of the other associated symptoms are believed to be directly related to the downward displacement of the brain, which is caused by the loss of CSF buoyancy. Horizontal diplopia, changes in hearing, and vertigo are present in at least one fourth of patients with spontaneous intracranial hypotension[2,4,6,8,20,29,49,63,70,84] and may be caused by stretching of the abducens, cochlear, and vestibular nerves, respectively. A similar mechanism could also explain rarely seen manifestations of intracranial hypotension such as facial numbness or pain (trigeminal nerve), facial weakness or spasm (facial nerve), and dysgeusia (chord of tympanum or glossopharyngeal nerve).[49,70] Transient visual obscurations or visual field defects also have been reported[29] and may be attributed to the stretching of the optic apparatus over the pituitary fossa. Distortion of the pituitary stalk has been implicated as a cause of hyperprolactinemia and galactorrhea associated with spontaneous intracranial hypotension.[85] Stretching of cervical nerve roots could even be implicated as a cause of the radicular arm pain occasionally found in patients with spontaneous intracranial hypotension. An alternative hypothesis to explain the disturbances of hearing or balance is that the abnormal change in CSF pressure is directly transmitted to that in the cochlea or labyrinth. Rarely, severe sagging of the brain may result in symptomatic diencephalic or hindbrain herniation.[3,59,70] Other unusual manifestations may include parkinsonism and cerebellar ataxia.[55] Local back pain may be present at the level of the spinal CSF leak,[70] and structural abnormalities of the nerve root sleeves may cause radicular symptoms. Thus, although uncommon, certain symptoms may aid in localizing the level of the CSF leak.