Spontaneous intracranial hypotension: The syndrome and its complications

Abstract

Spontaneous intracranial hypotension (SIH) is a syndrome that was largely unknown until the advent of MRI. The incidence of SIH is estimated at 5 per 100,000, which is half the incidence of subarachnoid hemorrhage. The major feature is a postural headache of acute or subacute onset. This headache is absent or minimal when the patient is lying down and rapidly worsens to great intensity when the patient sits or stands. Other features may include nausea, vomiting, vertigo, tinnitus, and marked exacerbation by Valsalva maneuver. SIH is due to a leak of cerebrospinal fluid from a tear in the dural membrane, which occurs most often at the exit zones where the cervical spinal roots leave the subarachnoid space. Other leak sites may be the vestibular system, the cribriform plate, or the pituitary fossa. If the leak continues, the brain loses buoyancy within the cranial space and sags toward the foramen magnum. This, in turn, may produce subdural hygroma or hematoma, brainstem compression, focal cranial nerve palsies, or cerebellar tonsillar herniation. The initial therapy is generally strict bed rest. If this fails, an epidural blood patch is usually successful in sealing the leak and restoring brain buoyancy. A significant minority of patients require a repeat epidural blood patch. If the blood patch fails, a surgical approach may be needed. Repair of the leak and restoration of brain buoyancy will stop the postural headache and, in most cases, will reverse the complications.

Audiovestibular impairments associated with intracranial hypotension

“…Our patients mostly had unilateral low-frequency SNHL while one showed bilateral low-and high-frequencies SNHL. These are consistent with the findings of earlier case reports on intracranial hypotension, which described unilateral or bilateral low-frequency SNHL with occasional progression to downsloping mild-to-profound SNHL [6][7][8][9][10][11][12][13][14][15][16][17]. In contrast, the caloric tests were normal in all.…”

“…A study of 30 consecutive patients with intracranial hypotension has described neurotological symptoms including dizziness (30%), tinnitus (20%), aural fullness (20%), and hearing loss (3%) [1], while another reported auditory symptoms in approximately 70% of the patients [6]. Earlier reports have also documented unilateral or bilateral low-frequency sensorineural hearing loss on audiometry with or without vertigo, likewise in Meniere's disease (MD) [6][7][8][9][10][11][12][13][14][15][16][17]. However, previous studies have mostly focused on auditory dysfunction, and no study has attempted objective documentation of vestibular dysfunction in intracranial hypotension.…”

Reversible coma and Duret hemorrhage after intracranial hypotension from remote lumbar spine surgery: case report

“…Normally, the buoyancy provided by CSF counteracts the downward pull of gravity on the brain, but the loss of spinal fluid in intracranial hypotension causes the brain to sag against the meninges, leading to orthostatic headaches. 3,11,23 In severe cases, nervous and vasculature structures are also placed under tension, which can cause disruption of neurological function and hemorrhage. 22,23 If left untreated, transtentorial and/or tonsillar herniation can occur.…”

Spontan İntrakraniyal Hipotansiyon: Kranial ve Spinal MRG Bulguları

“…Ortostatik (pozisyonel) baş ağrısı, ağrının ayağa kalktıktan sonar 15 dakika içinde ortaya çıkması ya da kötüleşmesi ve yattıktan sonra 30 dakika içinde kaybolması ile karakterizedir (6). Bizim olgularımızın hepsinde ortostatik baş ağrısı tanımlanmıştır.…”