Spontaneous Intracranial Hypotension Complicated by Subdural Effusions Treated by Surgical Relief of Cranial Venous Outflow Obstruction

Abstract

Spontaneous intracranial hypotension describes the clinical syndrome brought on by a cerebrospinal fluid (CSF) leak. Orthostatic headache is the key symptom, but others include nausea, vomiting, and dizziness, as well as cognitive and mood disturbance. In severe cases, the brain slumps inside the cranium and subdural collections develop to replace lost CSF volume. Initial treatment is by bed rest, but when conservative measures fail, attention is focused on finding and plugging the leak, although this can be very difficult and some patients remain bedbound for months or years. Recently, we have proposed an alternative approach in which obstruction to cranial venous outflow would be regarded as the driving force behind a chronic elevation of CSF pressure, which eventually causes dural rupture. Instead of focusing on the site of rupture, therefore, investigation and treatment can be directed at locating and relieving the obstructing venous lesion, allowing intracranial pressure to fall, and the dural defect to heal. The case we describe illustrates this idea. Moreover, since there was a graded clinical response to successive interventions relieving venous obstruction, and eventual complete resolution, it also provides an opportunity to consider particular symptoms in relation to cerebral venous insufficiency in its own right.

A paradigm for chronic fatigue syndrome: caught between idiopathic intracranial hypertension and spontaneous intracranial hypotension; caused by cranial venous outflow obstruction

“…Such cause or effect considerations do not apply if there is extracranial venous outflow obstruction and recently cases of (otherwise) idiopathic intracranial hypertension have been described caused by narrowing of the jugular veins between the styloid processes and the transverse processes of the C1 vertebra, with treatment of the venous narrowings bringing resolution of the clinical syndrome [ 27 , 28 , 29 , 30 ]. At the other end of the spectrum, we have reported cases of spontaneous intracranial hypotension caused by narrowing of the jugular veins at the same level, whose symptoms also resolved following treatment directed at the venous stenoses [ 31 , 32 ]. In these cases, taking jugular venous obstruction as the underlying cause of intracranial hypotension, then a procedure (for example, jugular venous stenting) that would normally be expected to reduce intracranial pressure, allowed the CSF leak to heal and intracranial pressure to revert to normal.…”

Life changing response to successive surgical interventions on cranial venous outflow: A case report on chronic fatigue syndrome

“…Observer bias cannot be discounted in a report without a control group, nor can the effect of placebo, especially when the treatment offered is based on an organic model of disease sympathetic to the widely held view among these patients that they have an illness with a physical cause. Nevertheless, the subtle clinical response to the diagnostic investigations witnessed in this case, the nuanced and incremental response to successive interventions (reminiscent of the response in other similar cases) (18,34), durable over the course of long follow-up, and easily reconciled with the limited success of the interventions themselves, would require a degree of sophistication and consistency in placebo effect that would be hard to credit.…”

“…She had the surgery 16 months after her first consultation. The surgical technique has been described previously ( 17 , 18 ).…”

Transverse sinus stenting without surgical repair in idiopathic CSF rhinorrhea associated with transverse sinus stenoses: a pilot study

“…[1][2][3] Restriction of the venous CSF outflow pathway as a result of transverse sinus (TS) stenosis (TSS) may result in the overflow of the lymphatic CSF outflow pathway and in the chronic erosion of the skull base and ultimately may lead to CSF leaks in some patients. [4][5][6][7] While a CSF leak may prevent clinical symptoms of intracranial hypertension from occurring in these patients, its closure is always indicated to prevent infectious complications such as bacterial meningitis. However, surgical repair of idiopathic CSF rhinorrhea is associated with a high risk of recurrence of the leak and a risk of subsequent intracranial hypertension.…”

“…6 Therefore, we can hypothesize that the restoration of a functional venous CSF outflow pathway with venous stenting may result in amelioration of the lymphatic outflow and thus resolution of the CSF leak in some patients. 5,[9][10][11][12] Thus, rather than treating the leak and its effects downstream, the goal is to help treat the cause of the leak upstream. Venous sinus stenting (VSS) has emerged as a promising treatment for IIH during the last decade.…”