Intracranial hypotension

Spontaneous intracranial hypotension: diagnostic and therapeutic implications in neurosurgical practice

Authors; Angelo F, Giuseppe M, Eliana M, Luisa C, Gennaro B.

Spontaneous intracranial hypotension syndrome (SIH) is a complex pathological entity due to reduction of cerebrospinal fluid (CSF) volume and results into a variegated symptomatology, ranging from orthostatic headache to more severe conditions, such as stupor and coma; several attempts have been done in the past to understand the exact pathophysiological mechanisms which underlie its phenomenology, as well as different therapeutic approaches to relieve symptoms and reverse the reduction of overall CSF volume, both focally (in the case of a clear localized CSF leak) or by reversing the pressure gradient between the venous system and the subdural and epidural compartments (in the case of idiopathic SIH). The Authors' experience is here reported, along with some pathophysiological and neuroradiological implications and considerations.

Intracranial Hypotension and Intracranial Hypertension

Authors: Esther L. Yuh a  and William P. Dillon

Intracranial pressure (ICP) is the pressure within the intracranial space. Intracranial hypotension is a clinical syndrome in which low cerebrospinal fluid volume (CSF) results in orthostatic headache. Severe cases can result in nausea, vomiting, photophobia, and, rarely, decreased level of consciousness and coma. CSF opening pressure can be within the normal range in spontaneous intracranial hypotension. Imaging tests therefore play a key and decisive role in the diagnosis, as well as treatment, of intracranial hypotension. Intracranial hypertension occurs in a chronic form known as idiopathic intracranial hypertension, as well as in a large variety of neurologic and systemic disorders. Symptoms include headache, nausea and vomiting, blurred vision, and in severe cases, altered level of consciousness that can progress to coma and death. Direct measurements of CSF pressure through lumbar puncture (in idiopathic intracranial hypotension) or invasive ICP monitoring (in acute intracranial hypertension) are the key diagnostic tests. Imaging is used primarily to determine treatable causes of increased ICP, to assess for impending brain herniation, and to evaluate ventricular size.

Headache caused by raised intracranial pressure and intracranial hypotension

Author: N M Ramadan.

Extremes of intracranial pressure commonly cause headache. Benign intracranial hypertension is a rare syndrome of increased intracranial pressure manifesting as headache, intracranial noises, transient visual obscuration, and palsy of the sixth cranial nerve. Endocrine disorders such as obesity and hypoparathyroidism, hypervitaminosis A, tetracycline use and thyroid replacement are probable causes of benign intracranial hypertension. In the majority of cases, however, it is idiopathic. Benign intracranial hypertension is though to be caused by cerebral edema, high cerebrospinal fluid outflow resistance and high cerebral venous pressure, or a combination of the three. The management of benign intracranial hypertension includes, symptomatic headache relief, removal of offending risk factor(s), and medical or surgical reduction of intracranial pressure. Spontaneous intracranial hypotension is more rare than benign intracranial hypertension. Postural headache (worse in the upright position) is the hallmark of spontaneous intracranial hypotension. Typically, the cerebrospinal fluid pressure is less than 60 mm H2O. Diminished cerebrospinal fluid production, hyperabsorption, and leak are postulated mechanisms of spontaneous intracranial hypotension. Empirical treatment includes bed rest, administration of caffeine, corticosteroids or mineralocorticoids, epidural blood patch, and epidural saline infusion.

Headaches caused by decreased intracranial pressure: diagnosis and management

Authors: Mokri, Bahram 

Current Opinion in Neurology: June 2003 - Volume 16 - Issue 3 - pp 319-326 Headache

Purpose of review: More patients with spontaneous intracranial hypotension are now being diagnosed, and it is realized that most cases result from spontaneous cerebrospinal fluid leaks. A broader clinical and imaging spectrum of the disorder is recognized. This paper reviews new insights into the variability of clinical manifestations, imaging features, etiological factors, anatomy of leaks, and implications of these in patient management.

Recent findings: Spontaneous intracranial hypotension should not be equated with post-lumbar puncture headaches. In a substantial minority of patients, headaches are not orthostatic and may mimic other types of headache. Additional diverse neurological manifestations may dominate the clinical picture and patients may occasionally have no headache at all. Reports on unusual presentations of the disorder continue to appear in the literature. Furthermore, additional imaging features of cerebrospinal fluid leaks are recognized. High-flow and slow-flow leaks may present diagnostic challenges, and require modification of diagnostic studies aimed at locating the site of the leak. Stigmata of connective tissue abnormality, especially abnormalities of fibrillin and elastin, are seen in a notable minority of patients, pointing to weakness of the dural sac as one of the etiological factors. After treatment of spontaneous intracranial hypotension, surgically or by epidural blood patch, a rebound and self-limiting intracranial hypertension may sometimes develop.

Summary: In the past decade, interest in spontaneous intracranial hypotension has been rekindled, with a substantial growth of knowledge on various aspects of the disorder. We are in the learning phase, and new information will probably appear in the future, with notable diagnostic and therapeutic implications.


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