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.