Headache Characteristics
Headache is the most common presenting symptom in idiopathic intracranial hypertension (IIH), typically reported in over 90% of patients.[1–3] Table 1 lists the common features and associated symptoms of headaches secondary to IIH. The headache due to IIH is frequently most severe and different in quality compared with prior headaches. In a case series of 63 patients with IIH, Wall[1] reported 92% of patients complained of headache. Of those who experienced headache, 72% of patients rated their headache as the most prominent symptom, and 78% reported headache as the initial symptom related to their diagnosis. Seventy-three percent of patients with headache reported daily symptoms.
In a prospective study of 50 patients with IIH, 85% of patients with headache described the headache as pulsatile, and 83% reported the pain gradually increased in intensity.[3] Sixty-three percent of patients reported the headache could be unilateral at times, and headaches typically lasted >1 hour in 89% of patients. Head pain was reported to be either generalized or focal, with half of patients reporting retrobulbar pain and 22% endorsing worsening pain with extraocular movements. Nearly two thirds of patients reported that headache awakened them from sleep.
Classically, head pain related to elevated intracranial pressure (ICP) is thought to worsen with maneuvers that increase ICP, such as lying down, bending over, coughing, or Valsalva maneuvers. However, only a minority of patients noted worsening of pain with bending over, standing, coughing, or sneezing in Wall's[1] extensive case series.
The pressure-related headache of IIH often has characteristics more common in migraine, including nausea/vomiting, photophobia, and phonophobia.[4] A recent study assessed the presence of allodynia in IIH patients.[5] Fifty percent of subjects were found to have allodynia, typically in a unilateral V1 distribution, and these patients more frequently had headache features similar to migraine. In addition, patients may report associated neck stiffness and shoulder or arm pain due to dilatation of spinal nerve root sleeves, leading to some overlap of symptoms with tension-type headaches.
The International Headache Society's international classification of headache disorders (ICHD-2) diagnostic criteria for headache attributed to IIH includes a progressive headache with at least one of the following characteristics: (1) daily occurrence, (2) diffuse and/or constant (nonpulsating) pain, and (3) aggravated by coughing or straining.[6] In addition, the headache should develop in close temporal relation to increased ICP, the headache should improve after withdrawal of cerebrospinal fluid (CSF) to reduce pressure to a physiological range, and the headache should resolve within 72 hours of persistent normalization of ICP. Patients must also meet the modified Dandy criteria for the diagnosis of IIH. As will be discussed later, patients with IIH frequently have persistent headache despite normalization of their ICP.
D'Amico et al[7] performed a pilot study to assess the applicability of the ICHD-2 diagnostic criteria for IIH patients. Sixty-three percent of IIH patients reported headache, a number lower than many previous studies. Headaches were daily or near-daily in 93% of patients, and described as diffuse or nonpulsating pain in 71.5% of patients. Pain was aggravated by coughing or straining in 57% of patients. All of the patients observed met the minimum ICHD-2 diagnostic criteria, with many also having migrainous-associated symptoms. These findings differ from the symptoms reported in Wall's 2 series, where a majority of patients reported pulsatile pain and few had worsening pain with Valsalva maneuvers, illustrating the varying qualities with which headache secondary to IIH can present.[1,3]
Although there are many typical features associated with the headache of IIH, there are no characteristics that are specific for high ICP. Other common accompanying symptoms of elevated ICP, including transient visual obscurations, photopsias, and pulse synchronous tinnitus, may help with the diagnosis of headache related to IIH. Table 1 .
Int Ophthalmol Clin. 2014;54(1):103-114. © 2014 Lippincott Williams & Wilkins
