Chapter 25 - Fainting, headache, and “bobble head”: Headache, syncope (fainting), and associated symptoms of atlantoaxial instability (AAI) and Chiari malformation

Abstract

There are many possible causes for feeling faint (presyncope) and fainting (syncope), which are common concerns among patients with EDS and HSD. Patients often report that the symptoms are worse upon standing or remaining upright for long periods of time; this phenomenon is called “orthostatic intolerance.” The patient described in this chapter had orthostatic intolerance and fainted multiple times daily, along with a constellation of neurological signs and symptoms called “cervical medullary syndrome” (CMS). The differential diagnosis for this combination of concerns includes Chiari malformation, instability at the craniocervical junction (where the skull meets the cervical spine), and instability between the top two cervical vertebrae (C1 and C2). CMS may result from several different anatomic or physiological consequences of Chiari or high cervical instability; symptoms may be due to alteration of the posterior circulation to the brain (vertebrobasilar syndrome), mechanical torsional stress (twisting) of the brainstem, changes in the cerebrospinal fluid (CSF) volume status, and/or compression of the C2 nerve roots (occipital neuralgia). In this case, the patient had a Chiari malformation in combination with atlantoaxial (C1–C2) instability and a kyphotic clivo-axial angle (CXA, the angle between the skull base and the upper cervical spine)—a situation called a “complex Chiari malformation.” She responded well to surgical decompression (providing more room for the brainstem) and stabilization of the craniocervical junction. The reader is also directed to chapters discussing Chiari malformation, atlantoaxial instability (AAI), tinnitus, dystonia, and postural orthostatic tachycardia syndrome (POTS).