++
The vast majority of headaches are of the tension, migraine,
and cluster types, which are classified as primary headaches and
are discussed in Chapter 18. Unfortunately, many patients develop refractory
headaches, which usually consist of one or more primary headache
disorders complicated by analgesic medication overuse, poor coping
patterns, or failure to identify triggers. In such cases, an interdisciplinary
management approach is needed.
++
Of particular concern to patients and clinicians are the secondary
headaches, also known as organic headaches, accounting for fewer
than 10% of all recorded headaches.1 By
definition, they are symptomatic of underlying disease, structural
pathology, or pain-inducing processes different from those traditionally
ascribed to the primary headaches. Organic headaches may be secondary
to elevated cerebrospinal fluid (CSF) pressure, known as benign
intracranial hypertension or pseudotumor cerebri; to bleeding from
congenital aneurysms or arteriovenous malformations (AVMs); to ischemic
or hemorrhagic stroke; as well as to pain caused by mass lesions
or mass effect, such as tumors, hematomas, AVMs, and trauma, or
infectious processes such as meningitis, encephalitis, and cerebral
abscesses. The clinical importance of organic headaches—despite
their relatively low prevalence compared with primary headaches—illustrates important
principles of diagnosis and treatment useful to the clinician prior
to obtaining specialist consultation.
++
This chapter focuses on the clinical signs, symptoms, and diagnostic
workup of selected categories of secondary headaches. Cerebral tumors,
stroke, subarachnoid hemorrhage, and vascular anomalies, spinal
headache (i.e., spontaneous CSF leaks or those caused by lumbar
puncture or epidural misplacement), and infection with the human
immunodeficiency virus (HIV) are some of the vehicles used to discuss
common clinical scenarios and approaches to decision making. The information
that follows is based on both the published literature and our clinical
experience as neurologists and headache and pain specialists.
++
Special emphasis is placed on the importance of maintaining patient
comfort, dignity, and self-esteem. This approach is crucial to the
success of therapy, even if success is not always defined as “cure,” and
is especially important in cases of terminal disease or those in
which the primary diagnosis or headache symptom is disrupting patient
and family dynamics.
++
Differentiating secondary from primary headaches can be difficult.
The quality of pain may be indistinguishable from that of migraine,
tension-type, or other primary headaches. In such cases, the International
Headache Society (IHS) states that the temporal relationship between
the headache and underlying pathology should be the deciding factor.2 Preexisting
headaches aggravated by an organic process are still considered
primary. If the onset of headache occurs in close proximity to the
underlying structural problem, it is considered secondary. Sometimes
the question is merely academic or impossible to answer. For example,
how does one classify long-standing, stereotypic, but side-locked
migraines when a magnetic resonance imaging (MRI) scan of the head,
obtained to evaluate the cause of new-onset seizures, reveals the
presence of an AVM ipsilateral to the headache, and in a position
to cause pain? Are the headaches then primary ...