Neurologic Syndromes

History

Important characteristics that aid in differentiating causes of headache are (1) pattern, duration, severity, location, and frequency of pain; (2) associated symptoms, such as fever or purulent rhinorrhea; (3) family history, triggering events, and efficacy of medications; and (4) presence of any underlying condition that predisposes to infection ( Table 23.1 ). Children who have headache coincident with other complaints in which headache is not the cardinal feature rarely have intracranial disease. Although fever is perhaps the most helpful clue in ascribing an infectious origin, its absence does not preclude serious infection. Fever is present in 95% of children with meningitis but in only 30%–70% of children with a brain abscess. ^,

Clues to intracranial disease (in approximate order of importance) include (1) abnormal neurologic examination (especially abnormalities in eye movement or gait); (2) papilledema; (3) headache worsened by cough, Valsalva maneuver, or change in position; (4) forceful vomiting after prolonged period of recumbency; (5) headache that awakens the child from sleep or is most severe on awakening; (6) change in prior headache pattern, especially headache of recent onset with progressive severity and frequency; and perhaps (7) lack of family history of migraine. Questions regarding appetite, activity level, hydration, and mental status also may help to identify the seriously ill child.

Physical Examination

Physical examination is directed to exclude life-threatening intracranial disease and begins with evaluation of mental status. Nonspecific terms, such as lethargy and fussiness, should be augmented or replaced by notation of interaction with the environment, consolable irritability, verbalization, and sense of well-being. Specific responses to verbal stimulation should be observed and recorded. If the examiner can elicit a smile from an infant or engage an older child in conversation, acute bacterial meningitis or meningoencephalitis is unlikely, although subacute brain abscesses or tumors are possible.

Meticulous attention to abnormalities in vital signs helps assess the diagnosis, pace of illness, and need for immediate intervention. Examples are tachycardia, hypotension, or orthostatic hypotension in the child with moderate to severe dehydration, toxic or septic shock, or the combination of bradycardia, systolic hypertension (wide pulse pressure), and slow, deep, respirations (Cushing triad) indicating increased intracranial pressure (ICP). Overt signs of impending herniation, such as hyperventilation, Cheyne-Stokes respiration (pattern of progressive increase in depth and sometimes rate of breaths followed by apnea) or ataxic respiration (chaotic gasping and apnea), bulging fontanel, fixed pupils, or anisocoria, must be identified quickly. The presence of papilledema is a specific but insensitive sign of raised ICP. It is rare in children with bacterial meningitis, given the relative rapidity of disease, but is notable in 40%–70% of children with brain abscess. ^, Abnormalities of cranial nerve function, asymmetry in strength, tone, or reflexes, gait changes, and papilledema help define an existing lesion; most children with a brain tumor have some abnormality demonstrable on careful neurologic examination.

Nuchal rigidity is present in one-fourth of patients with brain abscess and in more than 95% of children beyond the neonatal period with meningitis but can occur with posterior fossa tumors as well. Fever, headache, and nuchal rigidity can occur with acute bacterial pneumonia, especially that involving the upper lobes; tachypnea is almost invariably present but may have been overlooked.

Sinusitis is a relatively uncommon cause of headache in children (10%–15%) ; data from studies of adults reveal that many “sinus headaches” likely are migraine, but in up to 25% of children with sinusitis, headache is the chief complaint. The constellation of fever, purulent nasal discharge, frontal location of dull pain, and sinus tenderness usually identifies patients with sinusitis. In contrast, children with chronic “sinus headaches” as their only complaint most likely have migraines.

Evaluation

If examination reveals overt signs of increased ICP or focal deficits, brain imaging (computed tomography [CT] or magnetic resonance imaging [MRI]) is warranted urgently as the first study. Electroencephalogram is not recommended in the routine evaluation of headaches in children.

Much discussion has centered on whether a brain imaging study must be performed before lumbar puncture in the child with probable bacterial meningitis to diagnose increased ICP that might induce brain herniation after lumbar puncture. Herniation after lumbar puncture for bacterial meningitis has been reported, but such reports are retrospective in design or anecdotal and often involve a study population including the most critically ill patients, who sometimes have had herniation even without lumbar puncture. ^, Thus the published incidence of herniation in bacterial meningitis of 4%–6% is likely biased by both study design and publication bias. ^{, ,} It is clear that increased ICP accompanies bacterial meningitis, but in general, the diffusely increased ICP of meningitis, with or without performance of lumbar puncture, is much less likely to lead to brain herniation than the differentially increased (focal) ICP associated with intracranial mass lesions. Unfortunately, even a normal result of brain imaging study does not exclude the uncommon to rare likelihood of herniation. ^, A large prospective study of the utility of brain imaging in adults with suspected meningitis showed that imaging is overused and that clinical features alone may suffice to choose which patients can proceed to lumbar puncture without imaging. ^, Similar prospective pediatric data are lacking, but several case series show that clinical signs are more accurate than head imaging in prediction of impending herniation in children. In current practice, few children with suspected bacterial meningitis have ICP measured at the time of lumbar puncture; recent data suggest that the normal ranges of pressure are wider than once thought. ^,

Thus, in general, if meningitis is suspected in a child without papilledema or focal neurologic findings, a lumbar puncture can be performed without obtaining brain imaging. ^{, ,} Additional important but less common contraindications to lumbar puncture include clinically important cardiorespiratory compromise in a neonate or older child; infection in the skin, soft tissue, or epidural area overlying lumbar puncture site; and severe bleeding diathesis. ^,

In the uncommon child with suspected bacterial meningitis and signs of impending herniation or focal neurologic signs, blood cultures are obtained, antibiotics are administered, and an imaging study of the brain is performed urgently. Lumbar puncture is postponed until signs of herniation (as judged by both imaging studies and physical examination) have resolved.

A written and videographic review of lumbar puncture methods is available.

Management

Antibiotic therapy for infectious causes of headaches is that which is appropriate for the relevant infection (e.g., sinusitis, meningitis, or brain abscess). In addition, brain abscesses larger than 2.5 cm generally require therapeutic drainage procedures beyond simple diagnostic aspiration. Reviews of therapies for migraines in children are available in the literature. ^,