Altered mental status (AMS) is a broadly applied term used to describe any change in a patient’s baseline behavior, cognitive abilities, or awareness of and interaction with the environment. The presentation of altered mental status in a pediatric patient encompasses a wide variety of manifestations, ranging from confusion to coma, and is associated with a myriad of etiologies. The workup requires careful assessment of not only the patient’s presentation and examination, but also a detailed history of prodromal symptoms, potential exposures (both environmental and pharmacologic), and preceding trauma. The evaluation is frequently complicated by the fact that the patient is unable to participate in providing information due to either impaired mental state or developmental age, and clinicians must often rely on parents or caregivers to elicit contextual details to assist in the assessment. In particular, it is important to understand the patient’s baseline mental status and appreciate how the current presentation differs.

Initial evaluation should be targeted at stabilizing the patient by following the standard assessment and management of the patient’s airway, breathing, circulation, disabilities, and exposures. This is followed by a careful history from the patient (whenever possible) and/or parent(s) or caregivers, and should focus on the following elements:

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   Baseline behavior and neurologic state: This is particularly important given the developmental variations in norms among different pediatric age groups, and the variations observed among children with developmental and intellectual disabilities.

   
   
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   Onset and course of symptoms: Obtain information on the acuity, timing, and course of the symptoms. The impairments may be described as persistent, intermittent, acute, recurrent, progressive, or fluctuating.

   
   
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   Associated symptoms: Obtain a history of any concurrent or preceding symptoms including a history of fever, headache, seizures, hallucinations, nausea, vomiting, diarrhea, incontinence, changes in urinary frequency or oral intake.

   
   
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   Trauma: Obtain a careful history of preceding trauma or observed injuries, such as bruising, especially if no clear mechanism of injury exists.

   
   
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   Past medical history: Obtain a thorough account of existing medical and psychiatric conditions (chronic or acute) or recent procedures.

   
   
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   Medications: Obtain a detailed delineation of any prescription medication changes, including new medications, recent dose changes, or recent discontinuation of medications. Also collect a list of medications belonging to other household members to which the patient may have had access.

   
   
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   Social history: Obtain a history of access to or risk of recreational drug and alcohol use. Collect information on potential family members or household contacts using recreational drugs. Assess potential stressors in the home or at school.

   
   
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   Travel history/exposures: Obtain an account of recent travel within the United States and internationally. Assess outdoor activities and potential exposures to tick bites or mosquito bites. Obtain a history of environmental exposure, such as access to lead paint or household cleaning items. Assess for any other close contacts with similar symptoms.

   
   
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   Family history: Obtain a family history focusing on autoimmune disease, migraines, bleeding disorders, seizure disorders, and psychiatric illness.

The physical examination, including vital signs, can frequently offer clues to help narrow the differential diagnosis and direct the diagnostic workup to uncover the underlying cause.^1-5

Temperature: The presence of fever suggests an infectious or autoimmune etiology. Drug ingestions/overdoses (e.g. anticholinergics, sympathomimetics) or adverse drug reactions such as neuroleptic malignant syndrome or serotonin syndrome also present with hyperthermia.⁶

Hypothermia should elicit evaluations for potential metabolic or toxic exposures, including drug or alcohol ingestion, endocrinopathies, such as hypothyroidism, hypoglycemia, or possibly infectious etiologies (meningitis, sepsis). Prolonged exposures to cold air, especially in infants, may also result in hypothermia.

Heart rate: Bradycardia suggests a toxic ingestion or exposure (e.g. beta-blockers, calcium channel blockers, carbamates), hypothyroidism, hypoglycemia, or increased intracranial pressure due to central nervous system (CNS) hemorrhage, mass lesion, or infection.

Tachycardia points toward possible infections, hyperthyroidism, or ingestion (e.g. sympathomimetics, anticholinergics). Significant tachycardia without variability suggests supraventricular tachycardia.

Respiratory rate: Tachypnea is often the hallmark of infection or ingestions (e.g. salicylates, ethylene glycol). Patients with carbon monoxide poisoning or methemogobinemia may also present with tachypnea.

Hypopnea should lead to evaluation for ingestion (e.g. opioids), or for increased intracranial pressure (ICP), including CNS masses, infections, or hemorrhages.

Blood pressure: Hypertension points toward potential hypertensive encephalopathy or intracranial hemorrhage, posterior reversible encephalopathy syndrome (PRES), or toxic ingestion (e.g. sympathomimetics).

Hypotension favors further workup for infections, toxic ingestions (e.g. opioids, benzodiazepine), or significant dehydration.

Head and neck examination: Ecchymoses suggest possible trauma, whether accidental or inflicted. A bulging fontanelle in an infant is concerning for meningitis or trauma. Nuchal rigidity in an older child would suggest meningitis. Symmetric mydriasis or miosis would be consistent with a toxic ingestion. Asymmetric pupillary examination is concerning for an intracranial mass or hemorrhage. If papilledema is appreciated, the evaluation should focus on causes of increased ICP including meningitis, CNS mass, or intracranial hemorrhage. If signs of orbital cellulitis or sinusitis are present, the differential should include cavernous venous thrombosis or an epidural abscess.

Neurology examination: The neurological examination should first focus on a patient’s level of consciousness as compared to developmentally appropriate level of awareness and alertness. The most commonly used terms to describe impaired levels of consciousness are described in Table 19-1. The Glasgow Coma scale, including a modified version for the pediatric population, is frequently used to provide an objective measure of the level of impairment both on initial evaluation and during subsequent examinations (Table 19-2).^7,8

Most of the diagnoses on the differential for AMS can occur with any of the levels of impairment described in Table 19-1, depending on the severity or duration of symptoms. However, more significant impairment (e.g. stupor and coma) should result in a more expeditious and broader initial differential diagnosis and subsequent diagnostic evaluation.

Patients who present without changes in consciousness or only mild impairments can be assessed for changes in behaviors and cognitive abilities, when developmentally appropriate (usually in older children and adolescents). Agitation may be a sign of a drug or toxic ingestion or withdrawal, psychosis, or hyperthyroidism. Cognitive dysfunctions, including disorientation or difficulties with speech or memory may also be due to a toxic exposure, infectious etiologies (meningitis, encephalitis), CNS mass, traumatic brain injury (e.g. concussion, epidural hemorrhage), or intracranial hemorrhage.

Additional examination findings, such as hyperreflexia or asymmetric reflexes, as well as hemiplegias suggest a CNS infection, mass, or stroke. Psychomotor slowing would suggest neuroleptic malignant syndrome or a primary psychiatric illness.

AMS is used to describe a patient’s symptoms rather than a definable disease, and can thus be a manifestation of a multitude of disease processes that range from benign to life-threatening.^1,9 Most etiologies fall within a number of broad categories as outlined in Table 19-3.^2,3