Altered Mental Status

The term “altered mental status” (AMS) describes a change in a patient’s arousal and level of interaction with the external environment that differs from baseline. In the pediatric population, this definition takes into account the child’s age-appropriate developmental milestones and baseline neurologic function. The initial approach to a child with AMS in the emergency department (ED) begins with assessment and stabilization of ABCs (airway, breathing, and circulation) followed by a thorough history and physical examination. However, even after this initial assessment, the differential diagnosis often remains broad.

The following conditions related to altered mental status in children presenting to the ED are addressed in this section:

• Toxic Ingestions

• Syncope

• Seizures

• Status Epilepticus

• Meningitis

The following mnemonic can be helpful in the differential diagnosis of acute etiologies of AMS in children.

Toxic Ingestions

Ingestion of a toxic substance is a common cause of pediatric morbidity, with millions of both intentional and unintentional poisonings presenting to EDs in the United States each year. In children younger than 5 years, ingestions are usually the result of exploratory behaviors, whereas in children older than 11 years, deliberate ingestions with intent to self-harm must be more strongly considered. Child abuse by poisoning is not as common but remains in the differential diagnosis for young children (particularly aged <12 months) with AMS. In addition to ingestion of medications and illicit substances, children present with poisonings from plants and household chemicals (including detergents, auto supplies, and substances used in gardening/farming products).

Assessment

The evaluation of severe poisoning in a young child begins with rapid recognition and assessment with both the primary and secondary survey. In 2014, Calello and Henretig outlined the following general approach to pediatric poisoning.

(Reprinted from Calello DP and Henretig FM. Pediatric Toxicology: Specialized Approach to the Poisoned Child. Emerg Med Clin North Am 2014, with permission from Elsevier)

In all cases, consultation with a regional poison control center should guide acute management. The American Association of Poison Control Centers (1-800-222-1222 or www.poisonhelp.org) supports poison control centers in all 50 states. Be aware that you will be connected to the nearest center based on the phone number from which you are calling. Therefore, consider using hospital phones rather than cell phones to help with center data collection.

Family members should be encouraged to bring or send pictures of pill fragments, chemical containers, or other information about the substance(s) the child has or may have ingested to allow poison control consultants to identify offending agent(s) and make management recommendations. In instances of less severe or asymptomatic ingestion, a period of observation in the ED is often all that is warranted.

Common Toxidromes

The information gathered in the history and physical examination can illustrate a pattern of signs and symptoms associated with a certain toxic exposure.

Management

Most ingestions in children are managed with supportive care alone. Gastrointestional decontamination (including activated charcoal and gastric lavage) was formerly the mainstay of toxicologic management but has recently fallen out of favor due to limited supportive evidence and to the potential for harmful side effects (most notably aspiration). The following table provides a list of antidotes to common pediatric poisonings.

(Reprinted from Calello DP and Henretig FM. Pediatric Toxicology: Specialized Approach to the Poisoned Child. Emerg Med Clin North Am 2014, with permission from Elsevier.)

Syncope

Syncope is a sudden, brief loss of both consciousness and postural tone caused by cerebral hypoperfusion. Children who have experienced syncope recover spontaneously and completely, a distinction that is important when differentiating syncope from other causes of AMS. Syncope accounts for about 1% of ED visits among children aged 7 to 18 years and affects girls more often than boys. Syncope can broadly be classified into the following three types:

• Autonomic (vasovagal or neurocardiogenic) syncope is characterized by the brief failure of the autonomic nervous system to maintain blood pressure (and sometimes heart rate) at a level adequate for cerebral perfusion. Vasovagal syncope, “situational” syncope, and breath-holding spells are the most common cause of autonomic syncope in children and adolescents.

• Cardiac syncope is characterized by primary cardiac dysfunction and is most commonly caused by arrhythmias, structural heart disease (e.g., idiopathic hypertrophic subaortic stenosis), and inherited disorders of conduction (e.g., long QT syndrome) in children.

• Other syncope consists of conditions that either cause or mimic syncope. The most common condition is orthostatic intolerance, characterized by hypotension when moving from prone to standing. Other conditions include hypoglycemia, epilepsy, migraines, postural orthostatic tachycardia syndrome (POTS), toxic ingestions, dysautonomia, and psychogenic causes.

Assessment

The diagnosis of syncope is generally made from a thorough history (personal and family) and physical examination. The physical examination is usually normal in children with syncope. However, a focused exam should be performed concentrating on vital signs (including orthostatic) and a thorough cardiac examination including a normal ECG. Common characteristics of the history that can help elucidate the etiology of syncope include:

• Autonomic:

  • vasovagal: dizziness, diaphoresis, nausea, light-headedness, vision changes

  • situational: preceded by coughing, sneezing, micturition, defecation, laughter, breath-holding spell (hyperventilation prior to event)

• Cardiac:

  • exertion-related

  • chest pain (more commonly structural)

  • positive family history (sudden death, arrhythmia, or heart disease)

  • congenital heart disease

• Other:

  • orthostatic: occurs when moving from sitting to standing; recent blood or fluid loss

  • history of seizures, migraines, diabetes, medication or substance ingestion

Diagnosis

Diagnostic testing should include a 12-lead electrocardiogram (ECG) on every patient. Further diagnostic testing depends on the elicited history. Consider measurement of urine human chorionic gonadotropin (hCG) in adolescent females. Most children who present to the ED with syncope can be managed as outpatients and safely discharged home with education. Those with a cardiac etiology, toxin/ingestion, or with persistent altered mental status will usually require hospital admission.

Seizures

A seizure is the clinical expression of abnormal electrical activity in the brain. Seizures are characterized by transient, stereotyped, involuntary movements and/or alteration of consciousness. This section outlines the approach and management of children presenting to the ED with a chief concern of seizure. Additional information on seizures is available in the Epilepsy section in the Pediatric Neurology rotation guide.

Differential Diagnosis

A seizure is not a diagnosis but rather a symptom of underlying pathology. Following is a list of underlying seizure etiologies:

• neurologic: epilepsy, subtherapeutic anticonvulsants, hypoxic-ischemic injuries

• infectious: meningitis, encephalitis, brain abscess, febrile seizures, tuberculosis, toxoplasmosis

• trauma: intracranial hemorrhage, cerebral contusion, diffuse axonal injury

• metabolic: electrolyte imbalances (hypoglycemia, hyponatremia, hyperammonemia, etc.), hypertensive encephalopathy, inborn errors of metabolism

• toxicologic: ingestions, withdrawal

• oncologic: primary central nervous system (CNS) tumors, metastatic disease

Assessment

A focused history and physical examination can help guide a clinician’s diagnostic evaluation. Important aspects of the history and physical examination include:

History

• description or video of event — including level of consciousness, responsiveness, tongue biting, incontinence, semiology, duration, preceding aura

• history of seizures or epilepsy (if yes, any missed doses of medications or change in doses/medications)

• history of preceding trauma, toxin exposures or ingestions

• history of fever, systemic signs of illness, lethargy, diarrheal illness

• medical history, including ventricular shunts or abnormal development

• history of recent domestic or international travel

Physical Examination

• vital signs, signs of trauma, general appearance, hydration status

• neurologic exam: looking for any focal deficits, Todd paralysis (unilateral weakness occurring in the post-ictal period)

• meningeal irritation, obvious toxidromes

Diagnostic Tests

Based on the information elicited in the history and physical examination, the following laboratory, radiology, and other neurodiagnostic tests may be indicated:

• head CT (trauma)

• serum glucose (hypoglycemia)

• serum electrolyte panel (electrolyte disturbances)

• antiepileptic levels (subtherapeutic levels and/or nonadherence)

• lumbar puncture (meningitis, encephalitis, infectious etiologies)

• urine or serum drug screen (ingestion or toxidrome)

• brain MRI (mass, stroke)

Status Epilepticus

Prolonged seizure activity is a medical emergency. Status epilepticus is defined by either:

• a single seizure lasting >5 minutes OR

• persistent, recurrent seizures without return to baseline mental status

Assessment

The general approach to a child presenting to the ED in status epilepticus is as follows:

1. Establish ABCs and intravenous (IV) access.

• Identify and/or correct any reversible causes.

  • Consider electrolytes including glucose, infection, trauma, subtherapeutic antiepileptic drugs (AEDs), and toxins.

2. Administer first-line antiepileptic:

• First-line treatment is a benzodiazepine.

• If there is no IV access, consider alternative routes of administration (e.g., buccal midazolam or rectal diazepam).

• If patient is still seizing after 5 minutes, a second dose of benzodiazepine can be administered.

• As benzodiazepines cause respiratory depression, providers should be prepared to intubate any patient whose respiratory drive has been excessively depressed by benzodiazepine administration.

3. Administer second-line antiepileptic:

• Second-line treatment is levetiracetam OR phenytoin.

• Reassess 5 minutes after administration.

• If patient is still seizing, prepare for transfer to intensive care unit (ICU) and consult Neurology.

• Consider artificial airway.

4. Administer third-line medication:

• Third-line treatment is phenytoin OR valproate OR levetiracetam.

• Consider artificial airway.

A child who continues to seize despite third-line agents will likely require intubation, benzodiazepine infusion, and electroencephalogram (EEG) monitoring in a pediatric ICU.

Meningitis

Meningitis is inflammation of the membranes covering the brain and spinal cord (meninges). Meningitis can be caused by bacteria and viruses and other infectious and noninfectious processes. Bacterial meningitis is a medical emergency; delayed recognition and treatment can lead to poor neurological outcomes and death.

Epidemiology

The incidence of bacterial meningitis has dramatically decreased during the last three decades since the widespread implementation of the polyvalent pneumococcal conjugate and the Haemophilus influenzae type B (Hib) vaccine.

(Source: Children with Bacterial Meningitis Presenting to the Emergency Department During the Pneumococcal Conjugate Vaccine Era. Acad Emerg Med 2008.)

However, most cases of infectious meningitis are not due to a bacterial pathogen but rather to a viral pathogen. Of viral meningitis cases in children, the vast majority are caused by enterovirus. Other less common etiologies of meningitis include atypical bacterial infections (e.g., tuberculosis and rickettsial diseases, fungal and parasitic infections), and noninfectious causes (e.g., cancer, drugs, autoimmune/inflammatory conditions, and injuries).

Clinical Presentation

The signs and symptoms of meningitis (both bacterial and viral) vary by age group. The “classic” signs of headache, neck stiffness, and photophobia are more common in children older than 2 years:

• infants aged <3 months: lethargy, vomiting, irritability (especially with movement, also known as paradoxical irritability), altered sleep pattern, decreased feeding, fever, bulging fontanelle

• children aged 3 months to 24 months: irritability, fever, lethargy, nuchal rigidity

• children aged >2 years: fever, headache, neck pain, lethargy, nuchal rigidity, irritability

Seizures can be a late manifestation of bacterial meningitis in children and are often prolonged, focal, and recurrent when associated with fever.

Diagnosis

Cerebrospinal fluid (CSF): Meningitis is confirmed by sampling CSF via lumbar puncture. CSF will demonstrate pleocytosis in all cases of meningitis. Additional tests commonly run from the CSF sample include:

• Gram stain and culture

• gram stain will be positive for an organism in about two-thirds of bacterial meningitis cases

• positive cultures for bacteria are considered gold standard for diagnosis

• cell count

• glucose and protein

• additional infectious studies as dictated by patient age and history (e.g., herpes simplex virus [HSV] polymerase chain reaction [PCR]; enterovirus PCR)

Head imaging: Although no established criteria for head imaging prior to lumbar puncture exist for the pediatric population, clinicians generally consider imaging in the following situations:

• focal neurological findings

• concern for mass/malignancy

• papilledema

• immunocompromise

Management

Treatment of meningitis includes empiric antibiotic therapy with broad-spectrum agents that cross the blood-brain barrier and that effectively target the most common bacteria. Even if a viral or other etiology is suspected, most clinicians will continue broad-spectrum antibiotics until no bacterial organism is identified from CSF culture for at least 24 hours.

For more information on meningitis, see Meningitis and Encephalitis in the Pediatric Infectious Diseases guide