Pediatric emergency medicine trisk 102

that a significant apneic episode has not occurred, the patient can be discharged after appropriate counseling of the parents and arrangements for close follow-up The evaluation of a young child with apnea, however, rarely will be so straightforward If historical information indicates that significant apnea has occurred, the infant can be at risk for a recurrence of this potentially lifethreatening event An aggressive search for an underlying cause is necessary and may include laboratory studies, lumbar puncture, chest radiograph, and EKG Hospital admission should be arranged for observation and further diagnostic evaluation A significant apneic episode in the absence of systemic disease leaves the emergency physician in a quandary There may not be an explanation for the event that satisfies the physician or the anxious parents Thus, referral to an available specialist or center may be required There is considerable practice variation in the inpatient evaluation and management of an ALTE The approach that is usually pursued is designed to identify known causes of primary apnea It generally includes in-hospital observation with monitoring, a chest radiograph, and/or an EKG More significant events warrant further evaluation This may include an evaluation of the CNS with an electroencephalogram (EEG), and in some cases, a sleep study Gastroesophageal reflux is often recognized clinically Barium swallow can help identify anatomic abnormalities but are not reliable for the diagnosis of reflux Esophageal probes to measure pH and intraluminal impedance are rarely required, but can be utilized during hospitalization if the diagnosis is unclear An ultrasound can identify hydrocephalus or intraventricular hemorrhage, though a CT or MRI would be indicated if inflicted head injury is suspected Home cardiorespiratory monitoring is beyond the scope of emergency practice, but is not routinely recommended It is for this reason the AAP recommends utilizing BRUE guidelines to minimize practice variation In many instances, a thorough history and careful physical examination will suggest that a significant apneic event has not occurred and that there is no serious underlying illness In this situation, the emergency physician should reassure and educate the family before discharging the patient The parents also should be given specific instructions regarding indications for another emergent ED visit and a close follow-up visit to a primary care provider Suggested Readings and Key References Eichenwald EC; Committee on Fetus and Newborn, American Academy of Pediatrics Apnea of prematurity Pediatrics 2016;137(1) Regenbogen E, Zhang S, Yang J, et al Epidemiological trends among preterm infants with apnea A twelve-year database review Int J Pediatr Otorhinolaryngol 2018;107:86–92 Tieder J, Altman R, Bonkowsky J, et al Management of apparent life-threatening events in infants: a systematic review J Pediatr 2013;163:94–99 Tieder JS, Bonkowsky JL, Etzel RA, et al Brief resolved unexplained events (formerly apparent life-threatening events) and evaluation of lower-risk infants Pediatrics 2016;137:e1–e32 CHAPTER 15 ■ ACUTE ATAXIA JACLYN N KLINE, LUCA BARTOLINI INTRODUCTION Ataxia is defined as impaired coordination of voluntary movements, usually caused in children by cerebellar dysfunction or, less frequently, vestibular or proprioceptive afferent dysfunction While uncommon, acute ataxia in children is important to recognize, because an early diagnosis may have significant therapeutic implications Ataxia is usually associated with other signs of neurologic dysfunction, and the three most common causes of acute ataxia in children are: (1) Acute postinfectious cerebellar ataxia, (2) Drug ingestion, and (3) Guillain–Barré syndrome (GBS) and its variants (Table 15.1 ) HOW TO DIAGNOSE ATAXIA ON NEUROLOGIC EXAMINATION Ataxia can manifest as abnormal timing of contraction of agonist/antagonist muscles (dysrhythmia) and abnormal movement trajectory, resulting in frequent overshooting and overcorrecting (dysmetria) Symptoms and signs often relate to the anatomic location of the cerebellum that is affected by the underlying process Gait and truncal ataxia are observed in diffuse processes and those involving the cerebellar vermis Gait ataxia is the most common presentation and consists of a wide-based gait with inability to walk without support, especially on tandem gait When the deficit is more evident with the eyes closed, sensory or vestibular causes should be considered Young children may just refuse to ambulate Lesions in the cerebellar hemispheres or peduncles are associated with ipsilateral limb ataxia Appendicular ataxia, caused by lesions in the lateral hemispheres of the cerebellum that leads to ataxic movements in the extremities, can be unmasked by performing the rapid alternating movement, finger tapping, and finger-to-nose tests, especially if the examiner’s finger is held at the extreme of the patient’s reach and moved unpredictably Similarly, heel-to-shin test can be done for the lower extremities, but generally requires more cooperation and is rarely feasible in younger patients Overshoot can also be observed when the patient is asked to suddenly raise his outstretched arms from their lap to the level of the examiner’s hand This also allows detection of postural tremor, which is also a cerebellar sign Examination can be affected by the presence of upper or lower motor neuron signs, since weakness can easily be mistaken for ataxia or the two signs may coexist A very useful test that requires little strength to be performed and can help differentiate weakness from ataxia is done by asking the patient to follow one of the creases of her thumb with her index finger Truncal and appendicular ataxia may coexist in the presence of large lesions or diffuse processes Eye movement abnormalities in cerebellar dysfunction may be more difficult to detect; nystagmus is often present, and saccades may under- or overshoot the target Also, speech can be affected, with irregular changes in volume and rate (scanning speech) Ataxia can result from lesions outside of the cerebellum, when the cerebellar afferent or efferent pathways are disrupted, for example by a lesion in the pons, or by lesions in the posterior column - medial lemniscal pathway, which result in positive Romberg sign and loss of joint position sense DIFFERENTIAL DIAGNOSIS AND ROLE OF IMAGING AND LABORATORY TESTS While several diseases can manifest with ataxia (Table 15.2 ), the most common cause of acute ataxia in children with normal mental status is acute postinfectious cerebellar ataxia This condition is usually observed in toddlers (60% of patients in large series were aged between and years) and is characterized by a prodrome of nonspecific viral illness followed after days or up to to weeks by ataxia The clinical course is usually benign, with full return to baseline within months in 70% of children This remains a clinical diagnosis, as imaging and CSF analysis are usually unremarkable; sometimes, especially in younger patients where the examination may not be entirely reliable, brain MRI and lumbar puncture (LP) should be considered to rule out other causes, such as acute disseminated encephalomyelitis (ADEM—see below), because of potential treatment implications In a child with ataxia and abnormal mental status , urgent brain imaging (plain CT head or, ideally, brain MRI if available without significant delay) is warranted, and LP should be considered Imaging, particularly MRI, allows the clinician to rule-out brain tumors, demyelinating conditions, cerebellitis, and stroke CSF pleocytosis (>5 cells/mm3) may be observed in different conditions and while bacterial meningitis is unlikely in an ataxic child without fever or meningismus, viral meningoencephalitis remains a possibility, especially if the pleocytosis is primarily lymphocytic  ... unexplained events (formerly apparent life-threatening events) and evaluation of lower-risk infants Pediatrics 2016;137:e1–e32 CHAPTER 15 ■ ACUTE ATAXIA JACLYN N KLINE, LUCA BARTOLINI INTRODUCTION