Approach to Acute Ataxia in Childhood: Diagnosis and Evaluation Lalitha Sivaswamy, MD

FEATURE Approach to Acute Ataxia in Childhood: Diagnosis and Evaluation Lalitha Sivaswamy, MD opsoclonus myoclonus ataxia syndrome, must receive special mention because the underlying disease process may be ame- nable to surgical intervention. In the toddler- and school-age groups, certain conditions (such as stroke and acute cerebellitis) require immediate recognition and imaging, whereas others (such as post-infectious ataxia and concussion) require close follow-up. Finally, mention must be made of diseases outside of the central nervous system that can present with ataxia, such as Guillain-Barré syndrome. he word ataxia is derived from the Greek word ataktos, which T means “lack of order.” Ataxia is characterized by disturbances in the voluntary coordination of posture and movement. In children, it is most prominent during walking (the sine qua non being a staggering gait with impaired tandem), but it can also be present during sitting or standing, or © Shutterstock when the child is performing move- Abstract Lalitha Sivaswamy, MD, is Associate Profes- ments of the arms, legs, or eyes. sor of Pediatrics and Neurology, Department Ataxia refers to motor incoordination that is This review focuses on the etiol- of Neurology, Wayne State University School of usually most prominent during movement ogy and diagnostic considerations for Medicine; and Medical Director, Headache Clinic, or when a child is attempting to maintain a acute ataxia, which for the purposes of Children’s Hospital of Michigan. sitting posture. The first part of the review this discussion refers to ataxia with a Address correspondence to: Lalitha Sivas- focuses on the anatomic localization of symptom evolution time of less than wamy, MD, Department of Neurology, Wayne ataxia — both within the nervous system 72 hours.1 State University School of Medicine, Children’s and without — using a combination of his- Motor coordination requires sensory Hospital of Michigan, 3901 Beaubien, Detroit, MI torical features and physical findings. The input from muscles and joints. This sen- 48201; email: [email protected]. remainder of the review discusses etio- sory information is transmitted through Disclosure: The author has no relevant finan- logical considerations that vary depending myelinated axons, via the posterior cial relationships to disclose. on the age group under consideration. In columns of the spinal cord, to higher doi: 10.3928/00904481-20140325-13 infancy, certain specific diseases, such as centers in the cortex and basal ganglia. PEDIATRIC ANNALS 43:4 | APRIL 2014 Healio.com/Pediatrics | 153 FEATURE tions that may require immediate intervention. Presence of confusion, hallucinations, mood disturbances, or somnolence must be noted. Such symptoms may indicate toxic ingestion, demyelinating diseases such as acute disseminated encephalomyelitis (ADEM), stroke, or meningo-encephalitis. The presence of papilledema, pupillary dila- tion, and lateral rectus palsy indicates elevated intracranial pressure. Motor examination should focus on eliciting weakness in an anatomically significant pattern, such as one-half of the body or both lower extremities. Often, a younger child with hemiparesis or paraparesis will present with ataxia as opposed to focal weakness of the affected body part (ie, “paretic ataxia”). A detailed cerebellar exam should follow. Dysfunction of midline cerebellar structures causes truncal ataxia and head tremor. Disorders of the lateral aspects of the cerebellum cause limb Image courtesy of Lalitha Sivaswamy, MD. Image courtesy of Lalitha Sivaswamy, ataxia, which can be evaluated by the Figure 1. Fluid-attenuated inversion recovery (FLAIR) magnetic resonance imaging (MRI) demonstrating left cerebellar demyelinating lesion in a teenager with acute-onset ataxia. Similar lesions are noted in the finger-nose or finger-finger test, inten- cortex, as well. A final diagnosis of multiple sclerosis was made on the basis of imaging and investigations. tion tremor, and dysdiadochokinesia. In the lower extremity, one can perform These central structures generate their such as musculoskeletal pathology, can the heel-shin test to look for incoordina- modulating output, which is conveyed lead to clumsy gait. There are no clear tion. Cerebellar incoordination tends to through motor tracts that lay in the brain data regarding incidence or gender pre- be most prominent when movements stem and spinal cord and then conveyed diction of acute ataxia in the pediatric are performed slowly. Ataxia caused by through peripheral nerves to the rel- age group. pathology of the cerebellum is not ex- evant muscle groups, thereby closing acerbated by eye closure; therefore, a the action loop. The cerebellum exerts CLINICAL EVALUATION Romberg test will be negative. a modulating control at various lev- History Presence of nystagmus should be not- els of this loop. Furthermore, the ves- Important questions about patient ed with relevant details. Nystagmus may tibular system in the inner ear monitors history that may lead to an etiology arise from pathology in the vestibular angular and linear accelerations of the are summarized in Table 1. As can system (“peripheral” type) or the central head. This information is also conveyed be seen, there is significant overlap nervous system (“central”). Certain spe- to the cerebellum, which utilizes this in symptomatology between different cific types of nystagmus, such as opsoc- feedback to maintain posture.2 Ataxia disease states, so it may be difficult to lonus, may rarely be noted. can, therefore, arise from disturbances distinguish “central” from “peripheral” Finally, a comprehensive sensory in various parts of the nervous system causes by history alone. Symptom on- exam and an examination of deep ten- (eg, the cerebellum, brain stem, spinal set may occur in just a few minutes or don reflexes should be performed to rule cord, and peripheral nerves), as well over the course of hours or days. out diseases of peripheral nerves or roots as the inner ear (Figure 1). To equate (ie, “sensory” ataxia). Plantar responses ataxia with disease of the cerebellum Physical Examination are not affected by diseases of the cer- alone is, therefore, inaccurate. Finally, Physical examination should focus ebellum; hence, a positive Babinski test certain non-neurological conditions, on identifying life-threatening condi- is indicative of disease processes in the 154 | Healio.com/Pediatrics PEDIATRIC ANNALS 43:4 | APRIL 2014 FEATURE TABLE 1. Questions about Patient History that May Lead to an Etiology of Ataxia History Potential Etiology Localization of Disease Headache Basilar migraine Brain stem Frontal/temporal Space-occupying lesion* Cerebellum Occipital Acute onset in an unsupervised toddler or following Ingestion of toxins a fall Cerebellar concussion Brain Basilar migraine, stroke† Brain stem, cerebellum Space-occupying lesions* Posterior fossa Vomiting Concussion Benign paroxysmal vertigo Labyrinth ADEM Brain stem Recent history of fever, rash, gastrointestinal illness, Acute post-infectious cerebellar ataxia Cerebellum infectious contacts Acute cerebellitis† Cerebellum Kawasaki disease, polyarteritis nodosa, Henoch-Schöenlein purpura Guillan-Barré syndrome† Spinal roots and nerves Recent immunizations Acute post-infectious cerebellar ataxia Acute post-infectious cerebellar ataxia Cerebellum Recent history of viral illness Acute cerebellitis† Cerebellum Miller-Fisher syndrome Brain stem Benign paroxysmal vertigo Peripheral vestibular system Neuroblastoma* Sympathetic ganglia Nystagmus Multiple sclerosis Brain stem Drug ingestion Stroke† Brain stem, cerebellum Head or neck trauma in an adolescent (eg, during ski- Stroke Brain stem ing, diving, martial arts) Cerebellar concussion Cerebellum Post-ictal ataxia Brain Seizures Drug overdose Fluctuating drug levels ADEM Brain, spinal cord Encephalopathy (drowsiness, confusion, aggression, Multiple sclerosis Brain, spinal cord psychosis) Drug ingestion Benign paroxysmal vertigo Brain stem Dizziness (true vertigo, spinning sensation) Basilar migraine Brain stem Stroke† Cerebellum or brain stem Previous self-limiting episodes with family history Genetic episodic ataxias Not known History of emotional trauma Psychogenic Not applicable *Indicates conditions that are unlikely to present in an acute fashion. †Indicates conditions that require immediate attention. ADEM = acute disseminated encephalomyelitis. PEDIATRIC ANNALS 43:4 | APRIL 2014 Healio.com/Pediatrics | 155 FEATURE upper motor neuron pathway, outside of initial presentation, with relatively rapid differs from APCA by the presence, in the cerebellum. resolution over the next few days. The some cases, of systemic symptoms such mental status usually remains clear as fever and neck stiffness, symptoms ETIOLOGY ON THE BASIS OF AGE throughout the course of the illness. The and signs of raised intracranial pressure Infancy presence of extreme irritability should due to rapid compression of the fourth Opsoclonus Myoclonus Ataxia Syndrome raise suspicion about the diagnosis. ventricle, and risk of death; there- Opsoclonus myoclonus ataxia Examination reveals a pure cerebel- fore, there is a pressing need for early (OMA) syndrome can present as early lar syndrome with marked involvement therapy. There is considerable overlap as age 6 months. OMA syndrome is a of gait and significant truncal ataxia. between APCA and acute cerebellitis, paraneoplastic autoimmune phenom- so it may be difficult to distinguish be- enon characterized by chaotic

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