Inborn errors of metabolism (IEM) are inherited disorders characterized by abnormalities in enzyme or other cellular proteins involved in metabolism. These are relatively common problems, often possessing both systemic issues and coexisting movement disorders. Approximately one-third of patients with an IEM have a movement abnormality. , The most common movements described include dystonia, ataxia, and myoclonus. Approached in a different way, about 20% of children with…

Introduction and Overview This chapter focuses on the clinically and genetically heterogeneous neurodegenerative disorders known as hereditary spastic paraplegias (HSPs), emphasizing those that may begin in childhood. The primary feature of these diseases is bilateral leg spasticity when walking. , Specifically, this results from progressive pathology within axons in the corticospinal tracts and the dorsal columns of the spinal cord. The evaluation of gait disturbances is…

Introduction and Overview Parkinsonism is a constellation of signs and symptoms that are characteristically observed in Parkinson disease (PD), but that are not necessarily due to PD. Parkinsonism, sometimes referred to as hypokinetic-rigid or akinetic-rigid syndrome, is the primary type of hypokinetic movement disorder. As discussed elsewhere in this text, hyperkinetic movement disorders are far more common in children than is parkinsonism. Parkinsonism can arise from many different…

Introduction and Overview This chapter encompasses diseases and disorders of the cerebellum and its connections that cause problems coordinating movements. A vast number of conditions adversely affect cerebellar function in children, and thus, a systematic approach to diagnosis is helpful. These present to neurologists as referrals for clumsiness, balance problems, gait problems, tremor, poor coordination, and abnormal eye movements. The diagnoses can be classified broadly. A…

Introduction and Overview Tremor is common in children and adults. Prevalent forms, such as essential tremor (ET), have been well-studied in adults, but in children are less well characterized. , Tremor in children most frequently occurs in the hands, but other body parts, such as head, voice, legs may be also affected. Tremor may be isolated , meaning that pathophysiology is related to relatively isolated dysfunction…

Introduction and Overview This chapter discusses diseases and disorders where myoclonus is a prominent feature or may be prominent in some cases. These include genetically determined as well as acquired conditions. Myoclonic movements are quick muscle jerks, and thus startle/hyperekplexia, tics, and functional (psychogenic) jerks are often diagnostic possibilities. In pediatric neurology practice, myoclonus seldom occurs in isolation. Most myoclonus occurs in children who have epilepsy…

Introduction and Overview The term “dystonia” appears to have been first used when Oppenheim applied the description “dystonia musculorum deformans” in 1911 to a progressive childhood-onset syndrome characterized by twisted postures, muscle spasms, bizarre walking with bending and twisting of the trunk, and eventually fixed postural deformities. Wilson argued against the term dystonia, because he viewed the disorder as one of movement and not of tone.…

Introduction and Overview This chapter discusses diseases and disorders where chorea, athetosis, and ballism are prominent. Chorea, athetosis, and ballism are nonpatterned, hyperkinetic movement disorders which overlap and cannot be defined precisely as mutually exclusive phenomena. However, they are characterized by some salient features. Some authors place these hyperkinetic disorders on a continuum based on amplitude, velocity, and distribution: ballism → chorea → athetosis. In practice,…

Introduction and Overview Paroxysmal dyskinesias represent a group of hyperkinetic movement disorders that are characterized by episodes of abnormal movements that occur intermittently and unpredictably out of a background of normal activity. The specific type of dyskinesia may be dystonia, chorea (including ballism), or a combination of these and other hyperkinesias. Although many types of movement disorders in childhood are paroxysmal in nature, paroxysmal dyskinesias comprise a…

Introduction and Overview The definition, characteristics, classification, pathophysiology, disorders, and treatment of motor stereotypies continue to evolve. Historically, stereotypic movement disorders in children have been linked to autism and intellectual impairment, although they commonly occur in typically developing children. Motor stereotypies can be readily classified into two groups: “primary,” indicating an otherwise typically developing individual, and secondary, for those associated with other neurodevelopmental problems (e.g., autism).…

Introduction Tourette syndrome (TS), listed in the Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5) as Tourette disorder (TD), is named after the French physician Georges Gilles de la Tourette, who in 1885 reported nine patients with a condition he referred to as “maladie of tics.” Prior to the report, motor and vocal tics had been described in the setting of witchcraft, in historical…

Introduction The presence of a movement disorder in a child usually raises concerns about an underlying serious, progressive, degenerative, or metabolic disease. However, many movement disorders are benign and related to normal stages of development. In fact, it may be difficult to justify the term “disorder” in describing many of these movements. The developing nervous system may produce a variety of motor patterns that would be pathological…

Introduction Clinical assessment of movement disorders requires careful visual observation in order to fully characterize the phenomenology and the severity of the disorder. The definitions presented in Chapter 3 and detailed characteristics of individual movement disorders provided in Chapter 7, Chapter 8 and 10–16 rely on descriptions of characteristic spatial and temporal properties of both voluntary and involuntary movements in the specific disorders. Pattern recognition can…

Introduction The approach to the diagnosis of a pediatric movement disorder often overlaps with other areas of pediatric medicine in requiring a careful medical, developmental, family, and social history and comprehensive physical examination. An additional requirement, however, is the need to observe, either in person or via video, and characterize the phenomenology of the disordered movement. While technological advances such as neuroimaging and rapid genome sequencing…

Introduction Movement disorders are neurological syndromes that involve impaired performance of voluntary movements, dysfunction of posture, the presence of abnormal involuntary movements, or the performance of normal-appearing movements at inappropriate or unintended times. The abnormalities of movement are not due to weakness or abnormal muscle tone but may be accompanied by weakness or abnormal tone. By convention, movement disorders are divided into two major categories. The…

Introduction and Overview The objective of this chapter is to provide an overview of the basic anatomic and functional organization of the cerebellum and its inflow and outflow pathways as they relate to motor function and diseases affecting motor control. Understanding structures, pathways, circuits, and receptor systems will gain increasing importance to pediatric neurologists as insights are gained into disease pathophysiology and options for treatments emerge.…

Introduction The basal ganglia are large subcortical structures comprising several interconnected nuclei in the forebrain, diencephalon, and midbrain. Historically, the basal ganglia have been viewed as a component of the motor system. However, there is now substantial evidence that the basal ganglia interact with all of frontal cortex and with the limbic system. Thus, the basal ganglia likely have a role in cognitive and emotional function…