Movement Disorders

The human brain generates automatic and intentional movements that support successful achievement of goals necessary for survival, reproduction, and pleasure. The human nervous system is wired to produce some movements without training and many others through training or experience.

A movement disorder is a neurologic condition that results in too much movement (hyperkinetic disorders) or too little movement (hypokinetic disorders) and is not caused by weakness. For example, impaired ability to walk due to dystonia in the leg is a movement disorder. In contrast, impaired ability to walk due to a stroke is not a movement disorder. Movement disorders are generated by structural or signaling dysfunction in the circuits of the brain that include the basal ganglia and the cerebellum. Most movement disorders do not induce symptoms during sleep.

The basic neurologic approach to movement disorders involves first identifying the type of movement disorder. Such recognition is sometimes accomplished through visual pattern recognition. However, understanding principles of normal movement and applying definitions and rules are also helpful. Direct observation of movement phenomenology or observation of videos of the child recorded by caregivers are important. Combining phenomenology (the characterization of movements in a movement disorder) with the time course of the problem (acute, intermittent, chronic) helps to generate both an approach to diagnosis and an approach to treatment.

Diagnostically, key questions are whether “watch and wait,” testing (e.g., neuroimaging, genetic panels, chromosomal microarray, whole exome sequencing), or specialty referral are needed. Specialty consultation or referral may be more efficient than a large battery of diagnostic tests.

Therapeutically, key questions include whether the dysfunctional movement causes sufficient impairment to warrant behavioral therapy, physical or occupational therapy, oral medication, invasive treatment, or surgery.

This review covers movement disorders that are often benign (e.g., acute ataxia, tremor, and tics and stereotypies). Chorea/athetosis/ballism, dystonia, myoclonus, and parkinsonism are beyond the scope of this review, and a patient with such findings should be referred to a pediatric neurologist.

• Acute Ataxia

• Tremor

• Tics and Stereotypies

Acute Ataxia

Ataxia is a disturbance in the performance of voluntary or automatic coordinated movements due to disease in the cerebellum or in its afferent or efferent connections. Ataxia often manifests as “clumsiness” or difficulty with fine-motor tasks, at times accompanied by difficulties with eye movements (e.g., nystagmus), balance, stability of sitting or walking, slurring of speech, or a combination of these.

Acute ataxia indicates duration of less than 72 hours. The most common causes of acute ataxia in children are as follows:

• toxic ingestion

• postinfectious acute cerebellar ataxia

• infectious cerebellitis

Other causes of acute ataxia include:

• acute disseminated encephalomyelitis (ADEM)

• the Miller Fisher variant of Guillain-Barré syndrome (GBS)

• multiple sclerosis, head injury, posterior circulation stroke

• opsoclonus-myoclonus-ataxia syndrome (OMS)

• posterior fossa tumors (usually do not present acutely, but they can, particularly in toddlers)

Symptoms

Key symptoms suggesting the presence of ataxia include:

• staggering

• wide-based gait with frequent falls

• poor balance

• poor maintenance of truncal posture

• uncoordinated fine-motor movements with variable amplitude or rate

• intention tremor (tremor that increases when approaching a target)

• dysmetria (undershooting or overshooting an intended target)

• slurred speech

• nystagmus

• difficulty initiating or targeting rapid eye movements (saccades)

Symptom complexes: The following symptom complexes merit special consideration:

• Altered mental status, somnolence, fever, headache, and ataxia may suggest encephalitis or ADEM.

• Opsoclonus, myoclonus, irritability, and ataxia are hallmark features of OMS, which can be associated with neuroblastoma.

• Eye movement abnormalities and weakness with ataxia are suggestive of the Miller Fisher variant of Guillain-Barré syndrome. Miller Fisher syndrome is a rare, acquired nerve disease that is considered a variant of GBS. It is characterized by abnormal muscle coordination, paralysis of the eye muscles, and absence of the tendon reflexes. Symptoms may be preceded by a viral illness.

• Ocular malalignment (particularly inability to abduct the eyes) and papilledema on examination suggest elevated intracranial pressure, perhaps from an intracranial mass.

History and Examination

History: Important information to include in the history:

• onset of ataxia (can provide clues to etiology)

• associated features (e.g., headache, double vision, neck stiffness, fever, and altered mental status)

• recent infection

• recent trauma

• history of stroke (stroke as a cause of ataxia should be considered in a child with a history of prior stroke or disorders associated with stroke (see Pediatric Stroke in this rotation guide)

• recent ingestion of a toxin (in toddlers, there is often no history of witnessed ingestion)

• list of medications in the household (common medications and substances that can produce ataxia include anticonvulsants, benzodiazepines, alcohol, antihistamines, and heavy metals)

Examination: Important aspects of the exam include:

• Gait: An unsteady gait is a key examination finding in children with ataxia; it is very important to watch the child walk. The child should also be observed sitting or trying to sit unsupported because this may reveal truncal imbalance.

• Speech: Pay close attention to the child’s speech pattern because cerebellar ataxia can cause slurred speech. Ask the parents of young children if they have noticed any changes.

• Specific cerebellar examination maneuvers: These include finger-to-nose testing, toe-to-finger testing, and heel-to-shin testing.

• Eye movements: These include nystagmus, eye muscle paralysis, difficulty initiating saccades, consistently dysmetric saccades, and slow and jerky visual pursuits. Opsoclonus (involuntary, rapid, multidirectional eye movements) is an ominous sign, pathognomonic for OMS.

Laboratory, Imaging, and Diagnosis

Children with acute ataxia are often admitted to the hospital for evaluation and observation for resolution of symptoms versus continued worsening. Workup should be based on clinical presentation and include evaluation for serious conditions that can cause ataxia. Postinfectious acute cerebellar ataxia is the most common cause of acute ataxia and is a diagnosis of exclusion.

• Urine drug screening is useful even without a history of ingestion. Urine for a drug screen is simple to obtain, inexpensive, and should be performed routinely in all children who present with acute ataxia. Serum toxicology screening is also reasonable.

• Neuroimaging is recommended. MRI of the head without and with intravenous (IV) contrast is usually considered to be appropriate in children with acute ataxia and no history of recent trauma. Initial imaging with CT of the head without IV contrast is also acceptable. Contrast is usually not needed in patients with a history of recent trauma.

• Lumbar puncture is helpful in the evaluation of infectious or postinfectious causes of ataxia (it may show elevated leukocyte count) and of Miller Fisher syndrome (elevated cerebrospinal [CSF] protein with normal or comparatively mild elevation in leukocyte count).

• Nerve conduction study/electromyography (NCS/EMG) can be useful in diagnosing GBS.

• Abdominal imaging to evaluate for possible neuroblastoma is warranted in children with OMS. Consultation with neurology is advised.

Treatment

Cerebellar ataxia: No medications are available to treat or improve ataxia as a symptom. Treatment of an underlying condition may be helpful.

Postinfectious acute cerebellar ataxia is associated with a good prognosis and relatively quick recovery. Treatment is supportive. Physical and occupational therapy may be helpful. Some clinicians prescribe high-dose glucocorticoids, but data are limited on the use of glucocorticoids in this condition. Most patients show at least some recovery in the first week, with full recovery within a few months.

Ataxia due to toxic ingestion is usually associated with quick recovery, within hours to days, without any specific treatment.

Meningitis/encephalitis: Standard antibiotic and antiviral protocols are used for the treatment of acute infections. Inflammation within the central nervous system, particularly in the posterior fossa in cases with cerebellitis, can result in cerebral herniation and death.

ADEM and Miller Fisher variant of GBS are treated with immunomodulatory treatments, including glucocorticoids, intravenous immunoglobulin (IVIG), plasmapheresis, or a combination of the three.

Tremor

Tremor is a common movement disorder in children. Tremor is a rhythmic, oscillatory movement that is involuntary and often affects the extremities but can also affect the head, voice, and trunk. Tremor has many causes.

Evaluation

History and physical examination: A thorough history and physical examination is important in the evaluation of patients with tremor. Important clinical features include:

• age of onset

• involved body parts

• progression of tremor since onset

• when the tremor occurs

• how the tremor affects functioning

• other associated neurologic symptoms

• a complete list of medications (many medications cause tremor)

• family history of tremor

Classification: Physical examination should focus on classifying and describing the tremor as well as evaluating for other neurologic signs. Tremor is classified by whether it is present at rest or during actions.

• Resting tremor should be assessed with the patient sitting with hands in lap, palms up, with arms fully supported. The presence of tremor at rest is unusual in a child and is an indication for neurologic consultation.

• Action tremor

  • Postural tremor is assessed with arms fully extended in front, with palms down and fingers spread wide. The examiner should look for tremor and characterize it as regular and symmetric, asymmetric, or irregular and jerky. Jerky tremors are more likely to be associated with dystonia and warrant neurologic consultation. Similarly, any unusual posturing of the hands or hyperextension at the metacarpophalangeal joints should also be documented and referral considered.

  • Intention tremor is assessed with finger-to-nose testing. Intention tremor is noted to increase as the finger approaches the target.

The most common tremors encountered in children are enhanced physiological tremor and essential tremor.

• Physiological tremor is a benign finding in the general population characterized by a mild, usually bilateral postural or action tremor in the frequency of 8-12 Hz. These tremors are enhanced by anxiety, caffeine, stimulant medications, fasting, and physical exercise. Many people who have physiological tremor do not realize that they have a tremor or do not seek medical attention because it does not cause any dysfunction.

• Essential tremor is a tremor syndrome of the bilateral upper extremities and sometimes head, voice, or lower limbs in the absence of other neurologic signs. Essential tremor is a postural or intention tremor, or both. Onset of essential tremor peaks in the teenage years and in middle age. Patients often have a family history of essential tremor, but family history is not necessary for the diagnosis. Mild essential tremor does not require treatment, but severe essential tremor can be quite disabling, and tremors that affect functioning should be treated.

  • Propranolol and primidone are the most commonly used medications for the treatment of essential tremor. Propranolol should be avoided in children with severe asthma, diabetes, heart failure, or significant depression, as it can exacerbate these conditions.

Referral

Referral to neurology is recommended for patients with the following tremors:

• resting tremor

• asymmetric tremor

• tremor with unusual/dystonic posturing

• irregular, jerky tremor

• tremor with cerebellar findings (e.g., eye movement problems, dysmetria, or gait problems)

• functionally impairing postural or intention tremors

Tics and Stereotypies

Tics

Definition: Tics are patterned movements or vocalizations that look or sound the same each time that they occur. They may occur involuntarily or automatically, but sometimes they occur in response to uncomfortable premonitory urges or sensations. Tics can usually be suppressed or postponed, at least briefly, and tend to subside during purposeful movements of the same body region.

Presentation: The onset of tics is usually in childhood, after age 3 years. Early tics are usually “simple” and involve a limited number of muscles or body areas. Typical simple motor tics include blinking, eyes rolling or moving to the side, facial grimacing or scrunching, mouth gaping, head jerking, and shoulder shrugging. Typical simple phonic or vocal tics include sniffing, throat clearing, coughing, and grunting.

Diagnosis: The following are typical tic diagnoses:

• Provisional tic disorder is characterized by one or more brief bouts of tics in childhood, lasting less than one year, with the most recent bout in the past year.

• Transient tic disorder consists of one or more brief bouts of tics in childhood, lasting less than one year, with the most recent bout more than one year prior.

• Tourette syndrome is characterized by at least two different motor tics and one phonic or vocal tic that emerge and persist continuously, but not necessarily concurrently, for one year or more, with onset before age 18 (usually before age 10 years). Note that common phonic tics (e.g., sniffing, coughing, or throat clearing) can be under-recognized.

• Chronic motor/vocal tic disorder is the same as Tourette syndrome but involves either motor or vocal tics.

• Tics associated with autism spectrum disorder, obsessive-compulsive disorder (OCD), or anxiety are common in children with these or other developmental, behavioral, or psychiatric diagnoses.

• Drug-induced tics are one of several movements that can be triggered or unmasked by neurologic, psychiatric, or illegal drugs.

• Tics due to neurodegenerative disorders occur in the context of more-diffuse and -progressive neurologic problems.

Diagnosis: Formal diagnostic criteria from the Diagnostic and Statistical Manual of Mental Disorders(DSM-5 and prior) are based on history and observation. No medical diagnostic testing is needed in the vast majority of cases (no laboratory tests, electroencephalogram [EEG], or MRI).

Approximately 85% of children with a chronic tic disorder meet criteria for at least one comorbid behavioral or psychiatric diagnosis, the most common of which are attention deficit-hyperactivity disorder (ADHD) and OCD. Clinical presentation of tics should cue the physician to screen for these other diagnoses.

Management: Correct diagnosis, education, and anticipatory guidance are important. Managing peer interactions and parental expectations are also vital. Advocacy websites can be extremely helpful in severe cases. In a large proportion of cases, symptoms do not cause sufficient impairment to warrant medication. In terms of anticipatory guidance, tics in Tourette syndrome generally peak in frequency and severity in the later elementary or middle school grades, at which time they may be associated with social stigma. Affected children should be counseled to be honest with peers about the presence and usually benign nature of the symptoms. Bullying can be a problem for affected children but is less likely when children fit in socially in other ways (e.g., participation in extracurricular activities).

Treatment can be helpful when tics cause pain, functional interference, or social problems. Cognitive behavioral/habit-reversal training (Comprehensive Behavioral Intervention for Tics [CBIT]) can be utilized through a trained provider but is less helpful when anxiety or sensory urges are overwhelming. Medications approved by the U.S. Food and Drug Administration (FDA) include haloperidol, pimozide, and aripiprazole. However, due to the unfavorable adverse effect profiles of these medications, lower-risk medications such as guanfacine are often used off-label by primary care physicians. In the presence of refractory tics or impairing co-occurring diagnoses, referral to a specialist may be helpful.

Stereotypies

Stereotypies are patterned, repetitive, involuntary, purposeless, continuous movements that start in early childhood, occur in certain body areas, and last for months to years. Unlike tics, stereotypies are not accompanied by an urge to perform the movement. While most early tics are simple and involve the face, stereotypies often involve the hands or whole body. Tics often change over time, while stereotypies remain the same, or evolve minimally, throughout childhood and even into adulthood.

Common stereotypies include:

• hand and arm flapping

• rocking of the body

• clenching or stiffening of the body

• grimacing

• bringing hands up in front of the face

• a combination of these movements

Stereotypies can occur in any setting but often occur more frequently when children are excited, stressed, fatigued, engrossed, or bored. Sometimes children outgrow stereotypies, and other times they continue into adolescence and adulthood but become less frequent and more manageable. Children who are old enough to talk about their stereotypies sometimes report that the movements feel good. Stereotypies can be associated with autism, intellectual disability, or sensory deficits such as blindness, but they often occur in otherwise typically developing children.

Etiology: The cause of stereotypies is unknown. In a study of 100 children with unremarkable growth and development and stereotypies, 25% of the subjects had a family history of stereotypies, suggesting a genetic component.

Diagnosis: Stereotypies are sometimes misdiagnosed as seizures, tics, or both. Unlike many types of seizures, stereotypies are not associated with alterations in consciousness. Confusion may arise because some children dissociate from their surroundings and seem “unresponsive” while performing stereotypies. It is helpful to advise the caregiver to administer a strong tactile stimulus to ascertain interruptible nature of the episodes. Diagnosis is made by direct observation or observation of episodes recorded on a caregiver’s phone. EEGs and other testing are rarely needed.

Management: Stereotypies do not need to be treated and usually do not cause significant distress to the young child. As typically developing children mature, they often gain the ability to self-monitor more effectively and thereby inhibit stereotypies in social settings. Habit-reversal training may be considered in children and adults who wish to reduce or gain greater control over these movements.