23 Pediatric Movement Disorders

HUNTINGTON’S DISEASE 209 SYDENHAM’S 210 MUSCULORUM DEFORMANS 212 TIC DISORDERS 213

Huntington’s Disease • Hallervorden-Spatz disease. Huntington’s disease is a progressive degenerative dis- order with an autosomal dominant pattern of transmis- Vignette sion. The clinical manifestations in children are domi- nated by cognitive and behavior abnormalities, rigidity, An 8-year-old girl became irritable, apathetic, dis- loss of facial expression, decreased voluntary move- tractible, and lost interest in her schoolwork and ments, and . In the majority of childhood-onset dance classes. She was noted to have sudden jerk- cases there is an affected father. ing movements in her arms and started experienc- Wilson’s disease, which always needs to be ruled out ing generalized tonic-clonic seizures. A year later in a child presenting with signs of extrapyramidal system she was more withdrawn, not following questions dysfunction is an autosomal recessive disorder character- or commands, sometimes remaining in a catatonic ized by the accumulation of copper in the liver, basal posture. On examination, there was rigidity with ganglia, and cornea. Younger children usually present loss of facial expression. Her prior developmental with signs and symptoms of significant liver dysfunction history was unremarkable. She had no siblings. Her rather than neurological involvement. Neurological man- father had involuntary movements and grimacing ifestations, with only minimal symptoms of liver disease, and was demented. are more likely when the onset of symptoms is in the second decade (Fenichel). Speech abnormalities with Summary An 8-year-old girl with progressive cognitive dysarthria as well as dystonia and gait distur- impairment associated with seizures and parkinsonian bances are often the presenting neurological symptoms. features (rigidity, loss of facial expression). In the family Emotional lability and psychosis can also be the initial history, her father has , facial grimacing, and feature, but seizures and marked dementia are not usually involuntary movements. a significant characteristic of the disease except in few cases. Localization and Differential Diagnosis Hallervorden-Spatz disease is a familial disorder that The vignette describes an extrapyramidal disorder that manifests with signs of involvement of the extrapyrami- occurs during childhood and is associated with progres- dal system such as rigidity, dysarthria, , sive dementia and seizures. and gait dysfunction, in association with signs of pyra- The family history with a father affected by dementia midal involvement such as spasticity and hyperreflexia. and involuntary movements suggests a hereditary domi- Behavioral abnormalities and cognitive impairment can nant disorder. Among the hereditary, predominantly ex- occur and visual abnormalities such as retinitis pigmen- trapyramidal, syndromes occurring during late child- tosa and optic atrophy can also be present. Seizures are hood and adolescence the following should be considered not common. Typical pathological findings include hy- first: perpigmentation of the pallidum and substantia nigra. Other extrapyramidal disorders such as idiopathic tor- • Childhood and juvenile forms of Huntington’s sion dystonia, familial calcification of the basal ganglia, disease. juvenile paralysis agitans, chorea-acantocytosis, and so • Wilson’s disease. on are easily differentiated by their clinical features.

209 210 23. Pediatric Movement Disorders

Considering the information presented in the vignette, emotional, and fidgety. Irregular jerking move- Huntington’s disease is the preferred diagnosis. ments of her distal upper extremities and face were noted, and she seemed particularly troubled when Clinical Features eating, drinking from a cup, or writing. Her family and developmental histories were normal. Six Huntington’s disease (HD) in the pediatric population months earlier, while still in Mexico, she had ex- usually presents in the first decade of life (between 5 and perienced knee pain and swelling accompanied 12 years of age) with symptoms characterized by behav- with fever. Her family reported no other medical ioral and cognitive deterioration, rigidity, dystonia, and history. seizures. Seizures, which are usually not observed in adult pa- Summary A 10-year-old girl with onset of involuntary tients with HD, can be a prominent initial manifestation movements and prior history of knee pain, swelling, and and may affect about 50 percent of children with HD fever. (Menkes). Epileptic seizures can be represented by tonic- clonic convulsions, absence, and myoclonic seizures. Tonic-clonic or myoclonic status can also occur. Localization and Differential Diagnosis Rigidity causing gait disturbances is common, and The involuntary, irregular jerking movements that inter- dystonia, loss of facial expression and associated move- fere with activities such as writing or feeding in this pa- ments, and decreased voluntary movements are signifi- tient, plus the fidgety, restless, and overemotional behav- cant features in the majority of pediatric patients. Cho- ior observed by her teacher most likely are indications of reoathetosis and hyperkinesia are not common in the a choreic disorder. Childhood chorea can be attributed to pediatric age group with HD. various etiologies: Mental deterioration with progressive dementia is an important characteristic feature. Behavior abnormalities • Infectious disorders, such as Sydenham’s chorea, diph- manifest with irritability, distractibility, emotional labil- theria, viral , and so on. ity, negativism, and even catatonia. Most of childhood- • Immunological disorders, such as systemic lupus ery- onset cases have inherited the gene from an affected fa- thematosus, periarteritis nodosa, and sarcoidosis. ther. The HD gene has been localized to the short arm of • Drug-induced causes, such as related to the use of neu- chromosome 4 and contains an abnormal repeat of the roleptics, anticonvulsants, and so on. trinucleotide CAG (cytidine-adenine-guanidine). • Toxic causes, such as due to manganese, carbon mon- oxide, toluene, and alcohol. Diagnosis • Metabolic and endocrine disorders, such as hypogly- cemia, hyperglycemia, hypocalcemia, hyperthyroid- The diagnosis is based on the clinical features and family ism, and Addison’s disease. history. Neuroimaging studies demonstrate caudate atro- • Structural disorders, such as tumors and arteriovenous phy and PET studies reveal significant reduction in cau- malformations. date glucose metabolism. DNA analysis detects the ab- • Bilateral cerebral dysfunction, such as postanoxia. normal gene. • Genetic and hereditary degenerative disorders, such as childood Huntington’s disease, Hallervorden-Spatz Treatment disease, Lesch-Nyhan syndrome, and so on.

The treatment is symptomatic and is based on the use of Sydenham’s chorea (St. Vitus’ dance) is a well-known anti-parkinsonian medications to control rigidity and dys- choreic sequelae of infection with group A streptococcus. tonia. Behavioral abnormalities may respond to neurolep- It affects children between 5 and 15 years of age, par- tics. The use of (GABA agonist) and diltiazem ticularly females. A beta-hemolitic streptococcal infec- (calcium-channel blocker that might block the action of tion of the pharynx may occur 1 to 7 months prior to the glutamate on calcium channels) is controversial. onset of the neurological manifestations in most patients. The movements are typically choreoathetoid and prefer- entially involve the face and upper extremities, unilater- Sydenham’s Chorea ally or bilaterally. Sydenham’s chorea, polyarthritis, and carditis are important features of rheumatic fever, the re- sult of an antecedent group A streptococcal pharyngeal Vignette infection. A prior history of pharyngitis is not always given by the patient and families. The duration of the A 10-year-old Mexican immigrant was reported by chorea varies from three months to two years. her teacher as being restless, inattentive, over- Other infectious processes that can be responsible for Sydenham’s Chorea 211 the occurrence of chorea include bacterial, such as sub- • Hallervorden-Spatz disease is a rare autosomal reces- acute bacterial endocarditis, neurosyphilis, diphtheria, tu- sive disorder of iron metabolism, manifesting with berculosis, Lyme disease, and viral infections, such as choreic movements, , dystonia, rigidity, cog- , mononucleosis, HIV, Epstein-Barr, nitive impairment, retinitis pigmentosa, seizures, and varicella, pertussis, and so on. so on. Immunological causes of chorea include, in particular, • Pelizaeus-Merzbacher disease is an X-linked recessive systemic lupus erythematosus, Behc¸et’s disease, disorder of myelin formation characterized by invol- Schonlein-Henoch purpura, antiphospholipid antibodies untary movements with chorea or athetosis, cerebellar syndrome, and so on. Systemic lupus erythematosus in ataxia, pendular nystagmus, developmental regression, children can manifest with psychosis, seizures, cranial spasticity, optic atrophy, and so on. neuropathy, and rarely with chorea as the only presenta- • Fahr’s disease, or familial calcification of the basal tion. The presence of systemic symptoms such as fever, ganglia, manifests with choreoathetosis, mental im- rash, lymphadenopathy, hematuria, albuminuria, and so pairment, microcephaly, and seizures. There is pro- on, and laboratory studies, particularly antibodies against gressive calcification of the basal ganglia. DNA, help confirm the diagnosis. • Neuroacanthocytosis is characterized by chorea in as- Drug-induced causes are now considered the most sociation with seizures, orolingual dystonia, and acan- common cause of chorea in children (Robertson et al.). thocytosis (acanthocytes are abnormal erythrocytes Among the drugs, neuroleptics, anticonvulsants, anti- that have thorny projections from the cell surface). emetic, noradrenergic stimulants, and so on, can be in- • Ataxia-telangiectasia is a hereditary autosomal reces- cluded. Tardive indicates a condition associ- sive disorder clinically characterized by progressive ated with the use of neuroleptics and characterized by ataxia, telangiectasias, and recurrent sinopulmonary in- abnormal involuntary movements such as choreic move- fections. Choreoathetosis can also be observed, par- ments involving the face and limbs. Withdrawal emergent ticularly in infants. syndrome (Robertson et al.) refers to the first appearance • Benign familial hereditary chorea is an autosomal of involuntary movements and chorea after interruption dominant hereditary disorder manifesting with chorea, of neuroleptic treatment. dysarthria, and normal cognitive function. Toxic agents that may induce chorea include carbon • Genetic metabolic disorders such as GM1 and GM2 monoxide, thallium, toluene (glue sniffing), and so on. gangliosidosis, , lipofuscinoses, and so Metabolic and endocrine disturbances can also cause sec- on, can also include chorea in their symptomatology. ondary chorea. Electrolyte disturbances such as hypo- glycemia, hyperglycemia, hypocalcemia, hypomangane- Hereditary paroxysmal need also to be semia, and hepatic and renal failure can be responsible mentioned: for secondary chorea. The endocrine disorders primarily • Paroxysmal dystonic choreoathetosis is an autosomal include hyperthyroidism, but also hypoparathyroidism, dominant hereditary disorder that manifests with epi- Addison’s disease, and so on. Some vitamin deficiencies sodes of choreic movements and dystonia of various such as vitamin B , beriberi, and pellagra can present 12 duration from minutes to hours. with chorea. • Familial paroxysmal kinesiogenic choreoathetosis is a Chorea can also be secondary to diffuse cerebral dys- hereditary disorder characterized by brief, recurrent ep- function due to perinatal anoxia or decreased cerebral isodes of unilateral choreoathetosis precipitated by a perfusion due to postcardiopulmonary bypass. Structural sudden movement (Robertson). cerebral lesions like tumor, arteriovenous malformations or cerebrovascular accidents can also present with chorea. Trauma has also been involved in some cases. Clinical Features Hereditary degenerative disorders manifesting with Sydenham’s chorea represents a late sequelae of group A chorea include the following: streptococcal pharyngitis. The neurological manifesta- • Juvenile Huntington’s disease, as previously described, tions usually tend to present one to six months after the is an autosomal dominant disorder usually transmitted streptococcal infection. Affected children range from 5 to by the affected father and characterized by progressive 15 years of age and are preferentially girls. The disorder cognitive impairment, rigidity, seizures, and choreo- manifests insidiously or acutely with involuntary move- athetosis. ments that involve the face and distal part of the upper • Wilson’s disease is an autosomal recessive disorder of extremities. The involuntary movements disappear dur- copper metabolism characterized by hepatic failure and ing sleep or sedation. The child is first noted to be restless, neurological features particularly involving the extra- clumsy, and fidgety. The speech becames dysarthric, and pyramidal system with tremor, rigidity, dystonia, dys- hypotonia may create abnormal postures. The hand grip arthria, choreoathetosis, and so on. waxes and wanes when the child is asked to squeeze the 212 23. Pediatric Movement Disorders examiner’s hand, a phenomenon called “milkmaid sign.” Summary A 10-year-old boy with involuntary move- Seizures rarely occur. Behavioral dysfunction, includes, ments of his lower extremities consisting of abnormal in particular, tics and obsessive-compulsive disorder. plantar flexion and inversion of his ankles that progressed from age 6. In addition, left wrist flexion torticollis and Diagnosis facial grimacing are described. Birth and developmental history are normal. Mental status, cranial nerves, motor MRI of the brain, which is important in order to rule out strength, sensation, and reflexes are normal. In the family structural lesions, is usually normal but may show high history, one uncle has trouble with handwriting. signal on T2-weighted images in the head of the caudate and in the putamen. Some laboratory tests should be considered including Localization • Blood count and differential. The disorder affecting this child may be localized to pa- • Blood chemistry. thology involving the extrapyramidal system. The vi- • Thyroid function tests, erythrocyte sedimentation rate. gnette describes a case of dystonia, which by definition • Antinuclear antibodies titer. is characterized by sustained of ago- • Anticardiolipid antibodies. nist and antagonist muscles, frequently causing repetitive • Antistreptolisin O titer. abnormal movements and posture. In selected cases, other laboratory studies include • Blood smear for acantocytes. Diagnosis and Differential Diagnosis • Ceruloplasmin, serum copper. The vignette indicates a normal perinatal and develop- • VDRL. mental history and no past history of exposure to drugs • HIV. or toxins. The neurological examination shows a child • Heavy metal screen. with normal cognitive function and normal strength, sen- • Lysosomal enzymes. sation, and reflexes. This helps in narrowing the diag- Treatment nostic possibilities. A family history consistent with an uncle with “hand- Streptococcal infection should be aggressively treated writing problems” points to a hereditary disorder. Torsion with penicillin. Treatment of chorea is based on the use dystonia can clearly explain all the symptoms expressed of dopamine antagonists, , or valproate. in the vignette. It is a hereditary disorder characterized Neuroleptics with more specific D2 receptor antagonism by involuntary, sustained muscular contractions com- (such as haloperidol) are effective for the more intense monly involving the foot, with movements of plantar chorea, but carry a risk of tardive dyskinesia (O’Brien). flexion and inversion, which initially occur intermittently and then became constant. The most important consideration in the differential di- Dystonia Musculorum Deformans agnosis is Wilson’s disease since it is a treatable condition and needs to be excluded in all patients developing move- ment disorders. In Wilson’s disease, signs of hepatic dys- Vignette function may predominate in children. Neurological symptoms include rigidity, tremor, bradykinesia, and dys- A 10-year-old boy started having difficulty walking arthria in addition to dystonia. Kaiser-Fleisher rings are at the age of 6 because of intermittent abnormal characteristic and the serum ceruloplasmin is generally posture of his left foot with plantar flexion and in- decreased. version as it approached the ground. The symptoms Hereditary neurodegenerative disorders, such as Hunt- slowly progressed and, at age 9, the boy was unable ington’s disease, Hallervorden-Spatz syndrome, Fahr’s to walk because both feet were constantly flexed. disease, ceroid lipofuscinosis, ataxia-telangiectasia, neu- Eventually, involuntary flexion appeared at the left roacanthocytosis, and so on, may manifest with dystonia wrist as well as torticollis and facial grimacing. His but usually they are also characterized by other neurolog- medical and developmental history were normal. ical and multifocal abnormalities, such as mental deteri- The patient was the product of a full-term, uncom- oration, seizures, retinitis pigmentosa, and so on. plicated pregnancy. A paternal uncle in the family Symptomatic generalized dystonia may be secondary history had difficulty with handwriting. Upon ex- to a neoplastic or vascular process, trauma, encephalitis, amination the boy had normal intelligence. Cranial or hypoxic or metabolic . Secondary dys- nerves, motor strength, reflexes, and sensation were tonia in children is often caused by perinatal asphyxia intact. (Menkes). Vascular cerebral malformations and neoplas- Tic Disorders 213 tic conditions can present with localized or generalized Myoclonic dystonia is an inherited condition charac- dystonia that may mimic the idyopathic type. terized by torsion dystonia in association with myoclonic Dystonia can also be related to an acute brain infection jerks. or trauma, or can be secondary to toxic agents such as manganese or carbon monoxide, or drug ingestion such Treatment as neuroleptics, phenytoin, phenobarbital, anthistamines, and so on. The treatment of torsion dystonia is based on the use of Psychogenic dystonia is also a consideration in a small agents such as trihexyphenidyl (Artane), percentage of children but some clinical characteristics which is given in a dose that starts at 2 to 4 mg/day and such as bizarre movements, gait inconsistency, and de- is gradually increased up to 60 to 80 mg/day until the creased movement when the child is distracted, may help maximum benefit or intolerable side effects are encoun- the correct diagnosis. tered (Menkes). Baclofen has been beneficial in some pa- In summary, dystonia can be etiologically distin- tients. Intratheral baclofen has been used in selective guished into primary, or idiopathic, and secondary, or cases of severe intractable torsion dystonia. Levodopa ap- symptomatic. The idiopathic group is characterized by pears to be effective in patients with late-onset dystonia. disorders with dystonic postures as the only abnormality can be utilized in the treatment of facial and with absence of other neurological symptomatology. dystonia, but not in the generalized form. In intractable Symptomatic , which are associated with hered- cases, surgery may represent an option, particularly uni- itary or acquired disorders, usually present with a multi- lateral or bilateral pallidotomy. tude of symptoms including dementia, seizures, spastic- ity, hyperreflexia, ataxia, retinitis pigmentosa, and so on. Tic Disorders Clinical Features Idiopathic torsion dystonia is a familial or sporadic dis- order with various modes of inheritance: autosomal dom- Vignette inant, autosomal recessive, or X-linked recessive. Gen- An 8-year-old boy was referred to an allergist after eralized dystonia is the most common form observed in the teacher noticed that he was sniffing, coughing, children. The age of presentation varies between 6 and and clearing his throat with unusual frequency. The 12 years in children who have a normal developmental mother admitted that at home he seemed very ner- history. vous, often blinking, grimacing, grunting, or shoul- The first symptoms can present with intermittent in- der shrugging, especially while watching televi- voluntary posturing of the foot with plantar flexion and sion. These symptoms probably started at age 6. On inversion while the child walks, but not during rest or examination he was a very bright boy, with when he is running or walking backwards. With progres- occasional squeezing of his eyelids and nasal sion of the disease, the motor abnormalities became per- twitches. The neurological examination was unre- sistent and may spread to involve contiguous areas, such markable. Past medical and developmental history as the pelvic girdle muscles, shoulders, and spinal and were normal. neck muscles, often interfering with daily activities. Al- most all children for whom the dystonia begins in the Summary An 8-year-old boy with history of involuntary legs progress to have generalized dystonia within one to movements (motor tics) and involuntary making of five years (Robertson et al.). Dystonia of the tongue and sounds (phonic tics) since age 6. The neurological and pharyngeal and laryngeal muscles may cause dysarthria medical history are normal. and dysphagia. Paroxysmal dyspnea has also been de- scribed (Menkes). The dystonic movements disappear Localization, Differential Diagnosis, and during sleep and are exacerbated by stress, fatigue, and Diagnosis excitement. The neurological examination in idiopathic torsion Tics, characterized by involuntary, sudden, purposeless, dystonia does not reveal any abnormality except for the repetitive, stereotyped, motor movements or vocaliza- dystonic posture and movements. The intellectual func- tions, are the most common involuntary movement dis- tion is normal. orders of childhood (Erenberg). Tic disorders vary in se- Dopa-responsive dystonia, which affects children in verity from a transient tic disorder to Tourette’s syndrome the first decade of life, needs to be differentiated from (TS). Transient tic disorder, which is common in children, idiopathic torsion dystonia because of its characteristic has a duration of less than one year. Chronic tic disorder, diurnal fluctuations and excellent response to levodopa characterized by motor or vocal tics but not both, has a treatment. duration longer than a year. 214 23. Pediatric Movement Disorders

The boy described in the vignette has experienced both or a group of muscles. It can be focal, multifocal, seg- motor and vocal tics for over a year, therefore he strongly mental, or generalized, and can be physiological, e.g., represents a case of Tourette’s syndrome. Diagnostic cri- associated with or secondary to hypoxia or met- teria for Tourette’s syndrome, according to the DSM-IV- abolic, or toxic disorders. TR, include Dystonia manifests with prolonged muscle contrac- tions causing repetitive movements or abnormal postures. • Onset before 18 years of age. Dystonic tics, such as twisting, pulling, or squeezing, • Presence of multiple motor tics and one or more vocal usually are preceded by an urge and are responsible for tics. abnormal twisting or posturing that only last as long as • Recurrence of the tics many times a day, nearly every the tic. day, or intermittently throughout a period of more than Chorea is characterized by involuntary, irregular, rapid, one year. purposeless movements that cannot be suppressed but can • Etiology not related to the use of medications or other be incorporated by the patient in a semipurposeful move- medical conditions. ment and is not preceded by an urge to make the movement. Tics can be motor or vocal, simple or complex. Simple is definied as motor restlessness that cannot motor tics usually affect only one muscle and can be rep- be suppressed and does not have an urge to make the resented by eye blinking, eye movement, nose twitching, movement, and varies in severity from jumpiness and shoulder shrugging, mouth opening, and so on. Complex fidgetiness to inability to sit or stand still. motor tics can include more complex movement, often in Tardive dyskinesia, which typically occurs in patients sequence, such as jumping, twisting, spitting, touching, treated with neuroleptics, includes a variety of involun- smelling, rubbing, and copropraxia (obscene gestures). tary movements that can be choreoathetoid and dystonic, Simple vocal tics are represented by various noises or and preferentially involve the oral-buccal and lingual sounds, such as throat clearing, snorting, sniffing, cough- region. ing, or barking. Complex vocal tics include words, Stereotypes are involuntary stereotyped movements, phrases, echolalia, and coprolalia (obscene words or such as arm flapping and hand waving, that can occur phrases). Patients describe an “involuntary urge” like tin- during stress or excitement, and can decrease if the child gling or itching to perform the movement or make the is distracted. sound. The Tourette’s syndrome classification study Tics can be secondary to acute and chronic insult caus- group has defined these feelings as sensory tics: uncom- ing cerebral dysfunction, such as trauma, cerebrovascular fortable sensations that can be focal, localized, or gen- accident, encephalitis, and so on, or can be secondary to eralized, and are relieved by the movement of the affected metabolic disorders such as hypoglycemia, toxic agents body part. such as carbon monoxide, or drug ingestion such as neu- TS usually manifests in the first decade of life and has roleptics, lithium, levodopa, and so on. a male predominance. Motor and vocal tics are precipi- Hereditary neurodegenerative disorders can also be tated by stress, fatigue, and emotional excitement, and associated with tics, in particular neuroacanthocytosis, can be temporarily suppressed, for example, when the Huntington’s disease, Hallervorden-Spatz disease, and child is in school. Typically they increase when the child so on. is relaxing, for example, when watching television. Tou- rette patients tend to have obsessive compulsive behav- Treatment iors in over half the cases. Other disorders associated with The medical treatment of tic disorder is particularly im- Tourette syndrome include attention deficit–hyperactivity portant when tics affect the quality of life and create a disorder, mood disorder, depression, antisocial behavior, disabling psychosocial situation. anxiety disorder, dyslexia, and so on. The long-term prog- Alpha agonist agents, such as clonidine and guanadine, nosis of TS is favorable with spontaneous remission or are now the first line of treatment and may be particularly marked improvement of the symptoms in over half of the useful in children with hyperactivity. Neuroleptic drugs, cases. such as pimozide, haloperidol, and fluphenazine, have Other movement disorders need to be distinguished been widely used for TS. Pimozide is less sedative than from tics and enter in the differential diagnosis of the haloperidol but may cause prolonged QT interval. Halo- patient in the vignette. Hyperkinetic movement disorders peridol can have several adverse effects, such as acute that need to be differentiated from tics include myo- dystonic reactions, school phobia, depression, and par- clonus, dystonia, chorea, akathisia, tardive dyskinesia, kinsonism. Atypical neuroleptics (risperidone, olanza- stereotypes and psychogenic movement disorders. pine, and ziprasidone) have fewer motor adverse effects is defined as a brief, sudden, shock-like and are also used. Botulinum toxin has been considered movement caused by an abrupt contraction of a muscle for patients with disabling intractable tics. References 215

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