Editorial Reviews. Review. "This well-written, concise, and practical book has been a valuable resource for those caring for pediatric patients with neurological . Confidently diagnose and manage primary neurologic disorders of childhood with actionable, step-by-step assistance from Fenichel's Clinical. Fenichel GM, Clinical Pediatric Neurology, 5th Ed, , Elseiver - Download as PDF File .pdf), Text File .txt) or read online. neurologi anak.
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Confidently diagnose and manage primary neurologic disorders of childhood with actionable, step-by-step assistance from Fenichel's Clinical Pediatric. FENICHEL'S. CLINICAL. PEDIATRIC. NEUROLOGY. A Signs and Symptoms Approach. Seventh Edition. London, New York, Oxford, St Louis, Sydney, Toronto . The Publisher Library of Congress Cataloging-in-Publication Data Fenichel, Gerald M. Clinical pediatric neurology: a signs and symptoms approach / Gerald M.
All rights reserved. Madalina Gavrilescu. Ecaterina Galagan. The ankle tendon reflex may be difficult to elicit, however, when the tendon is tight for any reason. Many such disorders also disturb ocular motility see Chapter
Park MD. Cloherty and Stark's Manual of Neonatal Care. Pediatric Nephrology. Practical Paediatric Neurology. About the Author J. To get the free app, enter mobile phone number. See all free Kindle reading apps. Don't have a Kindle? Product details Paperback: Elsevier; 7 edition 20 May Language: English ISBN Customers who viewed this item also viewed.
Swaiman's Pediatric Neurology: Principles and Practice. Kenneth F. Swaiman MD. Essential Paediatric Pulmonology. Clinical Paediatrics. Share your thoughts with other customers. Write a product review. Top Reviews Most recent Top Reviews. There was a problem filtering reviews right now. Please try again later.
Verified Purchase. Good for case wise approch. Nice book.. See all 3 reviews. Most helpful customer reviews on Amazon. Not convinced about the format. It is structured by clinical problems which might be useful when considering a specific clinical question. But when studying you will find that metabolic disorders for examples are spread throughout the book and therefore a but difficult to get a global idea. Does not get to deep into topics in general.
Highly recommend! Belated review! The nature of the event requires surmising what transpired by listening to the eyewitness description offered by a family member or, worse, to the secondhand description that the parent heard from a teacher. Never accept a secondhand description. The most common confusion is between seizures and syncope.
Most people stiffen and tremble at the end of a faint. Spells seldom remain unexplained when viewed. Because observation of the spell is crucial to diagnosis, ask the family to videotape the spell. Most families either own or can borrow a video camera. Even when a purchase is required, it is more cost-effective than brain imaging studies, and the family has something useful to show for the expenditure.
Always ask the following two questions: Has this ever happened before? Does anyone else in the family have similar episodes? Often, no one offers this important information until requested. Episodic symptoms that last only seconds and cause no abnormal signs usually remain unexplained and do not warrant laboratory investigation.
The differential diagnosis of paroxysmal disorders is different in neonates, infants, children, and adolescents and presented best by age groups. With the exception of coma, these definitions are not standard. They are more precise, however, and more useful than such terms as semicomatose and semistuporous. The term encephalopathy describes a diffuse disorder of the brain in which at least two of the following symptoms are present: Encephalitis is an encephalopathy accompanied by cerebrospinal fluid CSF pleocytosis.
Lack of responsiveness is not always lack of consciousness. Infants with botulism see Chapter 6 may have such severe hypotonia and ptosis that they cannot move their limbs or eyelids in response to stimulation. They appear to be in a coma or stupor but are actually alert.
The locked-in syndrome a brainstem disorder in which the individual can process information but cannot respond and catatonia are other examples of diminished responsiveness in the alert state. Patients with increased neuronal excitability the high road become restless and then confused; next, tremor, hallucinations, and delirium an agitated confusional state develop.
Myoclonic jerks may occur. Seizures herald the end of delirium, and stupor or coma follow. Table 2—2 summarizes the differential diagnosis of the high road to coma. Tumors and other mass lesions are not expected causes. Instead, metabolic, toxic, and inflammatory disorders are likely. Instead, awareness progressively deteriorates from lethargy to obtundation, stupor, and coma. The differential diagnosis is considerably larger than that with the high road and includes mass lesions and other causes of increased intracranial pressure Table 2—3.
Table 2—4 lists conditions that cause recurrent encephalopathies. A comparison of Tables 2—2 and 3 shows considerable overlap between conditions whose initial features are agitation and confusion and conditions that begin with lethargy and coma; the disorders responsible for each are described together to prevent repetition. The usual causes of delirium are toxic or metabolic disorders diffusely affecting both cerebral hemispheres.
Schizophrenia should not be a consideration in a prepubertal child with acute delirium. Fixed beliefs, unalterable by reason, are delusions. The paranoid delusions of schizophrenia are logical to the patient and frequently part of an elaborate system of irrational thinking in which the patient feels menaced.
Delusions associated with organic encephalopathy are less logical, are not systematized, and tend to be stereotyped. A hallucination is the perception of sensory stimuli that are not present. Organic encephalopathies usually cause visual hallucinations, whereas psychiatric illness usually causes auditory hallucinations, especially if the voices are accusatory.
Stereotyped auditory hallucinations that represent a recurring memory are an exception and suggest temporal lobe seizures. History and Physical Examination Delirious children, even with stable vital function, require rapid assessment because the potential for deterioration to a state of diminished consciousness is real.
Obtain a careful history of the following: Examination of the eyes, in addition to determining the presence or absence of papilledema, provides other etiological clues. Small or large pupils that respond poorly to light, nystagmus, or impaired eye movements suggest a drug or toxic exposure. Fixed deviation of the eyes in one lateral direction may indicate that 1 the encephalopathy has focal features, 2 seizures are a cause of the confusional state, or 3 seizures are part of the encephalopathy.
The general and neurological examinations should specifically include a search for evidence of trauma, needle marks on the limbs, meningismus, and cardiac disease.
The distinction between painful and harmful headaches occurs before consultation. Nevertheless, families seek medical attention for a child with headache not only hoping to relieve pain, but also seeking assurance that the child does not have a serious intracranial disease. Not every headache is explicable, and the term psychogenic is not a synonym for idiopathic.
In my practice, I see two headache patterns among most children. One is chronic low-grade headache, and the other is an intermittent disabling headache. The cause of the former is either caffeine or analgesic abuse, and the latter is migraine.
Ten percent of children 5 to 15 years old have migraine. Children with migraine average twice as many days lost from school as children without migraine.
An initial headache classification proposed by the International Headache Society in has undergone several revisions with the newest published in International Headache Society, As a rule, only poorly understood disorders require classification by a committee.
Sources of Pain Table 3—1 lists pain-sensitive structures of the head and neck. The main pain-sensitive structures inside the skull are blood vessels. Mechanisms that stimulate pain from blood vessels are vasodilation, inflammation, and traction-displacement. Increased intracranial pressure causes pain mainly by the traction and displacement of intracranial arteries see Chapter 4. The brain parenchyma, its ependymal lining, and the meninges, other than the basal dura, are insensitive to pain.
The ophthalmic division of the trigeminal nerve innervates the arteries in the superficial portion of the dura and refers pain to the eye and forehead. The second and third divisions of the trigeminal nerve innervate the middle meningeal artery and refer pain to the temple. All three divisions of the trigeminal nerve innervate the cerebral arteries and refer pain to the eye, forehead, and temple.
In contrast, referred pain from all structures in the posterior fossa is to the occiput and neck. Several extracranial structures are pain sensitive.
Major scalp arteries are present around the eye, forehead, and temple and produce pain when dilating or stretched. Cranial bones are insensitive, but periosteum, especially in the sinuses and near the teeth, is painful when inflamed.
The inflamed periosteum is usually tender to palpation or other forms of physical stimulation. Muscles attached to the skull are a possible source of pain. The largest muscle groups are the neck extensors, which attach to the occipital ridge; the masseter muscles; and the frontalis muscle. The mechanism of muscle pain is incompletely understood but probably involves prolonged contraction. The extraocular muscles are a source of muscle contraction pain in patients with heterophoria.
When an imbalance exists, especially in convergence, long periods of close work cause difficulty in maintaining conjugate gaze, and pain localizes to the orbit and forehead. Pain from the cervical roots and cranial nerves is generally due to mechanical traction from injury or malformation. Pain follows this nerve distribution: Most often, headache, vomiting, personality change, and alterations in states of consciousness bring it to medical attention. Less frequently, diplopia or the observation that one or both eyes are turning in is the initial complaint.
The basis of referral for some children is the diagnosis of papilledema by another physician. Some conditions causing increased intracranial pressure are discussed elsewhere in this book see Chapters 2 , 3 , 10 , and This chapter is restricted to conditions in which symptoms of increased intracranial pressure are initial and prominent features.
Pressures greater than 20 mm Hg are abnormal. When the cranial bones fuse during childhood, the skull is a rigid box enveloping its content. Intracranial pressure is then the sum of the individual pressures exerted by the brain, blood, and cerebrospinal fluid CSF.
An increase in the volume of any one component requires an equivalent decrease in the size of one or both of the other compartments if intracranial pressure is to remain constant. Because the provision of oxygen and nutrients to the brain requires relatively constant cerebral blood flow, the major adaptive mechanisms available to relieve pressure are the compressibility of the brain and the rapid reabsorption of CSF by arachnoid villi. Infants and young children, in whom the cranial bones are still unfused, have the additional adaptive mechanism of spreading the cranial bones apart to increase cranial volume.
The rate of formation is approximately 0. In contrast, the rate of absorption increases linearly as CSF pressure exceeds 7 mm Hg. At a pressure of 20 mm Hg, the rate of absorption is three times the rate of formation.
Impaired absorption, not increased formation, is the usual mechanism of progressive hydrocephalus. Choroid plexus papilloma is the only pathological process in which formation sometimes can overwhelm absorption. When absorption is impaired, efforts to decrease the formation of CSF are not likely to have a significant effect on volume.
Slow progress in the attainment of developmental milestones may be caused by either static Table 5—1 or progressive Table 5—2 encephalopathies. In contrast, the loss of developmental milestones previously attained usually indicates a progressive disease of the nervous system, but also may result from parental misperception of attained milestones or by the development of new clinical features from an established static disorder as the brain matures Table 5—3. Two important questions require answers: In infants, the second question is often difficult to answer.
Even in static encephalopathies, new symptoms, such as involuntary movements and seizures, may occur as the child gets older, and delayed acquisition of milestones without other neurological deficits is sometimes the initial feature of progressive disorders. When it is clear that milestones previously achieved are lost or that focal neurological deficits are evolving, however, a progressive disease of the nervous system is a consideration.
It rapidly assesses four different components of development: Several psychometric tests amplify the results, but the Denver Developmental Screening Test in combination with neurological assessment provides sufficient information to initiate further diagnostic studies. Language Delay Normal infants and children have a remarkable facility for acquiring language during the first decade of life.
Children exposed to two languages concurrently learn both. Vocalization of vowels occurs in the first month, and by 5 months, laughing and squealing are established. At 6 months, infants begin articulating consonants, usually M, D, and B. These first attempts at vowels and consonants are automatic and sometimes occur even in deaf children. Receptive skills are always more highly developed than expressive skills because language must be decoded before it is encoded.
By 2 years of age, children have learned to combine at least 2 words, understand more than words, and follow many simple verbal directions. Developmental disturbances in the language cortex of the left hemisphere that occur before 5 years of age displace language to the right hemisphere.
This displacement does not occur in older children. Autistic Spectrum Disorders Infantile autism is a developmental disorder of brain function defined by behavioral characteristics. The terms autistic spectrum disorders ASD and pervasive developmental disorders classify the spectrum of behavioral consequences. Asperger disorder represents the high-functioning end of autistic spectrum disorders.
The high concordance in monozygotic twins, a 4. Autism has become an increasingly popular diagnosis. An apparent increasing incidence of diagnosis suggests to some investigators an environmental factor. Data do not confirm the notion, however, of an autism epidemic or causation by any environmental factor.
Most biological studies suggest prenatal factors. Clinical Features. Major diagnostic criteria are impaired sociability, impaired verbal and nonverbal communication skills, and restricted activities and interests Rapin, Failure of language development is the feature most likely to bring autistic infants to medical attention and correlates best with the outcome; children who fail to develop language before age 5 have the worst outcome.
The IQ is less than 70 in most children with autism. Some autistic children show no affection to their parents or other care providers, whereas others are affectionate on their own terms.
Autistic children do not show normal play activity; some display a morbid preoccupation with spinning objects, stereotyped behaviors such as rocking and spinning, and relative insensitivity to pain. An increased incidence of epilepsy in autistic children is probable. Infantile autism is a clinical diagnosis and not confirmable by laboratory tests.
Infants with profound hearing impairment may display autistic behavior, and tests of hearing are diagnostic. An electroencephalogram EEG is indicated when seizures are suspected.
Autism is not curable, but several drugs may be useful to control specific behavioral disturbances. Behavior modification techniques improve some aspects of the severely aberrant behavior. Despite the best program of treatment, however, these children function in a moderately to severely retarded range, although some individuals have islands of normal or extraordinary ability idiot savant. Bilateral Hippocampal Sclerosis Bilateral hippocampal sclerosis and the congenital bilateral perisylvian syndrome cause a profound impairment of language development.
The former also causes failure of cognitive capacity that mimics infantile autism, whereas the latter causes a pseudobulbar palsy see Chapter Infants with medial bilateral hippocampal sclerosis generally come to medical attention for refractory seizures. The syndrome emphasizes, however, that the integrity of one medial hippocampal gyrus is imperative for language development. Hearing Impairment The major cause of isolated delay in speech development is hearing impairment see Chapter Hearing loss may occur concomitantly with global developmental retardation, as in rubella embryopathy, cytomegalic inclusion disease, neonatal meningitis, kernicterus, and several genetic disorders.
Hearing loss need not be profound; it can be insidious, yet delay speech development. The loss of high-frequency tones, inherent in telephone conversation, prevents the clear distinction of many consonants that humans learn to fill in through experience; infants do not have experience in supplying missing sounds. The hearing of any infant with isolated delay in speech development requires audiometric testing. Crude testing in the office by slamming objects and ringing bells is inadequate.
Hearing loss is suspected in children with global retardation caused by disorders ordinarily associated with hearing loss or in retarded children who fail to imitate sounds. Other clues to hearing loss in children are excessive gesturing and staring at the lips of people who are talking.
Clinicians test two kinds of tone: Phasic tone is a rapid contraction in response to a high-intensity stretch. The tendon reflex response tests phasic tone. Striking the patellar tendon briefly stretches the quadriceps muscle. The spindle apparatus, sensing the stretch, sends an impulse through the sensory nerve to the spinal cord. This information is transmitted to the alpha motor neuron, and the quadriceps muscle contracts monosynaptic reflex.
Postural tone is the prolonged contraction of antigravity muscles in response to the low-intensity stretch of gravity. When postural tone is depressed, the trunk and limbs cannot maintain themselves against gravity, and the infant appears hypotonic.
The maintenance of normal tone requires intact central and peripheral nervous systems. Hypotonia is a common symptom of neurological dysfunction and occurs in diseases of the brain, spinal cord, nerves, and muscles Table 6—1.
One anterior horn cell and all the muscle fibers that it innervates compose a motor unit. The motor unit is the unit of force. Weakness is a symptom of all motor unit disorders. A primary disorder of the anterior horn cell body is a neuronopathy, a primary disorder of the axon or its myelin covering is a neuropathy, and a primary disorder of the muscle fiber is a myopathy.
In infancy and childhood, cerebral disorders far outnumber motor unit disorders. The term cerebral hypotonia encompasses all causes of postural hypotonia caused by a cerebral disease or defect. Spontaneous movement is lacking, full abduction of the legs places the lateral surface of the thighs against the examining table, and the arms lie either extended at the sides of the body or flexed at the elbow with the hands beside the head.
Pectus excavatum is present when the infant has long-standing weakness in the chest wall muscles. Infants who lie motionless eventually develop flattening of the occiput and loss of hair on the portion of the scalp that is in constant contact with the crib sheet.
When placed in a sitting posture, the head falls forward, the shoulders droop, and the limbs hang limply. Newborns who are hypotonic in utero may be born with hip dislocation, multiple joint contractures arthrogryposis , or both. Hip dislocation is a common feature of intrauterine hypotonia. The forceful contraction of muscles pulling the femoral head into the acetabulum is a requirement of normal hip joint formation.
Arthrogryposis varies in severity from clubfoot, the most common manifestation, to symmetrical flexion deformities of all limb joints. Joint contractures are a nonspecific consequence of intrauterine immobilization. Among the several disorders that equally decrease fetal movement, however, some commonly produce arthrogryposis and others never do.
Table 6—2 summarizes the differential diagnosis of arthrogryposis. As a rule, newborns with arthrogryposis who require respiratory assistance do not survive extubation unless the underlying disorder is myasthenia. The traction response, vertical suspension, and horizontal suspension further evaluate tone in infants who appear hypotonic at rest.
Grasping the hands and pulling the infant toward a sitting position initiates the response. A normal term infant lifts the head from the surface immediately with the body. When attaining the sitting position, the head is erect in the midline for a few seconds. During traction, the examiner should feel the infant pulling back against traction and observe flexion at the elbow, knee, and ankle.
After 33 weeks, the neck flexors show increasing success in lifting the head. At term, only minimal head lag is present; after attaining the sitting posture, the head may continue to lag or may be erect briefly, then fall forward. The presence of more than minimal head lag and of failure to counter traction by flexion of the limbs in the term newborn is abnormal and indicates hypotonia.
Flaccid leg weakness may be the initial feature of disturbances in the lumbosacral region, but other symptoms of spinal cord dysfunction are usually present.
Also, consult Table 12—1 when considering the differential diagnosis of flaccid leg weakness without arm impairment. Cerebral disorders may cause flaccid weakness, but dementia see Chapter 5 or seizures see Chapter 1 are usually a concomitant feature. Clinical Features of Neuromuscular Disease Weakness is decreased strength, as measured by the force of a maximal contraction.
Fatigue is inability to maintain a less than maximal contraction, as measured by exercise tolerance. Weak muscles are always fatigued more easily than normal muscles, but fatigue may occur in the absence of weakness. Conditions in which strength is normal at rest, but fatigue or cramps occur with exercise are discussed in Chapter 8.
Initial Complaint Limb weakness in children usually is noted first in the legs and then in the arms Table 7—1. This is because many neuromuscular disorders affect the legs before the arms, and walking is impaired. Delayed development of motor skills is often an initial or prominent feature in the history of children with neuromuscular disorders.
Marginal motor delay in children with otherwise normal development rarely raises concern and often is considered part of the spectrum of normal development. Prompts for neurological consultation in older children with neuromuscular disorders are failure to keep up with peers or easy fatigability. With proximal weakness, the pelvis fails to stabilize and waddles from side to side as the child walks.
Running is especially difficult and accentuates the hip waddle. Descending stairs is particularly difficult in children with quadriceps weakness; the knee cannot lock and stiffen. Difficulty with ascending stairs suggests hip extensor weakness. Rising from the floor or a deep chair is difficult, and the hands help to push off.
Stumbling is an early complaint when there is distal leg weakness, especially weakness of the evictors and dorsiflexors of the foot.
Falling is first noted when the child walks on uneven surfaces. Children with footdrop tend to lift the knee high in the air so that the foot clears the ground. The weak foot then comes down with a slapping motion steppage gait. Toe walking is commonplace in Duchenne muscular dystrophy DMD because the pelvis thrusts forward to shift the center of gravity, and the gastrocnemius muscle is stronger than the peroneal muscles.
Toe walking also occurs in upper motor neuron disorders that cause spasticity and in children who have tight heel cords but no identifiable neurological disease. Muscular dystrophy usually is associated with hyporeflexia, and spasticity is associated with hyperreflexia. The ankle tendon reflex may be difficult to elicit, however, when the tendon is tight for any reason. Adolescents, but usually not children, with weakness complain of specific disabilities.
A young woman with proximal weakness may have difficulty keeping her arms elevated to groom her hair or rotating the shoulder to get into and out of garments that have a zipper or hook in the back. Weakness of hand muscles often comes to attention because of difficulty with handwriting. Adolescents may notice difficulty in unscrewing jar tops or working with tools.
Teachers report to parents when children are slower than classmates in climbing stairs, getting up from the floor, and skipping and jumping. Parents may report a specific complaint to the physician, but more often, they define the problem as inability to keep up with peers. A child whose limbs are weak also may have weakness in the muscles of the head and neck. Specific questions should be asked about double vision, drooping eyelids, difficulty chewing and swallowing, change of facial expression and strength whistling, sucking, chewing, blowing , and clarity and tone of speech.
Weakness of neck muscles frequently is noticed when the child is a passenger in a car that suddenly accelerates or decelerates. The neck muscles are unable to stabilize the head, which snaps backward or forward.
Cramps can occur in normal children during and after vigorous exercise and after excessive loss of fluid or electrolytes. The characteristic electromyogram EMG finding for such cramps is the repetitive firing of normal motor unit potentials.
Stretching the muscle relieves the cramp. Partially denervated muscle is particularly susceptible to cramping not only during exercise, but also during sleep. Night cramps may awaken patients with neuronopathies, neuropathies, or root compression. Cramps during exercise occur also in patients with several different disorders of muscle energy metabolism.
The EMG characteristic of these cramps is electrical silence. Muscle stiffness and spasms are not cramps, but are prolonged contractions of several muscles that are able to impose postures. Such contractions may or may not be painful.
When painful, they lack the explosive character of cramps. Prolonged contractions occur when muscles fail to relax myotonia or when motor unit activity is continuous Table 8—1. Prolonged, painless muscle contractions occur also in dystonia and in other movement disorders see Chapter These pains are not true cramps. The muscle is not in spasm, the pain is diffuse and aching in quality, and the discomfort lasts for an hour or longer.
Stretching the muscle does not relieve the pain. These pains are not a symptom of neuromuscular disease and are called growing pains, for want of better understanding.
Mild analgesics or heat relieves symptoms. Exercise intolerance is a relative term for an inability to maintain exercise at an expected level. The causes of exercise intolerance considered in this chapter are fatigue and muscle pain. Fatigue is a normal consequence of exercise and occurs in everyone at some level of activity. In general, weak children become fatigued more quickly than children who have normal strength.
Many children with exercise intolerance and cramps, but no permanent weakness, have a defect in an enzyme needed to produce energy for muscular contraction Table 8—2. A known mechanism underlies several such inborn errors of metabolism.
Even when the full spectrum of biochemical tests is available, however, identification of a metabolic defect is not possible in some children with cramps during exercise.
Conditions that produce some combination of cramps and exercise intolerance are divisible into three groups: As a rule, the first and third groups are symptomatic at all times, whereas the second group is symptomatic only with exercise.
The first group usually requires an EMG for diagnosis. EMG is the initial diagnostic test in children with muscle stiffness that is not due to spasticity or rigidity. It usually leads to the correct diagnosis Table 8—3. The EMG features of CMUA are repetitive muscle action potentials in response to a single nerve stimulus; high-frequency bursts of motor unit potentials of normal morphology abruptly start and stop.
Rhythmic firing of doublets, triplets, and multiplets occur. During long bursts, the potentials decline in amplitude. This activity is difficult to distinguish from normal voluntary activity. CMUA occurs in a heterogeneous group of disorders characterized clinically by some combination of muscle pain, fasciculations, myokymia, contractures, and cramps Table 8—4.
The original name for neuromyotonia is Isaac syndrome. These disorders may be sporadic or familial in occurrence. When familial, the usual mode of transmission is autosomal dominant inheritance. Neuromyotonia The primary abnormality in neuromyotonia is in the nerve or the nerve terminal.
Most childhood cases are sporadic in occurrence, but some show a pattern of autosomal dominant inheritance.
An autoimmune process directed against the potassium channel may account for some sporadic cases Shillito et al, The clinical triad includes involuntary muscle twitching fasciculations or myokymia , muscle cramps or stiffness, and myotonia.
Excessive sweating frequently is associated with the muscle stiffness. The age at onset is anytime from birth to adult life. The initial features are muscle twitching and cramps brought on by exercise. Later these symptoms also occur at rest and during sleep. The cramps may affect only distal muscles, causing painful posturing of the hands and feet. As a rule, leg weakness is greater than arm weakness.
These disorders are not progressive and do not lead to permanent disability. Attacks of cramping are less frequent and severe with age. In some children, cramps and fasciculations are not as prominent as stiffness, which causes abnormal limb posturing associated frequently with excessive sweating. Leg involvement is more common than arm involvement, and the symptoms suggest dystonia see Chapter Limb posturing may begin in one foot and remain asymmetrical for months.
Most cases are sporadic. Muscle mass, muscle strength, and tendon reflexes are normal. Fasciculations are sporadic and seen only after prolonged observation. Some adult-onset cases are associated with malignancy, but this is never the case in children. Muscle fibers fire repetitively at a rate of to Hz, either continuously or in recurring bursts, producing a pinging sound. The discharge continues during sleep and persists after procaine block of the nerve. Carbamazepine and phenytoin, at usual anticonvulsant doses, are effective in reducing or abolishing symptoms.
The gene locus maps to 1p Characteristic features include short stature, skeletal abnormalities, and persistent muscular contraction and hypertrophy. The first group shows linkage to chromosome 1p SJS-1 corresponds to the original description of Schwartz and Jampel.
Bone deformities are not prominent at birth. CMUA of the face is the main feature producing a characteristic triad that includes narrowing of the palpebral fissures blepharophimosis , pursing of the mouth, and puckering of the chin.
Striking or even blowing on the eyelids induces blepharospasm. CMUA in the limbs produces stiffness of gait and exercise intolerance.