What is the Difference between Nystagmus and Ocular Motor Apraxia?

Patient Presentation
A 20-month-old male came to clinic with a gradual onset over at least 1 month of head-tilting in different directions throughout the day. He also had eye movements that were described as both eyes turning laterally slowly and then coming back centrally quickly. These movements could also be in other directions, but the movements were not described as rotary. Both the head-tilting and eye movements appeared together, and were increasing in the number of episodes. Daycare providers and other parents also noted the abnormal movements. His mother denied other strange posturing or movements of the limbs, trunk, face or vocalizations. She said that he did not seem clumsier with walking or fine motor movements. It was worse when he was crying, angry or when needing to visually fix on an object. For example, when feeding himself his head would tilt and eyes dart when scooping food, but he was able to easily move the spoon to his mouth. He had a URI infection about 2 weeks before the onset of symptoms. The past medical history was negative with slower language milestones being met but within normal range. There were no developmental milestone loss. The family history was negative for neurological, genetic and opthalmological disease. The father had some problems with school but finished with average grades and received his associate’s degree. The review of systems was negative including fever, headache, weight loss, other eye changes or rashes.

The pertinent physical exam showed a healthy appearing male with growth parameters in the 50-90%. HEENT showed pupils equal, round and reactive to light and accommodation. Lateral eye nystagmus was noted to the right and left that occurred with head tilting laterally or downward. head-tilting appeared to occur more with object fixation. Red reflexes were present bilaterally and symmetric but fundus examination could not be accomplished. Neurological examination showed cranial nerves intact, with normal muscle tone, strength and bulk. No truncal ataxia was noted, nor ataxia with walking. He was able to accurately pickup and place small objects with a pincer grasp. Deep tendon reflexes were normal. Skin examination was normal as was the rest of his examination. The differential diagnosis at this time included a visual abnormality, tics, pediatric autoimmune neuropsychiatric disorder associated with streptococcal infection (PANDAS), tumor of visual axis or central nervous system or occult neuroblastoma, and accidental poisoning. The work-up included a negative anti-streptolysin O, brain magnetic resonance imaging, 24 hour urine testing for VMA/HVA, and urine drug testing. A pediatric neuroophthalmologist was available and felt this was most consistent with the diagnosis of oculomotor apraxia with some nystagmus. They recommended monitoring. One year later, the patient’s clinical course showed that the head tiling and eye movements had decreased, yet stereotypical oblique head movements remained. No nystagmus was seen at this examination, although it was described by the mother.

Discussion
Clinically, positive motor signs such as hypertonia, chorea, tics, and tremor are often easily to elicit. But negative neurological signs are more difficult to elicit and quantify.
These include:

  • Weakness – “…the inability to generate normal voluntary force in a muscle or normal voluntary torque about a joint.” Weakness is usually present in many different postures, movements or tasks, but could be only seen in certain ones. Spinal muscle atrophy is one example.
  • Reduced selective motor control – “…impaired ability to isolate the activation of muscles in a selected pattern in response to the demands of a voluntary posture or movement.” For example, a child with congenital mirror movements.
  • Ataxia – “…inability to generate a normal or expected voluntary movement trajectory that cannot be attributed to weakness or involuntary muscle activity about the affected joints.” The path made by the movement is not expected. Walking in an undulating or inconsistent pattern is one example.
  • Apraxia – “…impairment in the ability to accomplished previous learned and performed complex motor activities that is not explained by ataxia, reduced selective motor control, weakness or involuntary motor activity.” The inability is secondary.
    Developmental apraxia is the same as apraxia but is “…a failure to have ever acquired the ability to perform the age-appropriate complex motor actions.” This inability is primary, as the ability never was acquired.
    Ataxia is distinguished from apraxia and developmental apraxia in that the former’s deficits are not specific to particular tasks which the latter’s are.

Learning Point
Ocular motor apraxia (OMA) is a problem in the initiation of horizontal saccadic eye movement. Saccades are spontaneous, quick movements of both eyes in the same direction. Children with OMA use head thrusting to help their visual fixation. OMA usually has a good outcome with normal visual acuity and improvements in the head thrusting over time as the child grows older. OMA can be associated with other problems such as Ataxia-telangectasia, Ataxia associated with Ocular Motor Apraxia types 1,2,3, Gaucher Disease, and others.

Nystagmus is a rhythmic, involuntary movement of the eye. There are two general types. Jerk nystagmus when there is a slow phase movement in one direction, followed by a quick phase movement in the opposite direction. Pendular nystagmus has equal phases in both directions. There are many variations defined by the direction of the quick phase, periodicity, amplitude and waveform characteristics. They may be congenital or acquired.

With nystagmus, the muscle movement is involuntary and is present more consistently rather than intermittently. With apraxia the muscle movement is voluntary but there is a problem with performing this movement. For example, the eyes are trying to fixate on a target but may overshoot the target and then quickly return to the original or another position. The eyes may appear to have nystagmus-type movement but the child is moving the eye voluntarily. Because apraxia is voluntary, it is usually more intermittent.

Questions for Further Discussion
1. What are indications for consultation with a neurologist or opthalmologist?
2. What is included in the differential diagnosis for nystagmus?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com, the National Guideline Clearinghouse and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for this topic: Neurological Diseases

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

Rudolph CD, et.al. Rudolph’s Pediatrics. 21st edit. McGraw-Hill, New York, NY. 2003:2404-2406.

Palau F, Espinos C. Autosomal recessive cerebellar ataxias. Orphanet J Rare Dis. 2006 Nov 17;1:47.

Sanger TD, Chen D, Delgado MR, Gaebler-Spira D, Hallett M, Mink JW, Taskforce on Childhood Motor Disorders. Definition and classification of negative motor signs in childhood. Pediatrics. 2006 Nov;118(5):2159-67.

Liu W, Narayanan V. Ataxia with oculomotor apraxia. Semin Pediatr Neurol. 2008 Dec;15(4):216-20.

Online Mendelian Inheritance in Man. Ocular Motor Apraxia, MIM ID 257550. Available from the Internet at http://www.ncbi.nlm.nih.gov/omim/257550 (rev. 7/13/2010, cited 3/29/11).

ACGME Competencies Highlighted by Case

  • Patient Care
    1. When interacting with patients and their families, the health care professional communicates effectively and demonstrates caring and respectful behaviors.
    2. Essential and accurate information about the patients’ is gathered.
    3. Informed decisions about diagnostic and therapeutic interventions based on patient information and preferences, up-to-date scientific evidence, and clinical judgment is made.
    4. Patient management plans are developed and carried out.
    5. Patients and their families are counseled and educated.
    7. All medical and invasive procedures considered essential for the area of practice are competently performed.
    8. Health care services aimed at preventing health problems or maintaining health are provided.
    9. Patient-focused care is provided by working with health care professionals, including those from other disciplines.

  • Medical Knowledge
    10. An investigatory and analytic thinking approach to the clinical situation is demonstrated.
    11. Basic and clinically supportive sciences appropriate to their discipline are known and applied.

  • Systems Based Practice
    23. Differing types of medical practice and delivery systems including methods of controlling health care costs and allocating resources are known.

    Author

    Donna M. D’Alessandro, MD
    Professor of Pediatrics, University of Iowa Children’s Hospital

  • How Common is Orbital Cellulitis?

    Patient Presentation
    A 9-year-old female came to clinic with swelling of the left eye for 1 day and 4 days of fever. She had previously been evaluated in a walk-in medical care office and treated for conjunctivitis with antibiotic drops two days previously. She currently had photophobia, blurred vision, headache above both eyes, but no oral, facial or ear pain. She had had rhinorrhea for the past week and denied trauma or insect bites. The past medical history and family history were non-contributory. The review of systems was otherwise negative.

    The pertinent physical exam showed a female with obvious facial swelling. Her vital signs were normal except for a temperature of 101.5&deg F. Her growth parameters were 10-25%. She could not open her left eye and the swelling and erythema extended above the eyebrow, into the cheek about 2 cm and laterally about 1 cm from the eye. With lid retraction, she had marked bulbar and palpebral conjunctival injection, photophobia, painful extraocular movements and proptosis. She had some limitations to inward gaze but it was difficult to assess because of pain. She was tender over the ethmoid sinuses with purulent rhinorrhea. She had no dental pain and the rest of her examination was normal. The diagnosis of orbital cellulitis was made. The radiologic evaluation of computed tomography of the orbits showed a medial wall, retrobulbar abscess formation and ethmoid sinusitis. The patient’s clinical course showed that Ophthalmology was consulted who placed her on intravenous broad-spectrum antibiotics and eye rinses. A respiratory culture grew Haemophilus influenza type B and the patient was placed on Ciprofloxacin for a 2-3 week antibiotic course. Outpatient follow-up at 12 days showed no opthalmological deficits and the patient was otherwise doing well.

    Case Image
    Figure 92 – Axial image from a CT scan of the orbits performed with intravenous contrast demonstrates sinusitis of the left ethmoid sinus and both sphenoid sinuses. There is left sided prespetal cellulitis anterior to the left orbit. Furthermore, there is a left sided subperiosteal abscess between the medial wall of the left orbit and the left medial rectus muscle.

    Discussion
    Orbital cellulitis is a serious infection whose complications can include meningitis, intracranial abscess, cavernous sinus thrombosis, carotid artery occlusion and vision loss. Orbital cellulitis itself is usually a complication of rhinosinusitis particularly of the ethmoid sinuses but also trauma.

    Haemophilus influenza type B usually has been the prevalent causative organism with Staphlococcus aureus and viridins streptococcus also being common causes. The microbiology appears to be changing though. A 25-year study shows that although immunization against Haemophilus influenza type B and pneumococcus have decreased the cases of invasive infections such as meningitis, epiglottitis and bacteremia, immunization does not appear to decrease the cases of orbital cellulitis. Yet a recent 5 year review of patients at a children’s hospital found that Streptococcus anginosus was an emerging pathogen in pediatric orbital infections. See To Learn More below.

    To learn more about the physical characteristics distinguishing periorbital (preseptal) cellulitis from orbital cellulitis click here.

    Learning Point
    Overall orbital cellulitis is generally an uncommon pediatric problem, especially in contrast to periorbital cellulitis. Exactly how uncommon depends on the research study but it is important to consider its possibility in any child presenting with swelling around the orbit. Some recent studies are abstracted below.

  • In a 10-year retrospective study of 52 patients less than 2 years of age with rhinosinusitis, orbital complications were evaluated and none had orbital cellulititis. This would be ~0 patients/year.

  • In another 10-year retrospective review, 6 patients with orbital complications secondary to acute sinusitis were evaluated and 1 had orbital cellulitis. This would be ~0.1 patients/year.

  • In a third 10-year retrospective review, 83 patients with preseptal or orbital cellulitis were evaluated and 14 had orbital cellulitis. This would be ~1.4 patients/year.

  • In a cross-sectional 3-year study, ~260 patients (adult and pediatric) with preseptal and orbital cellulitiis, 11 pediatric patients had orbital cellulitis. This would be ~3.6 patients/year.

  • In a 5-year retrospective review, a total of 94 patients were admitted to a large referral children’s hospital with confirmed orbital cellulitis. This would be ~18.8 patients/year.
  • In a 25-year retrospective review for admitted children < 7 years within the United States military healthcare system, there was no change in the incidence of orbital cellulitis during 5 consecutive 5-year time periods. The incidence of orbital cellulitis was stable at ~4/1000 admissions.

    Questions for Further Discussion
    1. What clinical features help to distinguish orbital cellulitis from periorbital cellulitis?
    2. What are indications for surgical treatment of orbital cellulitis?
    3. What are the complications of sinusitis?

    Related Cases

    To Learn More
    To view pediatric review articles on this topic from the past year check PubMed.

    Evidence-based medicine information on this topic can be found at SearchingPediatrics.com, the National Guideline Clearinghouse and the Cochrane Database of Systematic Reviews.

    Information prescriptions for patients can be found at MedlinePlus for this topic: Eye Infections

    To view current news articles on this topic check Google News.

    To view images related to this topic check Google Images.

    Cieslak TJ, Rajnik M, Roscelli JD. Immunization against Haemophilus influenzae type B fails to prevent orbital and facial cellulitis: results of a 25-year study among military children. Mil Med. 2008 Oct;173(10):941-4.

    Eviatar E, Gavriel H, Pitaro K, Vaiman M, Goldman M, Kessler A. Conservative treatment in rhinosinusitis orbital complications in children aged 2 years and younger. Rhinology. 2008 Dec;46(4):334-7.

    Babar TF, Zaman M, Khan MN, Khan MD. Risk factors of preseptal and orbital cellulitis. J Coll Physicians Surg Pak. 2009 Jan;19(1):39-42.

    Suhaili DN, Goh BS, Gendeh BS. A ten year retrospective review of orbital complications secondary to acute sinusitis in children. Med J Malaysia. 2010 Mar;65(1):49-52.

    Georgakopoulos CD, Eliopoulou MI, Stasinos S, Exarchou A, Pharmakakis N, Varvarigou A. Periorbital and orbital cellulitis: a 10-year review of hospitalized children. Eur J Ophthalmol. 2010 Nov-Dec;20(6):1066-72.

    Seltz LB, Smith J. Durairai VD, Enzenauer R, Todd J. Microbiology and Antibiotic Management of Orbital Cellulitis. Pediatrics. 2011;127;e566-e572.

    ACGME Competencies Highlighted by Case

  • Patient Care
    1. When interacting with patients and their families, the health care professional communicates effectively and demonstrates caring and respectful behaviors.
    2. Essential and accurate information about the patients’ is gathered.
    3. Informed decisions about diagnostic and therapeutic interventions based on patient information and preferences, up-to-date scientific evidence, and clinical judgment is made.
    4. Patient management plans are developed and carried out.
    7. All medical and invasive procedures considered essential for the area of practice are competently performed.
    8. Health care services aimed at preventing health problems or maintaining health are provided.
    9. Patient-focused care is provided by working with health care professionals, including those from other disciplines.

  • Medical Knowledge
    10. An investigatory and analytic thinking approach to the clinical situation is demonstrated.
    11. Basic and clinically supportive sciences appropriate to their discipline are known and applied.

  • Interpersonal and Communication Skills
    19. The health professional works effectively with others as a member or leader of a health care team or other professional group.

  • Systems Based Practice
    24. Cost-effective health care and resource allocation that does not compromise quality of care is practiced.
    25. Quality patient care and assisting patients in dealing with system complexities is advocated.

    Author

    Donna M. D’Alessandro, MD
    Professor of Pediatrics, University of Iowa Children’s Hospital

  • What Are the Indications for Anticoagulant Medication?

    Patient Presentation
    A 5-year-old male, previously-well, child was seen on the inpatient service for a coagulase-negative Staphylococcal empyema. He was receiving intravenous antibiotics and had had a chest tube for 4 days. On day 5 he was doing well clinically with decreased oxygen needs and his temperature was almost back to normal. However, his white blood cell count increased to 15.4 x 1000/mm2 and his platelet count increased to more than 1.052 million x 1000/mm2. As this was most likely a transient thrombocytosis, the team decided to monitor the patient. The following day his platelets were 898 x 1000/mm2 and his white count was 13.2 x 1000/mm2. He received a total of 10 days of intranvenous antibiotics and repeated complete blood counts were normal at discharge.

    Discussion
    While more research is being conducted on anticoagulation therapy for children, much is still gleaned from adult research and pediatric-specific research is needed. The usual adult indications for such treatment such as myocardial infarction and stroke are uncommon in the pediatric population, while other indications such as Kawasaki disease are unknown in the adult population. Fortunately for children, thromboembolic events are much less common overall.

    Transient thrombocytosis is often seen in myelodysplastic conditions such as leukemia and usually does not cause thromboembolic events. Treatment of the underlying disease process such as leukemia or infection in the patient above normally resolves the thrombocytosis. Choice of medication depends on the underlying condition and age. Aspirin (for antiplatelet activity) for example is commonly used for Kawasaki disease but coumadin (for its Vitamin K antagonist effects) and its derivatives are not used much in children. Injectable heparin derivatives such as enoxaparin are sometimes used in children. Other antiplatelet medications such as dipyridamole or clopidogrel are usually not used in children.

    Learning Point
    Indications for anticoagulant therapy are not absolute but treatment is usually indicated for:

    • Thromboembolic events, i.e. stroke, myocardial infarction, deep venous thrombosis, pulmonary embolism, etc.
    • Mechanical prosthetic heart valves
    • Endovascular stents
    • Arrhythmias such as atrial fibrillation
    • Known disease processes with increased risk for thromboembolic events such as Kawasaki disease and nephrotic syndrome

    Other potential indications include:

    • Central venous access devices
    • Congenital heart disease procedures such as a Fontan procedure
    • Myeloproliferative disorders

    Antithrombotic treatment is usually not indicated for transient thrombocytosis as noted above unless an actual thromboembolic event occurs, then treatment would be deteremined by the specific patient circumstances.

    Questions for Further Discussion
    1. Name 2 or more other common pediatric conditions with increased risk of thrombembolic events.
    2. Is anticoagulant therapy recommended for premature infants with intraventricular hemorrhage?

    Related Cases

    To Learn More
    To view pediatric review articles on this topic from the past year check PubMed.

    Evidence-based medicine information on this topic can be found at SearchingPediatrics.com, the National Guideline Clearinghouse and the Cochrane Database of Systematic Reviews.

    Information prescriptions for patients can be found at MedlinePlus for this topic: Platelet Disorders

    To view current news articles on this topic check Google News.

    To view images related to this topic check Google Images.

    Bonduel MM. Oral anticoagulation therapy in children. Thromb Res. 2006;118(1):85-94.

    Landolfi R, Di Gennaro L, Novarese L, Patrono C. Aspirin for the control of platelet activation and prevention of thrombosis in essential thrombocythemia and polycythemia vera: current insights and rationale for future studies. Semin Thromb Hemost. 2006 Apr;32(3):251-9.

    Flynn RW, MacDonald TM, Murray GD, Doney AS. Systematic review of observational research studying the long-term use of antithrombotic medicines following intracerebral hemorrhage. Cardiovasc Ther. 2010 Jun;28(3):177-84.

    ACGME Competencies Highlighted by Case

  • Patient Care
    2. Essential and accurate information about the patients’ is gathered.
    4. Patient management plans are developed and carried out.
    8. Health care services aimed at preventing health problems or maintaining health are provided.
    9. Patient-focused care is provided by working with health care professionals, including those from other disciplines.

  • Medical Knowledge
    10. An investigatory and analytic thinking approach to the clinical situation is demonstrated.
    11. Basic and clinically supportive sciences appropriate to their discipline are known and applied.

  • Systems Based Practice
    24. Cost-effective health care and resource allocation that does not compromise quality of care is practiced.

    Author

    Donna M. D’Alessandro, MD
    Professor of Pediatrics, University of Iowa Children’s Hospital

  • Does Oppositional Defiant Disorder Abate?

    Patient Presentation
    A 3-year-old female came to clinic for help with increased aggressiveness. She previously had been a difficult infant with persistent crying and difficulty with sleeping. Her parents do not remember a night where she did not refuse to go to bed, with multiple awakenings and crying all night. They had truly tried multiple behavior management plans under the direction of a child mental health social worker. She eventually would sleep someplace in the house. In the past 2-3 months, she had become more verbally aggressive to the family and child care providers. She would take away items from a child or adult who was using the items, and would throw items at other children trying to provoke reprimands. She had been observed to wait until an adult was watching and then deliberately make messes by tipping over plants, garbage or pulling items off shelving. She would easily become upset when she didn’t get her way and had temper tantrums that were difficult for her to calm down from. The church daycare had told the family that they could not have her participate in their program. The family history was significant for heart disease, depression, and a paternal cousin has been in jail because of “anger problems.” The review of systems was negative. The social history showed no changes in family living, jobs, stress, or depression. Family denies concerns for possible abuse.

    The pertinent physical exam showed a well-appearing female with normal growth parameters. She actively pulled books off the shelf in the examination room and initially verbally refused the mother and physician. She looked at the examiner with great anger but refused to talk during the examination which was normal. The diagnosis of a child with escalating oppositional and defiant behaviors was made. A referral was made to a psychiatrist. The physician suggested that the family try to ignore the irritating utterances and behaviors as much as possible, but that behaviors that were a threat to herself or her parents needed to be addressed. They made a safety plan for her and her parents including ways to appropriately restrain her if needed. If the family felt they could not keep her safe or were feeling physically threatened by her, they were to take her to the local emergency room for evaluation.

    Discussion
    Oppositional defiant disorder (ODD) is a disruptive behavior with elements of defiance, disobedience, negativism and hostility to authority. Depending on the classification system, ODD may be a precursor to, or subtype of conduct disorder as they both share characteristics. The DSM IV criteria can be found here. ODD can be diagnosed alone or is also associated with other disorders such as ADHD, depression, and anxiety. Children are often not diagnosed with ODD until school age, but data supports temperamental antecedents even in early infancy, including exhibiting extreme emotions and activity consistent with ODD but at an earlier developmental level.

    Learning Point
    Children with ODD may or may not have abatement of symptoms as they get older. One 5-year longitudinal study of children with preschool onset of ODD found that “there was a significant relationship between the presence of a … diagnosis of ODD [at the initial time period] with later continued diagnosis of ODD….younger children were more likely to have ODD subsequently.” A literature review of the developmental origin of disruptive behavior summarized the current literature about ODD by saying “… a) the vast majority of preschool children manifest these [ODD] behaviours; b) the vast majority also learn with age to use other means of solving problems; c) some need more time than others to learn; d) there does not appear to be substantial differences between females and males; e) approximately 7% of children could be considered chronic cases from childhood to adolescence;….”

    Questions for Further Discussion
    1. What is the DSM IV criteria for conduct disorder or antisocial personality disorder?
    2. What social and educational supports are available locally for children with ODD and their families?

    Related Cases

    To Learn More
    To view pediatric review articles on this topic from the past year check PubMed.

    Evidence-based medicine information on this topic can be found at SearchingPediatrics.com, the National Guideline Clearinghouse and the Cochrane Database of Systematic Reviews.

    Information prescriptions for patients can be found at MedlinePlus for this topic: Child Behavior Disorders

    To view current news articles on this topic check Google News.

    To view images related to this topic check Google Images.

    Lavigne JV, Cicchetti C, Gibbons RD, Binns HJ, Larsen L, DeVito C. Oppositional defiant disorder with onset in preschool years: longitudinal stability and pathways to other disorders. J Am Acad Child Adolesc Psychiatry. 2001 Dec;40(12):1393-400.

    Tremblay RE. Developmental origins of disruptive behaviour problems: the ‘original sin’ hypothesis, epigenetics and their consequences for prevention. J Child Psychol Psychiatry. 2010 Apr;51(4):341-67.

    Stringaris A, Maughan B, Goodman R. What’s in a disruptive disorder? Temperamental antecedents of oppositional defiant disorder: findings from the Avon longitudinal study. J Am Acad Child Adolesc Psychiatry. 2010 May;49(5):474-83.

    ACGME Competencies Highlighted by Case

  • Patient Care
    1. When interacting with patients and their families, the health care professional communicates effectively and demonstrates caring and respectful behaviors.
    2. Essential and accurate information about the patients’ is gathered.
    3. Informed decisions about diagnostic and therapeutic interventions based on patient information and preferences, up-to-date scientific evidence, and clinical judgment is made.
    4. Patient management plans are developed and carried out.
    5. Patients and their families are counseled and educated.
    7. All medical and invasive procedures considered essential for the area of practice are competently performed.
    8. Health care services aimed at preventing health problems or maintaining health are provided.
    9. Patient-focused care is provided by working with health care professionals, including those from other disciplines.

  • Medical Knowledge
    10. An investigatory and analytic thinking approach to the clinical situation is demonstrated.
    11. Basic and clinically supportive sciences appropriate to their discipline are known and applied.

  • Practice Based Learning and Improvement
    12. Evidence from scientific studies related to the patients’ health problems is located, appraised and assimilated.
    13. Information about other populations of patients, especially the larger population from which this patient is drawn, is obtained and used.

  • Interpersonal and Communication Skills
    17. A therapeutic and ethically sound relationship with patients is created and sustained.

    Author

    Donna M. D’Alessandro, MD
    Professor of Pediatrics, University of Iowa Children’s Hospital