Macrocephaly
Defined here as head circumference >3standard deviations above mean for age and gender.
Principal Causes of Macrocephaly
- Hydrocephalus
- Fluid collections
- Subperiosteal
- Subgaleal
- Subdural
- Benign enlargement of the extraaxialspaces of infancy (benign subdural effusions of infancy)
- Subdural hematoma
- Increased skull thickness
- Chronicsevere anemia
- Cranioskeletal dysplasias
- Megalencephaly
- Anatomic
- Benignfamilial macrocephaly
- Neurocutaneous disorders
- Megalencephaly with a neurologic disorder
- Other
- Metabolic
Clinical Features and Diagnosis
Hydrocephalus
Conditionin which cerebral ventricular system is enlarged because of excessive amountof cerebrospinal fluid.2 basic types of hydrocephalus: communicatingand noncommunicating.In communicating hydrocephalus, blockis outside ventricular system, usually at level of arachnoid granulations.May be due to meningitis, intracranial hemorrhage, meningeal malignancy,or choroid plexus papilloma.In noncommunicating hydrocephalus,block occurs in ventricular system, which impairs CSF flow throughnormal cerebrospinal pathways. May be due to malformations (aqueductalstenosis, Chiari malformations, Dandy-Walker syndrome) or mass lesions(brain tumor, arachnoid cyst, vein of Galen aneurysm) compressingventricular system. Aqueductal obstruction also may be producedby intraventricular hemorrhage and gliosis secondary to infection.Clinical presentation depends on ageof the child and underlying cause and severity of lesion. In earlyinfancy, excessive rate of head growth is usually initial finding,and head U/S is diagnostic. Acute or progressive increasein intracranial pressure may produce irritability, vomiting, lethargy,and full or tense anterior fontanelle. After anterior fontanellehas closed, most children with hydrocephalus have excessive rateof head growth but are otherwise asymptomatic until significantincrease in intracranial pressure occurs. In this circumstance,characteristic findings include severe headache, recurrent vomiting, seizures,alteration in consciousness, and papilledema.CT or MRI is diagnostic. Fluid Collections
Subperiosteal
Cephalohematoma is collection of blood insubperiosteum of cranial bone, usually parietal bone. Fluid collectionconforms to suture margins and is usually due to birth trauma. Diagnosisis usually clinical.
Subgaleal
Collection of blood in subgaleal space occurssecondary to birth trauma and presents as soft tissue mass. Usuallyresolves over several weeks, but calcification can occur and masscan persist for longer time.
Subdural
Benign Enlargement of Extraaxial Spaces of Infancy (BenignSubdural Effusions of Infancy)
Usual presentationof these benign collections of fluid is enlarged head in a child <2 yrsof age who is otherwise developing normally.Reason for these collections is unknown.CT or MRI is diagnostic. Subdural Hematoma
Enlargedhead size can occur with subdural hematoma.With significant increase in intracranialpressure, irritability, vomiting, bulging fontanelle, seizures,and alteration in consciousness are common findings.Usual cause is head trauma (accidentalor nonaccidental). Subdural hematomas also can become chronic andrebleed.Neuroimaging with head U/S,CT, or MRI is diagnostic. Increased Skull Thickness
Chronic Severe Anemia
Extensive marrow hyperplasia with chronicsevere anemia produces overgrowth of cranium, particularly frontaland parietal bones. Most striking example is homozygous beta-thalassemia [see Chap. 45, Pallor (Anemia)].
Cranioskeletal Dysplasias
Several cranioskeletal dysplasias—includingrickets, osteopetrosis, osteogenesis imperfecta, craniometaphysealdysplasia of Pyle, cleidocranial dysostosis, epiphyseal dysplasia,and diaphyseal dysplasia—can produce thickened skull. Skulland skeletal radiographs should be performed as initial step in diagnosis.
Megalencephaly
Megalencephalyrefers to increase in size and weight of brain, which may be dueto anatomic or metabolic cause.Anatomic refers to increase in numberor size of brain cells without metabolic abnormality or acute encephalopathy,whereas metabolic refers to accumulation of abnormal metabolic productswithout increase in number of cells.Head size is often enlarged at birthwith anatomic megalencephaly, whereas it is usually normal at birthwith metabolic megalencephaly.In infancy storage of abnormal metabolicproducts produces enlarged head size. Anatomic
Benign Familial Macrocephaly
Common causeof megalencephaly in which head circumference exceeds ninety-eighthpercentile for age.Results of neurologic exam and headCT studies are normal.Genetic transmission generally followsautosomal-dominant pattern. Neurocutaneous Disorders
Individuals with neurofibromatosis and tuberoussclerosis may have enlarged heads (see Chap. 13, Developmental Delay).
Megalencephaly with Neurologic Disorder
Some children with enlarged heads but withoutneurocutaneous disorder have seizures, learning disabilities, andmental retardation. Genetic transmission may be autosomal-dominantor autosomal-recessive.
Other
Other anatomic causes of enlarged head sizeinclude achondroplasia and cerebral gigantism (Sotos syndrome).See Chap. 23, Growth Deficiency:Weight and Height, and Chap. 68, Tall Stature.
Metabolic
Metabolic causes of megalencephaly includeTay-Sachs disease, generalized gangliosidosis, mucopolysaccharidoses,metachromatic leukodystrophy, Alexander disease, and Canavan disease.See Chap. 13, Developmental Delay.
Diagnostic Approach
Historyand physical exam provide important clues in diagnosis of macrocephaly.Age of child is important because hydrocephalusand anatomic causes of megalencephaly may be present at birth.Head circumference percentile shouldbe compared with height and weight percentiles using CDC growthcharts (2001). If weight, height, and head circumference are samepercentile and all are >3 standard deviations above meanfor age and gender, patient most likely is normal. Children whosehead circumference is out of proportion to other growth parametersshould be investigated.It is important to remember that inprotein-calorie malnutrition, normal head size may appear largewhen compared with body size.Combination of neuroimaging modalitiesis useful in diagnosis.Head U/S is usually performed initiallyin neonates and young infants.CT is preferred for trauma and acuteneurologic deficits.MRI is considered imaging procedureof choice for evaluation of neoplasms, certain vascular and hemorrhagiclesions, and inflammatory processes affecting brain. It is alsomore sensitive and specific than head U/S or CT for evaluationof brain malformations, myelination disorders, and neurodegenerativedisorders. Other investigations depend on suspecteddiagnosis from history, physical exam, and imaging findings. References
- Aicardi J. Diseases of the nervous system,2nd ed. London: Mac Keith Press, 1998.
- Avery ME, First LR, eds. Pediatric medicine, 2nd ed.Baltimore: Williams & Wilkins, 1994.
- Ball WS Jr, ed. Pediatric neuroradiology. Philadelphia:Lippincott-Raven, 1997.
- CDC Growth Charts: United States. U.S. Department ofHealth and Human Services. Centers for Disease Control and Prevention.National Center for Health Statistics. Division of Data Services. Hyattsville,MD, 2001. World Wide Web URL: http://www.cdc.gov/growthcharts.
- DeMyer W. Microcephaly, micrencephaly, megalocephaly,and megalencephaly. In: Swaiman KF, Ashwal S, eds. Pediatric neurology:principles and practice, 3rd ed. St. Louis: CV Mosby, 1999:301–311.
- Fenichel GM. Clinical pediatric neurology: a signsand symptoms approach, 4th ed. Philadelphia: WB Saunders, 2001.
- Kirks DR, ed. Practical pediatric imaging: diagnosticradiology of infants and children, 3rd ed. Philadelphia: Lippincott-Raven,1998.
- Online Mendelian Inheritance in Man (OMIM). McKusick-NathansInstitute for Genetic Medicine, Johns Hopkins University (Baltimore,MD) and National Center for Biotechnology Information, NationalLibrary of Medicine (Bethesda, MD), 2000. World Wide Web URL: http://www.ncbi.nlm.nih.gov/omim.
- Rudolph AM, ed. Rudolph's pediatrics, 20thed. Stamford, CT: Appleton & Lange, 1996.
- Volpe JJ. Neurology of the newborn, 4th ed. Philadelphia:WB Saunders, 2001.
'>
Book Source Details
- Book Title: The Diagnostic Approach to Symptoms and Signs in Pediatrics
- Author(s): Paul S. Bellet
- Year of Publication: 2006
- Copyright Details: The Diagnostic Approach to Symptoms and Signs in Pediatrics, Copyright © 2006 Lippincott Williams & Wilkins.
Other Book Chapters Related to Swollen head
Read excerpts from these other book chapters related to Swollen head:
Medical Books Excerpts
- HEADACHE
- "Algorithmic Diagnosis of Symptoms and Signs" (2003)
- [ read ]
- Headache
- "In A Page: Pediatric Signs and Symptoms" (2007)
- [ read ]
- HEADACHE
- "Differential Diagnosis in Primary Care" (2007)
- [ read ]
- Headache
- "Handbook of Signs & Symptoms (Third Edition)" (2006)
- [ read ]
- Headache
- "A Pocket Manual of Differential Diagnosis" (1999)
- [ read ]
- Headache
- "Professional Guide to Diseases (Eighth Edition)" (2005)
- [ read ]
- Headache
- "Professional Guide to Signs & Symptoms (Fifth Edition)" (2006)
- [ read ]
- Headache
- "The 10-Minute Diagnosis Manual: Symptoms and Signs in the Time-Limited Encounter" (2000)
- [ read ]
- Headache
- "Signs & Symptoms: A 2-in-1 Reference for Nurses" (2007)
- [ read ]
- Headache
- "The Diagnostic Approach to Symptoms and Signs in Pediatrics" (2006)
- [ read ]
- Macrocephaly
- "The Diagnostic Approach to Symptoms and Signs in Pediatrics" (2006)
- [ read ]
- Headache
- "Nursing: Interpreting Signs and Symptoms" (2007)
- [ read ]
Copyright Details: The Diagnostic Approach to Symptoms and Signs in Pediatrics, Copyright © 2008 Williams & Wilkins.
More About Causes of Swollen head
» Next page:
Headache (Nursing: Interpreting Signs and Symptoms)
Rate This Website
What do you think about the features of this website?
Take our user survey and have your say:
Website User Survey
Medical Tools & Articles:
Next articles:
Tools & Services:
Medical Articles:
Forums & Message Boards
- Ask or answer a question at the Boards:
