CONGENITAL AND BRAIN MALFORMATIONS (based on Tagnawa T) PART 2 Flashcards
What are the groups of central nervous system malformations?
Neural tube defects, encephaloceles, disorders of structure specification, disorders of posterior fossa, disorders of brain growth and size, and disorders of skull growth and shape.
What accounts for the largest proportion of congenital CNS anomalies?
Neural tube defects (NTDs).
When does the neural tube normally close during development?
Between the 3rd and 4th week of in utero development.
What are the causes of neural tube defects?
Unknown causes, hyperthermia, drugs (e.g., valproic acid), malnutrition, low red cell folate levels, chemicals, maternal obesity, diabetes, and genetic mutations affecting folate pathways.
What are the major neural tube defects?
Spina bifida occulta, meningocele, myelomeningocele, encephalocele, anencephaly, caudal regression syndrome, dermal sinus, tethered cord, syringomyelia, diastematomyelia, lipoma, and iniencephaly.
What is the cause of anencephaly?
Failure of anterior neuropore closure.
Why is anencephaly incompatible with life?
It results in the absence of much of the scalp, skull, and cerebrum, although residual portions of the brainstem may be present.
What are the features of spina bifida occulta?
A midline defect of the vertebral bodies without protrusion of the spinal cord or meninges, often asymptomatic with no neurologic signs.
What are the cutaneous manifestations of spina bifida occulta?
Hemangioma, skin discoloration, pit, lump, dermal sinus, or hairy patch.
What imaging modality is best for investigating spina bifida occulta?
MRI with contrast is the best choice, while ultrasonography may be used for initial screening in neonates.
What is myelomeningocele?
A bony defect of the spine containing both meninges and neural elements, resulting from failure of posterior neuropore closure.
What is the difference between meningocele and myelomeningocele?
Meningocele contains meninges only, while myelomeningocele contains both meninges and neural elements.
Where does myelomeningocele most commonly occur?
At the lumbar or lumbosacral levels, though it can also affect the cervical or thoracic regions.
What are the causes of myelomeningocele?
Unknown causes, nutritional deficiencies, environmental factors, and folate deficiency.
What are the treatment options for myelomeningocele?
A multidisciplinary approach including surgery, supportive care, and prognosis management.
What is a Chiari type II malformation?
A congenital defect involving a small posterior fossa with crowded and distorted contents, often associated with thoracolumbar myelomeningocele.
What structures are involved in Chiari II malformation?
Midbrain, hindbrain (pons, medulla, cerebellum), cervical spinal cord, and posterior fossa.
What are the symptoms of Chiari II malformation?
Symptoms result from the downward displacement of the cerebellar hemispheres and medulla into the foramen magnum.
What is the central feature of Chiari II malformation?
A small posterior fossa with crowded and distorted contents.
What is the most common maternal factor leading to neural tube defects?
Folic acid deficiency.
Which neural tube defect is asymptomatic and often detected incidentally?
Spina bifida occulta.
How is spina bifida occulta identified on imaging?
A defect in closure of the posterior vertebral arches and laminae, typically at L5 and S1.
What are the key features of anencephaly?
Absence of the scalp, skull, and cerebral cortex, with bulging eyes due to stented forehead and an open cranial cavity.
What is the significance of a dermal sinus in spina bifida?
It may indicate an underlying tethered cord or syringomyelia.
What is the best approach for diagnosing neural tube defects prenatally?
Maternal screening, including ultrasonography and genetic testing.
What is a common visible feature in a dermal sinus?
Hypertrichosis (faun tail) or a patch of hyperpigmentation over the lesion.
How does myelomeningocele differ from spina bifida occulta?
Myelomeningocele involves protrusion of meninges and neural elements, while spina bifida occulta has no protrusion.
What is the prognosis for patients with Chiari II malformation?
Depends on the severity of associated abnormalities and complications, requiring multidisciplinary care.
How does folate deficiency contribute to neural tube defects?
Folate is essential for neural tube closure; deficiency leads to incomplete closure, causing defects.
Which neural tube defect involves the posterior neuropore?
Myelomeningocele and meningocele.
Why is multidisciplinary care important for myelomeningocele?
It addresses the surgical, neurological, and supportive needs of the patient.
What are neuronal migration disorders (NMDs)?
A group of birth defects caused by abnormal migration of neurons in the developing brain and nervous system.
What is the function of the radial glial fiber system in neuronal migration?
It guides neurons to their proper site during brain development.
What is tangential migration responsible for?
The movement of progenitor neurons destined to become cortical interneurons.
What structural abnormalities are associated with NMDs?
Schizencephaly, porencephaly, lissencephaly, agyria, macrogyria, polymicrogyria, pachygyria, microgyria, micropolygyria, neuronal heterotopias, and agenesis of the corpus callosum.
What is lissencephaly?
The absence of cerebral convolutions with a poorly formed Sylvian fissure, resembling a fetal brain at 3-4 months of development.
What causes lissencephaly?
Faulty neuroblast migration during early embryonic life.
What are the key features of schizencephaly?
Presence of unilateral or bilateral clefts within the cerebral hemispheres due to abnormal morphogenesis; the cleft may be fused or unfused.
What is gray matter heterotopia (GMH)?
A disorder characterized by ectopic clusters of neurons located along the ventricular walls or in deep white matter.
What are the subtypes of neuronal heterotopias?
Periventricular nodular heterotopias, subcortical heterotopias (including band-type), and marginal glioneuronal heterotopias.
What is the most common clinical presentation of neuronal heterotopias?
Intractable seizures.
What causes hydrocephalus?
Impaired circulation and absorption of CSF or increased production of CSF due to congenital anomalies like aqueductal stenosis or choroid plexus papilloma.
What are the two main types of hydrocephalus?
Communicating (acquired) and non-communicating (congenital).
What is the treatment for hydrocephalus?
Ventriculoperitoneal (VP) shunting.
What are the causes of communicating hydrocephalus?
Achondroplasia, basilar impression, meningeal malignancy, meningitis, post-hemorrhagic conditions, and choroid plexus papilloma.
What are the causes of non-communicating hydrocephalus?
Aqueductal stenosis, X-linked mutations, mitochondrial disorders, Chiari malformation, Dandy-Walker malformation, and Klippel-Feil syndrome.
What is microcephaly?
A condition where the head circumference measures more than 3 standard deviations below the mean for age and sex.
What are the two types of microcephaly?
Primary (genetic) microcephaly and secondary (nongenetic) microcephaly.
What is hydranencephaly?
A condition where the cerebral hemispheres are absent or replaced by membranous sacs with remnants of cortical structures.
How is hydranencephaly treated?
Ventriculoperitoneal (VP) shunting to relieve pressure, though it does not restore brain development.
What is craniosynostosis?
Premature closure of cranial sutures resulting in abnormal skull shapes.
What are the types of craniosynostosis?
Primary (abnormal skull development) and secondary (failure of brain growth and expansion).
What is the treatment for craniosynostosis?
Surgery to place plates and allow brain growth.
What distinguishes hydranencephaly from hydrocephalus?
Hydranencephaly involves absent cerebral hemispheres, while hydrocephalus involves ventricular dilation due to CSF accumulation.
What is the role of chemical signals in neuronal migration?
They guide neurons from their origin to their proper neural circuits during development.
Why is hydrocephalus more common in congenital conditions?
It is often caused by anatomical obstructions like aqueductal stenosis or Chiari malformation.
What imaging findings suggest hydrocephalus?
Enlarged ventricles visible on MRI, especially dilation of lateral and third ventricles.
What are common signs of neuronal heterotopias on imaging?
Ectopic clusters of neurons visible along ventricular walls or in deep white matter.
What is the most common differential for hydrocephalus?
Hydranencephaly.
What is the consequence of faulty neuronal migration in lissencephaly?
Severe mental retardation, seizures, and absence of brain convolutions.
What are the features of schizencephaly on imaging?
Unilateral or bilateral clefts in the cerebral hemispheres, which may be fused or unfused.
How is VP shunting helpful in hydrocephalus?
It diverts excess CSF to the peritoneal cavity, relieving pressure in the brain.
What conditions are commonly associated with secondary craniosynostosis?
Failure of brain growth and expansion.
What is a common visible sign of gray matter heterotopia?
Clusters of neurons visible as nodules on MRI scans.
Why is microcephaly common in developmentally delayed children?
It often results from genetic or nongenetic factors that impair brain development.
What is the typical appearance of lissencephaly on imaging?
Smooth brain surface with absent convolutions and poorly formed Sylvian fissure.
Why does hydranencephaly not improve with shunting?
Because there are no cerebral hemispheres to recover function.
What is cerebral palsy (CP)?
A group of permanent disorders of movement and posture development caused by non-progressive disturbances in the developing fetal or infant brain.
What is the prevalence of cerebral palsy?
1.5 to 4 per 1,000 live births or children of a defined age range.
Why is cerebral palsy considered non-progressive?
The underlying pathology is static, though clinical manifestations may change over time.
What are common comorbidities in cerebral palsy?
Cognitive and learning difficulties, GERD, seizures, sensory impairments, scoliosis, hip dysplasia, and sleep disorders.
What are prenatal risk factors for cerebral palsy?
Hyperemesis gravidarum, intrauterine infections, toxemia, teratogenic drugs, maternal malnutrition, and chromosomal abnormalities.
What are perinatal risk factors for cerebral palsy?
Prematurity, breech delivery, intrauterine asphyxia, low Apgar score, seizures, and respiratory distress syndrome.
What are postnatal risk factors for cerebral palsy?
Head trauma, CNS infections, toxic encephalopathies, and cerebrovascular accidents.
What is the most common cause of cerebral palsy postnatally?
CNS infections.
What is the primary clinical manifestation of cerebral palsy?
Motor delay and abnormal muscle tone.
How is cerebral palsy diagnosed?
Through history and physical examination; it is a clinical diagnosis.
What is spastic cerebral palsy characterized by?
Increased muscle tone.
What is non-spastic cerebral palsy characterized by?
Decreased or fluctuating muscle tone.
What are the classifications of cerebral palsy based on topographical distribution?
Monoplegia, diplegia, hemiplegia, paraplegia, and quadriplegia.
What does monoplegia mean in cerebral palsy?
Only one limb is affected.
What does diplegia mean in cerebral palsy?
The legs are affected more than the arms, primarily impacting the lower body.
What does hemiplegia mean in cerebral palsy?
The arm and leg on one side of the body are affected.
What does paraplegia mean in cerebral palsy?
The lower half of the body, including both legs, is affected.
What does quadriplegia mean in cerebral palsy?
All four limbs are involved; ‘plegia’ indicates no movement, while ‘paresis’ indicates some movement.
What is the Gross Motor Function Classification System (GMFCS)?
A widely used system to classify cerebral palsy based on severity and gross motor function.
What are the levels of severity in cerebral palsy?
Mild, moderate, and severe.
What defines mild cerebral palsy?
The child can move without assistance and perform daily activities independently.
What defines moderate cerebral palsy?
The child requires braces, medications, or adaptive technology for daily activities.
What defines severe cerebral palsy?
The child requires a wheelchair and faces significant challenges in daily activities.
What therapies are available for cerebral palsy patients?
Physical therapy, occupational therapy, speech therapy, medications for spasticity, and surgical interventions.
What are common signs in the physical examination of cerebral palsy?
Delayed motor milestones, head lag, spasticity, and specific tone abnormalities in the lower extremities.
What are the most common prenatal infections associated with cerebral palsy?
Toxoplasmosis, rubella, cytomegalovirus, herpes, and syphilis.
How does prematurity increase the risk of cerebral palsy?
Premature infants are more likely to experience hypoxia, low Apgar scores, seizures, and respiratory distress syndrome.
What is the most common type of cerebral palsy?
Spastic cerebral palsy.
What is sialorrhea, a common comorbidity in cerebral palsy?
Excessive drooling or difficulty managing oral secretions.
Why is the timing of the insult important in diagnosing cerebral palsy?
It helps determine whether the condition is congenital or acquired postnatally.
What is the classification of cerebral palsy based on muscle tone?
Spastic, non-spastic, and mixed.
What are common gross motor challenges in cerebral palsy patients?
Difficulty walking, running, or performing coordinated movements.
Why are low Apgar scores significant in cerebral palsy?
They indicate potential birth asphyxia or other perinatal complications linked to brain injury.
How does breech delivery increase the risk of cerebral palsy?
It may result in hypoxia or traumatic brain injury during delivery.
What is the significance of the GMFCS in cerebral palsy management?
It helps guide therapy and interventions based on the child’s motor function level.
What are the most common postnatal causes of cerebral palsy?
Head trauma, CNS infections, and toxic encephalopathies.
Can the clinical manifestations of cerebral palsy change over time?
Yes, though the underlying pathology remains non-progressive.
Why are patients with cerebral palsy prone to osteopenia?
Reduced mobility and nutritional challenges contribute to decreased bone density.
What are common feeding challenges in cerebral palsy patients?
Dysphagia, growth delays, and nutritional deficiencies.
What is the role of early intervention in cerebral palsy management?
It helps improve motor function, communication, and overall quality of life.
What is the clinical classification of a patient with cerebral palsy?
Severity: Severe; Muscle tone: Spastic; Topographical location: Quadriparetic; GMFCS: V.
What are common associated conditions in cerebral palsy?
Developmental delay, ophthalmologic and hearing impairments, speech and language delay, feeding and swallowing dysfunction, seizures, and epilepsy.
What are the neuroimaging options for cerebral palsy?
CT scan and MRI; MRI is preferred for detailed brain imaging, but CT scan is more affordable.
When should metabolic or genetic testing be considered in CP patients?
If there is evidence of deterioration, episodes of metabolic decompensation, or developmental malformations.
What are the primary therapeutic interventions for cerebral palsy?
Physical therapy, occupational therapy, speech therapy, behavior therapy, and multidisciplinary team care.
What drugs are used to manage spasticity in cerebral palsy?
Diazepam, Tizanidine, Dantrolene, Baclofen (oral or intrathecal), and Botulinum toxin type A.
What is the role of Botulinum toxin in cerebral palsy management?
Injected into spastic muscles every three months, combined with rehabilitation, to reduce spasticity.
What is the Gross Motor Function Classification System (GMFCS)?
A system used to classify the severity of motor impairment in cerebral palsy patients.
What is the prognosis if a child older than 4 years has not achieved sitting balance?
Independent ambulation is unlikely.
What is the prognosis for a 2-4 year-old child who cannot sit?
The prognosis is poor.
What primitive reflexes indicate poor prognosis in cerebral palsy?
Persistence of sucking, swallowing, and Moro reflexes.
What are the main types of spasticity in cerebral palsy based on affected regions?
Hemiplegia (one side), Diplegia (legs more affected than arms), and Quadriplegia (all four limbs).
What is the difference between hemiplegia and diplegia in cerebral palsy?
Hemiplegia affects one side of the body, while diplegia primarily affects the legs.
What are the most common comorbid conditions in cerebral palsy?
Intellectual disability, seizures, feeding issues, scoliosis, and recurrent pneumonia.
What is the primary cause of cerebral palsy?
Lesions or insults to the developing brain, often due to hypoxic-ischemic events.
What is the significance of a multidisciplinary team approach in CP management?
It ensures comprehensive care, involving neurologists, therapists, social workers, and sometimes orthopedic surgeons.
What are the guidelines for prognostication in cerebral palsy?
Educate families on the lifelong nature of CP, and emphasize the importance of proper care to improve quality of life.
What are common causes of death in cerebral palsy patients?
Recurrent pneumonia and infections.
What therapeutic options lack strong evidence in cerebral palsy treatment?
Stem cell therapy, cannabinoids, and erythropoietin.
What is the role of erythropoietin in cerebral palsy?
Trials have shown it is not effective for treating CP.
Why is stem cell therapy not recommended for cerebral palsy?
There is insufficient evidence to support its safety or effectiveness.
What are the primary goals of physical therapy in cerebral palsy?
To improve mobility, posture, and overall motor function.
What is the effect of diazepam in cerebral palsy management?
It reduces spasticity but may cause increased drooling.
What is the role of therapeutic suits in cerebral palsy management?
They assist with posture and mobility but are expensive and not widely available.
What imaging findings are commonly seen in cerebral palsy patients?
Lesions indicating non-progressive brain damage, such as hypoxic-ischemic changes or malformations.
What is the significance of GMFCS Level V in cerebral palsy?
It indicates severe motor impairment, with the patient being unable to ambulate independently.
What is the long-term outlook for well-cared-for children with severe cerebral palsy?
They can live into adulthood if provided with proper care and support.
What is the role of cannabinoids in cerebral palsy treatment?
They are being studied for spasticity management, but evidence remains poor.
What is the primary treatment for spasticity in cerebral palsy?
A combination of medication (e.g., Baclofen, Botox) and rehabilitation.
Why is CT scan often preferred over MRI in resource-limited settings?
It is more affordable, although MRI provides better brain imaging.
What is the role of botulinum toxin in CP spasticity management?
It is injected into spastic muscles to reduce stiffness and improve mobility temporarily.
What are the main causes of recurrent infections in CP patients?
Feeding issues leading to aspiration pneumonia and weakened immune systems.
Why is feeding support critical in cerebral palsy management?
To prevent malnutrition, aspiration, and related complications.
What are the most effective interventions for speech delays in CP?
Speech therapy and augmentative communication devices.
What is the primary purpose of occupational therapy in CP?
To improve daily living skills and independence.
What is the key difference between spastic and non-spastic CP?
Spastic CP involves increased muscle tone, while non-spastic CP involves decreased or fluctuating tone.
What is the most common risk factor for hypoxic-ischemic encephalopathy leading to CP?
Birth asphyxia or perinatal complications like prolonged labor.
