Malformation and Dev Neuro Flashcards
Function of Cerebral Cortex
Higher brain function, including thought. Receives and processes sensations; initiates movement
Function of Thalamus
Sensory nerve impulses pass through here on their way to the cerebral cortex
Function of Hypothalamus
Controls the endocrine system. Regulates sleep, sexual function, body temperature and water content.
Function of Basal nuclei
Islands of gray matter; helps coordinate movement.
Funcntion of cerebellum
Involved in balance and control of muscle movement
Function of brainstem (general)
Relays nerve impulses between the spinal cord and the brain. Controls vital functions such as heart rate and breathing.
3 parts of brain stem
Midbrain, PONS, Medulla
Function of Midbrain
Vision, hearing, eye movement, body movement
Function of PONS
Involved in motor control, sensory analysis. Important for level of consciousness, sleep.
Function of Medulla
Maintains breathing.
What happens in gray matter?
Nerve impulses originate?
Two abnormalities of brain volume
- Megalencephaly
- Microencephaly
Incomplete / inadequate separation of the cerebral hemispheres (right and left)
Holoproencephaly
Network of fibers connecting two hemispheres have not developed. Fairly benign.
Agenesis of Corpus Colosum
Four forebrain abnormalities:
- Microencephaly
- Megaoencephaly
- Holoproencephaly
- Agenesis of Corpus colosum
What occurs with a forebrain abnormality? What’s the prognosis?
The development of the brain is affected. Often leads to stillbirth.
What occurs with neural tube defects? What is the prognosis?
Source of the problem is in the early development of the nervous system in utero. Prognosis varies widely.
Defect: When hte soft, bony components of the skull and brain are missing. Most severe form of neural defects. Tube fails to fuse at head region.
Ancephaly
A herniation or protrusion of brain and meninges through a defect in the skull, resulting in a sac-like structure.
Encephalocele
Where does encephalocele most commonly occur?
Most commonly in occipital portion (back of head). Also in temporal, frontal, nasopharyngeal
Caudal variations of neural tube defects (3), Which is the worst?
- Spinal bifida occluda
- Meningocele
- Myelomeingocele (spina bifida cystica)*** WORST.
Spina Bifida Occluda
- What is it?
- Clinical manifestations
- Failure of spinal cord to fuse
- “Hidden”
- Sometimes completely asymptomatic, sometimes there is a tuft of hair at the surface of the skin.
Meningocele
- What is it?
- What does it look like?
- Treatment
- Herniation of meninges and spinal fluid with spinal cord intact and in appropriate location
- Sac-like cyst of meninges filled with spinal fluid forms when the neural tube fails to close completely.
- Fairly easily corrected with surgery
Myelomeningocele (Spina Bifida Cystica)
- What occurs?
- Prognosis
- Clinical manifestations
- Spinal cord and nerve roots herneate into a sac comprising the meninges.
- Worst of the caudal spinal cord abnormalities.
- Clinical manifestations may impair ability to walk, bowel / bladder control.
When does neural development occur?
3rd week of gestation
What germ cells become neural tube
–> CNS?
Ectoderm
What cells become the peripheral nervous system (Cranial nerves, spinal cord)
NEural crest cells
Define “static encephalopathy”
A condition that happens as the result of a singular injury; is not progressive in nature.
What is the most common cause of perinatally induced cerebral palsy?
Ischemia
Cerebral Palsy Risk Factors – Prenatal Maternal (9)
- Metabolic diseases
- Nutritional deficencies (eg anemia)
- Twin or multiple births
- Bleeding
- Toxemia
- Blood incompatibilities
- Exposure to radiation
- Infection
- Premature labor
Cerebral Palsy Risk Factor in Prematurity
Asphyxia leading to cerebral hemorrhage
Cerebral Palsy Risk factors – Genetic
Absence of corpus callosum, aqueductal stenosis, cerebellar hypoplasia
Cerebral Palsy Risk factors – Congenital abnormalities of the brain
Unknown causes not evident on clinical examination
Cerebral Palsy Risk factors – Perinatal (5)
- Anesthesia or analgesia during labor and delivery
- Mechanical trauma during delivery
- Immaturity at bith
- Metabolic disorders
- Electrolyte disturbances
Cerebral Palsy Risk factors – Postnatal
- Head Trauma
- Infections
- Cerebrovascular accidents
- Toxicosis
- Environmental toxins
3 parts of the brain may be affected to cause cerebral palsy.
- Name them
- Which is the most common?
(1) The primary motor cortex **
(2) Basal ganglia
(3) The cerebellum
**Most common
Three categories of clinical features of cerebral palsy (and prevalence)
(1) Spastic (70-80%)
(2) Dystenetic (10-15%)
(3) Ataxic (<5%)
How can a patient adequately manage cerebral palsy against contractures (3)?
- Physical therapy
- Hand splinting
- Botox (limited benefit)
Three manifestations of spastic cerebral palsy
- Diplegia (both legs affected)
- Hemiplegia (one side of body affected)
- Quadriplegia (all 4 limbs affected)
