HLTH 2501: congenital neurological disorders and seizures Flashcards
hydrocephalus
is a condition mostly in infants is which excess CSF accumulates within the skull, compressing the brain tissues and blood vessels; this can occur because the sutures of the skull have no yet closed
why does excess CSF form in hydrocephalus?
because there is usually an obstruction in some area, causing more to be produced than is absorbed
two types of hydrocephalus
noncommunicating (obstructive) or communicating
noncommunicating hydrocephalus
occurs in babies when the flow of CSF through the ventricular system is blocked, usually at the aqueduct of Sylvius or the foramen magnu,
what does noncommunicating hydrocephalus result from?
a fetal developmental abnormality like stenosis, a neural tube defect or Arnold-Chiari malformation; the obstruction will lead to increased back pressure of fluid in the ventricles, which gradually enlarge
communicating hydrocephalus
occurs when the absorption of CSF through the subarachnoid villi is impaired, resulting in increased pressure of CSF in the system
atresia
is the absence of a canal or opening at the connecting channels between the ventricles
most common causes of hydrocephalus
stenosis, an atreisa, or a thickened arachnoid membrane
signs of hydrocephalus
enlarges head, scalp veins appear dilated, enlarged eyes (sunset sign), pupil response is slow, lethargy, and high-pitched dry
sunset sign
is when the white sclera of the eyes is visible above the coloured pupil; is a sign of hydrocephalus in infants
hydrocephalus signs in adults
decreased memory, difficulty in coordination, impaired balance, and urinary incontinence
when may hydrocephalus develop in adults?
from obstruction due to tumors, infection, or scar tissue, as well as meningitis
diagnosis for hydrocephalus
a CT or MRI
treatment for hydrocephalus
surgery to remove an obstruction or provide a shunt for CSF from the ventricle
spina bifida
refers to a group of neural tube defects that are congenital anomalies of varying severity
how do spina bifida disorders develop?
is failure of the posterior spinous processes on the vertebrae to fuse, which may permit the meninges and spinal cord to herniate, resulting in neurologic impairment
where does spina bifida most commonly develop?
the lumbar region
three types of spina bifida
spina bifida occulta, meningocele, and myelomeningocele
spina bifida occulta
develops when the spinous processes do not fuse, but when herniation of the spinal cord and meninges does not occur, leaving a small gap in the bones of the spine
how is spina bifida occulta diagnosed?
by a dimple or a tuft on hair present on the skin over the site
meningocele
spinous processes do not fuse but herniation of the meninges occurs through the defect and the meninges and CSF form a sac on the surface; neurological impairment is usually not present
myelomeningocele
the most serious form of spina bifida and occurs when there is herniation of the spinal cord and nerves along with the meninges and CSF, resulting in considerable neurological damage
what spina bifida is often seen in conjunction with hydrocephalus?
myelomeningocele
how is spina bifida generally diagnosed?
by alpha-fetoprotein that has leaked from the defect into the amniotic fluid surrounding the fetus and ultrasounds
spina bifida causes
is multifactorial; genetic conditions like anencephaly or environmental conditions like exposure to radiation, gestational diabetes, and deficits of vitamin A or folic acid
anencephaly
is the absence of cerebral hemispheres and superior cranial vault
what spina bifida disorders appear as a protruding sac over the spine?
meningocele and myelomeningocele
myelomeningocele neurological impairments
may be lost sensory and motor function at and below the level of the herniation, muscle weakness or paralysis, and bladder and bowel control may be lost
spina bifida treatment
surgical repair may be done in utero before birth and PT and OT after birth to manage neurological deficits
potential complications of surgery with spina bifida
rupture and infection
cerebral palsy
is a group of disorders marked by some degree of motor impairment, caused by genetic mutations, abnormal fetal formation, infection, or brain damage in the perinatal period
what may impact the brain in a child with cerebral palsy?
mechanical trauma, hypoxia, hemorrhage, hypoglycemia, hyperbilirubinemia, or infection
major causes of cerebral palsy
hypoxia or ischemia which can occur prenatally, perinatally, or postnatally
what can hypoxia be caused by?
placental complications, a difficult delivery, hemorrhage, aspiration, or respiratory impairment
kernicterus
occurs when bilirubin crosses the blood-brain barrier and damaged the neurons
what is cerebral palsy classified on?
the area affected (ex. quadriplegia or diplegia) or on the basis of the motor disability
4 types of cerebral palsy
spastic, dyskinetic, ataxic, and mixed
largest group of cerebral palsy
spastic paralysis
spastic paralysis
results from damage to the pyramidal tracts, the motor cortex, or from general cortical damage; is characterized by hyperreflexia, increased muscle tone, and the scissors gait
scissors gait
on the toes and with crossed legs
dyskinetic cerebral palsy
results from damage to the extrapyramidal tract, basal nuclei, and cranial nerves; characterized by athetoid, choreiform involuntary movements, and loss of coordination with fine movements
athetoid
slow, involuntary writhing
choreiform
rapid and jerky movements
ataxic cerebral palsy
commonly develops from damage to the cerebellum and manifests as loss of balance and coordination
why do spasms occur in cerebral palsy?
increased muscle tone
general signs of cerebral palsy
spasticity, unilateral use of hands and feet, writhing movements, unusual positions, impaired intellectual function, impaired communication and speech, seizures, and visual problems
why is communication hard for cerebral palsy individuals?
because of motor disability, possible impaired mentation, and visual or hearing defects
learning disabilities in those with cerebral palsy
ADD, spatial disorientation, and hyperactivity
what type of seizure is common for cerebral palsy individuals?
tonic-clonic
visual problems in those with cerebral palsy
astigmatism and strabismus
treatment for those with cerebral palsy
speech therapy, PT (Medak program), regular exercise, OT, seizure medication, and hearing devices
what do seizures result from?
uncontrolled, excessive discharge of neurons in the brain, which cause abnormal motor or sensory activity, and possibly loss of consciousness
what are recurrent seizures called?
convulsions or epilepsy
what are seizure disorders classified on?
their location in the brain and their clinical features (including EEG patterns during and between)
generalized seizures
have multiple foci or origins in the deep structures of both cerebral hemispheres and the brain them, and cause loss of consciousness
partial seizures
have a single or focal origin, often in the cerebral cortex, and may or may no involve altered consciousness; may progress to generalized seizures
primary seizures
are idiopathic
secondary seizures
are acquired with an identified cause such as PTSD
what systemic causes may cause seizures?
hypoglycemia or withdrawl from drugs
neurons causing seizures
are hyperexcitable and have a lowered threshold for stimulation; they can be stimulated by physiologic changes like alkalosis or flashing lights
how are seizures analyzed?
EEG’s and MRI’s
status epilepticus
is recurrent or continuous seizures without recovery of consciousness; can lead to hypoxia, hypoglycemia, acidosis, and decreased BP
causes of seizures
varies and is idiopathic but are associated with 4 genes, CP, head injuries, tumor, infections, hemorrhage in the brain, renal failure, and substance withdrawal
precipitating factors
are seizure triggers like physical stimuli, loud noises, bright lights, or biochemical stimuli like stress, excessive premenstrual retention, hypoglycemia, change in medication or hyperventilation (alkalosis)
another name for absence seizures
petit mal
absence seizures
common in children, last about 5-10 seconds, and may occur many times in a day; there is a brief loss of awareness, sometimes facial movements, and no memory of the episode
another name for tonic-clonic seizures
grand mal
tonic-clonic seizures
may occur spontaneously or after simple seizures; includes prodromal signs, an aura, loss of consciousness, strong muscle contraction, followed by a clonic stage and consciousness returning; the person is fatigued, with aching muscles after
prodromal signs of a tonic-clonic seizure
nausea, irritability, depression, or muscle twitching
aura
is a peculiar visual or auditory sensation, immediately preceding the loss of consciousness
tonic muscle contraction
is flexion, followed by extension of the limbs and rigidity in the trunk
clonic stage
is when the muscles alternately contract and relax, resulting in a series of forceful jerky movement; may involve foaming at the mouth and bowel and bladder incontinence
why may hypoxia occur with a seizure?
the individual may have airway obstruction due to excess saliva and tongue position, while contracting muscles have a higher need for O2
types of general seizures
tonic-clonic and absence
another name for partial seizures
focal seizures
partial seizures
arise from an epileptogenic focus, often related to a single area of damage in the cortex
signs of a partial seizure
repeated motor activity causing jerking or turning the head or eye aside, sensation such as tingling that beings in the one area and spreads, auditory or visual experiences, and memory and consciousness remain, although awareness is reduced
jacksonian seizure
is a focal motor seizure in which the clonic contraction begins in a simple area and spreads progressively
temporal lobe seizures
aka psychomotor seizures; these are complex, partial seizures that originate in the temporal lobes, but may also involve the frontal lobe and limbic system
signs of a temporal lobe seizure
an aura like the perception of a odd odor, bizarre behaviour like waving and clapping the hands, visual or auditory hallucinations or feeling of deja vu, and the person is unresponsiveness during the episode
treatment for seizures
anticonvulsant drugs like phenytoin raise the threshold for neuronal stimulation which are often combined with sedatives like phenobarbital
adverse effects for seizure medication
they may affect dosage of other medications, cause gingival hyperplasia, reduce WBC count, and reduce blood-clotting capability
