A. The neurologic system consists of two main divisions, the central nervous system (CNS) and the peripheral nervous system (PNS). The autonomic nervous system (ANS) is composed of both central and peripheral elements.
1. The CNS is composed of the brain and spinal cord
2. The PNS is composed of 12 pairs of the cranial nerves and the 31 pairs of the spinal nerves
3. The ANS is composed of visceral efferent (motor) and visceral afferent (sensory) nuclei in the brain and spinal cord. Its peripheral division is made up of visceral efferent and afferent nerve fibers as well as autonomic and sensory ganglia.
B. The brain is covered by three membranes.
1. The dura mater is a fibrous, connective tissue structure containing several blood vessels.
2. The arachnoid membrane is a delicate serous membrane
3. The pia mater is a vascular membrane
C. The spinal cord extends from the medulla oblongata to the lower border of the first lumber vertebrae. It contains millions of nerve fibers, and it consists of 31 nerves – 8 cervical, 12 thoracic, 5 lumber, and 5 sacral.
D. Cerebrospinal fluid (CSF) forms in the lateral ventricles in the choroids plexus of the pia mater.
It flows through the foramen of Monro into the third ventricle, then through the aqueduct of Sylvius to the fourth ventricle. CSF exits the fourth ventricle by the foramen of Magendie and the two foramens of Luschka. It then flowa into the cisterna magna, and finally it circulates to the subarachnoid space of the spinal cord, bathing both the brain and the spinal cord. Fluid is adsorbed by the arachnoid membrane.
1. Central nervous system
– The cerebrum is the center for consciousness, thought, memory, sensory input, and motor activity; it consists of two hemispheres (left and right) and four lobes, each with specific functions
– The frontal lobe controls voluntary muscle movements and contains motor areas, including the area for speech; it also contains the centers for personality, behavioural, autonomic, and intellectual functions and those for emotional and cardiac responses.
– The temporal lobe is the center for taste, hearing, and smell and, in the brain’s dominant hemisphere, the center for interpreting spoken language
– The parietal lobe coordinates and interprets sensory information from the opposite side of the body
– The occipital lobe interprets visual stimuli
– The thalamus further organizes cerebral function by transmitting impulses to and from the cerebrum. It also is responsible for primitive emotional responses, such as fear, and for distinguishing between pleasant and unpleasant stimuli
– The hypothalamus is an autonomic center that regulates blood pressure, temperature, libido, appetite, breathing, sleeping patterns and peripheral nerve discharges associated with certain behaviour and emotional expression. It also helps control pituitary secretion and stress reactions
– The cerebellum, or hindbrain, controls smooth-muscle movements, coordinates sensory impulses with muscle activity, and maintains muscle tone and equilibrium
– The brain stem, which includes the mesencephalon, pons, and medulla oblongata, relays nerve impulses between the brain and spinal cord
b. The spinal cord forms a two-way conductor pathway between the brain stem and the PNS. It is also the reflex center for motor activities that do not involve brain control
2. The PNS connects the CNS to remote body regions and conducts signals to and from these areas and the spinal cord.
3. The ANS regulated body functions, such as digestion, respiration, and cardiovascular function. Supervised chiefly by the hypothalamus.
Nursing process overview
Assessment. Neurologic assessment of children must be based on the developmental level of the child and should be aimed at determining if problems are acute or chronic, diffuse or focal, or stable or progressive.
1. Health history:
a. Elicit a description of symptoms, including onset, duration, location, and precipitation.
Cardinal signs and symptoms include:
– fainting and dizziness
– altered level of consciousness (LOC)
– abnormal gait, movements, or coordination
– developmental lags or loss of milestones
b. explore prenatal, personal and family history for risk factors for neurologic disorders.
– Prenatal: maternal malnutrition, drug use, alcohol use, and illness
– Personal: prematurity, perinatal hypoxia, birth trauma, delayed developmental
milestones, head injury, near drowning, toxic ingestions, meningitis, chronic illness, child abuse, chromosomal anomalies and substance abuse.
– Family: chromosomal anomalies, mental illness, neurologic disease, seizure disorders, mental retardation, learning problems, and neural tube defects.
2. Physical examination
a. Vital signs: also measure head circumference in children younger than 2 years
– Assess LOC, general appearance, behaviour, interactions, speech, behavioural changes
– Assess development
– Assess cranial nerve function such as papillary response
– Assess taste, olfaction, and tactile sense
– Observe abnormal movements such as tremors, seizure activity
– Assess cerebellar status such as gait, balance, coordination
– Assess reflexes
– Palpate the fontanels with infant upright position
– Assess muscle tone and strength
– Assess sensation and position sense
– Assess deep tendon and superficial reflexes
3. Diagnostic Tests:
Evaluating and diagnosing damage to the nervous system is complicated and complex. Many of the same symptoms occur in different combinations among the different disorders. To further complicate the diagnostic process, many disorders do not have definitive causes, markers, or tests.
In addition to a complete medical history and physical examination, diagnostic procedures for nervous system disorders may include the following:
– Computed tomography scan (Also called a CT or CAT scan.) – a diagnostic imaging procedure that uses a combination of x-rays and computer technology to produce cross-sectional images (often called slices), both horizontally and vertically, of the body. A CT scan shows detailed images of any part of the body, including the bones, muscles, fat, and organs. CT scans are more detailed than general x-rays.
– Electroencephalogram (EEG) – a procedure that records the brain’s continuous, electrical activity by means of electrodes attached to the scalp.
– Magnetic resonance imaging (MRI) – a diagnostic procedure that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body.
– Electrodiagnostic tests (i.e., electromyography (EMG) and nerve conduction velocity, or NCV) – studies that evaluate and diagnose disorders of the muscles and motor neurons. Electrodes are inserted into the muscle, or placed on the skin overlying a muscle or muscle group, and electrical activity and muscle response are recorded.
– Positron emission tomography (PET) – in nuclear medicine, a procedure that measures the metabolic activity of cells.
– Arteriogram (Also called an angiogram.) – an x-ray of the arteries and veins to detect blockage or narrowing of the vessels.
– Spinal tap (Also called a lumbar puncture.) – a special needle is placed into the lower back, into the spinal canal. This is the area around the spinal cord. The pressure in the spinal canal and brain can then be measured. A small amount of cerebral spinal fluid (CSF) can be removed and sent for testing to determine if there is an infection or other problems. CSF is the fluid that bathes the brain and spinal cord.
– Evoked potentials – procedures that record the brain’s electrical response to visual, auditory and sensory stimuli.
– Myelogram – a procedure that uses dye injected into the spinal canal to make the structure clearly visible on x-rays.
– Neurosonography – a procedure that uses ultra high-frequency sound waves that enable the physician to analyze blood flow in cases of possible stroke.
– Ultrasound (Also called sonography.) – a diagnostic imaging technique which uses highfrequency sound waves and a computer to create images of blood vessels, tissues, and organs.
Ultrasounds are used to view internal organs as they function, and to assess blood flow through various vessels.
Acute Bacterial Meningitis
Bacterial meningitis is an acute inflammation of the meninges and CSF. The advent of antimicrobial therapy has had a marked effect on the course and prognosis, although the use of conjugate vaccines against Haemophilus influenzae type b in 1990 has led to the most dramatic change in the epidemiology of bacterial meningitis.
Many bacteria can cause meningitis, but most common are group B streptococci during the 1st 2 mo of life and, thereafter, H. influenzae (type B), Neisseria meningitidis (meningococci) and Streptococcus pneumoniae (pneumococci). Meningococci exist in the nasopharynx of about 5% of people and spread by respiratory droplets and close contact. Only a small fraction of carriers develop meningitis; what makes them susceptible is unknown. Meningococcal meningitis occurs most often in the 1st year of life. It also tends to occur in epidemics among closed populations (eg, in military barracks, college dormitories, boarding schools).
Pneumococci are the most common cause of meningitis in adults. Especially at risk are alcoholics and people with chronic otitis, sinusitis, mastoiditis, CSF leaks, recurrent meningitis, pneumococcal pneumonia, or sickle cell disease. Incidence of pneumococcal meningitis is decreasing because of routine vaccination.
Gram-negative meningitis (most often due to Escherichia coli, Klebsiella sp, or Enterobacter sp) can occur in immunocompromised patients or after CNS surgery, CNS trauma, bacteremia , or hospitalacquired infections. Pseudomonas occasionally causes meningitis in immunocompromised or colonized patients. Haemophilus influenzae type b meningitis, now uncommon because of widespread vaccination, can occur in immunocompromised patients or after head trauma in unvaccinated people.
Staphylococcal meningitis can occur after penetrating head wounds or neurosurgical procedures (often as part of a mixed infection) or after bacteremia (eg, due to endocarditis). Listerial meningitis can occur at all ages and is particularly common among patients immunocompromised because of chronic renal failure, hepatic disorders, or corticosteroid or cytotoxic therapy after organ transplantation.
Bacteria typically reach the meninges by hematogenous spread from sites of colonization in the nasopharynx or other foci of infection (eg, pneumonia). Why some bacteria are more prone to colonize in CSF is not clear, but binding pili and encapsulation appear to play a role. Receptors for pili and other bacterial surface components in the choroid plexus facilitate penetration into CSF.
Bacteria can also enter CSF by direct extension from nearby infections (eg, sinusitis, mastoiditis) or through exterior openings in normally closed CSF pathways (eg, due to meningomyelocele, spinal dermal sinus, penetrating injuries, neurosurgical procedures).
The most common route of infection is vascular dissemination from a focus of infection elsewhere. For example, organisms from the nasopharynx invade the underlying blood vessels and enter cerebral blood supply or form local thromboemboli that release septic emboli into the bloodstream. Invasion by direct extension from infections in the paranasal and mastoid sinuses is less common. Organisms also gain entry by direct implantation after penetrating wounds, skull fractures that provide an opening into the skin or sinuses, lumber puncture or surgical procedures, anatomic abnormalities such as spina bifida, or foreign bodies such as an internal ventricular shunt or an external ventricular device. Once implanted, the organisms spread into the CSF, by which the infection spreads throughout the subarachnoid space.
The infective process is like that seen in any bacterial infection: inflammation, exudation, white blood cell accumulation, and varying degrees of tissue damage. The brain becomes hyperemic and edematous, and the entire surface of the brain is covered with a layer of purulent exudates that varies with the type of organism. For example, meningococcal exudates is most marked over the parietal, occipital, and cerebellar regions; the thick, fibrinous exudates of pneumococcal infection is confined chiefly to the surface of the brain, particularly the anterior lobes; and the exudates of streptococcal infections is similar to that of pneumonococcal infections, but thinner.
As infection extends to the ventricles, thick pus, fibrin, or adhesions may occlude the narrow passages and obstruct the flow of CSF.
A respiratory illness or sore throat often precedes the more characteristic symptoms of fever, headache, stiff neck, and vomiting. Kernig’s and Brudzinski’s signs appear in about 1?2 of patients. Adults may become desperately ill within 24 h, and children even sooner. Seizures occur in about 30%. Cranial nerveabnormalities (eg, 3rd [oculomotor] or 7th [facial] cranial nerve palsy; occasionally, deafness) and other focal deficits occur in 10 to 20%. In patients > 2 yr, changes in consciousness progress through irritability, confusion, drowsiness, stupor, and coma.
Opisthotonic posturing may occur. (neck and head hyperextended, to relieve discomfort).
Dehydration is common, and vascular collapse produces shock. Infection, particularly meningococcal, may be disseminated widely, to the joints, lungs, sinuses, and elsewhere. A petechial or purpuric rash commonly occurs in meningococcal meningitis. Examination of the head, ears, spine, and skin may reveal a source or route of infection. Spinal dimples, sinuses, nevi, or tufts of hair suggest a meningomyelocele.
In children < 2 yr, meningeal signs may be absent. In those < 2 mo, symptoms and signs are often nonspecific, particularly in early disease. Fever, hypothermia, poor feeding, lethargy, vomiting, and irritability are common presenting symptoms. Seizures, a high-pitched cry, and bulging or tight fontanelles are possible but often occur late. Subdural effusions may develop after several days; typical signs are seizures, persistent fever, and enlarging head size.
The elderly may have nonspecific symptoms (eg, confusion with or occasionally without fever). Meningeal signs may be absent or mild. Arthritis may restrict neck motion, often in multiple directions, and should not be mistaken for meningismus.
Partially treated meningitis: Patients seen early in the disease, before typical findings of meningitis appear, are sometimes diagnosed with otitis media or sinusitis and given oral antibiotics. Depending on the drug, the infection may be partially (but temporarily) suppressed. Patients may not appear as ill and have milder meningeal signs and slower disease progression. This situation can significantly hamper
recognition of meningitis.
Acute bacterial meningitis is suspected in children < 2 yr with lethargy, progressive irritability, a highpitched cry, a bulging fontanelle, meningeal signs, or hypothermia. It is suspected in patients > 2 yr with meningeal signs or unexplained alterations in consciousness, particularly in those with fever or risk factors.
Because acute bacterial meningitis, especially meningococcal, can be lethal within hours, it must be diagnosed and treated rapidly. Prompt lumbar puncture is required but should not delay immediate treatment with antibiotics and corticosteroids.
CSF pressure may be elevated. Gram stain shows organisms in CSF in 80% of patients. CSF neutrophil count usually exceeds 2000/?L. Glucose is usually < 40 mg/dL because of impaired CNS glucose transport and glucose consumption by neutrophils and bacteria. Protein is typically > 100 mg/dL. Cultures are positive in 90%; they may be falsely negative in patients who are partially treated. Latex agglutination tests can be used to detect antigens of meningococci, H. influenzae type b, pneumococci, group B streptococci, and E. coli K1 strains. However, these tests are not always routinely done because they probably add little to other routine CSF tests.
Prognosis and Treatment
Early antibiotics and supportive care have reduced the mortality rate of acute bacterial meningitis to < 10%. However, if meningitis is treated late or occurs in neonates, the elderly, or immuno-compromised patients, death is common. A poor outcome is predicted by persistent leukopenia. Survivors occasionally have deafness, other cranial nerve deficits, cerebral infarction, recurrent seizures, or mental retardation.
If acute bacterial meningitis is suspected, antibiotics and corticosteroids are given as soon as blood cultures are drawn. If the diagnosis is unclear and the patient is not very ill, antibiotics may be withheld pending CSF test results. Giving antibiotics before lumbar puncture slightly increases the probability of false-negative cultures, particularly with pneumococci, but does not affect other test results.
When initial CSF tests are inconclusive, a repeat lumbar puncture in 8 to 24 h (or sooner if the patient deteriorates) may help. If clinical and CSF findings continue to suggest aseptic meningitis, antibiotics are withheld. If the patient’s condition is serious, especially if antibiotics have been given (possibly producing falsely sterile cultures), antibiotics should be continued.
Choice of antibiotics depends on pathogen and patient age, common used mediations are: Penicillin G 200,000-300,000 u/kg/day, Also: Ampicillin, Claforan, Gentamycin. If resistant: Vancomycin.
Lumbar puncture should be repeated 24 to 48 h after starting antibiotics to confirm CSF sterility and conversion to lymphocytic predominance. Generally, antibiotics are continued for ≥ 1 wk after fever subsides and CSF is nearly normal (complete normalization may take weeks). Drug doses are not reduced when clinical improvement occurs because drug penetration commonly decreases as meningeal inflammation decreases.
Supportive therapy includes treatment of fever, dehydration, electrolyte disorders, seizures, and shock
A conjugated pneumococcal vaccine effective against 7 serotypes, including > 80% of organisms that cause meningitis, is recommended for all. Routine vaccination for H. influenzae type b is highly effective and begins at age 2 mo.
Spread of meningitis is prevented by keeping patients in respiratory isolation (droplet precautions) for the 1st 24 h of therapy. Gloves, masks, and gowns are used. Anyone who has face-to-face contact with the patient (eg, family and medical staff members) should receive postexposure prophylaxis. For meningococcal meningitis, it consists of meningococcal vaccine and chemoprophylaxis. Vaccination is especially important for containing epidemics. Chemoprophylaxis against meningococci is oral rifampin
CONDITION PRESSURE CELLS GLUCOSE PROTEIN
– Potential for injury: secondary brain injury R/T increase intracranial pressure or disease process.
– Altered comfort: pain R/T headache, muscular rigidity and I.V therapy
– Potential for injury: physiological R/T complications as seizures, hearing loss, and stress ulcer
– Fear/ anxiety child and the family R/T diagnosis of series disease.
– Assist with LP
– Position patient, reassure
– Monitor for changes in LOC, headache
– Initiate antibiotic therapy QUICKLY
– Monitor VS
– Neuro assessment:
– Patients hyperirritable QUIET environment
– Promote patient comfort:
– Control of fever: Acetaminophen. Avoid rapid reduction with shivering
– Pain relief:
– Mild analgesics: Codeine
– NO OPIATES: mask neuro symptoms
– Prevent complications:
– Increased ICP
– Monitor I/O, fluids
– Monitor electrolytes (esp Na)
– Seizure precautions Identify high risk
– Vaccinate when indicated
– Patient on contact isolation for 24 hours after antibiotic therapy begun
– Masks worn
– Immunosuppressed patients:
– Reverse isolation may be necessary to protect from nosocomial meningitis
Most common type, more prevalent in children < 4 yrs of age
– Approximately half due to entero viruses
– Occasionally associated with mumps or herpes
Symptoms, usually gradual:
– Headache, fever, malaise, GI symptoms.
– Signs of meningeal irritation develop 1-2 days after the onset of illness.
– CSF: clear, glucose level normal
– WBC count usually normal or mildly elevated
– Rest, quiet environment
– Fluids, anti-pyretic for fever
– Mild analgesics for headache
– Positioning for comfort
– Isolation: not necessary
– Handwashing (most transmitted via contact)
– Antimicrobial may be administered as a precaution