Infectious neurologic disorders
prepared By :
Dr. Bushra Kirallah
2nd semester-2024-20245
The infectious disorders of the nervous system include meningitis,
brain abscesses, various types of encephalitis.
The clinical manifestations, assessment, and diagnostic findings, as
well as the medical and nursing management, are related to the
specific infectious process.
Meningitis
Meningitis is: inflammation of the meninges, which cover and
protect the brain and spinal cord.
The three major causes of meningitis are bacterial, viral, and
fungal infections
Meningitis can be the main reason a patient is hospitalized, or it can
develop during hospitalization; it is classified as septic or aseptic.
Septic meningitis is caused by bacteria.
The bacteria Streptococcus pneumonia and Neisseria meningitides
are responsible for the majority of cases of bacterial meningitis in
adults. In aseptic meningitis, the cause is viral or secondary to
cancer or having a weakened immune system, such as in human
immune deficiency virus (HIV).
The most common causative agents are the enter viruses.
Aseptic meningitis occurs more frequently in the summer and early
fall.
Factors that increase the risk of bacterial meningitis include tobacco
use and viral upper respiratory infection, because they increase the
amount of droplet production.
Otitis media and mastoiditis increase the risk of bacterial meningitis,
because the bacteria can cross the epithelial membrane and enter the
subarachnoid space.
People with immune system deficiencies are also at greater risk for
development of bacterial meningitis
Pathophysiology
Meningeal infections generally originate in one of two ways:
through the bloodstream as a consequence of other infections or by
direct spread, such as might occur after a traumatic injury to the
facial bones or secondary to invasive procedures.
The N. meningitides bacteria exists in the throats and nasal passages
of approximately 10% of the general population and is transmitted
by secretion or aerosol contamination
Bacterial or meningococcal meningitis also occurs as an
opportunistic infection in patients with acquired immune deficiency
syndrome (AIDS) and as a complication of Lyme disease
Due to several outbreaks among men who have sex with men,(gay,
bisexual)
Once the causative organism enters the bloodstream, it crosses the
blood–brain barrier and proliferates in the cerebrospinal fluid (CSF).
The host immune response stimulates the release of cell wall
fragments and lipopolysaccharides, facilitating inflammation of the
subarachnoid and pia mater.
Because the cranial vault contains little room for expansion, the
inflammation may cause increased intracranial pressure (ICP).
CSF circulates through the subarachnoid space, where inflammatory
cellular materials from the affected meningeal tissue enter and
accumulate
Clinical Manifestations :
Headache and fever are frequently the initial symptoms.
Fever tends to remain high throughout the course of the illness.
The headache is usually either steady or throbbing and very severe
as a result of meningeal irritation
Meningeal irritation results in a number of other well-recognized
signs common to all types of meningitis:
1. Neck immobility: A stiff and painful neck (nuchal rigidity) can
be an early sign, and any attempts at flexion of the head are
difficult because of spasms in the muscles of the neck. Usually,
the neck is supple, and the patient can easily bend the head and
neck forward.
2. Positive Kernig sign: When the patient is lying with the thigh
flexed on the abdomen, the leg cannot be completely extended
Positive Brudzinski sign: When the patient’s neck is flexed (after
ruling out cervical trauma or injury), flexion of the knees and hips is
produced; when the lower extremity of one side is passively flexed,
a similar movement is seen in the opposite extremity.
Brudzinski sign is a more sensitive indicator of meningeal irritation
than Kernig sign.
3. Photophobia (extreme sensitivity to light): This finding is common due
to irritation of the meninges,
4. A rash can be a striking feature of N. meningitidis infection, occurring in
about half of patients with this type of meningitis.
5. Skin lesions develop, ranging from a petechial rash with purpuric
lesions to large areas of ecchymosis.
6. Disorientation and memory impairment are common early in the course
of the illness.
The changes depend on the severity of the infection as well as the
individual response to the physiologic processes
7. Behavioral manifestations are also common.
8. The illness progresses, lethargy, unresponsiveness, and coma may
develop.
9. Seizures can occur and are the result of areas of irritability in the
brain.
10. ICP increases secondary to diffuse brain swelling or
hydrocephalus
Assessment and Diagnostic Findings
If the clinical presentation suggests meningitis, diagnostic testing is
conducted to identify the causative organism.
A computed tomography (CT) scan is used to detect a shift in brain
contents
a lumbar puncture in patient with altered LOC, papilledema,
neurologic deficits, new onset of seizure, immunocompromised
state, or history of central nervous system (CNS) disease.
Bacterial culture and Gram staining of CSF and blood are key
diagnostic tests
Cerebrospinal Fluid Values Diagnostic for
Meningitis
Prevention
The Advisory Committee on Immunization Practices of the Centers
for Disease Control and Prevention, recommends that the
meningococcal conjugated vaccine be given to youth at 11 to 12
years of age, with a booster dose at 16 years of age. First-year
college students and members of the military who have not been
vaccinated are at higher risk.
People in close contact with patients with meningococcal meningitis
should be treated with antimicrobial chemoprophylaxis using
rifampin (Rifadin), ciprofloxacin hydrochloride (Cipro), or
ceftriaxone sodium (Rocephin).
Therapy should be started within 24 hours after exposure because a
delay limits the effectiveness of the prophylaxis.
Vaccination should also be considered as an adjunct to antibiotic
chemoprophylaxis for anyone living with a person who develops
meningococcal infection.
Medical Management Successful outcomes depend on the early
administration of an antibiotic agent that crosses the blood–brain
barrier into the subarachnoid space in sufficient concentration to halt
the multiplication of bacteria.
Penicillin G in combination with one of the cephalosporins (e.g.,
ceftriaxone sodium, cefotaxime sodium) is most often administered
intravenously (IV), optimally within 30 minutes of hospital arrival
Dexamethasone has been shown to be beneficial as adjunct therapy
in the treatment of acute bacterial meningitis and in pneumococcal
meningitis if it is given 15 to 20 minutes before the first dose of
antibiotic and every 6 hours for the next 4 days.
Dehydration and shock are treated with fluid volume expanders.
Seizures, which may occur early in the course of the disease, are
treated with anticonvulsant medications. Increased ICP is treated as
necessary
Nursing Management
The patient with meningitis is critically ill; therefore, many of the
nursing interventions are collaborative with the physician,
respiratory therapist,
Most patients will need the following nursing interventions:
➢ Instituting infection control precautions until 24 hours after
initiation of antibiotic therapy (oral and nasal discharge is
considered infectious).
➢ Assisting with pain management due to overall body aches and
neck pain
➢ Assisting with getting rest in a quiet, darkened room.
➢ Implementing interventions to treat the elevated temperature,
such as antipyretic agents and cooling blankets.
➢ Encouraging the patient to stay hydrated either orally or
peripherally .
➢ Ensuring close neurologic monitoring
➢ Neurologic status and vital signs are continually assessed. Pulse
oximetry and arterial blood gas values are used to quickly identify
the need for respiratory support if increasing ICP compromises
the brainstem.
➢ Blood pressure (usually monitored using an arterial line) is
assessed for early manifestations of shock, which precedes
cardiac or respiratory failure.
➢ Rapid IV fluid replacement may be prescribed, but care is taken
to prevent fluid overload.
➢ measures are taken to reduce body temperature as quickly as
possible.
➢Other important components of nursing care include the
following measures: Protecting the patient from injury secondary
to seizure activity or altered LOC Monitoring daily body weight;
serum electrolytes; and urine volume
specific gravity, and osmolality, especially if syndrome of
inappropriate antidiuretic hormone (SIADH) is suspected.
Preventing complications associated with immobility, such as
pressure ulcers and pneumonia
