Infections of the CNS: Meningitis

LIST OF INFECTIONS OF CNS

Dr. L. Surbala (MPT Neurology)

There are four main causes of infections of CNS Bacterial Viral Fungal Protozoal


Fungal infections Cryptococcal meningitis Brain abscess Spinal epidural infection


Protozoal infections Toxoplasmosis Malaria Primary amoebic meningoencephalitis


Bacterial infections Tuberculosis Leprosy Neurosyphilis Bacterial meningitis Brain abscess Neuroborreliosis


Viral infections Viral meningitis Eastern equine encephalitis St Louis encephalitis Japanese encephalitis West nile encephalitis Herpes simplex encephalitis Rabies California encephalitis virus Varicella-zoster encephalitis La crosse encephalitis Measles encephalitis Poliomyelitis

Slow virus infections, which include: Subacute sclerosing

panencephalitis Progressive

multifocal leukoencephalopathy

AIDS

MENINGITIS


INTRODUCTION It is an acute inflammation of meninges of brain

& spinal cord present with characteristic combination of pyrexia, headache & meningium (confusion or altered consciousness)

The inflammation may be caused by infection with viruses, bacteria, or other microorganisms, and less commonly by certain drugs

It can be life-threatening because of inflammation's proximity to brain & spinal cord; hence condition is classified as a medical emergency


CLINICAL FEATURES Acute onset of illness High grade of fever Severe headache Nuchal rigidity & pain Irritability & drowsiness Photophobia & phonophobia


Features of rapid ICP (normally between 6 and 18 cm water) Projectile vomiting, blurring of vision, altered sensorium &

convulsions, loss of pupillary light reflex, & abnormal posturing In infants up to 6 months of age, bulging of fontanelle

Septic shock & septicimia Cranial nerve damage Acute renal failure Meningitis caused by meningococcal bacteria may be

accompanied by a characteristic rash consists of numerous small, irregular purple or red spots

("petechiae") on trunk, LE, mucous membranes, conjuctiva, & (occasionally) palms or soles


COMPLICATIONS Meningitis can lead to serious long-term

consequences deafness epilepsy hydrocephalus cognitive deficits

if not treated quickly


TYPES Pyogenic / bacterial miningitis Tubercular miningitis Viral meningitis


PYOGENIC BACTERIAL MENINGITIS


PYOGENIC BACTERIAL MENINGITIS Causative organism

Neonates – E-coli, proteus Children – Haemiphillus influenzae type B,

Neisseria meningitidis (Meningococcus) Adolescent - N meningitidis Adult – streptococcus pneumoniae


Route of entry Direct contact of the CSF by Contaminated

lumbar puncture, Sinusitis, Trauma Ottitis media Through the blood stream

Incubation period 4- 24 hours


PATHOGENESIS The large-scale inflammation that during

meningitis largely be attributed to response of immune system

Immune cells of brain (astrocytes and microglia), respond by releasing large amounts of cytokines, hormone-like mediators that recruit other cells & stimulate other tissues to participate in an immune response.


The blood-brain barrier becomes more permeable, leading to "vasogenic" cerebral edema (swelling of brain due to fluid leakage from blood vessels)

Large numbers of WBC enter CSF, causing inflammation of meninges, & leading to "interstitial" edema (swelling due to fluid between cells).

In addition, walls of blood vessels become inflamed (cerebral vasculitis), which leads to a decreased blood flow and a third type of edema, "cytotoxic" edema


The three forms of cerebral edema all lead to an increased ICP together with low BP often encountered in acute infection,

Brain cells are deprived of oxygen & undergo apoptosis (automated cell death)


SIGNS Positive kernig’s sign & Positive brudjinski’s

Kernig's sign is assessed with patient lying supine, with hip & knee flexed to 90 degrees.

Positive Kernig's sign - pain limits passive extension of knee Brudzinski's sign – if positive, flexion of neck causes

involuntary flexion of knee & hip. Jolt accentuation maneuver helps determine whether

meningitis is present in patients reporting fever & headache The patient is asked to rapidly rotate his head horizontally;

if this does not make the headache worse, meningitis is unlikely

Papillary oedema


INVESTIGATIONS Blood analysis

TC is increased DC- neutrophillia ESR- normal Hb- normal

CSF analysis Glucose decreased Protiens increased (100-200mg/dl) Cells – neutophillia (>90%) CT or MRI scan is recommended prior to lumbar

puncture in suspects of risk


Gram stain to identify the organism Culture & sensitivity test Postmortem

The findings are widespread inflammation of pia mater and arachnoid layers

Cranial nerves & spinal cord, may be surrounded with pus


PREVENTION For some causes of meningitis, prophylaxis can be

provided in long term with vaccine against Haemophilus influenzae type B Meningococcus vaccines against Streptococcus pneumoniae with pneumococcal

conjugate vaccine (PCV) Childhood vaccination with Bacillus Calmette-Guérin (BCG)

Short-term antibiotic prophylaxis is also a method of prevention, particularly of meningococcal meningitis rifampicin, ciprofloxacin or ceftriaxone can reduce their risk

of infection , but does not protect against future infections


MANAGEMENT High dose intravenous antibiotic

Penicillin, Cephalosporin Rifampicin, norfloxacin, erythromycin

Mannitol to decrease the raised ICP Corticosteroids can also be used to prevent

complications from overactive inflammation IV fluids should be administered if hypotension or

shock are present Mechanical ventilation may be needed if level of

consciousness is low, or if evidence of respiratory failure


Seizures are treated with anticonvulsants Hydrocephalus may require insertion of a

temporary or long-term drainage device (cerebral shunt)


TUBERCULAR MENINGITIS It can be seen as a part of primary TB in

children & a part of secondary TB in adults The primary focus being in the lung


PATHOGENESIS TB bacilli reached all parts of body & remains

dormant in meninges When immunity is less the foci or bacilli will

rupture in CSF Produce TB meningitis & lots of exudates Obstruction of CSF circulation Damage to lower cranial nerves


CLINICAL FEATURES Gradually progressive disease Gradual onset of fever associated with

headache, general weight loss & weakness Loss of appetite Raised ICP Feature of lower cranial nerve paralysis (IX,

X, XI, XII) Difficulty in speaking, swallowing etc


INVESTIGATIONS Blood analysis

TC nearly normal DC – lymphocytosis ESR elevated

CSF analysis Turbid & cloudy High protien (500mg/ dl) Boderline increase in glucose Cell are increased (lymphocytosis)

Gram stain: gram positive ZN stain: AF bacilli CT scan with contrast: exudates can be seen


TREATMENT Anti – tubercular drugs Corticosteroids Mannitol


VIRAL MENINGITIS It is also known as aseptic meningitis Clinical presentation is similar to that of

acute pyogenic meningitis


INVESTIGATION Microbiological findings shows no microorganisms CSF glucose is normal Boderline increase in CSF cells (lymphocytes) &

protiens Gram stain is of no importance Polymerase chain reaction (PCR) amplify small traces of

DNA & detect presence of bacterial or viral DNA in CSF Assist in distinguishing various causes of viral meningitis

(enterovirus, herpes simplex virus 2 and mumps in those not vaccinated for this)

Serology (identification of antibodies to viruses) may be useful in viral meningitis


TREATMENT Viral meningitis typically requires supportive

therapy only Most viruses responsible for causing

meningitis are not amenable to specific treatment

Herpes simplex virus & varicella zoster virus may respond to treatment with antiviral drugs such as aciclovir


Mild cases of viral meningitis can be treated at home with conservative measures such as fluid, bed-rest, & analgesics.

Prognosis is good Gradually recovers without any treatment


PT ASSESSMENT History of presenting illness: acute or gradual onset of

illness, high grade fever Past history

Infectious history, trauma, spinal anaesthesia, lumbar puncture, sinusitis, ottitis media

Vital signs: temperature, BP, HR, RR Observation:

abnormal posturing may be seen Abnormal respiration Attitude of limb

Examination Level of conciousness, orientation, memory, speech Cranial nerve examination: signs of damage of lower cranial

nerves


Sensory screening: sensations may be intact Motor assessment

ROM, tonicity, reflexes, muscle power Chest examination: important in TB meningitis Respiratory assessment Gustatory examination: swallowing Bladder & bowel involvement Functional assessment Special test: kernig, brudjinski Investigations: blood & CSF examination, CT or MRI,

gram stain, serology


Problem list


PT MANAGEMENT (GOALS) Psychological support Positioning strategies & prevent bed sores Prevent chest complications Promote vital function Prevent DVT Promote integration of sensory input Postural correction General fitness exercise


PSYCHOLOGICAL SUPPORT Maintain a non threatening positive attitude Good support Gain confidence of the patient Counseling of family members & patient Give information as necessary only


POSITIONING STRATEGIES & PREVENT BED SORES Proper positioning with pads & cushions Use of water bed or foam mattress Regular inspection of the skin Use cotton clothing to absorb sweat Avoid dragging during transfer Regular turning & changing position


PREVENT CHEST COMPLICATIONS Breathing exercise, postural drainage &

suctioning as required Cervical & thoraxic mobility exercise Thoraxic expansion exercise Strengthening of respiratory muscles


PROMOTE VITAL FUNCTION Improve respiratory capacity with positioning &

tech s/a glossopharyngeal breathing exercise in respiratory paralysis

Keeping the neck in slight flexion improves respiratory capacity

Specific positioning increase air entry in targeted lobes


Massage & mechanical pressure provides reflex stimulus to improve peristalsis (kneading/ stroking)

Facilitate swallowing with positioning, right selection of food texture, oromotor stimulation

Maintaining cardio respiratory endurance with active exercise of possible muscle work


PREVENT DVT Active & passive ankle & toe exercise Active limb exercise Limb elevation Early mobilization as soon as possible Propped up position in bed & bed mobility

exercise


PROMOTE INTEGRATION OF SENSORY INPUT Stimulation by combined proprioceptive,

visual & auditory input Cues & commands Demonstration of activity Sensory re education if necessary Training in different environment


POSTURAL CORRECTION Proper positioning in the lying, sitting & all

functional position Use of braces, sitting & standing frames can

be helpful in children Stretching & strengthening of key postural

muscles Endurance training


GENERAL FITNESS EXERCISE Early mobilization & early propped up

position Moving around the bed Regular exercise with bouts of 15-20 min

session for 3-4 times a day Then progress to 30-45 min of exercise Maintenance can be done by 45- 60 min

session of exercise 3-5 times/wk

Infections of the CNS: Meningitis

Health & Medicine

Transcript of Infections of the CNS: Meningitis