Pneumococcal meningitis - Clinicals, Diagnosis, and Management

Neurology

Clinicals - History

Fact Explanation
Introduction Meninges are the lining that covers the brain and spinal cord. Meningitis is inflammation of the meninges around the brain and spinal cord. It is usually caused by an infectious pathogens such as bacteria, virus, fungi and parasites. Depending on the duration of the symptoms, it can be subdivided into acute and chronic form. Bacterial meningitis is a medical emergency requiring immediate treatment. Streptococcus pneumoniae is the most commonest causative pathogens for bacterial meningitis. Among bacterial causes of meningitis and is associated with the highest case-fatality rate in meningitis. It and is most commonest bacteria causing the permanent sequelae in the affected person. Introduction
Meninges are the lining that covers the brain and spinal cord. Meningitis is inflammation of the meninges around the brain and spinal cord. It is usually caused by an infectious pathogens such as bacteria, virus, fungi and parasites. Depending on the duration of the symptoms, it can be subdivided into acute and chronic form. Bacterial meningitis is a medical emergency requiring immediate treatment. Streptococcus pneumoniae is the most commonest causative pathogens for bacterial meningitis. Among bacterial causes of meningitis and is associated with the highest case-fatality rate in meningitis. It and is most commonest bacteria causing the permanent sequelae in the affected person.
Headache Once the organism entered through the blood brain barrier, immune system of the body gets activated to release various cytokines and chemokines with infiltration of granulocytes. Further it releases reactive oxygen radicals to cause more endothelial and nearby tissue damage. These can cause meningeal irritation, increased intracranial damage and cerebral edema. Headache
Once the organism entered through the blood brain barrier, immune system of the body gets activated to release various cytokines and chemokines with infiltration of granulocytes. Further it releases reactive oxygen radicals to cause more endothelial and nearby tissue damage. These can cause meningeal irritation, increased intracranial damage and cerebral edema.
Fever TNF-α, IL-1β, and IL-6 are released during the inflammatory response, triggering a series of other inflammatory mediators including pro- and anti-inflammatory cytokines, chemokines, reactive oxygen species and reactive nitrogen intermediates. Inflammation of the meninges and endothelium releases pyrogens causing fever. Fever
TNF-α, IL-1β, and IL-6 are released during the inflammatory response, triggering a series of other inflammatory mediators including pro- and anti-inflammatory cytokines, chemokines, reactive oxygen species and reactive nitrogen intermediates. Inflammation of the meninges and endothelium releases pyrogens causing fever.
Vomiting Vomiting is a common finding in the meningitis. Vomiting is the actual oral expulsion of gastrointestinal contents, due to the contractions of the gut and the thoracoabdominal wall musculature. Vomiting center is activated directly by irritants/toxic substances by the organism or indirectly by the stimuli from the cerebral cortex and thalamus, vestibular region, and chemoreceptor trigger zone (CRTZ) and due to the inflammatory response triggering the part of the brain which is in contact with blood. Also it can be due to the increased ICP and meningeal stretching. Vomiting
Vomiting is a common finding in the meningitis. Vomiting is the actual oral expulsion of gastrointestinal contents, due to the contractions of the gut and the thoracoabdominal wall musculature. Vomiting center is activated directly by irritants/toxic substances by the organism or indirectly by the stimuli from the cerebral cortex and thalamus, vestibular region, and chemoreceptor trigger zone (CRTZ) and due to the inflammatory response triggering the part of the brain which is in contact with blood. Also it can be due to the increased ICP and meningeal stretching.
Sensitivity to light (photophobia) Inability to tolerate light is due to the meningism that indicates inflammatory activation of the trigeminal sensory nerve fibers in the meninges. Sensitivity to light (photophobia)
Inability to tolerate light is due to the meningism that indicates inflammatory activation of the trigeminal sensory nerve fibers in the meninges.
Pain during retraction of the neck Due to the meningeal irritation. Pain during retraction of the neck
Due to the meningeal irritation.
Seizures Altered cerebral perfusion pressure can cause reduction of the cerebral blood flow and ischaemia. Seizures
Altered cerebral perfusion pressure can cause reduction of the cerebral blood flow and ischaemia.
Decreased alertness and drowsiness There can be increased intracranial pressure which may be due to the increased blood brain barrier permeability, swelling of the cellular elements of the brain, interstitial edema results from obstruction of flow in normal CSF pathways etc. Neuronal cell death and cerebral edema may also contribute to the drowsiness. Decreased alertness and drowsiness
There can be increased intracranial pressure which may be due to the increased blood brain barrier permeability, swelling of the cellular elements of the brain, interstitial edema results from obstruction of flow in normal CSF pathways etc. Neuronal cell death and cerebral edema may also contribute to the drowsiness.
Excessive crying, refusing the feeds Infants and young children present with nonspecific features. Excessive crying, refusing the feeds
Infants and young children present with nonspecific features.
Hearing loss Inflammation can extends to the cranial nerves, when the 8th nerve is involved that causes sensorineural type hearing loss. Hearing loss
Inflammation can extends to the cranial nerves, when the 8th nerve is involved that causes sensorineural type hearing loss.
Visual problems Visual problems Involvement of the optic and other cranial nerves related to the vision can be the cause. Visual problems
Visual problems Involvement of the optic and other cranial nerves related to the vision can be the cause.
History of immunodeficiency People with immune deficiency like malignancy, chemotherapy, long term steroid use, organ transplant and HIV AIDS are particularly vulnerable for the disease. History of immunodeficiency
People with immune deficiency like malignancy, chemotherapy, long term steroid use, organ transplant and HIV AIDS are particularly vulnerable for the disease.

Clinicals - Examination

Fact Explanation
Febrile Fever is one of the most common presenting features. This is due to the infection. Febrile
Fever is one of the most common presenting features. This is due to the infection.
Stiff neck Nuchal rigidity is present due to the meningeal irritation. Stiff neck
Nuchal rigidity is present due to the meningeal irritation.
Kernig sign This is a bedside diagnostic sign used to evaluate suspected cases of meningitis. Patient is kept in supine position, hip and knee are flexed, the knee is slowly extended by the examiner. It is positive if there is a resistance or pain during extension. Kernig sign
This is a bedside diagnostic sign used to evaluate suspected cases of meningitis. Patient is kept in supine position, hip and knee are flexed, the knee is slowly extended by the examiner. It is positive if there is a resistance or pain during extension.
Brudzinki sign Another sign of meningeal irritation. First one hand is kept behind the patient's head and the other on chest in order to prevent the patient from rising, passive flexion of the neck produces reflex flexion of the patient's hips and knees in a positive Brudzinski's sign. Brudzinki sign
Another sign of meningeal irritation. First one hand is kept behind the patient's head and the other on chest in order to prevent the patient from rising, passive flexion of the neck produces reflex flexion of the patient's hips and knees in a positive Brudzinski's sign.
Tachycardia and hypotension Fast heart rate is observed in hypotensive, confused patients. Tachycardia and hypotension
Fast heart rate is observed in hypotensive, confused patients.
Mental status changes Alteration in mental status is a poor prognostic indicator. Mental status changes
Alteration in mental status is a poor prognostic indicator.
Focal neurological signs Subdural effusion or cerebral-space-occupying lesions such as abscess formation can cause these symptoms. Abscees may be due to perivascular extension of the lesions and are infrequent. Pneumococcal meningitis may progress to an extensive suppurative myelitis causing focal signs. Focal neurological signs
Subdural effusion or cerebral-space-occupying lesions such as abscess formation can cause these symptoms. Abscees may be due to perivascular extension of the lesions and are infrequent. Pneumococcal meningitis may progress to an extensive suppurative myelitis causing focal signs.
Growth retardation and cognitive impairment Ischaemia can cause neuronal cell death and tissue damage, if the developing brain is affected child may ends up with poor growth. Cognitive impairment is most prominent after pneumococcal meningitis. Growth retardation and cognitive impairment
Ischaemia can cause neuronal cell death and tissue damage, if the developing brain is affected child may ends up with poor growth. Cognitive impairment is most prominent after pneumococcal meningitis.
Sensorineural hearing loss Cranial nerve palsies specially VIII the nerve palsy is the cause for this hearing loss. Sensorineural hearing loss
Cranial nerve palsies specially VIII the nerve palsy is the cause for this hearing loss.
Papilloedema This is due to the increased intracranial pressure. Increased blood brain barrier permeability, swelling of the cellular elements of the brain, interstitial edema results from obstruction of flow in normal CSF pathways as in hydrocephalus are the possible causes for the raised intracranial pressure. Papilloedema
This is due to the increased intracranial pressure. Increased blood brain barrier permeability, swelling of the cellular elements of the brain, interstitial edema results from obstruction of flow in normal CSF pathways as in hydrocephalus are the possible causes for the raised intracranial pressure.
Hydrocephalus There can be involvement of the ventricles causing ventriculitis. Inflamed areas are gradually fibrosed with creating an obstruction to the cerebrospinal fluid outflow, leading to hydrocephalus. Hydrocephalus
There can be involvement of the ventricles causing ventriculitis. Inflamed areas are gradually fibrosed with creating an obstruction to the cerebrospinal fluid outflow, leading to hydrocephalus.
Ear discharge/ inflammed pharynx Group a beta-hemolytic streptococci are a common cause of pharyngitis/ upper respiratory tract infections. Ear discharge/ inflammed pharynx
Group a beta-hemolytic streptococci are a common cause of pharyngitis/ upper respiratory tract infections.
Skin sepsis Group a beta-hemolytic streptococci are also responsible for the soft tissue infection. Skin sepsis
Group a beta-hemolytic streptococci are also responsible for the soft tissue infection.
Hyperventilation There is ncreased lactic acid in cerebrospinal fluid (CSF) in patients with meningitis which can result in increased ventilation and respiratory alkalosis. This will increase with the duration of the disease. Hyperventilation
There is ncreased lactic acid in cerebrospinal fluid (CSF) in patients with meningitis which can result in increased ventilation and respiratory alkalosis. This will increase with the duration of the disease.

Investigations - Diagnosis

Fact Explanation
Lumbar puncture Opening pressure will be elevated in meningitis. Regarding the protein content in the CSF, in bacterial meningitis there is markedly elevated protein (< 1 g/l), where as in other types that may be less prominent. CSF glucose level is decreased. Markedly elevated white blood cell count with predominant neutrophils is seen in pneumococcal meningitis. Bacterial antigen detection in the CSF for Streptococcus pneumoniae will be positive. Lumbar puncture
Opening pressure will be elevated in meningitis. Regarding the protein content in the CSF, in bacterial meningitis there is markedly elevated protein (< 1 g/l), where as in other types that may be less prominent. CSF glucose level is decreased. Markedly elevated white blood cell count with predominant neutrophils is seen in pneumococcal meningitis. Bacterial antigen detection in the CSF for Streptococcus pneumoniae will be positive.
Blood culture Is done if the patient seems to be septic or lumbar puncture can not be done safely due to the possibility of increased intracranial pressure before the antibiotics. Blood culture will isolate gram-positive cocci in pairs and chains. Blood culture
Is done if the patient seems to be septic or lumbar puncture can not be done safely due to the possibility of increased intracranial pressure before the antibiotics. Blood culture will isolate gram-positive cocci in pairs and chains.
Full blood count There can be elevated leucocytes in the blood. Full blood count
There can be elevated leucocytes in the blood.
Gram stain of the ear discharge Ear discharge analysis will show a small amount of pus cells and large numbers of Gram-positive cocci. Gram stain of the ear discharge
Ear discharge analysis will show a small amount of pus cells and large numbers of Gram-positive cocci.
Computer tomography(CT) scan of the head and Magnetic Resonance Imaging(MRI) CT scan will be even better as the first investigation specially to rule out the possibility of increased intracranial pressure before doing lumbar puncture. MRI will demonstrate the inflammatory dural meningeal process with enhanced uptake over the affected areas. This also show the intracranial complications such as brain edema, hydrocephalus and infarcts. Computer tomography(CT) scan of the head and Magnetic Resonance Imaging(MRI)
CT scan will be even better as the first investigation specially to rule out the possibility of increased intracranial pressure before doing lumbar puncture. MRI will demonstrate the inflammatory dural meningeal process with enhanced uptake over the affected areas. This also show the intracranial complications such as brain edema, hydrocephalus and infarcts.
Erythrocyte sedimentation rate(ESR) and C Reactive protein(CRP) Is elevated due to the inflammation. Erythrocyte sedimentation rate(ESR) and C Reactive protein(CRP)
Is elevated due to the inflammation.
Random blood sugar Should be done immediately especially if the patient is drowsy, to rule out the hypoglycaemia. Random blood sugar
Should be done immediately especially if the patient is drowsy, to rule out the hypoglycaemia.
Chest x-ray Plain chest radiography will show homogenous opacity in the affected area compatible with consolidation that occurs in bacterial pneumonia. Chest x-ray
Plain chest radiography will show homogenous opacity in the affected area compatible with consolidation that occurs in bacterial pneumonia.

Investigations - Management

Fact Explanation
CT imaging CT imaging is performed if there is poor response within 48 hours of antibiotic treatment. CT imaging
CT imaging is performed if there is poor response within 48 hours of antibiotic treatment.
Liver function tests Medications may alter the liver functions and therefore baseline value is needed before the treatment. Liver function tests
Medications may alter the liver functions and therefore baseline value is needed before the treatment.
Renal functions and serum electrolytes Syndrome of inappropriate Antidiuretic Hormone secretion is a complication of meningitis. This can cause hyponatraemia. Reduced intake of fluids can cause electrolyte imbalances. Medications may alter the renal functions and therefore baseline value is also needed. Renal functions and serum electrolytes
Syndrome of inappropriate Antidiuretic Hormone secretion is a complication of meningitis. This can cause hyponatraemia. Reduced intake of fluids can cause electrolyte imbalances. Medications may alter the renal functions and therefore baseline value is also needed.
MRI/CT brain Increased intracranial pressure is evident on MRI by severe sulcal effacement and midline shift on brain imaging. Therefore cranial CT should be done before the lumbar puncture, specially in those present with focal neurological deficits or seizures and those who have a disturbed consciousness due to the possible risk of cerebral herniation due to raised intracranial pressure. MRI/CT brain
Increased intracranial pressure is evident on MRI by severe sulcal effacement and midline shift on brain imaging. Therefore cranial CT should be done before the lumbar puncture, specially in those present with focal neurological deficits or seizures and those who have a disturbed consciousness due to the possible risk of cerebral herniation due to raised intracranial pressure.

Management - Supportive

Fact Explanation
Immediate management This is particularly important if the patient presents with confusion and drowsiness. Airway, breathing, circulation, disability and environment need to be attended. Random blood sugar is done to exclude hypoglycaemia. Lumbar puncture needs to be done before the antibiotics started ( if the possibility of increased intracranial pressure can be rule out) If it is not safe to do the LP blood culture is done and antibiotics are started as soon as possible without delay. Immediate management
This is particularly important if the patient presents with confusion and drowsiness. Airway, breathing, circulation, disability and environment need to be attended. Random blood sugar is done to exclude hypoglycaemia. Lumbar puncture needs to be done before the antibiotics started ( if the possibility of increased intracranial pressure can be rule out) If it is not safe to do the LP blood culture is done and antibiotics are started as soon as possible without delay.
Supportive management Antipyretics (i.e. acetaminophen) and antiemetics (i.e. promethazine) may be given. Hydration should be checked and due to the possibility of syndrome of inappropriate Antidiuretic hormone, 2/3 of maintenance is preferable. Usual recommended fluid intake is less than 800 mg/day. Monitoring of the vital parameters should be done during the initial period. Supportive management
Antipyretics (i.e. acetaminophen) and antiemetics (i.e. promethazine) may be given. Hydration should be checked and due to the possibility of syndrome of inappropriate Antidiuretic hormone, 2/3 of maintenance is preferable. Usual recommended fluid intake is less than 800 mg/day. Monitoring of the vital parameters should be done during the initial period.
Prophylaxis in high risk groups Patients who had a splenectomy are vulnerable for infections with encapsulated organisms like pneumococci. Therefore penicillin prophylaxis should be given after surgery. Prophylaxis in high risk groups
Patients who had a splenectomy are vulnerable for infections with encapsulated organisms like pneumococci. Therefore penicillin prophylaxis should be given after surgery.

Management - Specific

Fact Explanation
Antibiotic therapy-Cephalosporin Emperical antibiotic therapy should be started without any delay. Preferably lumber puncture/ blood culture is done prior to the antibiotic therapy. Currently third generation cephalosporin (cefotaxime or ceftriaxone) are used as the first-line treatment for pneumococcal meningitis. Ceftriaxone alone (100 mg/kg/24 hours) can be used as the empiric treatment for suspected bacterial meningitis for patients aged 2 months to 5 years of age. It is also used alone for patients older than 5 years and ampicillin plus an aminoglycoside or ceftriaxone plus ampicillin for infants less than 2 months of age. Antibiotic therapy-Cephalosporin
Emperical antibiotic therapy should be started without any delay. Preferably lumber puncture/ blood culture is done prior to the antibiotic therapy. Currently third generation cephalosporin (cefotaxime or ceftriaxone) are used as the first-line treatment for pneumococcal meningitis. Ceftriaxone alone (100 mg/kg/24 hours) can be used as the empiric treatment for suspected bacterial meningitis for patients aged 2 months to 5 years of age. It is also used alone for patients older than 5 years and ampicillin plus an aminoglycoside or ceftriaxone plus ampicillin for infants less than 2 months of age.
Antibiotic therapy-Ampicillin Suspected bacterial meningitis in patients aged 2 months to 5 years of age can be treated with ampicillin (200-400 mg/kg/24 hours) plus chloramphenicol (75-100 mg/kg/24 hours) and ampicillin alone can be given to patients older than 5 years. Ampicillin plus an aminoglycoside or cetriaxone plus ampicillin is given for infants less than 2 months of age. Ampicillin is changed to ceftriaxone if the pneumococci are resistant to penicillin. Antibiotic therapy-Ampicillin
Suspected bacterial meningitis in patients aged 2 months to 5 years of age can be treated with ampicillin (200-400 mg/kg/24 hours) plus chloramphenicol (75-100 mg/kg/24 hours) and ampicillin alone can be given to patients older than 5 years. Ampicillin plus an aminoglycoside or cetriaxone plus ampicillin is given for infants less than 2 months of age. Ampicillin is changed to ceftriaxone if the pneumococci are resistant to penicillin.
Antibiotic therapy - Penicillin Penicillin resistance is a recognized problem in treating pneumococcal meningitis. Before this problem was identified penicillin was the standard treatment for pneumococcal meningitis. When ampicillin was not available, Crystalline penicillin G (300,000 to 500,000 IU/kg every 4-6 h) can be used instead of ampicillin. Antibiotic treatment can be changed according to the sensitivity report. Antibiotic therapy - Penicillin
Penicillin resistance is a recognized problem in treating pneumococcal meningitis. Before this problem was identified penicillin was the standard treatment for pneumococcal meningitis. When ampicillin was not available, Crystalline penicillin G (300,000 to 500,000 IU/kg every 4-6 h) can be used instead of ampicillin. Antibiotic treatment can be changed according to the sensitivity report.
Vancomycin Vancomycin (60 mg/kg/24 hours) can be used to treat pneumococcal meningitis with reduced susceptibility to ceftriaxone. Vancomycin
Vancomycin (60 mg/kg/24 hours) can be used to treat pneumococcal meningitis with reduced susceptibility to ceftriaxone.
Steroids Dexamethasone (4 mg every six hours) is given to reduce the inflammatory response occur during the anti microbial treatment. Steroid therapy is of more value when given before or with the first dose of antibiotic. Dexamethasone may reduce case fatality in pneumococcal meningitis. Steroids
Dexamethasone (4 mg every six hours) is given to reduce the inflammatory response occur during the anti microbial treatment. Steroid therapy is of more value when given before or with the first dose of antibiotic. Dexamethasone may reduce case fatality in pneumococcal meningitis.
Pneumococcal conjugate vaccine Pneumococcal conjugate vaccine is important in preventing the invasive pneumococcal diseases. It is a10 valen congugated pneumococcal and some countries have included it in the routine immunization programme. Pneumococcal conjugate vaccine
Pneumococcal conjugate vaccine is important in preventing the invasive pneumococcal diseases. It is a10 valen congugated pneumococcal and some countries have included it in the routine immunization programme.

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