Tag Archives: Cerebrospinal fluid

Hydrocephalus

Definition:
Hydrocephalus (pronounced hi-dro-SEF-a-lus) is a potentially harmful build up of cerebrospinal fluid (CSF) in parts of the brain.
CLICK & SEE THE PICTURES…………

Images from a patient with normal pressure hyd...

Images from a patient with normal pressure hydrocephalus (NPH) showing pulsations of CSF with heartbeat. (Photo credit: Wikipedia)

Cerebrospinal fluid (CSF)A clear fluid produced in the brain’s ventricular system – the four cavities in the brain. It travels throughout the brain and in the area outside the brain and spinal cord. It bathes and protects or cushions the brain and spinal cord.

Hydrocephalus literally means water (hydro) in the head (cephalus). It is sometimes called water on the brain. The “water” is actually cerebrospinal fluid. Cerebrospinal fluid is normally present in areas both inside and outside the brain.

Children with hydrocephalus have too much cerebrospinal fluid in the areas of the brain called ventricles.

Ventricles are four small cavities in the brain that produce cerebrospinal fluid (CSF). This fluid flows through the ventricles to the area around the brain and spinal cord.
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The ventricles store and circulate cerebrospinal fluid. Children with hydrocephalus may also have extra fluid in spaces between the brain and the skull called the  subarachnoid spaces

Subarachnoid spaces  are the spaces lie between the three membranes protecting the brain. Cerebrospinal fluid moves through these spaces. Delicate connective tissue extends across them.

When a child’s cerebrospinal fluid cannot flow or be reabsorbed properly, it builds up. This makes the ventricles bigger and puts pressure on the tissues of the brain

Hydrocephalus is sometimes present at birth, although it may develop later. About 1 out of 500 children is born with the disorder. The outlook if  some one has hydrocephalus depends on how quickly the condition is diagnosed and whether any underlying disorders are present.

Symptoms:
The signs and symptoms of hydrocephalus vary by age group and disease progression.

In infants, common signs and symptoms of hydrocephalus include:

*An unusually large head
*A rapid increase in the size of the head
*A bulging “soft spot” on the top of the head
*Vomiting
*Sleepiness
*Irritability
*Seizures
*Eyes fixed downward (sunsetting of the eyes)
*Developmental delay

In older children and adults, common signs and symptoms of hydrocephalus include:

*Headache followed by vomiting
*Nausea
*Blurred or double vision
*Eyes fixed downward (sunsetting of the eyes)
*Problems with balance, coordination or gait
*Sluggishness or lack of energy
*Slowing or regression of development
*Memory loss
*Confusion
*Urinary incontinence
*Irritability
*Changes in personality
*Impaired performance in school or work

Hydrocephalus produces different combinations of these signs and symptoms, depending on its cause, which also varies by age. For example, a condition known as normal pressure hydrocephalus, which mainly affects older people, typically starts with difficulty walking. Urinary incontinence often develops, along with a type of dementia marked by slowness of thinking and information processing.
Causes:
The cause of hydrocephalus is excess fluid buildup in the brain.

Our brain is the consistency of gelatin, and it floats in a bath of cerebrospinal fluid. This fluid also fills large open structures, called ventricles, which lie deep inside the brain. The fluid-filled ventricles help keep the brain buoyant and cushioned.

Cerebrospinal fluid flows through the ventricles by way of interconnecting channels. The fluid eventually flows into spaces around the brain, where it’s absorbed into your bloodstream.

Keeping the production, flow and absorption of cerebrospinal fluid in balance is important to maintaining normal pressure inside your skull. Hydrocephalus results when the flow of cerebrospinal fluid is disrupted — for example, when a channel between ventricles becomes narrowed — or when your body doesn’t properly absorb this fluid.

Defective absorption of cerebrospinal fluid causes normal pressure hydrocephalus, seen most often in older people. In normal pressure hydrocephalus, excess fluid enlarges the ventricles but does not increase pressure on the brain. Normal pressure hydrocephalus may be the result of injury or illness, but in many cases the cause is unknown.

Risk Factors:
Premature infants have an increased risk of severe bleeding within the ventricles of the brain (intraventricular hemorrhage), which can lead to hydrocephalus.

Certain problems during pregnancy may increase an infant’s risk of developing hydrocephalus, including:

*An infection within the uterus
*Problems in fetal development, such as incomplete closure of the spinal column

Congenital or developmental defects not apparent at birth also can increase older children’s risk of hydrocephalus.

Other factors that increase your risk of hydrocephalus include:

*Lesions or tumors of the brain or spinal cord
*Central nervous system infections
*Bleeding in the brain
*Severe head injury

Complications:
The severity of hydrocephalus depends on the age at which the condition develops and the course it follows. If the condition is well advanced at birth, major brain damage and physical disabilities are likely. In less severe cases, with proper treatment, it’s possible to have a nearly normal life span and intelligence

Diagnosis:
Doctors will examine the child, looking for signs of hydrocephalus. They may also use techniques to monitor pressure inside your baby’s head. Doctors also use imaging tests to see signs of hydrocephalus. These tests include:

*CT scan (computerized tomography) of the head
*MRI (magnetic resonance imaging)

If the child has hydrocephalus, doctors may use ultrasound images of the brain to monitor the condition.
Treatment:
To treat hydrocephalus, doctors try to improve the flow of cerebrospinal fluid. Most often, they use surgery to do this.
Surgery:
Neurosurgeons most often perform three types of operations for hydrocephalus.

1.Shunts
The most common surgery for hydrocephalus is putting in a shunt.

A shunt is a small tube (catheter) that drains extra cerebrospinal fluid from a ventricle in your child’s brain to another area in the body. There, the fluid is either reabsorbed by your child’s body or passed out through the kidneys.

Neurosurgeons place one end of the small tube in the ventricle where extra fluid is causing problems. A valve in the tube controls the amount of fluid that runs through it. This controls the pressure in your child’s head. It also makes sure that the fluid flows in only one direction, away from the brain.
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The three areas a VP shunt can be placed in the head
The tube is placed under the skin and drains the fluid to another area of the body. The end of the tube most often is placed in the belly (abdomen). This is called a ventricular to peritoneal shunt. If the abdomen is not suitable for the tube, it may be placed in the heart (ventricular to atrial shunt), chest, or other areas. No matter where the tube ends, the fluid from the brain is reabsorbed by the body.

Placement of a VP shunt from the head to the belly.
Our neurosurgeons choose from many different types of shunts and valves, depending on your child’s needs. In some cases, they use a valve that can be adjusted from the outside by a small magnet. If your child has an MRI, these types of valves must always be reset immediately by one of our neurosurgery nurse practitioners.

2.Endoscopy:
An endoscope is a thin, flexible tube that carries a light and a camera. Surgeons can use it to see inside the body and perform some operations. Endoscopy requires smaller cuts (incisions) than other types of surgery (open surgery). It is a minimally invasive technique. Neurosurgeons use it to treat some types of hydrocephalus.

The approach made by an endoscope to make a hole in the ventricle so that the patient can avoid needing a shunt.
Some children have a complex type of the condition called multiloculated hydrocephalus. This happens when bleeding or infection causes scars within the ventricles of the brain. The scaring causes many small compartments of spinal fluid that do not connect with each other to develop.

In the past, doctors treated this condition by placing a separate shunt in each area with fluid and draining it. But by using an endoscope, they can make small holes in each of the areas. This connects them so they need only one shunt to drain the entire system.

3.Endoscopic third ventriculostomy (ETV)
Depending on your child’s brain structures and age, the neurosurgeon may talk with you about using an ETV instead of putting in a shunt.

During an ETV, the neurosurgeon makes a small hole in your child’s skull. Then the neurosurgeon uses an endoscope to reach the third ventricle in brain. Using the endoscope, the neurosurgeon makes a hole in the ventricle. This lets the extra fluid drain out and be reabsorbed.

An ETV lets neurosurgeons avoid putting in any permanent hardware, such as a shunt. Such a treatment may avoid the complications of using shunt hardware. But the treatment may fail and a shunt may be needed.

This video, developed by Anthony M. Avellino, MD, shows an example of an endoscopic third ventriculostomy procedure for treatment of obstructed hydrocephalus.

Prevention:

To reduce the risk of hydrocephalus:

*If you’re pregnant, get regular prenatal care. Following your doctor’s recommended schedule for checkups during pregnancy can reduce your risk of premature labor, which places your baby at risk of hydrocephalus and other complications.

*Protect against infectious illness. Follow the recommended vaccination and screening schedules for your age and sex. Preventing and promptly treating the infections and other illnesses associated with hydrocephalus may reduce your risk.

To prevent head injury:

*Use appropriate safety equipment. For babies and children, use a properly installed, age- and size-appropriate child safety seat on all car trips. Make sure all your baby equipment — crib, stroller, swing, highchair — meets all safety standards and is properly adjusted for your baby’s size and development. Older children and adults should wear a helmet while riding a bicycle, skateboard, motorcycle, snowmobile or all-terrain vehicle.

*Always wear a seat belt in a motor vehicle. Small children should be secured in child safety seats or booster seats. Depending on their size, older children may be adequately restrained with seat belts.

Should you be vaccinated against meningitis?

Ask your doctor if you or your child should receive a vaccine against meningitis, once a common cause of hydrocephalus. A meningitis vaccine is now recommended for people ages 2 and older who are at increased risk of this disease due to:

*Traveling to countries where meningitis is common

*Having an immune system disorder called terminal complement deficiency

*Having a damaged spleen or having had your spleen removed

*Living in a dormitory as a college freshman

*Joining the military

Disclaimer: This information is not meant to be a substitute for professional medical advise or help. It is always best to consult with a Physician about serious health concerns. This information is in no way intended to diagnose or prescribe remedies.This is purely for educational purpose

Resources:
http://sbhi.ie/images/What-is-ETV.pdf
http://en.wikipedia.org/wiki/Hydrocephalus
http://trialx.com/curebyte/2011/06/01/hydrocephalus-photos/
http://www.mayoclinic.com/health/hydrocephalus/DS00393

Gorlin syndrome

Alternative Names:Nevoid basal cell carcinoma syndrome (NBCCS),basal cell nevus syndrome, multiple basal cell carcinoma syndrome and Gorlin–Goltz syndrome

Definition:
Gorlin syndrome is an inherited medical condition involving defects within multiple body systems such as the skin, nervous system, eyes, endocrine system, and bones. People with this syndrome are particularly prone to developing a common and usually non-life-threatening form of non-melanoma skin cancers.

You may click to see more pictures of  Gorlin syndrome

People with the syndrome have a predisposition to multiple basal cell carcinomas (a form of skin cancer), jaw cysts and other generally harmless abnormalities in the bone. The severity of the disease can be wide-ranging.

About 10% of people with the condition do not develop basal cell carcinomas (BCCs). the name Gorlin syndrome refers to researcher Robert J. Gorlin (1923–2006).

First described in 1960, NBCCS is an autosomal dominant condition that can cause unusual facial appearances and a predisposition for basal cell carcinoma, a malignant type of skin cancer. The prevalence is reported to be 1 case per 56,000-164,000 population. Recent work in molecular genetics has shown NBCCS to be caused by mutations in the PTCH (Patched) gene found on chromosome arm 9q. If a child inherits the defective gene from either parent, he or she will have the disorder

Incidence:
About 750,000 new cases of sporadic basal cell carcinomas (BCCs) occur each year in the United States. Ultraviolet (UV) radiation from the sun is the main trigger of these cancers, and people with fair skin are especially at risk. Most sporadic BCCs arise in small numbers on sun-exposed skin of people over age 50, although younger people may also be affected. By comparison, NBCCS has an incidence of 1 in 50,000 to 150,000 with higher incidence in Australia. One aspect of NBCCS is that basal cell carcinomas will occur on areas of the body which are not generally exposed to sunlight, such as the palms and soles of the feet and lesions may develop at the base of palmer and plantar pits. One of the prime features of NBCCS is development of multiple BCCs at an early age, often in the teen years. Each person who has this syndrome is affected to a different degree, some having many more characteristics of the condition than others.

Components:-
Some or all of the following may be seen in someone with Gorlin Syndrome:

1.Multiple basal cell carcinomas of the skin
2.Odontogenic keratocyst: Seen in 75% of patients and is the most common finding. There are usually multiple lesions found in the mandible. They occur at a young age (19 yrs average).
3.Rib and vertebrae anomalies
4.Intracranial calcification
5.Skeletal abnormalities: bifid ribs, kyphoscoliosis, early calcification of falx cerebri (diagnosed with AP radiograph)
6.Distinct faces: frontal and temporopariental bossing, hypertelorism, and mandibular prognathism

What genes are related to Gorlin syndrome?
Mutations in the PTCH1 gene cause Gorlin syndrome. This gene provides instructions for making a protein called Patched-1, which functions as a receptor. Receptor proteins have specific sites into which certain other proteins, called ligands, fit like keys into locks. Together, ligands and their receptors trigger signals that affect cell development and function. A protein called Sonic Hedgehog is the ligand for the Patched-1 receptor. Patched-1 prevents cell growth and division (proliferation) until Sonic Hedgehog is attached.

The PTCH1 gene is a tumor suppressor gene, which means it keeps cells from proliferating too rapidly or in an uncontrolled way. Mutations in this gene prevent the production of Patched-1 or lead to the production of an abnormal version of the receptor. An altered or missing Patched-1 receptor cannot effectively suppress cell growth and division. As a result, cells proliferate uncontrollably to form the tumors that are characteristic of Gorlin syndrome.

You may click to learn more about the PTCH1 gene.

How do people inherit Gorlin syndrome?
Gorlin syndrome is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the features that are present from birth, such as large head size and skeletal abnormalities. An affected person often inherits a PTCH1 mutation from one affected parent. Other cases may result from new mutations in the gene. These cases occur in people with no history of the disorder in their family. For tumors to develop, a mutation in the other copy of the PTCH1 gene must occur in certain cells during the person’s lifetime. Most people who are born with one PTCH1 mutation eventually acquire a second mutation in certain cells and develop basal cell carcinomas and other tumors.

Causes:-
Gorlin syndrome is an autosomal dominant condition. The abnormal gene is found on chromosome 9. New mutations (where neither parent carries the gene) are common.

Diagnosis:
Diagnosis of NBCCS is made by having 2 major criteria or 1 major and 2 minor criteria.

The major criteria consist of the following:

1.more than 2 BCCs or 1 BCC in a person younger than 20 years;
2.odontogenic keratocysts of the jaw
3.3 or more palmar or plantar pits
4.ectopic calcification or early (<20 years) calcification of the falx cerebri
5.bifid, fused, or splayed ribs
6.first-degree relative with NBCCS.

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The minor criteria include the following:

1.macrocephaly.
2.congenital malformations, such as cleft lip or palate, frontal bossing, eye anomaly (cataract, colobma, microphtalmia, nystagmus).
3.other skeletal abnormalities, such as Sprengel deformity, pectus deformity, polydactyly, syndactyly or hypertelorism.
4.radiologic abnormalities, such as bridging of the sella turcica, vertebral anomalies, modeling defects or flame-shaped lucencies of hands and feet.
5.ovarian and cardio fibroma or medulloblastoma (the latter is generally found in children below the age of two).
People with NBCCS need education about the syndrome, and may need counseling and support, as coping with the multiple BCCs and multiple surgeries is often difficult. They should reduce UV light exposure, to minimize the risk of BCCs. They should also be advised that receiving Radiation therapy for their skin cancers may be contraindicated. They should look for symptoms referable to other potentially involved systems: the CNS, the genitourinary system, the cardiovascular system, and dentition.

Genetic counseling is advised for prospective parents, since one parent with NBCCS causes a 50% chance that their child will also be affected.

Treatment:
Although there’s no cure, the carcinomas can be treated by surgery, lasers or photodynamic therapy, which reduces scarring.

If there’s a family history of the syndrome, it’s possible for family members to be tested to see if they carry the faulty gene.

Those with Gorlin syndrome are now advised to avoid – or to take advice before undergoing – any radiation treatment, as it’s thought it may exacerbate the condition.

Treatment is usually supportive treatment, that is, treatment to reduce any symptoms rather than to cure the condition.

*Enucleation of the odontogenic cysts can help but new lesions, infections and jaw deformity are usually a result.
*The severity of the basal cell carcinoma determines the prognosis for most patients. BCCs rarely cause gross disfigurement, disability or death .

*Genetic counseling

Advice and support:-
•Gorlin Syndrome Group
•Tel: 01772 496849
•Email: info@gorlingroup.org
•Website: www.gorlingroup.org

Disclaimer: This information is not meant to be a substitute for professional medical advise or help. It is always best to consult with a Physician about serious health concerns. This information is in no way intended to diagnose or prescribe remedies.This is purely for educational purpose.

Resources:
http://www.bbc.co.uk/health/physical_health/conditions/gorlinsyndrome1.shtml
http://en.wikipedia.org/wiki/Nevoid_basal_cell_carcinoma_syndrome
http://ghr.nlm.nih.gov/condition/gorlin-syndrome
http://dermnetnz.org/systemic/gorlins.html

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Lumbar Puncture (or Spinal Tap)

Definition:
A lumbar puncture, also known as a spinal tap, uses a needle to remove a sample of fluid from the space surrounding the spinal cord. This fluid is known as cerebrospinal fluid (CSF). The test is used to diagnose meningitis infections and some neurological conditions.

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It is a procedure to collect cerebrospinal fluid to check for the presence of disease or injury. A spinal needle is inserted, usually between the 3rd and 4th lumbar vertebrae in the lower spine. Once the needle is properly positioned in the subarachnoid space (the space between the spinal cord and its covering, the meninges), pressures can be measured and fluid can be collected for testing.

Cerebral spinal fluid (CSF) is a clear fluid that circulates in the space surrounding the spinal cord and brain. CSF protects the brain and spinal cord from injury by acting like a liquid cushion. CSF is usually obtained through a lumbar puncture (spinal tap).

Preparation for the Test:

You will need to sign a consent form, which is generally required when the procedure is done outside of an emergency situation. Tell your doctor ahead of time if you have ever had an allergic reaction to lidocaine or the numbing medicine used at the dentist’s office.
Doctors routinely do a physical examination and in some cases order a brain scan before recommending a lumbar puncture, to make sure you do not have a medical condition that could put you at risk for movement of the brain during the procedure, a very rare but serious complication.

What happens when the test is performed?
Most patients wear a hospital gown. Typically, you lie on your side with your knees curled up against your chest. In some cases, the doctor asks you to sit on the bed or a table instead, leaning forward against some pillows.

The doctor feels your back to locate your lower vertebrae and feels the bones in the back of your pelvis. An area on your lower back is cleaned with soap. Medicine is injected through a small needle to numb the skin and the tissue underneath the skin in the area from which the sample is to be removed. This causes some very brief stinging.

A different needle is then placed in the same area and moved forward until fluid can be obtained through it from the spinal canal. Because the needle must be placed through a small opening between two bones, the doctor must sometimes move the needle in and out several times to locate the opening. Because of the numbing medicine used in this area, most patients experience only a sense of pressure from this movement. Occasionally some patients do get a sharp feeling in the back or (rarely) in the leg. Let your doctor know if you feel any pain.

Sometimes the doctor measures the pressure of the fluid before taking a sample. The pressure is measured with a tube that looks like a large thermometer held against the needle. The fluid sample collected is usually less than three tablespoons. You will not feel any discomfort when it is removed. After this, the needle is taken out. Usually a Band-Aid is the only dressing necessary.

The whole lumbar puncture, including set-up time, takes 30–45 minutes. The needle is in place for close to one minute.

Risk Factors:
The most common risk of a lumbar puncture is that it can cause a temporary headache. Lying down for a few hours after the test can make a headache less likely to occur. Other problems are rare and include infection or bleeding. Because the volume of fluid is small, a lumbar puncture almost never causes movement of the brain or spinal cord, a serious complication.

What Must you do special after the test is over?
You may be told to lie flat for a while after the test, sometimes for a few hours.

Time for the result of the test is known?
Depending on the tests being done on the fluid sample, results take anywhere from a few hours to a few days.
For more knowledge you may click to see:-…………………...(1).…….(2).…….(3)
Resources:
http://www.health.harvard.edu/diagnostic-tests/lumbar-puncture.htm
http://www.clarian.org/ADAM/doc/CancerCenter/10/000303.htm

http://www.nlm.nih.gov/medlineplus/ency/imagepages/9587.htm

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Meningitis

Definition;
Meningitis is an inflammation of the protective membranes covering the brain and spinal cord, known collectively as the meninges. Meningitis may develop in response to a number of causes, most prominently bacteria, viruses and other infectious agents, but also physical injury, cancer, or certain drugs. While some forms of meningitis are mild and resolve on their own, meningitis is a potentially serious condition due to the proximity of the inflammation to the brain and spinal cord. The potential for serious neurological damage or even death necessitates prompt medical attention and evaluation. Infectious meningitis, the most common form, is typically treated with antibiotics and requires close observation. Some forms of meningitis (such as those associated with meningococcus, mumps virus or pneumococcus infections) may be prevented with immunization.

CLICK & SEE THE PICTURES

Anatomy of the brain. In meningitis, the meninges that line the brain become swollen and inflamed.

Signs and symptoms
Severe headache is the most common symptom of meningitis (87 percent) followed by nuchal rigidity (“neck stiffness”, 83 percent). The classic triad of diagnostic signs consists of nuchal rigidity (being unable to flex the neck forward), sudden High fever[1] and altered mental status. All three features are present in only 44% of all cases of infectious meningitis.[2] Other signs commonly associated with meningitis are photophobia (inability to tolerate bright light), phonophobia (inability to tolerate loud noises), irritability and delirium (in small children) and seizures (in 20-40% of cases). In infants (0-6 months), swelling of the fontanelle (soft spot) may be present.

Nuchal rigidity is typically assessed with the patient lying supine, and both hips and knees flexed. If pain is elicited when the knees are passively extended (Kernig’s sign), this indicates nuchal rigidity and meningitis. In infants, forward flexion of the neck may cause involuntary knee and hip flexion (Brudzinski’s sign). Although commonly tested, the sensitivity and specificity of Kernig’s and Brudzinski’s tests are uncertain.[3]

In “meningococcal” meningitis (i.e. meningitis caused by the bacteria Neisseria meningitidis), a rapidly-spreading petechial rash is typical, and may precede other symptoms. The rash consists of numerous small, irregular purple or red spots on the trunk, lower extremities, mucous membranes, conjunctiva, and occasionally on the palms of hands and soles of feet. Other clues to the nature of the cause may be the skin signs of hand, foot and mouth disease and genital herpes, both of which may be associated with viral meningitis.

Diagnosis:

Investigations
Suspicion of meningitis is generally based on the nature of the symptoms and findings on physical examination. Meningitis is a medical emergency, and referral to hospital is indicated. If meningitis is suspected based on clinical examination, early administration of antibiotics is recommended, as the condition may deteriorate rapidly. In the hospital setting, initial management consists of stabilization (e.g. securing the airway in a depressed level of consciousness, administration of intravenous fluids in hypotension or shock), followed by antibiotics if not already administered.

Investigations include blood tests (electrolytes, liver and kidney function, inflammatory markers and a complete blood count) and usually X-ray examination of the chest. The most important test in identifying or ruling out meningitis is analysis of the cerebrospinal fluid (fluid that envelops the brain and the spinal cord) through lumbar puncture (LP). However, if the patient is at risk for a cerebral mass lesion or elevated intracranial pressure (recent head injury, a known immune system problem, localizing neurological signs, or evidence on examination of a raised ICP), a lumbar puncture may be contraindicated because of the possibility of fatal brain herniation. In such cases a CT or MRI scan is generally performed prior to the lumbar puncture to exclude this possibility. Otherwise, the CT or MRI should be performed after the LP, with MRI preferred over CT due to its superiority in demonstrating areas of cerebral edema, ischemia, and meningeal inflammation.

During the lumbar puncture procedure, the opening pressure is measured. A pressure of over 180 mm H2O is indicative of bacterial meningitis.

The cerebrospinal fluid (CSF) sample is examined for white blood cells (and which subtypes), red blood cells, protein content and glucose level. Gram staining of the sample may demonstrate bacteria in bacterial meningitis, but absence of bacteria does not exclude bacterial meningitis; microbiological culture of the sample may still yield a causative organism. The type of white blood cell predominantly present predicts whether meningitis is due to bacterial or viral infection. Other tests performed on the CSF sample include latex agglutination test, limulus lysates, or polymerase chain reaction (PCR) for bacterial or viral DNA. If the patient is immunocompromised, testing the CSF for toxoplasmosis, Epstein-Barr virus, cytomegalovirus, JC virus and fungal infection may be performed.

CSF finding in different conditions:-
Condition……………………………..Glucose…………Protein…………….. Cells
Acute bacterial meningitis…………. Low high…… high………….. often > 300/mm³
Acute viral meningitis…………….. Normal normal or high mononuclear,……< 300/mm³
Tuberculous meningitis…………….. Low……….. high pleocytosis, mixed < 300/mm³
Fungal meningitis…………………. Low…………high………………. < 300/mm³
Malignant meningitis………………. Low…………high usually mononuclear
Subarachnoid hemorrhage……………..Normal normal, or high Erythrocytes

In bacterial meningitis, the CSF glucose to serum glucose ratio is < 0.4. The Gram stain is positive in >60% of cases, and culture in >80%. Latex agglutination may be positive in meningitis due to Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae, Escherichia coli, Group B Streptococci. Limulus lysates may be positive in Gram-negative meningitis.

Cultures are often negative if CSF is taken after the administration of antibiotics. In these patients, PCR can be helpful in arriving at a diagnosis. It has been suggested that CSF cortisol measurement may be helpful.

Aseptic meningitis refers to non-bacterial causes of meningitis and includes infective etiologies such as viruses and fungi, neoplastic etiologies such as carcinomatous and lymphomatous meningitis, inflammatory causes such as sarcoidosis (neurosarcoidosis)) and chemical causes such as meningitis secondary to the intrathecal introduction of contrast media.

Although the term “viral meningitis” is often used in any patient with a mild meningeal illness with appropriate CSF findings, certain patients will present with clinical and CSF features of viral meningitis, yet ultimately be diagnosed with one of the other conditions categorized as “aseptic meningitis”. This may be prevented by performing polymerase chain reaction or serology on CSF or blood for common viral causes of meningitis (enterovirus, herpes simplex virus 2 and mumps in those not vaccinated for this).

A related diagnostic and therapeutic conundrum is the “partially treated meningitis”, i.e. meningitis symptoms in patients who have already been receiving antibiotics (such as for presumptive sinusitis). In these patients, CSF findings may resemble those of viral meningitis, but antibiotic treatment may need to be continued until there is definitive positive evidence of a viral cause (e.g. a positive enterovirus PCR).

Prediction rules
The Bacterial Meningitis Score predicts reliably whether a child (older than two months) may have infectious meningitis. In children with at least 1 risk factor (positive CSF Gram stain, CSF absolute neutrophil count = 1000 cell/µL, CSF protein = 80 mg/dL, peripheral blood absolute neutrophil count = 10,000 cell/µL, history of seizure before or at presentation time) it had a sensitivity of 100%, specificity of 63.5%, and negative predictive value of 100%

Causes
Most cases of meningitis are caused by microorganisms, such as viruses, bacteria, fungi, or parasites, that spread into the blood and into the cerebrospinal fluid (CSF).[8] Non-infectious causes include cancers, systemic lupus erythematosus and certain drugs. The most common cause of meningitis is viral, and often runs its course within a few days. Bacterial meningitis is the second most frequent type and can be serious and life-threatening. Numerous microorganisms may cause bacterial meningitis, but Neisseria meningitidis (“meningococcus”) and Streptococcus pneumoniae (“pneumococcus”) are the most common pathogens in patients without immune deficiency, with meningococcal disease being more common in children. Staphylococcus aureus may complicate neurosurgical operations, and Listeria monocytogenes is associated with poor nutritional state and alcoholism. Haemophilus influenzae (type B) incidence has been much reduced by immunization in many countries. Mycobacterium tuberculosis (the causative agent of tuberculosis) rarely causes meningitis in Western countries but is common and feared in countries where tuberculosis is endemic.

Treatment
Bacterial meningitis
Bacterial meningitis is a medical emergency and has a high mortality rate if untreated.[9] All suspected cases, however mild, need emergency medical attention. Empiric antibiotics must be started immediately, even before the results of the lumbar puncture and CSF analysis are known. Antibiotics started within 4 hours of lumbar puncture will not significantly affect lab results. Adjuvant treatment with corticosteroids reduces rates of mortality, severe hearing loss and neurological sequelae in adults, specifically when the causative agent is Pneumococcus.

Age group Causes
Neonates Group B Streptococci, Escherichia coli, Listeria monocytogenes
Infants Neisseria meningitidis, Haemophilus influenzae, Streptococcus pneumoniae
Children N. meningitidis, S. pneumoniae
Adults S. pneumoniae, N. meningitidis, Mycobacteria, Cryptococci
The choice of antibiotic depends on local advice. In most of the developed world, the most common organisms involved are Streptococcus pneumoniae and Neisseria meningitidis: first line treatment in the UK is a third-generation cephalosporin (such as ceftriaxone or cefotaxime). In those under 3 years of age, over 50 years of age, or immunocompromised, ampicillin should be added to cover Listeria monocytogenes.[11] In the U.S. and other countries with high levels of penicillin resistance, the first line choice of antibiotics is vancomycin and a carbapenem (such as meropenem). In sub-Saharan Africa, oily chloramphenicol or ceftriaxone are often used because only a single dose is needed in most cases.

Staphylococci and gram-negative bacilli are common infective agents in patients who have just had a neurosurgical procedure. Again, the choice of antibiotic depends on local patterns of infection: cefotaxime and ceftriaxone remain good choices in many situations, but ceftazidime is used when Pseudomonas aeruginosa is a problem, and intraventricular vancomycin is used for those patients with intraventricular shunts because of high rates of staphylococcal infection. In patients with intracerebral prosthetic material (metal plates, electrodes or implants, etc.) then sometimes chloramphenicol is the only antibiotic that will adequately cover infection by Staphylococcus aureus (cephalosporins and carbapenems are inadequate under these circumstances).

Once the results of the CSF analysis are known along with the Gram-stain and culture, empiric therapy may be switched to therapy targeted to the specific causative organism and its sensitivities.[citation needed]

*Neisseria meningitidis (Meningococcus) can usually be treated with a 7-day course of IV antibiotics:
*Penicillin-sensitive — penicillin G or ampicillin
*Penicillin-resistant — ceftriaxone or cefotaxime
*Prophylaxis for close contacts (contact with oral secretions) — rifampin 600 mg bid for 2 days (adults) or 10 mg/kg bid (children). Rifampin is not recommended in pregnancy and as such, these patients should be treated with single doses of ciprofloxacin, azithromycin, or ceftriaxone
*Streptococcus pneumoniae (Pneumococcus) can usually be treated with a 2-week course of IV antibiotics:
*Penicillin-sensitive — penicillin G
*Penicillin-intermediate — ceftriaxone or cefotaxime
*Penicillin-resistant — ceftriaxone or cefotaxime + vancomycin
*Listeria monocytogenes is treated with a 3-week course of IV ampicillin + gentamicin.
*Gram negative bacilli — ceftriaxone or cefotaxime
*Pseudomonas aeruginosa — ceftazidime
*Staphylococcus aureus
*Methicillin-sensitive — nafcillin
*Methicillin-resistant — vancomycin
*Streptococcus agalactiae — penicillin G or ampicillin
*Haemophilus influenzae — ceftriaxone or cefotaxime

Viral meningitis
Patients diagnosed with mild viral meningitis may improve quickly enough to not require admission to a hospital, while others may be hospitalized for many more days for observation and supportive care. Overall, the illness is usually much less severe than bacterial meningitis.

Unlike bacteria, viruses cannot be killed by antibiotics although drugs such as acyclovir may be employed, especially if herpes virus infection is either suspected or demonstrated.[4]

Fungal meningitis
This form of meningitis is rare in otherwise healthy people but is a higher risk in those who have AIDS, other forms of immunodeficiency (an immune system that does not respond adequately to infections) and immunosuppression (immune system malfunction as a result of medical treatment). In AIDS, Cryptococcus neoformans is the most common cause of fungal meningitis; it requires Indian ink staining of the CSF sample for identification of this capsulated yeast. Fungal meningitis is treated with long courses of highly dosed antifungals.

Complications
In children there are several potential disabilities which result from damage to the nervous system. These include sensorineural hearing loss, epilepsy, diffuse brain swelling, hydrocephalus, cerebral vein thrombosis, intra cerebral bleeding and cerebral palsy. Acute neurological complications may lead to adverse consequences. In childhood acute bacterial meningitis deafness is the most common serious complication. Sensorineural hearing loss often develops during first few days of the illness as a result of inner ear dysfunction, but permanent deafness is rare and can be prevented by prompt treatment of meningitis.

Those that contract the disease during the neonatal period and those infected by S. pneumoniae and gram negative bacilli are at greater risk of developing neurological, auditory, or intellectual impairments or functionally important behaviour or learning disorders which can manifest as poor school performance.

In adults central nervous system complications include brain infarction, brain swelling, hydrocephalus, intracerebral bleeding; systemic complications are dominated by septic shock, adult respiratory distress syndrome and disseminated intravascular coagulation. Those who have underlying predisposing conditions e.g. head injury may develop recurrent meningitis.Case-fatality ratio is highest for gram-negative etiology and lowest for meningitis caused by H. influenzae (also a gram negative bacilli). Fatal outcome in patients over 60 years of age is more likely to be from systemic complications e.g. pneumonia, sepsis, cardio-respiratory failure; however in younger individuals it is usually associated with neurological complications. Age more than 60, low Glasgow coma scale at presentation and seizure within 24 hours increase the risk of death among community acquired meningitis.

Prevention

Immunization
Vaccinations against Haemophilus influenzae (Hib) have decreased early childhood meningitis significantly.

Vaccines against type A and C Neisseria meningitidis, the kind that causes most disease in preschool children and teenagers in the United States, have also been around for a while. Type A is also prevalent in sub-Sahara Africa and W135 outbreaks have affected those on the Hajj pilgrimage to Mecca. Immunisation with the ACW135Y vaccine against four strains is now a visa requirement for taking part in the Hajj.

Vaccines against Type B Neisseria meningitidis are much harder to produce, as its capsule is very weakly immunogenic masking its antigenic proteins. There is also a risk of autoimmune response, and the porA and porB proteins on Type B resemble neuronal molecules. A vaccine called MeNZB for a specific strain of type B Neisseria meningitidis prevalent in New Zealand has completed trials and is being given to many people in the country under the age of 20 free of charge. There is also a vaccine, MenBVac, for the specific strain of type B meningoccocal disease prevalent in Norway, and another specific vaccine for the strain prevalent in Cuba.

Pneumococcal polysaccharide vaccine against Streptococcus pneumoniae is recommended for all people 65 years of age or older. Pneumococcal conjugate vaccine is recommended for all newborns starting at 6 weeks – 2 months, according to American Association of Pediatrics (AAP) recommendations.

Mumps vaccination has led to a sharp decline in mumps virus associated meningitis, which prior to vaccination occurred in 15% of all cases of mumps.

Prophylaxis
In cases of meningococcal meningitis, prophylactic treatment of close relatives with antibiotics (e.g. rifampicin, ciprofloxacin or ceftriaxone) may reduce the risk of further cases.

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Disclaimer: This information is not meant to be a substitute for professional medical advise or help. It is always best to consult with a Physician about serious health concerns. This information is in no way intended to diagnose or prescribe remedies.This is purely for educational purpose.

Sources:http://en.wikipedia.org/wiki/Meningitis

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