The name meningitis is derived from the term meninges (dura, pia, and arachnoids’

membranes)

• Meninges are the protective membranes covering the central nervous system

• When these membranes are inflamed we use the term meningitis

• Meningitis is a potentially serious condition owing to the proximity of the inflammation

to the brain and spinal cord

Causes of Meningitis

• Most cases of meningitis are caused by microorganisms (infectious meningitis) such as

Viruses

Bacteria

Fungi or

Parasites

• These microorganisms spread into the blood and into the cerebrospinal fluid (CSF)

• Non-infectious causes of meningitis though not common include

Cancers, (neoplastic conditions e.g carcinomatous meningitis)

Systemic lupus erythematosus

Physical injury (subarachnoid hemorrhages)

Chemicals (chemical meningitis)

• Neisseria meningitidis (‘meningococcal’) and Streptococcus pneumoniae

(‘pneumococcal’) are the most common pathogens in patients without immune

deficiency

• Meningococcal infection is more common in children

• Staphylococcus aureus may complicate neurosurgically operations, and Listeria

monocytogenes is associated with poor nutritional state and alcoholism

• Acute bacterial meningitis may be caused by the following in order of frequency

Pneumococci - Streptococcus pneumoniae

 Haemophilus influenzae

Meningococci - Neisseria meningitidis

Coliforms - Escherichia coli

Salmonella - Salmonella typhi

Staphylococci - Staphylococcus aureus

Streptococci - Streptococcus pyogenic

Causes of Meningitis by Age Group

Neonate

Gram-negative bacilli (Escherichia

coli), Proteus spp and Gram+ve B

streptococci

Listeria monocytogenes

Pre-school

child Haemophilus influenzae

Mycobacterium Tuberculosis

Neisseria meningitidis

Streptococcus pneumoniae

Older

children and

adult

Streptococcus pneumoniae

Neisseria meningitidis

Listeria monocytogenes

Mycobacterium Tuberculosis

Haemophilus influenzae

Staphylococcus aureus

Predisposing Factors for Meningitis

• Ear infections (otitis media, mastoiditis)

• Sinusitis

• Respiratory infections

• Malnutrition

• Head injuries

• Septicaemia and diarrhea especially in the newborns

• Immune suppression e.g. HIV

Clinical Features of Meningitis

Most Common Clinical Features

• Headache

• Neck stiffness or inability to flex the neck forward

Others

• Fever

• Altered mental status

• Photophobia (inability to tolerate bright light)

• Delirium (in small children)

• Seizures (in about 20-40% of cases)

• Swelling of the fontanel (in infants 0-6 months)

• Rash (petechial rash) common in meningococcal meningitis, 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.

Clinical Signs

• There are two clinical tests that can be done to suggest the diagnosis of meningitis namely

Kerning’s and Brudzinski’s sign; however, these signs may be absent as well in many

cases of meningitis.

CMT 05211 Internal Medicine II NTA Level 5 Semester 2 Student Manual

Session 3: Meningitis, Convulsions and Coma 31

Differential Diagnosis

• Severe malaria

• Viral meningoencephalitis

• Subarachnoid hemorrhage

Management of Meningitis

• Patients suspected of having meningitis should be referred for investigation and treatment

at higher-level (hospitals).

Investigations

• Cerebral spinal fluid (CSF) analysis should be done following lumbar puncture

• The CSF sample is examined for

Check opening pressure

White blood cells count

Red blood cells

Proteins content estimation

Glucose level estimation

Gram staining (determines if bacteria are responsible for the disease causation)

Microbiological culture (in some equipped hospitals)

Other Investigations

• Electrolytes

• Liver and kidney function

• Complete blood count

• Chest X-ray

• If the patient is immunocompromised other CSF tests can be done to isolate infections

like:

Toxoplasmosis

Epstein-Barr virus

Cytomegalo virus

Fungal infection (cryptococcal meningitis)

Treatment

• Meningitis cases are best treated at hospitals and some few equipped health centers. At

dispensary level, give only pre-referral treatment as shown below;

First dose antibiotic: if bacterial meningitis is suspected, antibiotics can be given

immediately (preferably within 1 hour of arrival to the facility)

IV fluids

Antipyretics

Then refer the patient as soon as possible for prompt management

General Management

• Secure the airway in an unconscious patient.

• Administer of intravenous fluids in hypotension or shock.

• Position the patient on the left lateral (if is conscious).

• Administer antibiotics if not already administered.

• Antibiotics of choice are

Crystalline benzylpenicillin 6 MU at once 3 MU 6-hourly or Ampicillin and

Chloramphenicol 1g every 6-hours.

These drugs are active against Pneumococci, H. influenzae, Meningococci, E. coli and

Salmonellae spp.

Note: Penicillin is not active against E. coli or Salmonella spp)

• Viral meningitis has no specific treatment except for severe cases where acyclovir can be

given.

• Cryptococcal meningitis is treated with Fluconazole, 400mg OD intravenous or

Amphotericin B 0.7 mg/kg/day IV x 14 days and later on the suppressive dosage of

Fluconazole to prevent a recurrence.

Definition and Causes of Coma

• Coma: The unnatural situation of reduced alertness and responsiveness represents a

continuum that in its severest form is called a coma, a deep sleep-like state from which the

patient cannot be aroused.

Causes of Coma

• Metabolic Disturbances

Drug overdose

Diabetes mellitus

Hypoglycaemia

Ketoacidosis

Hyperosmolar coma

Hyponatraemia

Uraemia

Hepatic failure

Respiratory failure

Hypothermia

Hypothyroidism

• Trauma

Cerebral contusion

Extradural haematoma

Subdural haematoma

• Cerebrovascular Disease

Subarachnoid haemorrhage

Intracerebral haemorrhage

Brain-stem infarction/haemorrhage

Cerebral venous sinus thrombosis

• Infections

Meningitis

Encephalitis

Cerebral abscess

General sepsis (septicaemia)

• Others

Epilepsy

Brain tumour

Thiamine deficiency

Alcohol intoxication

Clinical Feature, Differential Diagnosis and Investigations of Coma

Clinical Feature

• Unconscious for more than half an hour

Differential Diagnosis

• Meningitis

• Encephalitis

• Cerebral abscess

• Subarachnoid haemorrhage

• Brain-stem infarction/haemorrhage

• Drug overdose

• Diabetes mellitus

Hypoglycaemia

Ketoacidosis

Hyperosmolar coma

Diagnosis

• Perform Glasgow Coma Score

Glasgow Coma Scale

Assessment of Level of Consciousness

• Asses the level of consciousness by using Glasgow coma scale

Glasgow Coma Scale (GCS)

Eye Opening

• Spontaneous 4

• To voice 3

• To pain 2

• None 1

Verbal Response

• Oriented 5

• Confused 4

• Inappropriate words 3

• Incomprehensible sounds 2

• None 1

Motor Response

• Obey command 6

• Localises pain 5

• Withdraws (pain) 4

• Flexion (pain) 3

• Extension (pain) 2

• None 1

Total

• Total Score 3-15

• Mildly severe 15-13

• Moderately severe 12-8

• Severe 7-3

• This predicts the severity and expectation of the patients and must be done frequently

• It guides the clinician whether the patient’s condition improves or deteriorates over time

Investigations

• Depends on the most likely cause of coma

• Collateral history and physical examination

• Findings may suggest type of investigations to be done

Blood sugar

Perform lumbar puncture to obtain cerebral spinal fluid for analysis

Serum electrolytes analysis

Liver function tests

Blood slide for malaria parasites

• Others

CT scan of brain (when appropriate)

Treatment and Prognosis of Coma

• Refer the patient immediately after initial resuscitation using ABCs protocol.

• The immediate goal in acute coma is the prevention of further nervous system damage.

• Hypotension, hypoglycemia, hypercalcemia, hypoxia, hypercapnia, and hyperthermia

should be corrected rapidly and attentively.

• An oropharyngeal airway is adequate to keep the pharynx open in drowsy patients who

are breathing normally.

• Tracheal intubation is indicated if there is apnea or upper airway obstruction,

hypoventilation, emesis or if the patient is liable to aspirate because of coma.

• Intravenous access is established and naloxone and dextrose are administered if narcotic

overdose or hypoglycemia is even remote possibilities and thiamine is given with glucose

in order to avoid eliciting Wernicke disease in malnourished patients.

• In cases of suspected basilar thrombosis with brainstem ischemia, intravenous heparin or

a thrombolytic agent is often utilized keeping in mind that cerebella and pontine

hemorrhages resemble basilar artery occlusion (this should be done in a hospital).

• In situation of coma hypotonic or hypertonic solutions should NOT be given (it is best to

give isotonic solutions such as normal saline or ringers).

• Cervical spine injuries must not be overlooked particularly prior to attempting intubation

or the evaluation of oculocephalic responses.

• Headache accompanied by fever and meningismus indicates an urgent need for

examination of the CSF to diagnose meningitis.

• If the lumbar puncture in a case of suspected meningitis is delayed for any reason

antibiotics such as a third generation cephalosporin should be administered as soon as

possible (then efforts to do LP should be done without delay).

• Hyperosmolar therapy with mannitol or an equivalent agent is the mainstay of

intracranial pressure reduction.

Prognosis

• The prediction of the outcome of coma must be considered in reference to long-term care

and medical resources.

• Metabolic comas have a far better prognosis than traumatic comas.

• All schemes for prognosis in adults should be taken as approximate indicators and

medical judgments must be tempered by factors such as age, underlying systemic disease

and general medical condition.                                                                                

REFFERNCES;

•      Braunwald & Fauci (2001). Harrison’s principles of internal medicine 15th Ed.  Oxford: McGraw Hill

•      Davidson, S (2006). Principles and practice of medicine 20th Ed.  Churchill: Livingstone.

Kumar & Clark (2003) Textbook of clinical medicine. Churchill: Livingstone.

•      Douglas Model (2006): Making sense of Clinical Examination of the Adult patient. 1st Ed. Hodder Arnold

•      Longmore, M., Wilkinson, I., Baldwin, A., & Wallin, E. (2014). Oxford handbook of clinical medicine. Oxford

•      Macleod, J. (2009). Macleod's clinical examination. G. Douglas, E. F. Nicol, & C. E. Robertson (Eds.). Elsevier Health Sciences.

•      Nicholson N., (1999), Medicine of Non-communicable diseases in adults. AMREF

•      Stuart and Saunders (2004): Mental health Nursing principles and practice. 1st Ed. Mosby

•      Swash, M., & Glynn, M. (2011). Hutchison's clinical methods: An integrated approach to clinical practice.