Meningitis - B. Pharma 2nd Semester Pathophysiology notes pdf

Meningitis

Content

       Meningitis

       Etiopathogenesis

       Clinical features

       Diagnosis

Objective

At the end of the class the students will be able to

       Define  meningitis

       Difference between pachymeningitis, leptomeningitis

       Discuss  the etiology, pathogenesis and clinical Acute Pyogenic Meningitis, Chronic (Tuberculous and Cryptococcal) Meningitis,

Meningitis


It is inflammatory involvement of the meninges.

       Meningitis may involve the dura called pachymeningitis,

        leptomeninges (pia-arachnoid) termed leptomeningitis

       Pachymeningitis: inflammation from chronic suppurative otitis media or from fracture of the skull.

       Extradural abscess may form by suppuration between the bone and dura- penetrate the dura and form a subdural abscess.

Leptomeningitis, commonly called meningitis- infection

       Infectious meningitis is broadly classified into 3 types:

1. acute pyogenic,

2. acute lymphocytic (viral, aseptic)

3. chronic (bacterial or fungal)

Acute Pyogenic Meningitis

       Acute pyogenic or acute purulent meningitis is acute infection of the pia-arachnoid and of the CSF enclosed in the subarachnoid space.

ETIOPATHOGENESIS-Acute Pyogenic Meningitis

Causative organisms vary with age of the patient

  1. Escherichia coli
  2. Haemophilus influenzae
  3. Neisseria meningitidis
  4. Streptococcus pneumoniae

       routes of infection as follows:

1. Most commonly by the blood stream.

2. From an adjacent focus of infection.

3. By iatrogenic infection such as introduction of microorganisms at operation or during lumbar puncture.

Symptoms of Meningitis


CLINICAL FEATURES AND DIAGNOSIS of MENINGITIS

Acute bacterial meningitis is a medical emergency.

        The immediate clinical manifestations are fever, severe headache, vomiting, drowsiness, stupor, coma, and occasionally, convulsions

       The diagnosis is confirmed by examining CSF

1. Naked eye appearance of cloudy or frankly purulent CSF.

2. Elevated CSF pressure (above 180 mm water).

3. Polymorphonuclear neutrophilic leucocytosis in CSF(between 10-10,000/μl).

4. Raised CSF protein level (higher than 50 mg/dl).

5. Decreased CSF sugar concentration (lower than 40 mg/dl)

6. Bacteriologic examination by Gram’s stain

Acute Lymphocytic (Viral, Aseptic) Meningitis

       Acute lymphocytic meningitis is a viral or aseptic meningitis, especially common in children and young adults.

       Etiologic agents are numerous viruses such as enteroviruses, mumps, ECHO viruses, coxsackie virus, Epstein-Barr virus, herpes simplex virus-2, arthropode-borne viruses and HIV

       viral meningitis has a benign and self-limiting clinical course of short duration and is invariably followed by complete recovery

Chronic (Tuberculous and Cryptococcal) Meningitis

       There are two principal types of chronic meningitis—bacterial (tuberculous meningitis) and fungal (cryptococcal meningitis)

       Tuberculous meningitis occurs in children and adults through haematogenous spread of infection from tuberculosis

       Cryptococcal meningitis develops particularly in debilitated or immunocompromised persons, usually as a result of haematogenous dissemination from a pulmonary lesion

CLINICAL FEATURES AND DIAGNOSIS

       Tuberculous meningitis manifests clinically as headache, confusion, malaise and vomiting

Summary

       Meningitis is inflammatory involvement of the meninges

       Acute pyogenic or acute purulent meningitis is acute infection of the pia-arachnoid and of the CSF enclosed in the subarachnoid space

       Acute lymphocytic meningitis is a viral or aseptic meningitis, especially common in children and young adults.

       There are two principal types of chronic meningitis—bacterial (tuberculous meningitis) and fungal (cryptococcal meningitis)

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