DISEASES OF THE NERVOUS SYSTEM CHAPTER 24 Copyright © 2012 John Wiley & Sons, Inc. All rights reserved.

Anatomy Review Central Nervous System Peripheral Nervous System Meninges 3 layers covering the brain Blood Brain Barrier Exceptionally impermeable capillary network © 2012 John Wiley & Sons, Inc. All rights reserved.

Bacterial Diseases of the Brain and Meninges - Meningitis Symptoms Headache, fever, chills, stiff neck Diagnosis via CSF culture Meningococcal meningitis Neisseria meningitidis 15% mortality due to Rx delays Infants, young adults Fatigue, overcrowding Death due to endotoxin shock Penicillin Vaccine does not cover all strains © 2012 John Wiley & Sons, Inc. All rights reserved.

Bacterial Meningitis Haemophilus influenzae type B ( Hib) Commonest cause of meningitis prior to vaccine development 30-50% carrier rate in children Fatal without treatment Seizures, mental retardation common in survivors Largest cause of mental retardation in U.S.A. and world-wide Streptococcus pneumoniae Commonest adult cause of bacterial meningitis Spreads from other sites Blood Lungs 40% mortality rate Cocktail vaccine for pneumonia is effective © 2012 John Wiley & Sons, Inc. All rights reserved.

Viral Meningitis Self limiting, non-fatal More common, less serious than bacterial meningitis Enterovirus and mumps virus most common © 2012 John Wiley & Sons, Inc. All rights reserved.

Viral Diseases of the Brain and Meninges - Rabies Rhabdoviridae inclusions seen in brain Re-emerging in U.S.A. with cats as carriers Fatal encephalitis 20-60 day incubation Virus travels to CNS slowly and replicates slowly Agitation, confusion, hallucinations Death within days of CNS symptoms Hydrophobia seen as throat muscles are infected and spasm Vaccination can be used to “cure” © 2012 John Wiley & Sons, Inc. All rights reserved.

Tetanus Clostridium tetani Anaerobic, endospore former Found in soil, manure Vaccine is available (10 yr) Puncture wounds Spastic paralysis, respiratory failure Antitoxin and antibiotics for treatment © 2012 John Wiley & Sons, Inc. All rights reserved.

Botulism Clostridium botulinum Flaccid paralysis, respiratory failure Botulotoxin in contaminated canned goods (honey fed to infants) Wounds may rarely be infected Antitoxin (Ab) will neutralize preformed toxin © 2012 John Wiley & Sons, Inc. All rights reserved.

Viral Nerve Diseases – Poliomyelitis Poliovirus (Picornaviridae) Affinity for CNS motor neurons Fever, back pain, muscle spasms Young/old may suffer permanent paralysis Virus is excreted in human feces, problem in developing nations Vaccines are available Eradication target year – soon! © 2012 John Wiley & Sons, Inc. All rights reserved.