Spirochete Infections: Lyme Disease Epidemiology Borrelia burgdorferi spirochete transmitted to humans by ixodid ticks (which in the United States infest deer, mice). Usually in wooded areas of United States; peak…

Spirochete Infections: Leptospirosis Epidemiology: hosts include humans, wild animals, domestic animals (cats, dogs, cattle). Humans infected via exposure to infested animal tissue or urine, or contaminated ground water, soil, vegetation….

Spirochete Infections: Neurosyphilis Definition Infection of brain, meninges, or spinal cord by Treponema pallidum. Required: (a) syndrome consistent with neurosyphilis (meningitis, meningoencephalitis, meningomyelitis, cerebral infarcts, dementia paralytica, tabes dorsalis, congenital…

Neurosarcoidosis Granulomatous multisystem disease of unknown cause, sometimes involving CNS, peripheral nerves, or muscle. Epidemiology Prevalence 3–50 per 100,000 population worldwide. More frequent in African Americans than others in United…

Fungal and Yeast Infections CNS fungal infection: meningitis, meningoencephalitis, abscess, granuloma, arterial thrombosis. Subacute meningitis, meningoencephalitis most common. Lungs, skin, hair usually primary sites. Pathogenic fungal infections (occur in normal…

AIDS Dementia, myelopathy due to HIV infection are AIDS-defining illnesses. CNS Pathogenesis HIV enters CNS in primary infection. May produce no symptoms, acute self-limited syndrome, or chronic disorder. Possible causes:…

Viral Infections After viral multiplication in extraneural tissues, dissemination to CNS occurs by hematogenous route or spread along nerve fibers. General Comments CNS Viral Syndromes Meningitis: headache, photophobia, stiff neck;…

Focal Infections Malignant External Otitis Infection in external auditory canal; spreads to soft tissues to cause cellulitis and abscess. Risk factors: diabetes in almost all patients; also advanced age, HIV…

Bacterial Infections and Aseptic Meningitis Acute Purulent Meningitis Progression for hours. Polymorphonuclear pleocytosis usually present in CSF. General Considerations Routes of meningeal infection: (a) blood (septicemia or spread from distant…

DNA Diagnosis Several hundred diseases amenable to DNA diagnosis. List is rapidly expanding. Examples provided in chapters on specific inherited conditions. For further information: http://www.genetests.org serves as an online textbook…