Meningococcal disease describes infections caused by the bacterium Neisseria meningitidis (also termed meningococcus). It has a high mortality rate if untreated but is vaccine-preventable. While best known as a cause of meningitis, it can also result in sepsis, which is an even more damaging and dangerous condition. Meningitis and meningococcemia are major causes of illness, death, and disability in both developed and under-developed countries. There are approximately 2,600 cases of bacterial meningitis per year in the United States, and on average 333,000 cases in developing countries. The case fatality rate ranges between 10 and 20 percent. The incidence of endemic meningococcal disease during the last 13 years ranges from 1 to 5 per 100,000 in developed countries, and from 10 to 25 per 100,000 in developing countries. During epidemics the incidence of meningococcal disease approaches 100 per 100,000. Meningococcal vaccines have sharply reduced the incidence of the disease in developed countries. The diseases pathogenesis is not fully understood. Neisseria meningitidis colonises a substantial proportion of the general population harmlessly, but in a very small percentage of individuals it can invade the bloodstream, affecting the entire body, most notably limbs and brain, causing serious illness.
Provisional tic disorder approximately replaced transient tic disorder: because initially presenting tics may eventually be diagnosed as chronic tic disorder or Tourettes, transient suggested it could only be defined in retrospect (though that perception did not follow the DSM-IV-TR definition). The term provisional "satisfies experts with a more systematic epidemiological approach to disorders", but should not imply that treatment might not be called for. Differentiation of chronic motor or vocal tic disorder: DSM-5 added a specifier to distinguish between vocal and motor tics that are chronic. This distinction was added because higher rates of comorbid diagnoses are present with vocal tics relative to motor tics. Now includes as Tourettes Disorder patients with tics who experienced a 3-month or longer remission since the first tic, as long as the first tic was at least a year ago. Stimulant use as a cause removed: there is no evidence that the use of stimulants causes tic disorders. New categories, Other specified and Unspecified: for tic disorders that result in significant impairment to the individual yet do not meet the full criteria for other tic disorders. The new categories account for tics with onset in adulthood, or tics triggered by other medical conditions or illicit drug use. References
External links

The Tourette Syndrome Classification Study Group. "Definitions and classification of tic disorders". Arch Neurol. 1993 Oct;50(10):1013-6. PMID 8215958. Retrieved on 2005-03-22
Walkup JT, Ferrão Y, Leckman JF, Stein DJ, Singer H. Tic disorders: some key issues for DSM-V (PDF). Depress Anxiety. 2010 Jun;27(6):600–10. PMID 20533370 doi:10.1002/da.20711