AUTOIMMUNE LIMBIC ENCEPHALITIS (CASE REPORTS).

Limbic encephalitis (LE) is an autoimmune or paraneoplastic disease that affects the medial temporal lobes. The patient will usually present with cognitive impairment, psychiatric changes, and seizures. Autoimmune limbic encephalitis (LE) is a challenging diagnosis as it is not always included in the typical paraneoplastic/autoimmune panels. Anti-GAD antibodies are associated with various disease including type I diabetes mellitus, various autoimmune processes, some neoplastic and infectious diseases. Thus, it is not as specific as some of the antibodies causing LE. We are presenting two cases of isolated anti-GAD antibody-associated limbic encephalitis. Both patients were adults who developed status epilepticus and refractory seizures, cognitive impairment and mood instability. Patients' cerebrospinal fluid (CSF) and serum anti- GAD antibodies were elevated and after treatment returned to normal reference range. The diagnosis for both patients was delayed (by over one month following hospitalization), both patients required prolonged hospitalization and rehabilitation after discharge. Patient's condition improved only after immunotherapy, but required several antiepileptic drugs for seizure control. The diagnosis was more difficult in the first patient, who had numerous other medical problems including ESRD and moderately severe microvascular changes on brain imaging. In this particular patient, it was hard to appreciate any signal changes on MRI in the mesial temporal lobes given the underlying white matter disease. We recommend inclusion of anti- GAD antibody in the paraneoplastic/encephalopathy panels in order to decrease missed cases of this important cause of LE as well as to hasten the diagnosis. This is a treatable disease, and timely diagnosis is imperative to improve outcomes.

Risk factors for diphtheria: a prospective case-control study in the Republic of Georgia, 1995-1996.

The large-scale resurgence of diphtheria in the former Soviet Union offered a unique opportunity to evaluate risk factors for the transmission of respiratory diphtheria; therefore, a prospective case-control study was done in the republic of Georgia. In total, 218 diphtheria cases (hospitalized between October 1995 and March 1996) and 408 matched controls participated. One hundred cases (45%) were /=15 years of age (range: <1 to 75 years). In the multivariate analyses, the following risk factors were found to be significant: lack of vaccination (matched odds ratio [mOR]=19.2), household exposure to diphtheria (mOR=7.4), exposure to skin lesions (mOR=5.8), history of eczema (mOR=3.4), fever with myalgia prior to illness (mOR=2.6), having tonsils (mOR=4.4), sharing a bed (mOR=1.9), sharing cups and glasses (mOR=2.7), and taking a bath less than once a week (mOR=2.6). These findings emphasize primary prevention through immunizations, secondary prevention following exposure to diphtheria (and to suspicious skin lesions), and adherence to strict standards of personal hygiene.

Epidemic diphtheria in the Republic of Georgia, 1993-1996: risk factors for fatal outcome among hospitalized patients.

Epidemic diphtheria reemerged in the republic of Georgia in November 1993. To identify risk factors for fatal outcomes, clinical and epidemiologic data on all hospitalized diphtheria patients were examined. Medical charts of patients from 1993-1995 were reviewed. A total of 659 cases and 68 deaths were identified (case fatality rate [CFR] = 10.3%). Fifty-two percent of all cases and 68% of deaths were in children 3 days) between onset of symptoms to antitoxin treatment were significantly associated with fatal outcomes. Immunization of children and 40- to 49-year-old adults was required to rapidly control the epidemic.

Direct polymerase chain reaction for detection of toxigenic Corynebacterium diphtheriae strains from the Republic of Georgia after prolonged storage.

A total of 226 paired nose and throat swab specimens from 113 clinical diphtheria cases from the republic of Georgia were analyzed by direct polymerase chain reaction targeting both A and B subunits of the diphtheria toxin gene, tox. Even after prolonged transport and extensive storage (7-14 months) of the clinical specimens in silica gel packages, direct polymerase chain reaction detected the diphtheria tox gene in 54% of the specimens. Specimens obtained by throat swab were three times more likely than those obtained by nose swab to be positive for Corynebacterium diphtheriae.

Diphtheria in the Republic of Georgia: use of molecular typing techniques for characterization of Corynebacterium diphtheriae strains.

Sixty-six Corynebacterium diphtheriae strains (62 of the gravis biotype and 4 of the mitis biotype) isolated during the Georgian diphtheria epidemic of 1993 to 1998 and 13 non-Georgian C. diphtheriae strains (10 Russian and 3 reference isolates) were characterized by (i) biotyping, (ii) toxigenicity testing with the Elek assay and PCR, (iii) the randomly amplified polymorphic DNA (RAPD) technique, and (iv) pulsed-field gel electrophoresis (PFGE). Fifteen selected strains were ribotyped. Six RAPD types and 15 PFGE patterns were identified among all strains examined, and 12 ribotypes were found among the 15 strains that were ribotyped. The Georgian epidemic apparently was caused by one major clonal group of C. diphtheriae (PFGE type A, ribotype R1), which was identical to the predominant epidemic strain(s) isolated during the concurrent diphtheria epidemic in Russia. A dendrogram based on the PFGE patterns revealed profound differences between the minor (nonpredominant) epidemic strains found in Georgia and Russia. The methodologies for RAPD typing, ribotyping, and PFGE typing of C. diphtheriae strains were improved to enable rapid and convenient molecular typing of the strains. The RAPD technique was adequate for biotype differentiation; however, PFGE and ribotyping were better (and equal to each other) at discriminating between epidemiologically related and unrelated isolates.