Substantia nigra depigmentation and exposure to encephalitis lethargica.

OBJECTIVE: Parkinsonism has occasionally been reported as a consequence of infectious diseases. The present study examines the clinical and pathological correlates of parkinsonism across birth cohorts in relation to critical exposure to the encephalitis lethargica epidemic in the early 1900s. METHODS: The study population consisted of 678 participants in the Nun Study, of whom 432 died and came to autopsy. Qualitative indices of substantia nigra (SN) depigmentation were verified in a subset of 40 randomly selected subjects using quantitative stereological techniques. SN depigmentation, detected neuropathologically, was correlated with clinical parameters of Parkinson disease, age, and birth cohort. RESULTS: SN depigmentation was detected in 57 (13.2%) of the cohort. Although qualitative SN depigmentation correlated modestly with age (p = 0.02), it correlated best with birth cohort (p = 0.009) for women born in the years 1895-1899. Quantitative measures of SN depigmentation were increased in this birth cohort compared to age matched subjects from flanking birth cohorts 1890-1894 and 1900-1904 (p < 0.001). SN depigmentation correlated with speed of 6- and 50-foot walk (p < 0.0001), up and go test (p < 0.0001), and hand coordination (p < 0.0001). INTERPRETATION: Subjects in the birth cohort 1895-1899 would have been in their late teens and 20s at the onset and during the peak of the encephalitis lethargica epidemic. These were precisely the age ranges of persons who were most often affected by the illness. These data suggest the possibility that the coexistence of parkinsonism and SN depigmentation in this birth cohort may have resulted from the yet undetermined infectious agent responsible for encephalitis lethargica.

Canine tonsillar squamous cell carcinoma -- a multi-centre retrospective review of 44 clinical cases.

OBJECTIVES: To review the presenting clinical signs, treatment and survival of dogs with tonsillar squamous cell carcinoma and, if possible, to identify useful prognostic indicators. METHODS: Medical records of 44 dogs were reviewed retrospectively. Clinical signs, clinical stage, time of diagnosis, treatment and outcome were recorded. Data were analysed using the Kaplan-Meier, log-rank, Student's t test, Kruskal-Wallis test and Chi-square/Fisher Exact test as appropriate. RESULTS: The most frequent clinical signs were cough (12 dogs, 27%), enlarged lymph nodes (11 dogs, 25%) and dysphagia (11 dogs, 25%). Anorexia and lethargy were less common but were significantly associated with a poor outcome. No matter what treatment modalities were used, survival times were short and median survival time for all the dogs in the study was 179 days. However, there were a small number of long-term survivors. CLINICAL SIGNIFICANCE: Dogs with tonsillar squamous cell carcinoma that suffered anorexia and lethargy had shorter survival times than patients without these clinical signs. Although surgery, chemotherapy and radiotherapy seem to increase the median survival time of dogs diagnosed with tonsillar squamous cell carcinoma, there is no highly effective treatment for canine tonsillar squamous cell carcinoma.