Brain radiation-related black dots on susceptibility-weighted imaging.

Small blood vessel injury is a feature of post irradiation brain. Susceptibility weighted imaging (SWI) is a technique that exploits the magnetic properties of tissues, such as blood and iron content and is thus sensitive to hemorrhage as a marker of small vessel injury. Our purpose was to assess post irradiation brain findings using SWI. We evaluated 12 patients with follow-up MRI studies who underwent cranial irradiation for primary or metastatic tumors. From their clinical records, the latency interval, type of radiation, and total dose were established. The number and the distribution of "black dots" on SWI were analyzed. We also compared the findings on SWI with those seen on other MRI sequences. In all patients, black dots were clearly identified on SWI, while on conventional MRI (T2 and FLAIR) none were visible. Two patients with glial tumors received radiation with fields conforming to tumor beds, while all other patients received whole brain irradiation or craniospinal radiation. The total radiation doses ranged from 45-54 Gy. Latency interval between the time of irradiation and time of detection of the black dots was four to 60 months (mean, 31 months). In ten patients diffuse black dots were observed and in two patients these were located in the irradiated field. Black dots occurred in the cerebrum, cerebellum, and choroid plexuses. None of these dots showed enhancement. Follow-up in four patients showed that the numbers of these black dots had increased. Black dots were not present before radiation in any patient. Radiation-related black dots are an effect of cranial irradiation and may be related to small vessel damage. SWI is a sensitive technique for evaluation of these black dots.

Varicella zoster CNS vascular complications. A report of four cases and literature review.

This study explored the neurologic vascular complications of varicella zoster virus (VZV). We describe four patients presenting at our institution with neurologic involvement by VZV. MR and MRA studies of the intracranial arterial circulation in the head were read by board-certified radiologists using standard clinical procedures. On MRI, three patients had acute infarcts and in two instances irregularities and narrowings of vessels were visible. Many of these complications are recognized to be due to a vasculopathy affecting small or large vessels and resulting in cerebral infarctions and rarely hemorrhages. The pattern of cerebral infarction and vascular abnormalities is not specific and resembles those of vasculitis/vasculopathy from other causes. The central nervous system (CNS) vascular complications of VZV should be considered in the patients with simultaneous primary or prior VZV infection whose imaging studies show cerebral infarction and/or vasculitic appearing intracranial arteries.

Uso de substâncias psicoativas entre estudantes de Medicina de Salvador (BA) / Psychoactive substance use by medical students from Salvador (BA)

CONTEXTO: Estudos indicam que estudantes de Medicina, apesar do seu dedutível conhecimento sobre os efeitos das substâncias psicoativas, consomem-nas em proporção semelhante à dos jovens de mesma idade na população geral. OBJETIVO: Analisar o padrão local do consumo dessas substâncias entre graduandos de Medicina e contribuir na formulação de atividades preventivas. MÉTODOS: Aplicação de questionário semi-estruturado no qual foi avaliada a freqüência de uso das substâncias psicoativas entre os estudantes, assim como as principais razões apontadas para o consumo. Foram analisados 404 questionários obtidos entre alunos dos seis anos de curso das duas maiores escolas médicas de Salvador. RESULTADOS: As drogas mais utilizadas no critério uso na vida foram álcool (92,8 por cento) e lança-perfume (46,2 por cento). O uso de álcool apresentou-se constante nos seis anos de curso. Entretanto, o uso de tabaco, lança-perfume e tranqüilizantes aumentou significativamente para os alunos dos últimos anos (p < 0,05). Há um maior consumo de drogas pelo gênero masculino. Diversão foi apontada como razão mais importante para o uso dessas substâncias (58,7 por cento das respostas válidas). CONCLUSÃO: O consumo de substâncias psicoativas entre estudantes de Medicina de Salvador é considerado alto, em concordância com o que se constatou em outros trabalhos científicos.

BACKGROUND: Studies have shown that medical students consume psychoactive substances at the same rates as the same age youth on general population, despite their predictable knowledge about drugs effects. OBJECTIVE: To analyze the local pattern of psychoactive substances use among medical students and contribute for the formulation of preventive activities. METHODS: The frequency of psychoactive substances use was evaluated by a self-administered anonymous questionnaire that also asked the main reasons for that use. Four hundred and four students in the first to sixth year from the two biggest medical schools in Salvador answered the questionnaire. RESULTS: The lifetime use was bigger for alcohol (92.8 percent) and inhalant (46.2 percent). Alcohol use was constant for the students from first to sixth year of course, but it was not statistically significant (p > 0.05). However, tobacco, inhalants and tranquilizers use had a significant increase at the last two years of course students (p < 0.05). It was verified a bigger drugs use by the male gender. "Fun" was shown as the first main reason for psychoactive substances (58.7 percent of the valid answers). CONCLUSION: Psychoactive substances consume rates by medical students from Salvador are as high as the ones shown on other scientific researches about this subject.