Brain : a journal of neurology
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Nitric oxide (NO) has been implicated in migraine pathogenesis based on the delayed development of typical migraine headache 4-6 h after infusing the NO donor nitroglycerin [glyceryl trinitrate (GTN)] to migraineurs. Furthermore, inhibiting the synthesis of NO by treatment with a NO synthase (NOS) inhibitor attenuates spontaneous migraine headaches in 67% of subjects. Because NO has been linked to inflammation and cytokine expression, we investigated the delayed consequences of brief GTN infusion (30 min) on the development of meningeal inflammation in a rat model using doses relevant to the human model. ⋯ In addition to cytokine induction, macrophage iNOS upregulation and oedema formation after GTN infusion, dural mast cells exhibited granular changes consistent with secretion at 4 and 6 h. Because iNOS was expressed in dural macrophages following topical GTN, and in the spleen after intravenous injection, the data suggest that the inflammatory response is mediated by direct actions on the dura and does not develop secondary to events within the brain. Our findings point to the importance of new gene expression and cytokine expression as fundamental to the delayed response following GTN infusion, and support the hypothesis that a similar response develops in human meninges after GTN challenge.
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In contrast to childhood brainstem gliomas, adult brainstem gliomas are rare and poorly understood. The charts of 48 adults suffering from brainstem glioma were reviewed in order to determine prognostic factors, evaluate the effect of treatment and propose a classification of these tumours. Mean age at onset was 34 years (range 16-70 years). ⋯ Low-grade tumours have a clinicoradiological pattern that is so characteristic that the need for a potentially harmful biopsy is debatable. The optimum timing of treatment for supratentorial low-grade tumours remains unclear. In high-grade gliomas, the prognosis remains extremely poor despite aggressive treatment with radiotherapy and chemotherapy.