A drug belonging to a class known as diuretics, meaning that they cause the person taking them to pass more urine than usual. Diuretics are used in the treatment of heart failure or high blood pressure. They also reduce the rate at which cerebrospinal fluidThis clear, water-like fluid forms, for the most part, within the brain, more specifically inside the ventricles of the brain. Blood flows through structures inside the ventricles, called the choroid plexuses, and clear fluid is produced as a result, passing into the ventricle. This process is akin to blood flowing through the kidneys and urine being produced as a result. An important difference is that, unlike urine, the cerebrospinal fluid is not passed out of the body periodically. Instead, the fluid is re-absorbed back into the blood stream, mostly via the arachnoid granulations, into the cerebral venous sinuses. In the course of a 24-hour period, most healthy adults will produce about 500mls (or a pint) of cerebrospinal fluid, although at... is formed by the choroid plexusThis structure (more accurately a series of structures) lies within all four ventricles of the brain. Viewed through a ventriculoscope, it has the appearance of pink seaweed. Blood flows through the choroid plexus and clear, water-like fluid, i.e. cerebrospinal fluid, is produced, passing into the ventricles. Not all of the cerebrospinal fluid forms from the choroid plexuses but a substantial proportion does, probably at least half of the daily production of about half a litre, or one pint. and can sometimes relieve symptoms of Chiari malformationAn anatomical abnormality affecting the lowermost part of brain, where it joins the spinal cord, at the top of the neck. Various sub-types are described - see under their individual names. The term hindbrain hernia is sometimes used to incorporate all forms. by reducing the “pressure from above”, which may tend to push the herniated cerebellar tonsilsThe lower-most part of the cerebellum is made up of a pair of structures, one on each side of the midline, known as the tonsils. These structures have no relationship with the tissue at the back of the throat, which becomes inflamed and sore with a viral infection. It is simply the case that the same Latin term was applied by (presumably) different anatomists, at different times and working in different places, to name these very different body parts. The word tonsilla literally means a stump; Roman ships were moored to “tonsilla” when in port. into the foramen magnumThe large, ovoid opening at the base of the skull, measuring about 3 x 3.5cm, through which the spinal cord passes, to continue on as the brain stem.. Another drug which has similar effects is acetazolamideA drug used, amongst other indications, to reduce the formation of cerebrospinal fluid. In a minority of people it can relieve headaches associated with Chiari malformations. See also Furosemide (Frusemide). More but many people do not tolerate some of the side effects of this preparation.