In primary brain tumor, cerebrospinal fluid protein level is elevated in up to 70% of patients and cell count in about 30% of cases. One or the other is abnormal in 65%–80% of cases. Electroencephalogram (EEG) is abnormal in about 70%–75% of patients (literature range, 70%–92%), brain scan in about 80%–85% (65%–96%), and CT in about 90%–95% (85%–100%). Therefore, CT scan (or magnetic resonance imaging [MRI]) is clearly the best single test for primary brain tumor (or any space-occupying brain lesion), whereas EEG adds little, if anything, to CT or brain scan information. About 15%–25% (range, 4%–37%) of brain tumors are metastatic (“e condary”). The most common site of origin is lung (about 40% of metastatic brain tumors; literature range, 35%–60%). Next is breast (about 25%; range, 20%–30%); third is probably melanoma (about 10%–15%) or kidney (about 10%). The GI tract (including pancreas) contributes about 5%, and the remainder is shared by various primary sites.
Tag: central nervous system
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Central Nervous System Infection by Other Fungi
Candida is said to be the most common fungal infection of the CNS. About one half of the patients with Candida CNS infection have a lymphocytic pleocytosis and about one half show a predominance of neutrophilis. Some reports have indicated a surprisingly high rate of CNS involvement in the systemic mycoses (blastomycosis, 3%-10%; histoplasmosis, up to 50%; coccidioidomycosis, up to 50%). These fungi most often produce a lymphocytic pleocytosis, but neutrophils may predominate. Cerebrospinal fluid glucose levels are typically reduced but may be normal.
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What is Multiple Sclerosis(MS)?
Damage to your nerves
Multiple Sclerosis is a disease of the central nervous system (CNS); it damages the protective coating around the nerve fibres (Figure 1.1) which transmit messages to all parts of your body, especially those controlling muscular and sensory activity. It is thought to be an ‘autoimmune disease’: this is where your body’s own immune system appears to attack itself. As the damage to the protective coating around the nerve fibres – called
‘myelin’ – increases, it leads to a process known as ‘demyelination’ (Figure 1.2), where the coating is gradually destroyed. These nerves then become less and less efficient at transmitting messages. The messages, as it were, ‘leak’ from the nerve fibres where demyelination has occurred, rather like the loss of an electric current through a cable that is not insulated. As the messages ‘leak’, they become weaker and more erratic, thus leading to greater and greater difficulty in controlling muscles or certain sensory activities in various parts of your body.
Problems of repair
Which nerve fibres are demyelinated, in which order, and at what rate, varies very widely between individuals, so the corresponding loss of muscular and sensory control also varies widely. Moreover, even when damage does occur to the myelin, it is sometimes gradually repaired (i.e. some remyelination occurs) through internal body repair mechanisms; also, what might be described as ‘inflammation’ at the site of the damage often becomes less over time. However, in Multiple Sclerosis the rate of repair is slower than the rate at which the myelin is damaged; so the damage tends to accumulate more and more throughout the CNS. This damage results in plaques or lesions, which take the form of patchy scarring (areas of multiple ‘sclerosis’) where the demyelination has occurred. Thus the name ‘multiple sclerosis’ has evolved.