CSF silicon in dementia: a prospective study.

We designed a prospective study to determine whether CSF silicon elevation is specific for Alzheimer-type dementia (ATD) and whether it is related to the severity of cognitive or functional impairment. We found elevated CSF silicon in 30% of 23 ATD patients but in only 1 of the 23 age-matched nondemented controls. In all ATD patients with elevated CSF silicon, symptoms began after age 65. Thirty-four percent of 29 patients with other types of dementia also had elevated CSF silicon. Therefore, elevated CSF silicon concentrations are not specific for ATD, but they correlate with age and severity of functional impairment in late-onset ATD.

Cerebrospinal fluid trace element content in dementia: clinical, radiologic, and pathologic correlations.

Using inductively coupled argon plasma emission spectroscopy, we measured 19 trace elements in cerebrospinal fluid of 265 patients who were undergoing diagnostic lumbar puncture. Thirty-three patients had Alzheimer-type dementia (ATD); 16 patients had other dementing illnesses; and 20 had no neurologic disease. There were seven cases of autopsy-proven Alzheimer's disease (AD) and eight autopsy controls. We found elevated CSF silicon in 24% of ATD and 71% of AD patients. We found no relationship between CSF aluminum, arsenic, lead, or manganese and ATD, AD, or other dementing illnesses.

Silicon as a potential uremic neurotoxin: trace element analysis in patients with renal failure.

We analyzed multiple trace elements in tap water, dialysis fluids, and CSF of patients on dialysis and with chronic renal insufficiency. Before placement of a deionizer in the dialysis unit, we found elevated levels of aluminum, barium, copper, silicon, and zinc in tap water and dialysis fluids. These were corrected by the deionizer. CSF silicon content was increased in patients with chronic renal insufficiency and on dialysis; CSF aluminum, barium, copper, and zinc were normal.