IV Immunoglobulin Is Effective in Patients With Diabetes and CIDP
NEW YORK, January 9 (Reuters Health)—The results of a study published in the January Journal of Neurology, Neurosurgery, and Psychiatry suggest that intravenous immunoglobulin (IVIg) therapy is effective in diabetics with chronic inflammatory demyelinating polyneuropathy (CIDP).

“CIDP seems to be more common in patients with diabetes than in the general population,” Dr. Stefano Jann and colleagues, from Niguarda Hospital, Milan, Italy, wrote. “The long-term outcome of these patients after receiving IVIg is unclear, and the precise optimal regimen needed has yet to be ascertained,” they noted. “Moreover, the influence of chronic hyperglycemia on this neuropathy is not clear.”

The researchers conducted a prospective follow-up study to assess the long-term clinical effectiveness of IVIg in 198 consecutive diabetic patients with CIDP. They also examined the impact of chronic hyperglycemia on CIDP.

Of the 198 patients, 16 diabetic patients (8%) had demyelinating polyneuropathy that fulfilled the most restrictive diagnostic criteria for CIDP. They were treated with at least one course of IVIg at a dose of 2 g/kg administered over five days. Improvement was defined as a decrease of at least 4 points in the Neuropathy Impairment Score (NIS). If the patients responded, they were re-treated in case of relapse. All of the patients were followed for at least 40 months.

Significant improvements after immunotherapy and during follow-up occurred. Of the 16 patients, two (12.5%) did not respond to treatment. The median number of treatments at the end of the study was four. NIS points changed from an average of 38 at baseline to 16 at the end of the study, and scores on the modified Rankin scale decreased from a mean of 3.5 to 1.8.

“Eight patients developed distal sensory disturbances during the follow-up, and four of these patients complained of distal paresthesias but no neuropathic pain,” Dr. Jann and colleagues reported. “Sensory disturbances were detected after 30 months (mean time) from baseline.”

J Neurol Neurosurg Psychiatry. 2009;80(1):70-73.

Diabetes Linked With Distinctive Pattern of Dementia-Related Brain Injury
NEW YORK, January 12 (Reuters Health)—Diabetes affects the type of cerebral injury seen in patients with dementia, showing a different pattern of injury, compared with patients with dementia but without diabetes. Moreover, antidiabetes therapy can impact the cerebral pathology.

Diabetes is known to be a risk factor for dementia in elderly individuals, noted Dr. Joshua A. Sonnen, from the University of Washington, Seattle, and colleagues. However, the mechanisms underlying the association, the link between diabetes and Alzheimer’s disease or vascular cognitive impairment, and the impact of diabetes therapy have been unclear.

To shed light on these questions, the research team analyzed clinical and autopsy data from 196 deceased subjects who were included in the Adult Changes in Thought Study, a community-based study of incident dementia. Biochemical tests of frozen brain tissue were available for 57 of the subjects.

Seventy-one subjects had dementia, and the remaining 125 did not, according to the report published in the January 12 online Archives of Neurology. In patients with dementia, diabetes was associated with increases in microvascular infarcts and cortical interleukin-6 levels. In those without diabetes, increases in β-amyloid peptide load and F2-isoprostane levels in the cerebral cortex were seen.

In demented patients with treated diabetes, microvascular infarcts in deep cerebral structures were increased. In those with untreated diabetes, an increase in the amyloid plaque burden was noted.

Arch Neurol. 2009 Jan 12; [Epub ahead of print].

Free Serum Copper Tied to Alzheimer’s Progression
NEW YORK, January 23 (Reuters Health)—An increased level of free serum copper—that is, copper not bound to ceruloplasmin—appears to be associated with greater cognitive decline in Alzheimer’s disease (AD) patients, Italian researchers reported in the January 6 Neurology.

“We previously reported a deregulation of the ceruloplasmin-copper relationship specific to AD patients,” lead investigator Dr. Rosanna Squitti told Reuters Health. “Elevation of the serum pool of non–ceruloplasmin-bound copper ... also correlated with the typical deficits and markers of the disease.”

In the current study, Dr. Squitti, of Fatebenefratelli Hospital, Rome, and colleagues followed 81 patients with mild or moderate AD for a year. After adjustment for baseline scores on the Mini-Mental State Examination (MMSE), free copper predicted the annual change in MMSE, raising the explained variance from 2.4% (using only sex, age, and education) to 8.5%, a significant difference.

The only predictor of a decline in MMSE of 3 or more points was free copper (odds ratio, 1.23). In addition, patients with hyperlipidemia who had higher levels of free copper seemed more prone to greater cognitive impairment.

“Changes in activities of daily living and instrumental activities of daily living—which predict future functional decline, institutionalization, and death—were evaluated in relation to copper status,” the authors wrote. “Patients with higher levels of free copper at baseline seemed to have a faster and more pronounced evolution of disabilities, in parallel with the progression of cognitive decline.”

Neurology. 2009;72(1):50-55.

Reuters Health Information: February 2009