A University of Pittsburgh study headed by Stephen T. DeKosky, MD, has uncovered a completely different mechanism behind mild cognitive impairment. In older people with mild cognitive impairment, the brain produces more choline acetyltransferase (ChAT), in what researchers believe is an attempt by the brain to maintain normal memory function. The results run contrary to prevalent opinions and may explain why current medications do not improve memory function effectively. They suggest that “the brain increases production of ChAT on its own in people with mild cognitive impairment, and that cholinesterase inhibitors may therefore be effective if used in patients who have a deficit in ChAT,” Dr. DeKosky said. However, because that deficit is found only in patients with end-stage Alzheimer’s disease, “we should spend more time researching ways to slow down or stop the early stages of neurodegeneration,” he added. The study was published in the February Annals of Neurology.

As reported in the January 22 Neurology, the case of a 31-year-old woman with intractable temporal lobe epilepsy and ictal orgasm, a phenomenon in which seizures are preceded by “orgasm-like euphoric erotic feeling,” has led a group of Hungarian researchers to suggest that orgasmic aura, and possibly physiological orgasm, originate in the right hemisphere of the brain. In the 22 case reports on orgasmic aura published since 1945, researchers found that 89% of the patients with EEG data had temporal foci, 87% of which were right-sided. All nine patients with sufficient data on ictal onset area had right-sided seizure onset. Researchers suggest the right amygdala might be at least one area responsible for producing orgasm sensation.

A man who suffered an incomplete spinal cord injury is walking again. The quadriplegic, wheelchair-dependent patient can now walk up to 1,000 feet with only moderate fatigue and no aid beyond a walker. Richard Herman, MD, performed the first surgical implantation of stimulating electrodes in a patient with spinal cord injury for the purpose of assisting locomotion. Dr. Herman then employed the Epidural Spinal Cord Stimulation therapy pioneered by Edgar Garcia-Rill, PhD, and Robert Skinner, PhD, in conjunction with Partial Weight Bearing Therapy. Long duration pulses (0.2 to 2 ms) at low frequencies (0.5/s to 10/s) achieved an immediate improvement in the speed, duration, and endurance of walking. The results of this first clinical trial of its kind were published in the February Spinal Cord and will be featured in a documentary for the Discovery Channel later this year.

Frequent participation in cognitively stimulating activities is associated with a reduced risk of Alzheimer’s disease, according to a study published in the February 13 JAMA. Researchers followed more than 700 dementia-free patients (ages 65 and older) for an average of 4.5 years, assessing the time they spent engaging in activities that involve significant information processing. Analysis of annually administered cognitive tests comparing the scores of 111 participants who developed Alzheimer’s disease during follow-up with those who remained disease free determined that a 1-point increase on the cognitive tests correlated with a 33% reduction in risk of Alzheimer’s disease and a 47% reduction among those whose cognitive activity scores were highest. “Further research should help better sort out whether cognitive activities can be prescribed to reduce risk of Alzheimer’s disease, and why that may be so,” said Elisabeth Koss, PhD.

Excessive daytime sleepiness is common in patients with Parkinson’s disease, even those who are independent and do not have dementia. Sudden-onset sleep without warning is infrequent. Researchers in Canada surveyed 638 highly functional patients with Parkinson’s disease (no dementia), assessing them with the Epworth Sleepiness Scale and the Inappropriate Sleep Composite Score. Excessive daytime sleepiness was present in 327 (51%), including 213 (51%) of 420 drivers. Sixteen patients (3.8%) experienced at least one episode of sudden-onset sleep while driving. In three patients it occurred without warning. Dopamine agonists had no effect on scores or on the risk of falling asleep while driving, and patients should be warned not to drive if they doze under unusual circumstances, the researchers concluded. The results were published in the January 23 JAMA.

A study to determine the extent of supplemental oxygen use in ischemic stroke patients and whether patients receiving oxygen actually had indications for its use concluded that oxygen use was justified in only 45.6% of cases. These results, published in the January Archives of Internal Medicine, were derived from a review of 167 patient charts, which yielded 600 inpatient days. Supplemental oxygen therapy was received during some portion of hospitalization by 102 patients (61.1%). Of the 322 days that patients received oxygen, only 147 met at least one criterion for oxygen use, while of the 384 days in which no criteria were met, oxygen was still administered 45.6% of the time (175 days). Researchers indicate that opportunities exist for a substantial (45%) conservation of resources by withholding oxygen when not medically justified by established criteria.

A study published in the February Stroke shows that fevers after coronary bypass surgery are associated with measurable cognitive declines. In 300 patients, researchers found a relationship between the maximum postoperative temperature in the first 24 hours and significant cognitive decline. Maximum temperature ranged from 37.2°C to 39.3°C, with patients having the greatest hyperthermia also having the highest rates of cognitive dysfunction. Thirty-nine percent of the patients in the study were found to have cognitive deficits six weeks after surgery. “High temperatures make a bad situation even worse,” researchers said. “Strategies that keep the brain cool could protect brain cells and [possibly] provide some protection against cognitive decline.”

In one of the largest national studies of its kind, researchers found that both caregiver and patient health care costs increase dramatically as symptoms worsen in patients with Alzheimer’s disease. The study, in the February Journal of the American Geriatrics Society, showed that for a six-month period, costs approximated $20,000 for a typical high-functioning patient and $35,000 for a patient with severe dementia. Caregivers missed 2.6 days of work to care for a patient with mild symptoms and 8.7 days for a patient with severe symptoms. Hospitalizations also increased from 1.8 to 3.4 days with severity of symptoms. “The study provides an impetus for earlier treatment to help keep Alzheimer’s disease at a less severe stage,” said lead author Gary Small, MD.

A study in the January 22 Neurology documents data demonstrating that relatives of patients with multiple sclerosis have a higher risk of developing the disease than does the general population. “The study confirmed previous findings suggesting that asymptomatic relatives of multiple sclerosis patients have an increased risk of developing brain autoimmune damage,” said Krzysztof Selmaj, MD. Thirty relatives of patients with multiple sclerosis who had no previous history of neurologic deficits showed subtle, normal-appearing brain tissue changes in an alternative test using magnetization transfer imaging, a tool which provides “a more complete assessment” than MRI, which can reveal multiple sclerosis lesions but not “these more subtle changes,” Dr. Selmaj explained.

By enhancing the brain’s natural protective response to Huntington’s disease, researchers were able to alleviate the uncontrollable tremors and prolong the lives of mice with a neurological disorder that mimics Huntington’s disease. Their findings, published in the February Nature Medicine, suggest that a similar strategy may be effective in humans. The mice, treated with cystamine injections, showed signs of improvement as their tremors and abnormal movements decreased in severity and their life spans increased by an average of 20%. However, the protein aggregates, a potential cause of Huntington’s disease, remained unchanged. Thus, while the findings suggest that cystamine could someday offer hope to patients with Huntington’s disease, the researchers recommend that the quest for other, potentially better compounds should continue.

Vitamin C may provide a promising new way of improving the delivery of drugs into the brain, according to researchers in Italy. The addition of vitamin C to drugs such as nipecotic acid facilitated their ability to interact with the SVCT2 transporter and enhanced drug absorption across the blood-brain barrier. Thus far the studies, published in the January Journal of Medicinal Chemistry, have been confined to mice, and while the results have yet to be confirmed in humans, researchers remain confident that their finding “could have implications for treating a variety of disorders in the central nervous system, including viral infections, brain lesions, and neurodegenerative diseases.”

Early administration of acetaminophen (3,900 mg/d) to afebrile patients with acute stroke may result in a small reduction in core body temperature and a modest promotion of hypothermia, researchers reported in the January Stroke. Thirty-nine stroke patients were randomized to receive 650 mg acetaminophen or placebo every four hours for 24 hours. Core body temperature was measured every 30 minutes. Patients receiving acetaminophen tended to have lower core body temperatures (by a margin of 0.22¡C), less hyperthermia, and more hypothermia. “However,” lead author Scott E. Kanser, MD, cautioned, “further investigations with larger study populations and longer follow-up periods may be warranted to determine whether the small effect on temperature translates into a measurable effect on clinical outcome.”

First-degree relatives of African-Americans with Alzheimer’s disease have a higher cumulative risk of dementia than do those of whites with Alzheimer’s disease. Questionnaire and supplemental record data was collected between May 1991 and March 2001 for a cohort of 17,639 first-degree biological relatives and 2,474 spouses of 2,339 white Alzheimer’s disease patients and 2,281 first-degree relatives and 257 spouses of 255 African-Americans with Alzheimer’s disease; the risk analysis revealed a cumulative risk of dementia by age 85 of 43.7% for first-degree relatives of African-Americans. This compared to only a 26.9% risk for whites. Likewise, spousal risk was higher in African-Americans (though not significantly), while increase in risk of dementia, as well as an elevated risk for female relatives, was similar in both populations. The results were published in the January 16 JAMA.

NR