In the News

New Developments in Alzheimer's Show Promise
Several new studies on Alzheimer's disease raise hope for new treatments and offer an understanding of disease progression. Here's a look at a few.

• By measuring cerebrospinal fluid concentrations of amyloid beta42 peptide and tau protein, researchers at the University of Pennsylvania say they have devised a test capable of confirming or ruling out Alzheimer's disease. The authors of the study published in the online edition of the Annals of Neurology were able to identify AD at the earliest stages, before dementia symptoms appeared and extensive irreversible damage occurred. For the study, CSF was collected from 410 volunteers from 56 sites across the US and Canada. CSF samples taken from 56 people with confirmed AD based on post-mortem autopsy diagnosis were also measured to establish threshold values for these biomarkers.
  
  Measured against normal, healthy adults of the same age, a pattern of changes materialized in people with MCI or AD. Tau concentrations increased while amyloid beta42 levels decreased as the disease progressed.
  
  Overall, the test was 87 percent accurate. The test accurately ruled out AD in 95.2 percent of subjects. It positively predicted the conversion from MCI to AD at a clip of 81.8 percent. In the CSF samples from the post-mortem-confirmed AD patients, the amyloid beta42 concentration threshold was most sensitive and revealed AD at nearly a 97 percent rate.


• A high-density genome-wide analysis of participants in the Alzheimer's Disease Neuroimaging Initiative (ADNI) is more than 95 percent complete. The ongoing $60 million project involves MRI and PET brain imaging and blood, urine and spinal fluid biomarker studies of more than 800 people, half of whom have MCI. The primary goal of ADNI is to "determine whether brain imaging, other biological markers, and clinical and neuropsychological assessment can accurately measure the progression of MCI and early AD." All data are available to qualified investigators through www.loni.ucla.edu/ADNI.


• Losing brain cells in the hippocampus is associated with a higher probability of developing dementia, according to a study published in Neurology (72: 999-1007). Researchers followed 64 people with AD, 44 with MCI, and 34 with no memory or thinking problems. MRI scans were performed on all participants at baseline and again a year and a half later, on average, to measure the volume of the whole brain and the hippocampus area and calculate the rate of shrinkage over time. Twenty-three people with MCI developed AD, along with three other healthy participants.
  
  For participants who did not have dementia at the start of the study, "those with smaller hippocampal volumes and higher rates of shrinkage were two to four times as likely to develop dementia as those with larger volumes and a slower rate of atrophy."


• A new generation of molecular imaging agents called Avid AD-45 and a high sensitivity, experimental research PET brain scanner named NeuroPET are being studied to scan amyloid plaque. Ideally, high sensitivity will provide high quality brain scans using lower doses of radioactive agents, allowing patients to undergo more frequent diagnostic scans to monitor response to therapy.
  
  Investigational radioactive "tracer" chemicals connect inside the brain to markers for specific diseases, such as AD or Parkinson's, coupled with high tech scanners that produce 3-D images of these disease-specific diagnostics distributed within the brain, according to Avid Radiopharmaceuticals, one of the product developers.

Food for Thought
A medical food is now available for management of mild-to-moderate dementia with the launch last month of Axona (Accera). The once-daily prescription product, described by the manufacturer as providing alternative energy to the brain, is formulated to improve brain metabolism and associated energy imbalances in patients with AD.

According to Jeffrey L. Cummings, MD, Director of the Mary S. Easton Center for Alzheimer's Disease Research at UCLA and a consultant for Accera, the theory behind development of Axona moves beyond the role of amyloid in AD. "The amyloid hypothesis is alive and well although subject to constant refinement," Dr. Cummings observes. "This does not preclude developing therapies addressing other types of disturbances in AD including hypometabolism. The Axona approach may well stimulate further investigation into medical foods or other dietary approaches."

In a double-blind, randomized study involving patients with probable mild-to-moderate AD, those taking Axona had significant improvements in ADAS-Cog scores by day 45. Treated patients maintained slight improvement from baseline at day 90 versus controls, who declined.

The powder formulation is provided in individual packets to be dissolved in water and taken with breakfast. In trials, Axona was found to be safe and well-tolerated.

In addition to offering cognitive benefit, Axona may point to new directions in AD research and therapy. "The data regarding Axona are evolving," Dr. Cummings says. "They raise interesting questions and point in new directions." However, he notes there is still much to learn. "We need to know more before we would say that the Axona data are reforming the way we look at the disease," he adds.

New Mexico Rolls Out Medical Marijuana Initiative
President Barack Obama didn't endorse legalization of marijuana for personal use as a way to stimulate the economy, but the New Mexico Department of Health has approved the first nonprofit in the state to produce medical marijuana for patients in the department's Medical Cannabis Program.

The Health Secretary will consider the health needs of "patients and the public safety" in determining the number and location of licenses the department approves. Patients in the Medical Cannabis Program can also apply to produce up to four mature plants and 12 seedlings for personal use. So far, 23 patients have been approved to be their own producers. Nonprofits are allowed to produce up to 95 mature plants and seedlings and maintain a usable inventory.

The department will not release the name or location of the producer citing safety concerns and will notify certified patients how to contact the licensed producer. Under current state law, several neurologic conditions qualify for the medical marijuana program (Table). Patients in hospice care could also qualify.

The health board announced it would be willing to reconsider petitions for chronic pain, bipolar disorder, arthritis, and others. If a patient does not have a qualifying condition and their physicians feels they would benefit from marijuana, that person can petition the Medical Advisory Board to add their condition to the current list.

The bill was hotly contested. "Medically it just really has no value," argued Rep. John Heaton, a pharmacist, to the Santa Fe New Mexican. "For us to approve a drug like this tells our children and tells the rest of the people in this state that we, somehow as leaders, give tacit approval to the use of this drug."

Proponents of the bill point to prescription drug abuse figures to counter criticism about marijuana's societal effect. About 2.1 million people abused or became dependent on psychotherapeutics used non-medically in 2007, according to Substance Abuse and Mental Health Services Administration. In 2008, seven of the top 10 drugs abused by teenagers were prescribed or purchased over the counter, according to the National Institute on Drug Abuse.

Illinois is weighing a similar bill, according to the Southtown Star.

Short Takes
Vertigo, Osteoporosis Linked. Patients with osteoporosis are more likely to also have vertigo, according to a new study (Neurology 72: 1069-1076). Researchers followed 209 people with benign positional vertigo without known cause and compared to 202 people with no history of dizziness. They found that those with vertigo were three times more likely to have osteoporosis and people with osteopenia were twice as likely to experience vertigo as those who didn't suffer from the disorder. "In both women and men, the lowest T scores were decreased in patients with BPV compared with those in controls," the authors write. "Furthermore, the prevalences of osteopenia (–2.5 < T score < –1.0) and osteoporosis (T score ≤–2.5) were higher in both women and men with BPV than in controls."

Tick, tick, tick. A protein in tick saliva has shown potential to limit the severity of myasthenia gravis in an animal model (Annals of Neurology 65(1):67-75). Previous research showed rEV576 works as a complement inhibitor to avoid setting off an immune response in ticks' hosts. In rats with mild and severe myasthenia gravis, rEV576 treatment improved the health of rats with reduced weakness and weight loss.

FDA Actions
EEG System Cleared. Astro-Med, through its Grass Technology Product Group, has won FDA approval to sell a new neuromonitoring system. It received the OK for the intended use of recording the EEG and computed EEG trends over extended time periods to assist health care professionals observe long-term changes. As well as displaying and recording the EEG waveforms, the device also computes graphical trends of EEG features like amplitude integrated EEG trend, frequency trends and Burst-Suppression Patter trends.

Sleep Drug Coming Soon. Patients requiring pharmacologic assistance for sleep initiation will have access to Edluar (zolpidem, Orexo/Meda), which was formerly called Sublinox. The 5mg and 10mg sublingual tabets received FDA clearance last month for short-term treatment of insomnia. The agent will be marketed inthe US by Meda with a launch date in the second half of this year.