Memory loss not enough to diagnose Alzheimer’s

Relying on clinical symptoms of memory loss to diagnose Alzheimer’s disease may miss other forms of dementia caused by Alzheimer’s that don’t initially affect memory, reports a new Northwestern Medicine study.

There is more than one kind of Alzheimer’s disease. Alzheimer’s can cause language problems, disrupt an individual’s behavior, personality and judgment or even affect someone’s concept of where objects are in space.

If it affects personality, it may cause lack of inhibition. “Someone who was very shy may go up to grocery store clerk — who is a stranger — and try to give her a hug or kiss,” Rogalski said.

This all depends on what part of the brain it attacks. A definitive diagnosis can only be achieved with an autopsy. Emerging evidence suggests an amyloid PET scan, an imaging test that tracks the presence of amyloid — an abnormal protein whose accumulation in the brain is a hallmark of Alzheimer’s — may be used during life to determine the likelihood of Alzheimer’s disease pathology.

Full story is available from Northwestern University website.

New technique generates human neural stem cells for tissue engineering, 3D brain models

Tufts University researchers have discovered a new technique for generating rapidly-differentiating human neural stem cells for use in a variety of tissue engineering applications, including a three-dimensional model of the human brain, according to a paper published today in Stem Cell Reports. The work could pave the way for experiments that engineer other innervated tissues, such as the skin and cornea, and for the development of human brain models with diseases such as Alzheimer’s or Parkinson’s.

Researchers converted human fibroblasts and adipose-derived stem cells into stable, human induced neural stem cell (hiNSC) lines that acquire the features of active neurons within as few as four days, compared to the typical four weeks, according to the paper. The neural stem cells are hardy, can be frozen, passaged indefinitely, and have unique attributes that allow them to grow well in vitro with other cell types, such as skeletal muscle. When injected into an early stage chicken embryo, the hiNSCs incorporated into the brain as well as the neurons of the peripheral nervous system that innervate tissues in a developing limb.

Full story is available from Tufts University website.

A virtual brain helps decrypt epilepsy

Researchers at CNRS, INSERM, Aix-Marseille University and AP-HM have just created a virtual brain that can reconstitute the brain of a person affected by epilepsy for the first time. From this work we understand better how the disease works and can also better prepare for surgery.

Worldwide, one percent of the population suffers from epilepsy. The disease affects individuals differently, so personalized diagnosis and treatment are important. Currently we have few ways to understand the pathology’s mechanisms of action, and mainly use visual interpretation of an MRI and electroencephalogram. This is especially difficult because 50% of patients do not present anomalies visible in MRI, so the cause of their epilepsy is unknown.

Researchers have succeeded for the first time in developing a personalized virtual brain, by designing a base “template” and adding individual patient information, such as the specific way the brain’s regions are organized and connected in each individual. Mathematical models that cause cerebral activity can be tested on the virtual brain. In this way, scientists have been able to reproduce the place where epilepsy seizures initiate and how they propagate. This brain therefore has real value in predicting how seizures occur in each patient, which could lead to much more precise diagnosis.

Moreover, 30% of epileptic patients do not respond to drugs, so their only hope remains surgery. This is effective if the surgeon has good indications of where to operate. The virtual brain gives surgeons a virtual “platform.” In this way they can determine where to operate while avoiding invasive procedures, and especially prepare for the operation by testing different surgical possibilities, seeing which would be most effective and what the consequences would be, something that is obviously impossible to do on the patient.

In the long run, the team’s goal is to provide personalized medicine for the brain, by offering virtual, tailored, therapeutic solutions that are specific for each patient. The researchers are currently working on clinical trials to demonstrate the predictive value of their discovery. This technology is also being tested on other pathologies that affect the brain, such as strokes, Alzheimer’s, degenerative neurological diseases, and multiple sclerosis.

A press release can be found on The National Center for Scientific Research (CNRS) website.