1. HUS/Tero Hanski
Tools for diagnosing Alzheimer’s www.salwe.fi
disease in early stage
A project launched in SalWe’s Mind and Body Programme has focused on studying the diagnosis of
mild cognitive impairment and Alzheimer’s disease, by using auditory event-related potentials.
Alzheimer’s disease is a slow and progressively wors- about one percent of the world’s GNP. The number of
ening disease of the brain, characterised by damage these patients is expected to double in the next 20 years.
to specific brain regions. Diagnosis of the disease at
the earliest possible stage has high priority because As many as 120,000 people in Finland suffer from the
medications are available to slow the symptoms of syndrome of mild cognitive impairment.
its progress.
Sensory gating and Alzheimer’s disease
Approximately 70,000 people in Finland suffer from A group of researchers in SalWe’s Mind and Body Pro-
Alzheimer’s disease. gramme has been studying the presence of the sen-
sory gating deficit in mild cognitive impairment and
Progressive memory disorders have become a major Alzheimer’s disease by using auditory event-related
challenge to health care in Europe and the United potentials. The group consists of researchers from the
States. It has been estimated that, among these diseases, hospital district of Helsinki and Uusimaa, the Univer-
Alzheimer’s disease alone causes costs equivalent to sity of Helsinki and Aalto University.
SalWe - Strategic Centre for Science, Technology and Innovation in Health and Well-being

2. “Sensory gating is impaired among
patients with mild cognitive impairment
and Alzheimer’s disease.”
Sara Liljander, HUS Medical Imaging Center
“The brain’s ability to inhibit incoming repetitive and “The study confirms that the brain’s sensory gating
irrelevant sensory inputs, and thus to avoid sensory mechanism is impaired among patients with mild cog-
overload, is known as sensory gating. The mechanism nitive impairment and Alzheimer’s disease. The results
is thought to be related to the cholinergic deficit that also suggest that auditory ERPs are applicable to in-
is a feature of Alzheimer’s disease,” says Sara Lil- dividual diagnosis of organic brain diseases. It may
jander, a specialising medical physicist at the depart- even be possible to use ERPs to distinguish incipient
ment of clinical neurophysiology of Jorvi Hospital. Alzheimer’s disease from mild cognitive impairment,”
Sara Liljander explains.
When brief changes in the electrical activity of the
brain, caused by an external stimulus, are linked to It is possible that GE Healthcare Finland and Elekta
a task given to the subject and the subject’s men- use the research findings in their existing measuring
tal state, the responses are called event-related po- technology.
tentials, or ERPs. Cognitive potentials are generated
in connection with a memory task, recognition of a
stimulus or some other cognitive process.
“ERPs offer an objective, non-invasive and cost-ef- Lisätietoja
fective method for testing cognitive processes and
sensory gating.” Sara Liljander
specialising medical physicist
HUS Medical Imaging Center
Towards a diagnostic solution Jorvi hospital
The research was carried out on three groups: patients Clinical neurophysiology
with mild cognitive impairment, patients with incipi- sara.liljander@hus.fi
+358 50 428 4308
ent Alzheimer’s disease and a normal control group.
Audio stimuli were delivered to both ears via head-
phones and the state of brain electrical activity was Juhani V. Partanen
docent, chief physician
recorded with an electroencephalogram EEG.
HUS Medical Imaging Center
Jorvi hospital
Clinical neurophysiology
juhani.v.partanen@hus.fi
SalWe - Strategic Centre for Science, Technology and Innovation in Health and Well-being