Cerebral hypoperfusion in familiar amyloid polyneuropathy

Familiair amyloid polyneuropathy(FAP) is a form of systemic amyloïdosis, in
which a broad diversity of organs is affected by accumulation of
amyloidfibrils. One of the most important clinical manifestations of FAP is a
combined sensory and motor polyneuropathy. In some patients with FAP cognitive
disorders, thought to be due to accumulation of amyloidfibrils in the
vesselwall. However, a MRI of metabolic PET-scan does not show pathological
changes.
In a similar fashion accumulation of amyloidfibrils is found in the vesselwall
of patients with Alzheimer's disease. Perfusion and metabolic positron emission
tomography has shown a decreased perfusion and metabolism in the
parietotemporal cortex. The hypotheses of another scientific research in
Alzheimer's disease, conducted at the UMCG, is that the perfusion deficits run
ahead of metabolic changes.
Therefore, it is hypothesized that pathological changes of the vesselwall lead
to diminished perfusion and in turn to decreased metabolism in FAP patients
with cognitive disorders.

The goal of this study is to investigate the possible pathophysiology of
cognitive disorders in patients with familiar amyloid polyneuropathy (FAP).
Hypothesis: Familiair amyloid polyneuropathy patients with mild cognitive
disorders show decreased cerebral perfusion, especially in the parietotemporal
cortex, compared to patients without cognitive disorders.

After signing the consentform patients with familair amyloid polyneuropathy
will be invited to the out-patient clinic of the department of Neurology
(UMCG). At this visit a general physical and neurological examination together
with cognitive screeningtests will be performed.
On the day of the positron emission tomography, after veneus cannulation of the
patient, radio-active water will given intraveneusly. The scanwill take a mere
10 minutes. Together with the preparation in advanced and once the scan is
finished the PET investigation does not take longer than one hour of the
patients time.
The collected perfusiondata will be compared to the perfusional data from a
database with healthy volunteers. Furhtermore, in the case where a FAP patient
has already received a FDG-PET on clinical ground, a comparison between
perfusion and metabolisme will be made.
The data will be analyzed on voxel-level with the Statistical Parametric
Mapping (SPM) and compared to the data of healty volunteers.

According to the international and national radiation criteria for patients the
radiation dose for this study falls in the category 'mild risk' (BS2001,
IRCP62).