Læknablaðið : fylgirit - 01.09.1993, Blaðsíða 36

34
LÆKNABLAÐIÐ/FYLGIRIT 24
V 6
Mælingar á TSH-receptor antibodies
Gu&mundur Sigþórsson, Matthías
Kjeld. Rannsóknastofan í Domus Medica,
Rannsóknastofa Landspítalans.
Ofstarfsemi í skjaldkirtli stafar oftast af
sjálfsofnæmi og myndast IgG mótefni gegn
TSH viötökum (receptors), sem hafa í flestum
tilfellum.líkt og TSH, örvandi áhrif á kirtilinn.
TSH-viötaka mótefni ættu því aö vera sérhæf
mæling fyrir þennan sjúkdóm og aöferöir
hafa veriö aö þróast. Hérlendis hafa engar
slíkar mælingar veriö geröar fram aö þessu.
Viö höfum því mælt þessi mótefni (TSH-
receptor antibodies (TRAb)), meö aöferö,
sem notast viö uppleysta viötaka, í sermi hjá
fjórum hópum fólks; heilbrigöum, hyper-
thyroid og tveimur hópum sjúklinga eftir
geislajoömeöferö, euthyroid og hypothyroid
á T4 meöferö. Styrkur mótefnanna í sermi er
metinn eftir getu þeirra til aö hindra bindingu
geislamerkts TSH viö viötökin og er gefinn
upp í hundraöshlutum.
Hjá 17 heilbrigöum einstaklingum á ýmsum
aldri reyndust gildin vera frá 0 til 12.9,
meöaltal 7.15%, hjá 12 hyperthyroid sjúkl.
voru gildin frá 6.1 til 79.5, meöaltal 39.4%.
Hjá sjúklingum eftir geislameöferö mældust
gildin frá 1.7 til 22.7, meöaltal 13.5% fyrir
euthyroid hópinn og frá 4.45 til 67.6, meöaltal
18.7% fyrir hypothyroid hópinn. Bæði
hyperthyroid sjúklingarnir og þeir, sem höföu
fengiö geislameöferö voru marktækt hærri en
heilbrigöir (p<0.001). Sjúklingahóparnir tveir,
sem höföu fengiö geislameöferö voru
marktækt lægri (p<0.001) en hyperthyroid
hópurinn, en ekki var marktækur munur á
milli þeirra innbyröis. Frekari tengsl
mótefnanna viö hormónastyrk í sermi voru
könnuö og veröa kynnt. Niöurstöður þessara
mótefnamælinga benda til þess aö
geislameöferö á ofstarfandi kirtli lækki
mótefnastyrk í sermi, en aö undirliggjandi
sjúkdómur sé í flestum tilfellum áfram til
staöar. Hugsanlegt er aö TRAb mælingar geti
komiö aö gagni viö aö meta horfur sjúklinga
eftir geislameöferö, en ennþá hefur
tiltölulega lítið birst um þaö efni.
V 7 A STUDY OF REGIONAL CEREBRAL BLOOD
FLOW' AND EVENT RELATED POTENTIALS IN
CHRONIC SCHIZOPHRENIC PATIENTS.
S.B.Stefánspon*, E.Pétufsson^,
G.Elíasson"> Ó.Bjarnason ^and D.Daviðsson*
Departments of Psychiatry and Nuclear Medicine”,
Landspitalinn, Iceland.
Regional cerebral blood flow (rCBF) and event related
potentials (ERP) have been reported abnormal in
schizophrenic patients. Our aim was to study whether
there is a relationship between these two indicators of
abnormal cerebral function in schizophrenic patients.
rCBF, as revealed by single photon emission computed
tomography (SPECT), and the P3 component of the
auditory ERP were studied in a group of 9 patients (age
21-35 years) and 8 normal subjects (age 20-48 years).
The patients fulfilled DSM-in criteria for schizophrenia
and were al! on neuroleptic medication. Auditory stimuli
consisted of a series of 250 Hz and 1000 Hz tones
presented binaurally at 75 dB The subjects were asked
to count the 1000 Hz tones which occurred irregularly
with 25% probability. The amplitude of the P3
component of the ERP evoked by the 1000 Hz tone
was measured at the vertex. SPECT was performed with
Starcam 3000 gamma camera after i.v. injection of 555
MBq ofTc-99m-hexamethylpropyIeneamineoxim.
Quantitative evaluation of rCBF was done on 4 sagittal
slices in each hemisphere. Each slice was 1.9 cm thick
and was divided into 10 regions of interest (ROI), each
with an area of 4 x 4 cm Maximal counts in each ROI
was divided by the sum of maximal counts in 6 slices of
the cerebellum. This ratio was used as a measure of
rCBF in each ROI. rCBF was found to be lower in the
patient group than in the control group in the left medial
ffontal region (P = 0.03) but higher in the left medial
fronto-temporal region (P = 0.04). The P3 component
ofERP had lower amplitude in the patients than in the
controls (P = 0.04). The blood flow pattem suggest a
left fronto-temporal dysfunction in the schizophrenic
patients. For some of the patients there was evidence
of reduced rCBF in other cerebral regions, a possible
reflection of the very varying symptomatology in
schizophrenia. No convincing relationship was found
between the rCBF pattem and the reduced P3
amplitude in the patient group.