Læknablaðið - 01.04.1978, Blaðsíða 15

LÆKNABLAÐIÐ
49
ustu byrjunareinkenni eru frá lægri motor
neuronum og mikið oftar í griplimum en
ganglimum. í þessari byrjun sjúkdómsins
eru fyrstu einkenni langoftast distalt og
ríkjandi er symmetrisk útbreiðsla þeirra.
Fæstir sjúklingarnir höíðu sögu um sjúk-
dóma sem tilgátur hafa verið um sem frum-
crsck eða meðvirkandi orsök í M.N.D. Nið-
urstöður þessar eru allar svipaðar þeim sem
annars staðar gerist að því þó undanskildu,
að fleiri sjúklingar lifa hér lengur en ann-
ars staðar með þennan sjúkdóm. Ellefu
sjúklingar, 8 karlar og 3 konur, höfðu lif-
að lengur en í 10 ár, þar af einn í 24 ár.
Fimm þes.sara siðastöldu eru enn á lífi.
Þrjátíu sjúklinganna fullnægðu sjúk-
dómrgreiningunni ALS kliniskt, en 6 sjúk-
dcmsgreiningunni PMA og 1 PLS. Niður-
stöður benda tij þess að rök megi leiða
að því að M.N.D. sé oftast ALS og oftar
en talið hefur verið cg að hinar einstöku
sjúkdómsmyndir M.N.D., sem ganga undir
ýmsum sjúkdóm.sheitum, séu oftast und-
anfarastig í ALS, sem sé þannig til í
króniskri mynd. Tveir flokkar ALS finn-
ast, þ.e. hinn tilfallandi (sporadic) og sá
ættgengi. ALS sjúklingar hér hafa hins-
vegar ekki sérkenni Guam-gerðarinnar
hvað t'ðni og ættgengi viðkemur (sjúkdóm-
urinn er þar 50—100 sinnum algengari en
annars staðar). í beinu framhaldi er álykt-
að. að þessar mismunandi sjúkdómsmyndir
(PMMA, PMA, PLS og PBP) eigi sér sömu
orsakir en ónæmisþættir og samsetning og
efnaskipti motor neuron kerfis ákvarði
kliniska útbreiðslu og hraða sjúkdómsins.
Horfur virðast óháðar því frá hvaða
hluta motor neurcn kerfisins fyrstu ein-
kenni koma fram, en horfur á langlífi í
sjúkdómnum eru meiri ef byrjunarein-
kenni eru hægfara og ef einkenni koma
seint fram frá fleiri en einum hluta motor
neuron kerfisins.
SUMMARY.
The results of an epidemiological study on
M N.D. in Iceland during the period 1951-1970
are presented. There are 37 patients, 22 men
rnd 15 women. The M/F ratio is 1.47:1. The
annual incidence is 0.8:100.000, the prevalence
6 5:100.000 at the end of the survey and the
death rate is 0.7:100.000 per year. The farnily
incidence is 5.5%. The disease is rare under
the age of 40 and the peak onset age for both
sexes was between the age of 50—60 years
with mean-onset age for both sexes 55,5 years.
The mean survival time for both sexes was 7
years, 5,47 years for women and 8 years
for men.
The most common inital symptom was that of
lower motor neuron disease, found in 29 pati-
ents. The disease process started in the upper
limbs in 19 patients, in the lower limbs in 6,
and in both upper and lower limbs simulta-
neously in 4. There was dominantly distal initiai
involvement in these cases. Only 2 patients
had presented with symptoms of progressive
lateral sclerosis and 6 patients presented with
symptoms of progressive bulbar paresis. All
patients except two had symmetrical symptoms
and signs early in their disease. Fasciculations
were present early in all patients except one.
Thirty patients developed the classical picture
of amyotropic lateral sclerosis, but on clinical
grounds 6 patients were grouped as progressive
muscular atrophy, never developing clinical
evidence of upper motor neuron involvement.
One patient had only evidence of pyramidal
tract involment hence classified PLS.
Regarding possible predisposing factors minor
traumas were found in 3 patients. Seven
natients had had gastric ulcers, 2 of them had
had resection of the stomach. None of those
patients had any clinical or biochemical evi-
dence of malabsorption. Three patients had suf-
fered from rheumatoid arthritis. One
patient began his M.N.D. after vaccina-
tion and an infectious disease similar to Ice-
land (Akureyri) disease. No other suggested
causative or predisposing factors were found.
With the exception of the long mean survivai
time these findings correspond to those re-
ported by most authors.
The cases of amyotrophic lateral sclerosis
are all of the sporadic type, except 2 of the
familial group. None of the cases of amyotro-
phic lateral sclerosis had any resemblance to
the familial amyotrophic lateral sclerosis
patients of Guam.
Different from the results of all other sur-
veys is a relatively high number of patients
living for more than 10 years. Eleven patients,
8 men and 3 women lived 11—24 years, 5 of
them being still alive in 1976
The Ivgh proportion of AL3 suggests that
mo"t cases of M.N.D. are ALS and that cases
described as PMMA, PMA, PLS and PBP are
oniy precursors of ALS. Slowly progressing
cases under these headings might as well be
called chronic ALS. This view is supported
by the fact that 9 of the 11 cases surviving
more than 10 years gradually developed the
classical picture of ALS, although they might
earlier in the course of their disease have
been correctly called clinically PMMA and
Lter PMA. It is also strengthened by the fact
tb°t 3 cases that had failed to show clinicaliy
anv evidence of upper motor neuron involve-
me "t had clear evidenco cf cortico-spinal tracts
involvement of post mortem examination.