Olfactory dysfunction in Guamanian ALS, parkinsonism, and dementia.
OBJECTIVE
To assess whether olfactory deficits are present in the general Guamanian Chamorro population and to evaluate olfaction in each of the four neurodegenerative disease syndromes of Guam: ALS, pure parkinsonism, pure dementia, and the combined parkinsonism-dementia complex (PDC).


BACKGROUND
Olfactory dysfunction was previously reported in patients with PDC of Guam.


METHODS
We developed a culturally adjusted olfactory test battery, derived from the original University of Pennsylvania Smell Identification Test (UPSIT), and administered this to Chamorro residents with ALS (n=9), pure parkinsonism (n=9), pure dementia (n=11), PDC (n=31), and 53 neurologically normal Chamorro and 25 North American control subjects.


RESULTS
Similar, marked olfactory dysfunction was found in all four syndromes of Guamanian neurodegenerative disease. This correlated poorly with measures of parkinsonism and cognition. In the neurologically normal Chamorro control group, six subjects (11%) had very low olfactory scores; these were less than the lowest North American score, raising a question of subclinical neurodegenerative disease.


CONCLUSIONS
Marked olfactory deficits are common to all four Guamanian neurodegenerative syndromes, and suggest the possibility of similar central neuropathologic substrates. The deficit in the Guamanian ALS group contrasts with idiopathic ALS, in which olfactory function has been reported to be only slightly compromised.
Ahlskog
J E
JE
Department of Neurology, Mayo Clinic and Mayo Foundation, Rochester, MN 55905, USA.
Waring
S C
SC
Petersen
R C
RC
Esteban-Santillan
C
C
Craig
U K
UK
O'Brien
P C
PC
Plevak
M F
MF
Kurland
L T
LT
D000328:Adult; D000368:Aged; D000690:Amyotrophic Lateral Sclerosis / Q000503:physiopathology*; D003704:Dementia / Q000503:physiopathology*; D005260:Female; D006141:Guam; D006801:Humans; D008297:Male; D008875:Middle Aged; D015146:Midwestern United States; D009410:Nerve Degeneration / Q000503:physiopathology; D009833:Olfactory Pathways / Q000503:physiopathology*; D010300:Parkinson Disease / Q000503:physiopathology*; D012720:Severity of Illness Index; D012903:Smell / Q000502:physiology