TY - JOUR
T1 - Guamanian neurodegenerative disease
T2 - Electrophysiologic findings
AU - Ahlskog, J. Eric
AU - Litchya, William J.
AU - Petersen, Ronald C.
AU - Waring, Stephen C.
AU - Esteban-Santillan, Concepcion
AU - Chen, Kwang Ming
AU - Harper, C. Michel
AU - Craig, Ulla Katrina
AU - Kurland, Leonard T.
N1 - Funding Information:
The authors wish to thank Rita Bevacqua, RN and the staff of the Micronesian Health Study on Guam and Deitra Pickett, LPN and the staff of the Mayo Clinical Research Center, Rochester, MN for their assistance in the conduct of this study. The Government of Guam is gratefully acknowledged for underwriting transportation expenses for patients and control subjects flown to the Mayo Clinical Research Center, Rochester, MN. Supported by grants AG-08802, AG-08031 and M01-RR00585 from the National Institutes of Health, Bethesda, MD.
PY - 1999/6/15
Y1 - 1999/6/15
N2 - Amyotrophic lateral sclerosis (ALS), parkinsonism and/or dementia are highly prevalent among the Chamorro population of Guam. The incidence of Guamanian ALS has markedly declined in recent years, but these incidence figures may reflect underascertainment of subclinical disease. Guamanian Chamorro patients have not been systematically studied using modern clinical neurophysiological techniques. Electromyography (EMG: needle exam and nerve conduction studies) was used to study 29 patients with the major subtypes of Guamanian neurodegenerative disease, as well as 11 neurologically normal Guamanian Chamorro subjects. Central conduction was assessed by somatosensory evoked potentials (SEP's) in 16 patients. EMG evidence of peripheral neuropathy, (often subclinical) was found in 45% of Guamanian patients but no Chamorro control subjects. Diabetes mellitus, which is highly prevalent in this population, was present in some, but not all of these cases. Clinically unsuspected motor neuron disease was identified by EMG in only one of the 23 Guamanian patients with parkinsonism and/or dementia and in none of the 11 Chamorro control subjects. Two of seven patients with the clinical phenotype of Guamanian ALS had a more benign EMG pattern on the needle electrode exam with absence of fibrillation and fasciculation potentials. Three of 16 patients (all with parkinsonism and dementia) had mildly abnormal tibial SEP's. No patient had EMG evidence of myopathy or a defect of neuromuscular transmission. We conclude: (1) peripheral neuropathy may be a manifestation of Guamanian neurodegenerative disease; (2) the declining prevalence of ALS on Guam is not associated with the development of a subclinical form of motor neuron disease; (3) the substantial overlap of Guamanian ALS with parkinsonism-dementia reported in prior decades is no longer apparent; (4) abnormal central conduction, as assessed by tibial SEP's, is present in some patients with Guamanian parkinsonism-dementia. Copyright (C) 1999 Elsevier Science B.V.
AB - Amyotrophic lateral sclerosis (ALS), parkinsonism and/or dementia are highly prevalent among the Chamorro population of Guam. The incidence of Guamanian ALS has markedly declined in recent years, but these incidence figures may reflect underascertainment of subclinical disease. Guamanian Chamorro patients have not been systematically studied using modern clinical neurophysiological techniques. Electromyography (EMG: needle exam and nerve conduction studies) was used to study 29 patients with the major subtypes of Guamanian neurodegenerative disease, as well as 11 neurologically normal Guamanian Chamorro subjects. Central conduction was assessed by somatosensory evoked potentials (SEP's) in 16 patients. EMG evidence of peripheral neuropathy, (often subclinical) was found in 45% of Guamanian patients but no Chamorro control subjects. Diabetes mellitus, which is highly prevalent in this population, was present in some, but not all of these cases. Clinically unsuspected motor neuron disease was identified by EMG in only one of the 23 Guamanian patients with parkinsonism and/or dementia and in none of the 11 Chamorro control subjects. Two of seven patients with the clinical phenotype of Guamanian ALS had a more benign EMG pattern on the needle electrode exam with absence of fibrillation and fasciculation potentials. Three of 16 patients (all with parkinsonism and dementia) had mildly abnormal tibial SEP's. No patient had EMG evidence of myopathy or a defect of neuromuscular transmission. We conclude: (1) peripheral neuropathy may be a manifestation of Guamanian neurodegenerative disease; (2) the declining prevalence of ALS on Guam is not associated with the development of a subclinical form of motor neuron disease; (3) the substantial overlap of Guamanian ALS with parkinsonism-dementia reported in prior decades is no longer apparent; (4) abnormal central conduction, as assessed by tibial SEP's, is present in some patients with Guamanian parkinsonism-dementia. Copyright (C) 1999 Elsevier Science B.V.
KW - Electromyography
KW - Guam
KW - Guamanian neurodegenerative disease
KW - Motor neuron disease
KW - Neuropathy
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U2 - 10.1016/S0022-510X(99)00103-3
DO - 10.1016/S0022-510X(99)00103-3
M3 - Article
C2 - 10465496
AN - SCOPUS:0033563767
SN - 0022-510X
VL - 166
SP - 28
EP - 35
JO - Journal of the neurological sciences
JF - Journal of the neurological sciences
IS - 1
ER -