Machado-Joseph-Azorean disease. A ten-year study
H. L. Fowler
In a ten-year study of Machado-Joseph-Azorean disease (MJAD), three
distinct syndromes emerged: ataxia syndrome (11 patients), ataxia-motor
neuron-extrapyramidal syndrome (four), and ataxia-motor
neuron-extrapyramidal syndrome (two). Three patients had such advanced
disease that classification was not possible. These syndromes more
accurately describe functional deficits than did previous classifications.
Spread of neuronal degeneration from the cerebellar system to the motor
neurons of the spinal cord and brain stem was found for the first time, to
my knowledge, in five patients and to the motor neurons and the
extrapyramidal system in two of 14 patients followed up. There is no
dementia, and peripheral neuropathy is a late complication common to all
syndromes. World presence of MJAD could have begun with Portuguese overseas
expansion in 1415. Alternatively, the possibility of multiple spontaneous
mutations must be considered. Genetic sameness depends on a specific
genetic marker, which is not yet available. For accurate genetic
counseling, a nonspecific biologic marker for this disease is sought, and
electronystagmography changes may prove helpful. This is particularly
important as this illness, like Huntington's disease, is usually not
manifest until the child-bearing years or after.
