Quantitative study of intermediolateral column cell counts in Machado-Joseph disease

The number of intermediolateral column (ILC) neurons in 6 alternating segments from the 2nd to 12th thoracic segment of the spinal cord were studied in 4 cases with Machado-Joseph disease (MJD), 3 cases with olivopontocerebellar atrophy (OPCA), a case with Shy-Drager syndrome (SDS), and 5 normal controls. We counted the number of ILC neurons with clearly defined nucleoli in 12 sections of each segment, each section 20 microns thick and taken at 100 microns intervals and then divided the 6 alternating segments into 3 groups, upper (Th2, 4), middle (Th6, 8) and lower (Th10, 12). In each of the three groups of normal control cases, the number of ILC neurons had decreased with aging. In all MJD cases, the number of ILC neurons had moderately decreased in comparison with age-matched controls. One of the MJD cases showed a marked decrease in the number of ILC neurons, as did the SDS case. The ILCs of the entire thoracic spinal cord in the MJD cases were moderately involved.