SPINAL CORPORA-AMYLACEA AND MOTOR-NEURON DISEASE - A QUANTITATIVE STUDY

Objective-To test the hypothesis that as there is growing evidence tha t corpora amylacea, or amyloid bodies, in the CNS are derived primaril y from neurons, it might be expected that their numbers in the spinal cord would decline with loss of neurons in motor neuron degeneration a s they do in the retina on destruction of ganglion cells by glaucoma. Methods-The numbers of corpora amylacea were counted in PAS stained tr ansverse sections of the lumbar cord from 27 patients with motor neuro n disease and 21 control subjects of similar age and sex mix, The numb ers and sizes of corpora amylacea were determined both in the anterior horn grey matter and in the sub-meningeal white matter regions in eac h case. Results-In both groups the total numbers in the white matter a nd submeningeal regions ranged from 160 to more than 5000/section and there was minimal significant difference between the two groups, No re lation with age was found in this narrow age range. The mean diameters of the corpora amylacea were significantly less in the grey matter of both groups than in the submeningeal regions. However, their densitie s in the grey matter of the anterior horn were significantly reduced i n the spinal cord sections in the motor neuron disease group, but only where few motor neurons remained. Conclusions-These findings support the view that corpora amylacea may arise from neurons, and suggest tha t that there may be two compartments, one mobile and one static, the s econd most likely remaining in the periphery of the spinal cord for pr olonged periods.