Light and ultrastructural pathology of spinal cords in sporadic forms of amyotrophic lateral sclerosis from South Asia.

Motor neuron disease, considered synonymous with amyotrophic lateral sclerosis (ALS), is seen frequently in India. Its aetiopathogenesis is one of the major enigmas in neuroscience. In India only a limited epidemiological data of this neurodegenerative disorder is available and the problem is further compounded by a lack of autopsy study on this devastating disease. We report the neuropathological findings of three autopsied cases diagnosed as amyotrophic lateral sclerosis on the clinical basis of weakness, wasting and fasciulations in all limbs. There was no involvement of the sensory, cerebellar and extra-pyramidal systems. Terminally all had profound respiratory muscle weakness as is the usual cause of death in patients with motor neuron disease. The major findings in the anterior horn cells of the spinal cord were significant and asymmetrical loss of motor neurons, increased central chromatolysis, presence of argyrophilic axonal spheroids, occurrence of Bunina bodies, hyaline bodies, and occasional neurofibrillary tangles. There was loss of axons in the anterior roots. Electron microscopic studies revealed accumulation of skeins of 10 nm neurofilaments, both in intraneuronal hyaline inclusions and the axonal spheroids. No definite temporal correlation in the evolution of the pathological lesions and the duration of the illness is evident in our study.