What is the pathology of MND

• In MND there is  loss of large motor neurons in spinal cord & brainstem
• Gliosis
• Spheroids are interwoven disorganized neurofilaments in proximal axons
• Bunina bodies are intracytoplasmic inclusion bodiesi neurons
• There is  loss of giant Betz cells , other neuronal loss in DRG & Clarkes’ nucleus
• 1/3 of motoneurons are destroyed before muscle atrophy becomes apparent
• Peripheral nerve shows secondary degeneration of axons & myelin
• Surviving motoneurons will develop collaterals branches
• Atrophy of the degenerated muscles is a prominent finding