Progressive wasting and weakness of muscles due to motor neuron degeneration
Because the regulation assigns a fixed minimum of 30% without listing criteria that separate one level from another, evidence that confirms the diagnosis and documents the nature and extent of your muscle wasting and weakness is what matters most. Medical records showing a confirmed diagnosis of progressive muscular atrophy help establish the condition. Neurological examination findings that describe the degree of muscle weakness, loss of muscle mass, and any functional limitations support the picture of how the condition affects you. Statements from you or people who know you that describe how muscle weakness limits your ability to work, carry out daily tasks, or use your arms, hands, or legs can round out the record. If the condition affects both sides of your body, records that document involvement on each side are relevant to how the ratings are combined.
Conditions that are often caused or made worse by this one. If you have any of these, they may be claimable as secondary service connection.