Conduction velocity of nerve is reduced in all of the following conditions, except

Acute motor axonal neuropathy (AMAN) is a variant of Guillain-Barre syndrome. It is characterized by acute paralysis and loss of reflexes without sensory loss. Pathologically, there is motor axonal degeneration with antibody-mediated attacks of motor nerves and nodes of Ranvier The syndrome typically presents as a progressive flaccid symmetric paralysis with areflexia, often causing respiratory failure. Electromyographic studies and nerve conduction studies show normal motor conduction velocity and latency with decreased amplitude of compound muscle action potentials. Pathologically, it is a noninflammatory axonopathy without demyelination.Antibodies attack the coating of the motor neurons without causing inflammation or loss of myelin. It does not affect sensory neurons, so sensation remains intact despite loss of movement Ref Harrison20th edition pg 2456