Spastic paraplegia can be caused by the following except

Harrison's principles of internal medicine17th edition.and Vishram singh textbook of clinical neuroanatomy 2nd edition. *Myelopathy from cervical spondylosis is a common cause of spastic or spastic-ataxic gait *Subacute combined degeneration(vitaminB12 deficiency )causing myelopathy is characterised by subacute paraesthesia in hand and foot ,loss of vibration and position sensation,progressive ataxic and spastic weakness. *Lesion in pyramidal tract ie upper motor neuron lesion result in loss of voluntary movement of opposite half of body below the level of lesion .muscles are actually not paralysed but the muscles supply by upper and lower motor neurons lost its control .so the tone of LMN muscles are increased and lead to spastic paralysis . Ref Harrison20th edition pg 2766