<prompt> Brachial plexus injury with horners syndrome, nerve root level involved is -C5C6C7T1  <response>: Ans. is d i.e., T1 Horners syndrome It is seen in patients with brachial plexus injury with lesion at T1 root level. In it T1 root is injured proximal to white ramus communicans to first thoracic sympathetic ganglion. Patient presents with ptosis, miosis, anhydrosis, enophthalmos, and loss of ciliospinal reflex-may be associated. Loss of ciliospinal reflex is seen as sympathetic fibres to the head and neck leave the spinal cord through nerve T1. 