An injured person is presented with paralysis of adductor pollicis, hypothenar muscle weakness, and loss of sensation in palmar and dorsal aspect of 4th and 5th finger. Where is the site of lesion?

(B) Guyon's canal# Guyon's Canal:> On the palm, the ulnar nerve passes under a ligament between two small wrist bones, the pisiform and hamate. The tunnel formed by the bones and ligaments is called Guyon's canal.> The Ulnar Nerve supplies sensation to the little finger and half of the ring finger. It is critical that the area of compression be localized to either the wrist (Guyon's canal), or the elbow (cubital tunnel), or the neck (thoracic outlet syndrome, cervical radiculopathy) by physical examination and electrical studies prior to embarking on a treatment. All three may cause numbness and tingling in the same ring and small fingers.> A syndrome is a set of symptoms and physical findings that point to a certain diagnosis. All the symptoms and physical findings are not always present.> Various symptoms and physical findings may be present in different grades of severity.> Guyon's Canal syndrome Guyon's Canal syndrome is numbness and tingling in the ring and small fingers caused by irritation of the ulnar nerve in the Guyon's canal.> Symptoms Symptoms begin with a feeling of pins and needles in ring and little finger. This is followed by decreased sensation and eventually weakness and clumsiness in the hand as the small muscles of the hand are involved.