A 36-year old school teacher was evaluated for headaches and left arm weakness. The headaches began approximately 2 years previously, following an episode of severe coughing. Dull occipital pain had persisted on and off since that time. In addition, she had noted dull pain in the left hand during the past year. Six months ago she noted the onset of progressive numbness and weakness of the left hand and she reports that she is now unable to distinguish the temperature of bath water with her left hand. During the past month she also has found that her walking is "stiffer than usual." There have been no bowel or bladder abnormalities and her general health is otherwise well.
Examination was remarkable for mild thoracic kyphoscoliosis. Cranial nerve testing revealed a pupillary asymmetry (left, 1 mm, right 3 mm). Both pupils were round and reactive. There was, in addition, a left ptosis; the left side of her face appeared drier than on the right. There was marked atrophy of all muscle groups in the left arm. There was complete loss of pain and temperature perception from C5 to T1 on the left and patchy abnormalities of pain and temperature sensation in the right forearm. Position and vibration perception were normal throughout. She was areflexic in the left arm and hyperreflexic in the right arm and in both legs, with moderate spacticity of both legs. Gait was mildly stiff legged, but otherwise unremarkable
What could be the cause for the unequal size of pupils and ptosis?
Why would one side of her face be drier?
Which area in the spinal cord could be involved to give the above symptoms?
What do you think the diagnosis is ?