Case 2.   Limp Arm

This patient noticed that her left arm went "limp." It lasted about 20 minutes, then things were fine. She drove herself to the emergency room where they thought she might be having a heart attack. When cardiac testing showed no problems, she was sent home. The next day she noticed "numbness" in two fingers that lasted a bit longer but resolved completely. The third day she again complained of numbness in the same two fingers, and was admitted to the hospital. She got worse, with problems involving her face, her enunciation of words ("I lisped"), and her left arm. Auscultation of her neck revealed a carotid bruit.  Right carotid stenosis, greater than 70%, was confirmed by ultrasound and cerebral arteriography.  It was also found that she had developed significant external to internal carotid blood flow through anastomoses of these vessels around her right eye. She was treated surgically (a carotid endarterectomy) and given antihypertensive medications, a statin agent, and a daily aspirin. She has had no further problems.

Diagrams
 

Expert Note  Case 2.
Limp Arm

Diagrams

This patient had not one but a series of TIAs initially caused by temporary ischemia in the arm and hand area of the right motor and perhaps somatosensory cortex, both supplied by carotid branches. TIAs in carotid artery territory typically produce varying combinations of:
  • one-sided limb weakness, clumsiness, or paralysis
  • one-sided numbness, (paresthesias, or loss of sensation
  • some problem with language (production or comprehension)
  • some problem articulating words, often described as 'slurring' words (dysarthria)
  • partial or complete homonymous visual field defects (often not described by patients)

The patient's well-established collateral circulation involving her ophthalmic artery suggests that carotid stenosis had been steadily progressing over a period of time. Usually plaque ulceration or rupture, which encourages thrombus formation, occurs when there is significant stenosis of the carotid artery. Surgical removal of accumulated plaque by carotid endarterectomy has been shown to significantly decrease the risk of stroke in patients like this.