2

2 CASE 2


A 54-year-old woman returns to her oncologist for continuing treatment of recurrent ovarian cancer. It is 2 days since treatment, and she is now complaining of paresthesia of the hands and feet and difficulty in fastening buttons due to muscle weakness in the hands.


The patient began treatment for recurrent ovarian cancer 2 months ago. The treatment regimen includes paclitaxel, 150 mg/m2; gemcitabine, 800 mg/m2; and cisplatin, 75 mg/m2, three times a week for 6 cycles. She was diagnosed with diabetes mellitus type 2 at age 35 and has been successfully managed with Ultralente insulin. The patient has lost body hair due to the chemotherapy. Her appetite remains good, and nausea is managed.



PHYSICAL EXAMINATION



VS: T 37°C, P 75/min, R 18/min, BP 128/84 mm Hg, BMI 34

PE: Sensory neuropathy (tingling) present in the hands. Deep tendon reflexes were diminished bilaterally.


LABORATORY STUDIES


None ordered



DIAGNOSIS


Taxol-induced peripheral neuropathy



COURSE


The sensory and motor neuropathies resolved over the next 5 days.



PATHOPHYSIOLOGY OF KEY SYMPTOMS


Normal neuromuscular transmission requires the release of acetylcholine from the synaptic vesicles in the alpha (α)-motor neuron presynaptic nerve terminal (Fig. 2-1), diffusion across the synaptic cleft, and binding to the receptors at the motor end plate region of the skeletal muscle cell. The acetylcholine is degraded by the enzyme acetylcholinesterase into acetate and choline. The choline is transported back into the presynaptic terminal and returned to the recycled portion of the vesicle. Acetylcholine is resynthesized, and the vesicle is ready for reuse.


image

FIGURE 2–1 Synthesis and recycling of synaptic vesicles and their content.

< div class='tao-gold-member'>

Related posts:

  1. 28
  2. 23
  3. 58
  4. 71

Stay updated, free articles. Join our Telegram channel
Tags:
Jul 4, 2016 | Posted by in PHYSIOLOGY | Comments Off on 2

Full access? Get Clinical Tree
Get Clinical Tree app for offline access