Question

Sarah Mitchell is a 68-year-old female who is normally healthy. However, about five days ago she began to feel very fatigued and started to experience a burning and tingling sensation on her right thigh.

You ask to see the area and upon visual inspection, you notice 3–4 small, red, swollen areas with vesicles on the posterior aspect of her right thigh. She describes the pain to you, saying “it feels like the back of my leg is on fire and it hurts so bad.” She denies being exposed to any excessive heat sources, any changes in her diet, and any changes in the type of body soap, lotion, or laundry detergent she is using. All other physical findings are within normal limits, but her oral temperature is 100.6˚F. She complains about being under a lot of stress for the past three months because she has been helping take care of her husband, who is in the end stages of Alzheimer’s disease. She has no known drug allergies, is a non-smoker, and attends a water aerobics class twice a week. You suspect she may be suffering from a particular viral infection, so you ask if she had chickenpox as a child. Sarah confirms that she had chickenpox and measles during childhood. Her answer confirms your suspicions that she is likely suffering from shingles (herpes zoster) due to varicella-zoster virus infection.

1. Based on what you know about their stimuli, which type of sensory receptor is activated and causing Sarah’s symptoms of pain and paresthesia?

2. The virus infecting Sarah lies dormant in the dorsal root ganglion. Does the dorsal root and its ganglion carry sensory input, motor output, or both?

3. Based on the pattern of skin vesicles and pain, which of Sarah’s peripheral nerves is infected? If Sarah had skin vesicles on the anterolateral region of her neck, Transverse cutaneous nerve is infected.It belongs to cervical plexus to which peripheral nerve plexus does this nerve belong?

4. If Sarah had skin vesicles on the anterolateral region of her neck, which peripheral nerve is infected by the virus? To which peripheral nerve plexus does this nerve belong?

5. If Sarah had a viral infection that affected neuron function in the ventral root of the same spinal nerve, how would the signs and symptoms be different than those she has now?

Answer 1

Nociceptors are sensory receptors that detect signals from damaged tissue or the threat of damage and indirectly also respond to chemicals released from the damaged tissue. Nociceptors are free (bare) nerve endings found in the skin , muscle, joints, bone and viscera.

1)nociceceptor
2)somatic sensory, sensory input
3)fibular (peroneal) nerve ( sacral plexus)
4)transverse cutaneous nerve, cervical plexus
5)The symptoms that are caused by affected ventral roots are the following:
Loss of movement in the extremities
Back pain
Pain radiating into the buttocks
Pain radiating down the legs
Numbness, tingling, burning of the hands or feet
Fatigue
Fever
Weakness

Sarah on the other hand oral fever, she has a burning sensation of the thigh but no numbness