W11: Somatosensory Deficits

Question 1

Pathophysiology: What do somatosensory deficits include?

Answer 1

Somatosensory
- Touch
- Pain
- Temperature
- Kinaesthetic sense

Visual
- Help us make decisions for motor planning based on environment

Vestibular system
- Contributes to posture and balance

**In the case of damage to one of those you can still function by relying on another system to maintain balance and movement control.

Question 2

Pathophysiology: Damage to what can result in somatosensory deficit?

Answer 2

Damage to any of the afferent sensory neural pathways or brain regions.

Including:
- Spinal and peripheral nerves
- Dorsal column injuries
- Spinothalamic tracts
- Somatosensory cortex

Question 3

Pathophysiology: What type of sensation travels through the dorsal column?

Answer 3

DEEP (D for dorsal and deep)

*Also vibratory and proprioception

Question 4

Pathophysiology: What type of sensation travels through the spinothalamic tracts? Provide two exampels

Answer 4

SUPERFICIAL (S for spinothalamic and superficial)

*Pain and temperature

Question 5

Pathophysiology: What is the ventral spinothalamic tract responsible for?

Answer 5

Light touch

Question 6

Pathophysiology: Differnce between dorsal and spinothalamic pathway?

Answer 6

Dorsal –> primary afferent neuron enters SC, ascends ipsilaterally (same side of the body), makes a synapse with a 2nd order neuron then crosses over. Information detected by one side of the body is detected by the other side of the cortex.

Spinothalamic –> Primary neuron enters SC, synapses with second order neuron, 2nd order neuron crosses to the opposite side and ascends to the thalamus where it synapses with the thalamocortical neuron. That way informaiton detected by one side of the body is interpreted by the opposite side of the cortex.

Question 7

Clinical presentation: somatosensory deficit

Answer 7

Reduced ability to sense feeling produced by pressure receptors in the skin

Question 8

Clinical assessment tools: impairment = decreased sensation

Answer 8

• Sharp/blunt test –> for superficial assessment?
• NHSS item 8 (stroke)
• Nottingham Sensory Assessment

Note: Light touch assesses ventral spinothalamic tract & pinprick = lateral spinothalamic. Looking for if the patient can detect the stimulus, can they discriminate sharp and blunt, can they quantify the stimuli. Can use dermatomes to assess the impacted area eg to evaluate sciatic nerve tap the hamstring region.

Question 9

Clinical assessment tools: Impairment = decreased proprioception

Answer 9

• Big toe/Big thumb test
• Limb modelling

Question 10

Treatment

Answer 10

• Sensory re-education
• Mirror therapy
• Electrical stimulation
• Adaptations and modifications – OT
• Medications (antidepressants and anticonvulsants)