Sensory disturbances

Sensory disturbances

1. Sensory disturbances. Pain.
The I.M. Sechenov First Moscow State Medical University
Chair of nervous diseases

2. Special
•vision, hearing, smell, taste
General
•superficial (exteroception)
•pain
•temperature
•tactile
•deep (proprioception)
•vibration
•muscle-joint
•spatial
•pressure
•complex types of sensation
•location
•stereognosis
•visceral (inretoception)
Types of sensation

3. Types of receptors
Somatosensory receptors in the skin:
•Free nerve ending (pain, temperature)
•Tactile disk of Merkel
•Peritrichial nerve endings around a
hair follicle (touch)
•Tactile corpuscle of Meissner.
•Vater−Pacini corpuscle (pressure,
vibration)
•End bulb of Krause (cold?)
•Ruffini corpuscle (warmth?)
Receptors in muscle, tendons, and
fascia:
•Annulospiral ending of a muscle
spindle (stretch)
•Golgi tendon organ (tension)
•Golgi−Mazzoni corpuscle (pressure)

4. Cross section of a mixed peripheral nerve
From Baehr, Duus' Topical Diagnosis in Neurology, 2005, Thieme

5. Classification of sensory nerve fibres
Type of
fibre
Sensation
Diameter
(m)
Velocity of
conduction
(m/s)
А b tactile, vibration 5 - 12 30 - 70
А d
pain (fast, well
localized), cold
2 - 5 12 - 30
С
pain
(delayed, poorly
localized), heat
0,4 - 1,2 0,5 - 2

6. Sensory pathways

7. The cortical representation of different
parts of the body
The cortical representation of different parts of the body in the primary somatosensory cortex of
the postcentral gyrus (left) and the primary motor cortex of the precentral gyrus (right) in the
human being. (After Penfield, W., H. Jasper: Epilepsy and the Functional Anatomy of the Human
Brain. Little, Brown, Boston 1954.)

8. Sensory disturbances
•Hypoesthesia – decrease of sensation
•Hyperesthesia – increase of sensation
•Anaesthesia – loss of sensation
•Dysesthesia – abnormal sensation
•Paresthesia – sensation of tingling,
burning, pricking, or numbness of a
person's skin

9. Peripheral
(polyneuropathic)
Peripheral
(mononeuropathic)
Types of sensory disturbances

10. Segmental –
radicular
Segmental –
dissociated
disturbance:
- All types
- superficial
- deep
sensation
Types of sensory disturbances

11. Spinal conductive
Types of sensory disturbances
disturbance:
- All types
- superficial
- deep
sensation

12. Medullar
(alternating)
Hemispheral
(hemitype)
disturbance:
- All types
- superficial
- deep
sensation
Types of sensory disturbances

13. Monofilament
Cylinder with a plastic
and metal tips
Tuning-fork
tactile temperature vibration
Devices to assess the sensation

14. Additional methods for investigation of
sensory fibers
•Electroneuromyography (EMG)
the amplitude of evoked potential
and velocity of conduction for
sensory nerves
•Somatosensory evoked potentials
Early and late components
•Quantitative sensory testing
Heat, cold, vibration and pain thresholds

15. PainPain
An unpleasant sensory and emotional experience
associated with actual or potential tissue damage
or described in terms of such damage
International association for the study of pain, 1986

16. •Transient
short duration
•Acute
within a period of injury and healing
•Chronic
beyond the normal healing period
PainPain
• Local
• Referred
• Irradiating

17. Nociceptive
•is caused by stimulation of peripheral nerve fibers that respond
only to stimuli approaching or exceeding harmful intensity
(nociceptors); described as throbbing, aching, bursting
Neuropathic
•is caused by damage or disease affecting any part of the
nervous system involved in bodily feelings (the somatosensory
system); described as “burning,” “tingling,” “electrical,”
“stabbing,” or “pins and needles
Psychogenic
•is pain caused, increased, or prolonged by mental, emotional, or
behavioral factors
PainPain

18. Peripheral mechanisms of neuropathic pain
• Spontaneous ectopic activity
• Sensitization of pain receptors
• Pathological interaction of fibers (ephapse)
• Hypersensitivity to catecholamines

19. Central mechanisms of pain
•Central sensitization
•“Wind up” phenomenon
• Disinhibition

20. Gate control theory

21. Types of pain sensation disturbances
•Hypoalgesia – decrease of pain sensation
•Analgesia – loss of pain sensation
•Hyperalgesia – increase of pain sensation
•Hyperpathia - a painful syndrome characterized by an
abnormally painful reaction to a stimulus, especially a
repetitive stimulus, as well as an increased threshold
•Allodynia - a pain due to a stimulus which does not
normally provoke pain
•Anaesthesia dolorosa - is pain felt in an area (usually of
the face) which is completely numb to touch

22. Neuropathic pain
Trigeminal
neuralgia
Postherpetic
neuralgia

23. Diabetic
polyneuropathy
Radiculopathy
(root compression)
Neuropathic pain

24. Phantom limb painPost stroke pain
Neuropathic pain

25. Complex regional pain syndrome
Neuropathic pain
•The most common symptoms overall are
burning and electrical sensations,
described to be like "shooting pain".
•The patient may also experience muscle
spasms, local swelling, abnormally
increased sweating, changes in skin
temperature (usually hot but sometimes
cold) and color (bright red or a reddish
violet), softening and thinning of bones,
joint tenderness or stiffness, and/or
restricted or painful movement.
•Type I, formerly known as reflex
sympathetic dystrophy does not have
demonstrable nerve lesions.
•Type II, formerly known as causalgia, has
evidence of obvious nerve damage.

26. Diagnosis of pain
•Anamnesis
•Physical investigation
•Evaluation of pain intensity (VAS)
•Additional methods of investigation(MRI, EMG)

27. •Massage
•TENS
•Acupuncture
•Neurostimulation
•Neurosurgery
•Physiotherapy
•Biofeedback
•Psychotherapy
Non-pharmacological treatment of pain

28. •Local anesthetics
•NSAIDs
•Opiates
•Antidepressants
•Anticonvulsants
Pharmacological treatment of pain