This document defines and describes various sensory symptoms. It distinguishes between positive symptoms, which represent excessive sensory activity and include tingling, pricking, and other abnormal sensations. Negative symptoms represent sensory loss and include numbness. Specific terminology is defined, such as paresthesia, dysesthesia, hypoesthesia, anesthesia, hypalgesia, hyperalgesia, and hyperpathia. Disorders of deep sensation affecting proprioception are also described.

1. Sensory symptoms

2. TERMINOLOGIES
• Words used to characterize sensory
disturbance.

3. PARESTHESIAS
Typically refers to tingling or pins and needles
sensation but may include a wide variety of
other abnormal sensation, except pain.

4. DYSESTHESIAS
It is a more generalized term which denote all
types of abnormal sensations including painful
ones, regardless of whether a stimulus is
evident.

5. HYPESTHESIA/HYPOESTHESIA
Refers to reduction in cutaneous sensation to
a specific type of testing such as pressure,
light touch, and warm & cold stimuli.

6. ANESTHESIA
Refers to complete absence of skin sensation
to the same stimuli plus pinprick.

7. HYPALGESIA OR ANALGESIA
This refers to reduced or absent pain
perception (nociception) , such as perception
of the pricking quality elicited by a pain.

8. HYPERESTHESIA
Means pain or increased sensitivity in
response to touch.

9. ALLODYNIA
Describes the situation in which a non painful
stimulus once perceived is experienced as
painful even excruciating.
Eg: elicitation of a painful stimuli by
application of vibrating tuning fork

10. HYPERALGESIA
Denotes severe pain in response to a mildly
noxious stimuli.

11. HYPERPATHIA
It is a broad term which encompasses all the
phenomena described by hyperesthesia,
allodynia, & hyperalgesia.
With hyperpathia the threshold for a sensory
stimulus s increased and perception is
delayed, but once felt , is unduly painful.

12. Disorders of deep sensation arising from muscle
spindles, tendons,& joints, affect propriocepton.
•Manifestation include (particularly when eyes
closed or in dark)
Imbalance
clumsiness of precision movement sensory
Unsteadiness of gait. ataxia

13. other findings on examination usually include
reduced or absent joint position & vibratory
sensibility and absent deep tendon reflex in the
affected limbs.
Romber’s sign is positive - which means the
patient sways markedly of topples when asked to
stand with feet close together and eyes closed.
In severe state of deafferentiation involving deep
sensation, the patient cannot walk or stand or even
sit unsupported.

14. PSEUDOATHETOSIS
Is continuous involuntary movements of the
outstretched hands and fingers occur,
particularly with eyes closed.

15. SENSORY SYMPTOMS
NEGATIVE SYMPTOMS POSITIVE SYMPTOMS

16. POSITIVE SYMPTOMS….
• The prototypical positive symptom is tingling,
that is pins and needle sensation.
• Other positive symptoms include altered
sensations that are described as
 Pricking
 Band like
 Lightening like shooting feeling (lancinations)
 aching

17. Cont…
.
 Knifelike
 Twisting
 Drawing
 Pulling
 Tightening
 Burning
 Searing
 Electrical
 Or raw feelings

18. Positive symptoms usually results from impulses
.
generated at sites of lowered threshold or
heightened excitability, along a peripheral or
central sensory pathway.
The nature and severity of the abnormal
sensation depend on the-
Number
Rate
Timing
Distribution of ectopic impulses, and
Type and function of the nervous tissue from which
they arise.

19. Since positive symptoms represents excessive
.
activity of sensory pathways- they are not
represented as sensory loss on examination

20. Negative symptoms…..
• Negative symptoms represents loss of sensory
functions and are characterized by diminished
or absent feeling.
• It is often experienced as numbness.
• It is estimated that at least half half the
afferent axons innervating a given site are lost
or functionless before a sensory deficit can be
demonstrated by clinical examination.

21. The threshold of sensory symptoms varies
with how rapidly function is lost in sensory
nerve fibre.
If the rate of loss is low-lack of cutaneous
feelings may be unnoticed by the patient -and
difficult to demonstrate on examination, even
though few sensory fibers are functioning.

22. If rate of loss is rapid- both positive and
negative phenomenon are easily identified.

23. Thank u……