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Sensation
Kinds and types of
sensory disturbance
Syndromes of lesion
Sensation
is an ability of an organism to
accept stimuli from external and
internal environment
Classification of sensation
І. Classification,
which is based on
the place of originating of stimuli:
 Exteroceptive
 Interoceptive
 Proprioceptive
Classification of sensation
ІІ. Classification, which is based on biological
principle of originating of sensation:
 Protopatical (vital, nociceptive, thalamic).
This ancient sensation is typical for the
primitive nervous system of our ancestors
 Epicritical sensation is connected with cortex
and it is based on the differentiation of
stimuli according to their modality, intensity,
localization etc
Classification of sensation
In clinical practice usually we use
classification, which is based on the kind
of stimuli:
 Superficial
 Deep
 Complicated
Superficial sensation
- light touch
 pain
 temperature
 Trihoesthesia – is a sensation of touch of
hair
 Hydroesthesia – is a sensation of humidity
 Sensation of electrical current
 Feeling of tickling
 Superficial pain – is
a feeling of pain,
which can be tested
with a corsage pin or
pinwheel (acutely or
bluntly, pricks or does
not prick)
 Light touch
(tactile)
sensation – is
feeling of touch,
which may be
examined by
touch of cotton,
end of hammer,
paintbrush
 Temperature sensation
– is feeling of cold or hot,
which may be tested by
application of glass tubes
filled with iced (10 C)
and hot (43 C) water to
the skin
Deep sensation
This includes joint and vibratory sense and
pain from the deep-lying somatic
structures, namely, muscle, ligaments,
fascia, bone, and so on.
 Feeling of mass (baroesthesia) – is the
ability to distinguish different weights
 Feeling of pressure - is the ability to
distinguish pressure from touch
 Joint sense (bathyesthesia) - is
the ability to distinguish position
and passive movements in joints
The joint sense
The loss of joint sense, which is called
bathyanesthesia, results in disturbance of
muscular coordination and is known as
sensitive ataxia.
Sensitive ataxia is divided on:
 static
 dynamic
Static ataxia in legs can be
investigated by means of
Romberg’s test - patient is asked
to stand directly with the extended
forward arms and feet together. In
case of ataxia difficulty of standing
and instability occurs. That is
magnified while eyes are closed.
Static ataxia in arms can be examined by
follows: we ask patient to extend forward
arms and to place fingers separately. In
case of ataxia consensually spontaneous
(involuntary forced) movements
(pseudoathetosis) in fingers of arms
occurs.
Dynamic ataxia in arms may be examined
by means of finger-to-nose test, and in
legs - heel-to-knee test.
Vibration sense
(pallesthesia) –
 is the
ability to
distinguish
different
vibration
 Kinesthesia - is a sensation of
movement of dermal fold
Complicated sensation
 Localization sense - is the ability to
point an exact place of the stimuli
 Discrimination sense (two-point
discrimination) - tests the ability of
the patient to differentiate one stimulus
from two. It may be examined by
Weber’s circus
 Baragnosis – is the impaired ability to
distinguish different weights
 Graphism – is the ability to determine figures
and numbers traced on the skin with the closed
eyes. Graphesthesia – impaired graphism is
very sensitive indicator of parietal lobe damage.
Complicated sensation
 Stereognosis (Three-point
distinction) is the ability to
identify familiar object placed in
the palm of the patient by
palpation when the eyes are
closed
Anatomy of Superficial sensation
tracts
This tract carry out pain, temperature and part of
tactile sense and has three neurons.
 The 1 neuron is situated in unipolar cell bodies in
ganglion spinalis of dorsal root of the spinal cord
and homologous ganglia of the Cranial nerves.
 The 2 neuron - is situated in dorsal horns of the
spinal cord. The axons create tractus
Spinothalamicus. The axons of these neurons
cross the midline through the ventral commissura
and go to the opposite lateral funiculus of the
spinal cord in the lateral spinothalamic tracts.
 The 3 neuron – are nuclei of thalamus. The
axons form Thalamocortical tract
Sensory
Homunculus
Anatomy of Deep sensation explorers
 The first neuron – is in the unipolar cell bodies in the
dorsal root ganglia of the spinal cord and homologous
ganglia of the cranial nerves
- Medial Holl’s tract fibers pass from Th4 and below (carries
out deep sense from lower extremities and bottom of trunk)
- Lateral Burdach’s pathway - from Th4 and higher (carries
out deep sense from upper extremities and top of a trunk)
 The second neuron - is in Holl’s and Burdach’s nuclei of
medulla oblongata. The axons of the second neuron create
Bulbothalamic tract. The fibers of this path are crossed on
olives level of medulla oblongata, on the Pons of brain stem
they join of Spinothalamic tract lateral and create a
medial closed loop (lemniscus medialis) The axons of
the 2-d neurons carry all sorts of sensation from opposite
side of the body
 The third neuron - is in thalamus, from which cells
thalamocortical tract starts
Sensory innervation of the face
 The first neuron of face, nasal sinuses, oral cavities and
nose sensory conductors are situated in Trigeminal
(Gasser’s ganglion). Those for larynx mucouse membrane,
pharynx, radix of tongue - in ganglions of Vague and
Glossopharyngeal nerves (ganglion superior and inferior).
Those for 2/3 front of tongue - in a geniculate ganglion
(ganglion geniculi) of facial nerve
 The second neurons are situated in the sensitive nuclei of
the adequate cranial nerves in brain stem. The axons of
the second neuron make decussate and after that join
medial closed loop, in which structure pass to ventrallateral nuclei of a thalamus
 The third neuron is in thalamus. The axons form
thalamocortical tract, pass through internal capsule, a
radiate crown and are ended in lower parts of postcentral
gyrus
Trigeminothalamic
Tract
A. trigeminal ganglion
B. trigeminal sensory
nucleus
C. thalamus (VPM)
D. cerebral cortex (S I)
1. spinal tract of
trigeminal nerve
2. ventral
trigeminothalamic tract
3. dorsal
trigeminothalamic tract
4. corona radiata
V. trigeminal nerve
Objective sorts of sensory disorders
 Anesthesia - complete loss of any sorts of
sensation. For example:
 Analgesia - loss of pain sense.
 Thermoanesthesia - loss of a temperature sense
 Bathyanesthesia - loss of deep joint sense
 Astereognosia - loss of stereognostic sense
 Topanesthesia - loss of localization sense
 Pallanesthesia – loss of vibratory sense
 Hypoesthesia - lowering of sensation.
 Hyperesthesia – increasing of sensation
Objective sorts of sensory disorders
 Dysesthesia - distortion of sensitivity, when
instead of one stimulus the patient feels
absolutely other. For example, warm touch
one feels as cold
 Hyperpathia - results from rise of a
threshold of energization, when there are
strong, unpleasant, badly localized
sensations of stimuli. Thus the mild stimuli
are not received absolutely. In basis of
hyperpathia the disturbance of the analytical
function of cortex lays
 Synesthesia - sensation of stimuli not only
in a place of its plotting, but also in the other
place
Objective sorts of sensory disorders
 Polyesthesia - means sensation of one
stimulus as several ones
 Alloheyria - sensation of stimuli in
symmetrical sites on an opposite body part
 Alloesthesia - sensation of stimuli in the
other place
 Dissociation of sense - phenomenon of
fallout of some kind of sensitivity while
saving others in the area of segment
innervation
Subjective sorts of sensory
disturbances:
 Paresthesia is a creeping sensation,
cold, burning sensation, fever,
numbness, itch, the pricking etc.
Frequently paresthesia is the first sign of
nervous system lesion
 Pain The pain sensations can arise at
stimuli by the pathological process of
sensitive analyzers at any level (from
receptors up to cortex)
Sorts of pain
1. Local pain - is pain, for example, at
palpation of the nervous trunk. That is pain,
which coincides with the place of lesion
2. Projectional pain - is a pain in zone of
innervation not only in place of stimuli, but
also distally on a course of nerves or roots.
To projection belongs the stump neuralgia pain in absent segments of an extremity
after its ablation
Sorts of pain
3. Irradiating pains - are pains, which are
distributed from one nerve branch to another, not
struck. For example, at neuralgia of the first
branch of trigeminal nerve the pain is distributed
to zone of innervation of the second or the third
branches, in upper or lower jaw, in ears etc
4. Displayed pains - are pains in zones ZacharyinHed’s at diseases of inner organs, when
irradiation arises to certain zone on skin through
cells of dorsal horns of spinal cord. For example,
pain on ulnar territory of the left forearm and
paintbrush at angina pectoris
Sorts of pain
5. Causalgia (Greek causes - burning
sensation, algos - pain). It is intensive
thermalgia originating, for example, at
traumas. It is pain without stimulation
6. Reactive pains - are pains that originate
at expansion of nerves. The pains can
arise at palpation of pain points and at
band spread of nervous trunks
Straight leg raising test
Straight leg raising test
Types of sensory disturbances
Peripheral type
 Mononeuritic (or neural)
 Polyneuritic
 Plexal
Segmental (sectional) type
 Segmental - radicular
 Segmental - dissociated
Conductive type
 Spinal
 Cerebral
The peripheral type
 Mononeuritic (or neural) pattern - is
observed at lesion of one peripheral nerve
and consists of disturbance of all sorts of
sensation in innervative zone of this nerve.
 there is a pain in the field of nerve
 sometimes hyperpathia, hyperalgesia,
causalgia,
 tension signs of nerve
 pain at palpation
The peripheral type
The peripheral type
 Polyneuritic pattern - is observed at
multiple, frequently symmetric lesion of all
peripheral nerves
 Appears by sensory disturbance in distal
parts of extremities as "socks" on legs and
"gloves" on arms
 The “stocking-glove” pattern of sensory loss
is typical for peripheral neuropathy
The peripheral type
 Plexal pattern - occurs at lesion of
peripheral plexus and appears by sensation
disturbance in innervative zone of a plexus
and pains
The segmental (sectional) type
disturbance of sensation is observed at
lesion of sensitive fibbers at segment level
of spinal cord
 Segmental - radicular pattern
 Segmental – dissociated pattern
Sectional body building
Lesion of dorsal root:
- pain
- loss of all sorts of
sensation in its zone
innervation according to
the segmental type
(transversal strip on a
trunk and longitudinal
strip on extremities)
- areflexion
Lesion of spinal nerve:
- pain
- loss of all sorts of
sensation in its zone
innervation according to
the segmental type
(transversal strip on a
trunk and longitudinal
strip on extremities)
- peripheral paresis of
segmental muscules
The segmental (sectional) type
 Segmental - dissociated pattern is
observed at lesion of dorsal horns of spinal
cord and front grey soldering.
 loss or lowering pain and thermoanesthesia
and saving tactile and joint sense in given
segment.
 The sensitive disturbance are observed in
certain dermatomes as "jacket" or "half
jacket" at lesion of dorsal horns of spinal
cord in thoracic segments, or "trousers" - at
lesion of dorsal horns of spinal cord in
lumbar segments
Conductive type
The lesion of sensory explorers in:
 Spinothalamic tract
 Holl’s and Burdach’s pathways
 Bulbothalamic tract
 Medial closed loop
 Thalamocortical tract
Conductive
type
 Spinal
 Cerebral
Spinal pattern
 Descending
 Ascending,
depending on extraor intramedular
lesion
 Monotype
 Hemitype
Conductive type
Cerebral subtype
 Brain stem
 The thalamic
 Capsular
 Cortical
Multiple peripheral
nerves lesion
 loss all kinds of
sensation in distal parts
of extremities «gloves» and «socks»
 pains
 paresthesias
 distal peripheral paresis
 distal autonomic
disorders
Dorsal root lesion
• loss all kinds of
sensation by
segmental type in
innervative
segment
• pain
 areflexion
Types of sensory disturbances
Types of sensory disorders