Exam 2 Flashcards
What are multimodal sensations?
Combination of both superficial and deep sensations that are subject to integration with higher cortical functions and memory
Where is the association cortex for somatosensory, visual and auditory functions?
Inferior parietal lobe
The inferior parietal lobe is the association cortex for what 3 multimodal sensations?
Somatosensory, visual, and auditory
Stereognosis test
Patient identifies object in hand
Barognosis test
Patient assess relative weight of similar shape and size object in hands
Topognosis
Touch patient on their skin and ask them to point to the spot you just touched
Graphognosis
Write a letter or number on patients chest, back or palm and have them identify it
2 point discrimination and normal measurements
Determine at what distance a patient can determine 2-point discrimination
Finger tips: 2-4mm
Dorsum of finger: 4-6mm
Palm: 8-12mm
Dorsum of hand: 20-30mm
Somatognosis?
Patients ability to know a body part is their own
Nosognosis:
Ability of patient to know that he is ill
Ex: hemiplegia, patient believes they are healthy
Aka for graphognosis
Graphesthesia
Problems with sterognosis, barognosis, topognosis, graphognosis, 2 point discrimination, somatognosis or nosognosis would indicate an issue where?
Association cortex in the inferior parietal lobe
Somatic sensation is conscious perception of what 5 things?
Touch Pain Temperature Vibration Proprioception
What are the two main somatosensory systems?
Posterior column pathways
Anterolateral pathway
What sensations does the posterior column pathway mediate?
Proprioception
Vibration
Fine, discriminative touch
What sensations do the anterolateral pathways mediate
Pain
Temperature
Crude touch
What sensations does the lateral spinothalamic pathway mediate?
Superficial pain
Temperature
(Pinch your lateral neck it hurts)
What sensations does the anterior spinothalamic tract mediate?
Crude touch
Could be very crude and touch your anterior
Pathway of posterior columns
Stimuli carrie
Posterior columns pathway: stimuli is carried by _____ ____ neurons and enter the ____ ______ via the ____ _____ ____. From here it ____ the spinal cord ______ in _____ _____.
Primary sensory Spinal cord Dorsal root ganglion Ascends Ipsilaterally Posterior columns
After ascending the spinal cord ipsilaterally in posterior columns it synapses in ____ ____ nuclei with secondary axons that then _____ and _____ in the ____ ______. From here it synapses in the _____ and is distributed to ____ ____ _____
Posterior column nuclei
Synapse and ascend in the medial lemniscus
Thalamus and is distributed to primary somatosensory cortex
What kind of findings are seen in posterior column pathway lesions
Ipsilateral
Pain, temperature and crude touch are carried by ___ _____ neurons and enter the spinal cord via ___ ___ ____. From here they synapse with ___ ____ neurons immediately in ___ _____ of the spinal column. From here they _______ and ascend in the ____ _____. Then it synapses in the ____ and is distributed to ____ ____ cortex
Primary sensory
Dorsal root ganglion
Secondary sensory neurons in gray matter
Deccussate and ascend in the spinothalamic tract
Synapse in thalamus and distribute to somatosensory cortex
Sensation with posterior column lesion
Tingling, numb
Sensation with anterolateral lesions
Sharp, burning, or searing pain
Sensory loss can be caused by lesions where
Peripheral nerves Nerve roots Posterior columns Anterolateral pathways Thalamus Primary somatosensory cortex
Sensations in spinothalamic tract
Light touch
Sharp
Temperature
Sensations in dorsal columns
Vibration
2 point discrimination
Proprioception
Superficial sensory examination aka?
Exteroceptive/cutaneous examination
What is part of the superficial sensory examination
Light touch
Pain
Temperature
What is tested in light touch examination
Anterior spinothalamic tract
Tactile disc of merkle
Testing dermatomes
What is a dermotome
Area of skin innervation by a single spinal nerve
What does the sharp touch examination test
Lateral spinothalamic tract
What does temperature examination test
Lateral spinothalamic tract
Unnecessary if pain is fine—why it is rarely performed
-better at localizing area of dysfunction
Allogynia
Painful sensations provoked by normally non-painful stimuli
Anesthesia/analgesia
Absence of all sensation/pain
Dysethesia
Unpleasant, abnormal, or painful sensation
HYPESTHESIA/hypoesthesia
Decreased sensation
Hyperesthesia
Increased sensation
Paresthesia
Abnormal sensation
Myelo-
Spinal cord
Radiculo-
Nerve root
Neuro-
Nerve
General presentation of myelopathy
Pain: neck, arm, lower back, leg
Usually bilateral
Sensation: abnormal pattern
General presentation of radiculopathy
NR
Pain: dermatomal
Usually unilateral
Sensation: dermatomal
General presentation of neuropathy
Pain: follows nerve distribution
Usually unilateral
Sensation: peripheral nerve distribution
Common causes of compression
Disc hernation DJD Trauma Inflammatory changes Tumors
Posterior cord lesion causes and characteristics
Vibration and position sense loss at injury site and distal
Due to: Trauma Compression from tumors MS B12 deficiency and tables dorsalis
Most common cause of radiculopathy
Disc derangement
Pressure from IVF narrowing
Compression of a dorsal nerve root
Radiculopathy
Characteristics of radiculopathy
- Numbness and tingling
- Loss of vibration and position sense
- Hyporeflexia with NO muscle atrophy (NO input of stretch but muscle shortens/lengthening normal)
- sensory loss dermatomally
- LMNL characteristics of reduced strength, reflexes, sensation
What may cause numbness and tingling, loss of vibration or position sense, hyporeflexia, sensory loss in dermatomes, LMNL characteristics of reduced strength, reflexes and sensation?
Compression of dorsal nerve root—Radiculopathy
Mononeuropathy characteristics
Unilateral loss in distribution of peripheral nerve
Sensory lost first (vibration often earliest affected)
DTR depressed
MC causes of mononeuropathy
Trauma
Autoimmune
Polyneuropathy characteristics
Bilateral loss in glove and stocking distribution
- sensory lost first (vibration) & LONGEST nerves affected first
- DTR depressed
MC causes of polyneuropathy
- DM
- malnutrition of alcoholism
- Lyme disease/inflammatory/autoimmune conditions
What tissues are devoid of nociceptos
Articulate cartilage
Inner annulus and nucleus of intervertebral disc
Synovial membranes
What are mechanical noxious stimuli
Acute trauma
Repetitive microtrauma
Subluxation complex
Thermal noxious stimuli
Exposure to excessive heat/cold
Chemical noxious stimuli
- histamine
- prostaglandins
- plasma kinins
- potassium
- serotonin
- substance P—released directly from damaged tissue
Type A Delta fibers characteristics and what they relay?
Lightly myelinated
Relay a sharp, stinging sensation
Type C pain transmission and characteristics
Unmyelinated
Aching, burning type of pain