Somatosensory Lesions Flashcards
Anesthesia
Complete loss of touch sensation
Hypesthesia
. Hypoesthesia
. Partial loss of touch sensation
Hyperesthesia
. Abnormal inc. sensitivity of skin when touched
Paresthesia
. Spontaneous sensations (burning, tingling, pins and needles)
Dysesthesia
. Impaired touch sensation short of anesthesia
. Disagreeable sensation is produced by ordinary stimuli
. Abnormal sensations experienced in absence of stimuli
. Allodynia is condition in which ordinarily non-painful stimuli evoke pain
Analgesia
. Complete loss of pain appreciation
T/F all anesthetics are analgesics, but all analgesics are not anesthetics
T
Hypalgesia
. (Hypoalgesia)
. Partial loss of pain appreciation
Hyperalgesia
. Hyperpathia
. Abnormal inc. sensitivity to painful stimuli
Radicular pain
Shooting pain in a dermatome
Causalgia
. CRPS
. Severe burning pain persistent and related to trauma
. Radiates to areas outside affected nerve
. Associated w/ RSD
Mononeuropathy
. Sensory loss restricted to one area of body
Polyneuropathy
Pattern of sensory loss symmetric for both side of body
. Multiple peripheral nn. Affected
Dissociated sensory loss
. Spinal cord lesions
. No other level of CNS level will cause this
. Brown-Sequard syndrome: one leg losses pain, one leg loss touch and proprioception
Spinal n. Lesions
. Ipsilateral loss or reduction of sensation in area of distribution of that spinal n./ receptor
. May affect all sensations being transmitted through particular n.
DCML lesion
. Loss or diminished sensations related to this system are noticeably distally
. Difficulty in localizing tactile cues and diminished sense of 2-point discrimination
. Diminished vibratory sense
. Diminished sense of direction (difficulty perceiving what direction object moves on skin)
. Impairments of conscious proprioception
Unilateral lesion of dorsal columns in spinal cord or dorsal nuclei
. Lost or diminished sensation in all ipsilateral dermatomes at and below spinal cord level of lesion
. Lost or diminished sensations on ipsilateral body if lesion is in dorsal column nuclei
Unilateral lesion of medial lemniscus, VPL thalamic nucleus, fibers of internal capsule or cerebral cortex
. Lost or diminished sensations seen contralateral to the lesion
DCML impairments of conscious proprioception
. Direction and extent of movements not well-perceived
. Passive movements felt as touch or pressure sensations
. Loss of conscious proprioception greatly impairs performance of voluntary motor movements (positive rhomberg, dorsal ataxia)
Dorsal column ataxia
. Poor coordination of voluntary movements
. Seen in neurosyphilis
. Degeneration of dorsal columns in lumbosacral levels of spinal cord
. Loss of secondary modalities (stereognosia) w/o loss of primary modalities is a sign of what lesion?
. Lesion of post. Parietal lobe
. Area 3,1,2 in postcentral gyrus perceives basic stimuli
. Area 5 and 7 of parietal lobe receives inputs from 3,1,2 and visual, auditory, limbic motor systems to assign meaning to stimuli
Effects of posterior parietal lobe lesions
. Inability to recognize object by touch alone (astereognosia)
. Inability to detect nu,bears or letters written on skin (agraphesthesia)
Extinction phenomenon
. Tactile or visual stimulus perceived normally when presented to 1 side only
. When stimulus is presented on side opposite lesion simultaneously w/ identical stimulus on normal side, the patient neglected the stimulus on opposite side of lesion
. Type of hemineglect
Unilateral lesions of STT in spinal cord
. Los or diminished pain, temp, and crude touch sensations in contralat. Dermatomes below spinal cord lesion
Unilateral lesion of STT in brainstem, VPL, fibers of internal capsule or cerebral cortex
. Lost or diminished pain, temp, and crude touch sensations contralat. To lesion
Lesion localized in VPL of thalamus
. Initial loss of all sensations from contralat. Side of body (including pain)
. Overtime patient may experience pain in all or part of constralat. Side of body
. Used to be called thalamic pain syndrome/Dejerine-Roussy syndrome but now called central post-stroke pain (CPSP)
. Pain described as spontaneous burning
. Sudden onset of intense pain set off w/ innocuous stimuli
. Pain due to SRTT still being intact carrying slow pain info
Clinical symptoms seen after lesions to ALS
. Inability to recognize pain and temperature sensations (analgesia and thermoanesthesia)
. Diminished ability to recognize touch sensations (hypesthesia/hypoesthesia)
Peripheral lesions of trigeminal system
. Ipsilateral loss or diminished sense of pain, temp., discriminative abilities, conscious proprioception, and vibration in distribution of trigeminal division that is damaged
. Ipsilateral flaccid paralysis and profound atrophy of mm. Of mastication if V3 is affected
. Trigeminal neuralgia
Unilateral lesion of trigeminal motor nucleus or fibers
. Ipsilateral flaccid paralysis and profound atrophy of mm. Of mastication
Unilateral lesion of trigeminal sensory nuclei
. Lost or diminished sensation ipsilateral to lesion (spinal = pain/temp, chief = discriminative sensation)
Unilateral lesion of VTTT or higher neural structures (VPM, internal capsule fibers, cerebral cortex)
. Lost or diminished sensations contralat. To lesion
. Usually all forms of sensation affected if lesion is at or above level of chief sensory nuclei
. Only pain and temperature senses affected if lesion is at level of spinal trigeminal nucleus
