brain phantoms Flashcards
Lateral spinothalamic tract
Pain, temp, coarse touch
Dorsal columns tract
Fine touch, pressure, vibration, proprioception
Somatosensory cortex
- Parietal lobe post-central gyrus
- Receives and processes sensory info from thalamic third-order nucleus
- In each hemisphere, the contralateral half of the body is represented in somatosensory cortex as a sensory homunculus
Phantom limb pain
Perception of pain in a limb that no longer exists
Residual limb pain
Pain originating from actual site of amputated limb - common post-operatively
Pathophysiology of PLP
- Trauma to nerves and surrounding tissues
- Disruption of normal neural signals involved with missing limb
- Initiation of regenerative processes in affected area
- Damaged nerves start to sprout neuromas (traumatic neuroma)
- Spontaneous firing results in unregulated afferent input
Acoustic neuromas
Slow-growing, benign tumour of acoustic nerve
Sx: dizziness, hearing loss, tinnitus, numbness
Treatment of PLP
- Pharmacological: analgesics, antidepressants, anticonvulsants
- Non-pharmacologic options: electrical nerve stimulation, spinal cord stimulation, mirror therapy (move intact limb in front of mirror to create visual representation of missing limb, provides visual feedback to brain to result in neuronal reorganisation)
Alien hand syndrome
I- nvolves uncontrollable, involuntary movements of the hand
- Pt feels hand is not under their control
Frontal AHS
disinhibited grasping at objects in visual field, pt aware limb belongs to them but have difficulty controlling movements, lesions in motor area/corpus callosum
Callosal AHS
inter-manual conflict (limb conflicts with opposite unaffected limb), arises from corpus callosal lesions (stroke, midline tumour), arises from disconnection between two hemispheres
Posterior AHS
involuntary, clumsy movements and parietal deficits, pt has subjective feeling that their hand doesn’t belong to them, injury in parietal lobe +/- thalamus and occipital lobe
