Miscellaneous clinical pain & neuroanatomy

Miscellaneous clinical notes space-chronic pain

*Allodynia to cold is an indicator of central sensitization

*Patient's especially sensitive to cold are more likely to be sympathetically maintained

*Cord injury,

CRPS space-four criteria for diagnosis

#1. In inciting event

#2. Pain out of proportion

#3. Vasomotor autonomic phenomenon

#4. Lack of an alternative explanation for the pain

*This is a controversial topic because of disability implications of this diagnosis

Three drugs with NMDA receptor antagonism

Amantadine

Dextromethorphan

Methadone

Treating migraine in a pregnant patient

Thorazine or magnesium

Treatment of chronic pain

#1  cool water, compounded cream consisting of ketamine and amitriptyline

#2 anti-inflammatory agents, antidepressants and antiepileptic agents

-Antidepressants good for neuropathic pain, and epileptic prescription for neuralgic patients

#3 dorsal cord stimulators peripheral nerve stimulator is

#4 intrathecal pump

#5 motor cortex and deep brain stimulator implantation

#6 destructive procedures although not currently recommended and is only recommended for terminal patients because of major complication anesthesia dolorosa which has no known treatment

Localization in clinical neurology of Paul Brazis textbook notes

Weber syndrome - third nerve palsy with contralateral hemiparesis lesion at the crus cerebri

The descending corticospinal tract has ~1million fibers on a side, only 3% originate from Betz cells (layer V in the primary motor cortex)

*Cortical spinal neurons also arise from postcentral gyrus and a somatosensory cortex, lateral prefrontal supplemental motor and cingulate gyrus as well

eponym for the pyramidal decussation -Mistichelli crossing - anywhere between 75-90%.

Cortical spinal fibers that descend ipsilaterally do so in Turcks bundle otherwise known as the anterior

corticospinal tract - although most of these will eventually decussate as well only 2% at the end remained

ipsilateral innervating axial musculature

Corticobulbar pathway- descends in the genu of the internal capsule

The ventral aspect of the facial nucleus innervating the lower two thirds has a crossed supranuclear input

Emotional facial movements do not descend via the internal capsule, the right cerebral hemisphere is dominant for facial expression or motion

Three direct pathways of cortical input to the basal ganglia

#1 internal capsule

#2 external capsule

#3 subcallosal fasciculus

Indirect pathways for cortical input to the basal ganglia

cortical thalamic striate pathway

Cortical olivary pathway

Cortical pontine pathway

Cortical association areas projected predominantly to the caudate nucleus

Sensorimotor cortical areas projected predominantly to the basal ganglia

The cortex also directly inputs the substantia nigra subthalamic nucleus and claustrum

Cortical thalamic pathway-descending feedback mechanism for ascending thalamco cortical fibers -also known as the thalamic radiations, also known as corticofugal pathway. descending mainly in the anterior limb of the internal capsule

Thalamic nuclei involved in cortical thalamic pathway feedback

anterior nucleus -> posterior cingulate gyrus

ventral lateral -> primary motor cortex

anterior ventral -> supplementary motor cortex

posterior -> sensory cortex

LGN -> primary visual cortex

MGN -> primary auditory cortex

Dorsomedial -> prefrontal cortex

Cortical hypothalamic tract

Multiple inputs to the hypothalamus (prefrontal cingulate amygdala olfactory hippocampus septal)