Module 21 Somatosensory Disorders and Pain Syndromes

This set of vocabulary flashcards covers sensory pathways, pain transmission mechanisms, various pain classifications and syndromes, and headache types based on the Module 21 lecture notes.

First-order neurons

Sensory receptors with cell bodies in dorsal root ganglia, which are organized by dermatomes.

Second-order neurons

Neurons that synapse in the spinal cord and follow either the discriminative pathway for spatial orientation or the spinothalamic tract for pain and crude touch.

Third-order neurons

Neurons that travel from the thalamus to the somatosensory cortex in the parietal lobe to facilitate perception and judgment.

Neospinothalamic tract

A pathway consisting of fast-conducting fibers that transmit sharp, localized pain directly to the thalamus.

Paleospinothalamic tract

A pathway using unmyelinated C fibers for slow, diffuse pain that travels via the brainstem to the limbic system and cortex.

Acute pain

A short-duration, severe, and self-limiting warning system; inadequate relief can lead to circulatory issues and delayed recovery.

Chronic pain

Pain that persists for years and is a leading cause of disability, influenced by biological, psychological, and environmental factors.

Hyperesthesia/Hyperalgesia

Increased sensitivity resulting from a decreased pain threshold or an increased response to stimuli.

Paresthesia

A pins-and-needles sensation caused by severe nerve irritation or compression.

Hypoesthesia/Hypoalgesia

The loss of tactile, temperature, or pain sensation due to severe pathology.

Allodynia

Pain triggered by non-painful stimuli (such as wind or light touch) without an apparent cause, associated with abnormal tissue innervation.

Neuropathic Pain

Pain caused by peripheral nervous system dysfunction, leading to widespread pain and sensory deficits from causes like tumor compression or diabetes.

Trigeminal Neuralgia (Tic Douloureux)

A condition characterized by sharp, stabbing facial pain and tics, often caused by demyelination of trigeminal axons due to compression.

Postherpetic Neuralgia (Shingles)

Localized vesicular eruption and pain along dermatomes caused by the reactivation of dormant varicella virus in the dorsal root ganglia.

Phantom Limb Pain

Tingling, squeezing, burning, or cramping sensations felt in an amputated limb.

Primary Headaches

Headaches that are not caused by another medical condition, including migraine, cluster, tension, and chronic daily headaches.

Secondary Headaches

Headaches resulting from underlying conditions such as meningitis, brain tumors, aneurysms, or trauma.

Migraine without aura

A pulsing, throbbing headache lasting 1-2 days, often accompanied by nausea, vomiting, and light or sound sensitivity.

Cluster headaches

Rare headaches occurring mostly in men in their 30s, involving severe, unrelenting unilateral pain that occurs in clusters over weeks or months.

Tension headaches

A common headache type triggered by stress, dehydration, or caffeine, presenting as dull, diffuse aching without nausea.

Chronic daily headaches

Headaches occurring 15 or more days per month for at least 3 months.

TMJ headaches

Referred pain to the face, head, neck, or ear caused by malocclusion or teeth grinding.

NSAIDs

Pharmacologic treatments that decrease vascular sensitivity and reduce inflammation.

TENS

Transcutaneous electrical nerve stimulation, an electrical modality used for pain management.

Adjuvant analgesics

Non-traditional pain relief medications including tricyclic antidepressants, anti-seizure medications, and neuroleptics.