Spinal Cord Lesions and Disorders Overview

Study Notes

Spinal Cord Lesions and Neurological Disorders

Tabes Dorsalis:
- Caused by syphilis, affecting the lower thoracic and lumbosacral regions of the spinal cord.
- Symptoms and signs:
  - Stabbing pains in the lower limbs
  - Numbness in the lower limbs
  - Hypersensitivity of the skin to touch, heat, and cold
  - Loss of sensation in parts of the trunk and lower limbs
  - Loss of bladder fullness awareness
  - Impaired posture and limb movement appreciation
  - Loss of pain sensation in specific areas (e.g., side of nose, forearm, leg)
  - Ataxia (unsteadiness in gait), worsened in the dark or with eyes closed
  - Hypotonia (loss of muscle tone)
  - Loss of tendon reflexes (e.g., knee and ankle jerks)
Muscle Tone:
- State of continuous partial muscle contraction.
- Dependent on the integrity of the reflex arc and muscle spindles.
- Involves afferent neurons entering the spinal cord via the posterior root and synapsing with the effector neuron (lower motor neuron).
Pyramidal and Extrapyramidal Tracts:
- Pyramidal tract: refers to the corticospinal tracts when concentrated in the medulla oblongata pyramids.
- Extrapyramidal tracts: encompass other tracts besides the corticospinal tract.
Upper Motor Neuron Lesions:
- Damage to descending tracts, resulting in various signs depending on the lesion location.
Spasms:
- Sudden, involuntary muscle contractions, often involving large muscle groups.
- Associated with lesions involving descending tracts, but not the corticospinal tract.
Athetosis:
- Continuous, slow, involuntary, and dysrhythmic movements.
- Consistent in a given patient and cease during sleep.
- Linked to lesions in the corpus striatum.
Chorea:
- Series of rapid, involuntary, jerky, and purposeless movements.
- Often coarse and continuous.
- Occurs with lesions of the corpus striatum.
Dystonia:
- Frequent, sustained contractions of hypertonic muscles.
- Leads to bizarre postures.
- Results from lesions of the lentiform nucleus.
Myoclonus:
- Sudden contraction of an isolated muscle or part of a muscle.
- Occurs irregularly, often involving limbs.
- Can be associated with conditions affecting the reticular formation and cerebellum.
- Normal myoclonic jerks often occur when falling asleep and are thought to be temporary re-activation of the reticular formation.
Hemiballismus:
- Rare involuntary movement disorder confined to one side of the body.
- Usually involves proximal extremity musculature and uncontrolled limb movements.
- Lesion is located in the opposite subthalamic nucleus.
Acute Spinal Cord Injury:
- Annual incidence in the US is approximately 10,000.
- Usually catastrophic due to minimal regeneration of severed nerve tracts.
- Treatment focuses on anatomical realignment and stabilization of the vertebral column or spinal cord decompression.
- Patients undergo intensive rehabilitation to optimize remaining neurological function.
- Recent research shows promise with drugs like gangliosides and methylprednisolone given soon after injury.
Chronic Compression of the Spinal Cord:
- Excluding acute injuries, compression can be extradural or intradural.
- Intradural compression: can arise outside (extramedullary) or inside (intramedullary) the spinal cord.
  - Extradural causes: herniated discs, infections, primary/secondary tumors, and abscesses.
  - Intradural causes: primary spinal cord tumors, meningiomas, and nerve fibromas.
Clinical Signs of Spinal Cord Injury:
- Early signs often include pain (in involved vertebrae or radiating from spinal nerve roots), worsened by coughing or sneezing.
- Pain often occurs at night or when recumbent.
- Interference with motor function: partial or complete muscle paralysis, loss of tone, and muscle wasting.
- Often the corticospinal tracts are affected.
- Sensory loss: muscle joint sense, touch and pain in the affected region.
- Pain and sensory loss on the opposite side of the body...

Description

This quiz explores spinal cord lesions, particularly tabes dorsalis, and their neurological implications. Participants will learn about symptoms, muscle tone, and the impact of these conditions on body functioning. Test your knowledge on the complexities of spinal cord health and associated disorders.