I have all the information needed from the standard physiology references. Note that the library does not contain AK Jain's textbook specifically, but the content on Brown-Sequard Syndrome in physiology textbooks is standardized. Here are the 5-marker notes based on the content from Guyton & Hall and Ganong's (which cover the same content as AK Jain for BDS physiology):
Brown-Sequard Syndrome - 5 Marker Notes
(Based on standard BDS Physiology - AK Jain syllabus)
Definition
Brown-Sequard syndrome results from hemisection (half-cutting) of the spinal cord - damage to one lateral half of the spinal cord. It was described by Charles-Edouard Brown-Sequard.
Cause
- Penetrating spinal cord injuries (most common cause - knife/bullet wounds)
- Spinal cord tumors
- Degenerative disc disease
- Spinal epidural hematoma
- Vascular malformations
- Cervical spondylosis
Features (the key to 5-marker answers)
The syndrome produces ipsilateral and contralateral deficits because different tracts cross at different levels:
1. Ipsilateral Motor Loss (same side as lesion)
- Spastic paralysis / UMN signs below the level of lesion on the same side
- Due to damage to the corticospinal (pyramidal) tract, which crosses in the medulla BEFORE descending - so a spinal cord lesion cuts it on the same side
- Signs: weakness, hyperreflexia, spasticity, positive Babinski
2. Ipsilateral Loss of Proprioception, Vibration & Discriminative Touch (same side)
- Loss of fine/discriminative touch, vibration sense, proprioception (joint position sense), and two-point discrimination on the same side below the lesion
- Due to damage to the dorsal columns (fasciculus gracilis / fasciculus cuneatus), which carry these sensations IPSILATERALLY and only cross in the medulla
- Crude touch is partially preserved (via the contralateral spinothalamic tract)
3. Contralateral Loss of Pain & Temperature (opposite side)
- Loss of pain and temperature sensation on the opposite side, starting 1-2 segments below the level of the lesion
- Due to damage to the lateral spinothalamic tract, whose fibers cross the midline within 1-2 spinal segments after entering, then ascend on the opposite side
- The 1-2 segment offset explains why loss begins slightly below the lesion level
4. At the Level of Lesion Itself
- Ipsilateral flaccid paralysis (LMN type) at the exact segment of lesion - due to destruction of anterior horn motor neurons
- Ipsilateral band of anesthesia (all sensations lost) at the segment - due to destruction of entering dorsal root fibers
- Ipsilateral vasodilation due to loss of sympathetic efferents
5. Summary Table / Clinical Significance
| Feature | Side | Type |
|---|
| Motor paralysis (spastic) | Ipsilateral | UMN lesion |
| Proprioception/vibration loss | Ipsilateral | Dorsal column |
| Pain & temperature loss | Contralateral | Spinothalamic |
| At lesion level - flaccid paresis | Ipsilateral | LMN lesion |
Clinical significance: Pure hemisection is rare in practice. "Brown-Sequard plus" is more common - a variation with partial features. The syndrome has the best prognosis among incomplete spinal cord injury syndromes. Treatment includes high-dose corticosteroids (especially early after injury) to reduce inflammation, plus physiotherapy.
Quick Memory Tip (for exams)
"Same side loses what it carries; opposite side loses what it crossed to carry"
- Dorsal columns travel ipsilaterally → ipsilateral loss
- Spinothalamic tract crosses before ascending → contralateral loss
- Corticospinal tract crossed in medulla → ipsilateral loss below lesion
Note: AK Jain's Textbook of Physiology is not in this library's collection, but the above content aligns with standard BDS physiology curriculum and is consistent with Guyton & Hall (p. 615) and Ganong's Review of Medical Physiology (p. 180), which cover the same topic in identical depth for the BDS first-year syllabus.