Brown Squard syndrome

Hemisection of the cord results in a lesion of each of the three main neural systems: the principal upper motoneuron pathway of the corticospinal tract, one or both dorsal columns, and the spinothalamic tract. The hallmark of a lesion to these three long tracts is that the patient presents with two ipsilateral signs and one contralateral sign. Lesion of the corticospinal tract results in an ipsilateral spastic paresis below the level of the injury. Lesion to the fasciculus gracilis or cuneatus results in an ipsilateral loss of joint position sense, tactile discrimination, and vibratory sensations below the lesion. Lesion of the spinothalamic tract results in a contralateral loss of pain and temperature sensation starting one or two segments below the level of the lesion. At the level of the lesion, there will be an ipsilateral loss of all sensation, including touch modalities as well as pain and temperature, and an ipsilateral flaccid paralysis in muscles supplied by the injured spinal cord segments (Figure IV-4-15).

Polio a. Flaccid paralysis b. Muscle atrophy c. Fasciculations d. A reflexive

Polio a. Flaccid paralysis b. Muscle atrophy c. Fasciculations d. A reflexive

Tabes dorsalis a. Bilateral dorsal column signs below lesions b. Associated with late stage syphilis, plus Romberg sign: sways with eyes closed

Tabes dorsalis a. Bilateral dorsal column signs below lesions b. Associated with late stage syphilis, plus Romberg sign: sways with eyes closed

Amyotrophic lateral sclerosis (ALS)

a. Progressive spinal muscular atrophy (ventral horn)

b. Primary lateral sclerosis (corticospinal tract)

• Spastic paralysis in lower limbs

• Increased tone and reflexes

■ Flaccid paralysis in upper limbs

Anterior spinal artery (ASA) occlusion a. DC spared b. All else bilateral signs

Anterior spinal artery (ASA) occlusion a. DC spared b. All else bilateral signs

Figure IV-4-14. Lesions of the Spinal Cord I

Subacute combined degeneration a. Vitamin B12, pernicious anemia; (AIDS)

b. Demyelination of the:

• Dorsal columns

• Spinocerebellar tracts

• Corticospinal tracts (CST)

Syringomyelia a. Cavitation of the cord (usually cervical)

b. Bilateral loss of pain and temperature at the level of the lesion c. As the disease progresses, there is muscle weakness; eventually flaccid paralysis and atrophy of the upper limb muscles due to destruction of ventral horn cells

Hemisection: Brown-Sequard syndrome a. DC: Ipsilateral loss of position and vibratory senses at and below level of the lesion b. Spinothalamic tract: Contralateral loss of P&T below lesion and bilateral loss at the level of the lesion c. CST: Ipsilateral paresis below the level of the lesion d. LMN: Flaccid paralysis at the level of the lesion e. Descending hypothalamics: Ipsilateral Horner syndrome (if cord lesion is above T2)

• Facial hemianhydrosis

Figure IV-4-15. Lesions of the Spinal Cord II

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