Localization of spinal cord

lesion

Anatomy of spinal cord

Functions of spinal cord• Sensory • Motor• Autonomic functions

Sensory conduction

Ascending/ sensory tracts in spinal cord are

A. Tracts in dorsal/posterior white column

B. Tracts in lateral white columnC. Tracts in ventral white column

Dorsal column pathway

Includes• Fasciculus gracilis• Fasciculus cuneatus

Sensations in it are (fine touch, pressure, tactile localization, tactile discrimination, vibration sensation, stereo gnosis)

Tracts in lateral white column

1. Lateral spinothalamic tract(SGR)2. Ventral spinocerebellar tract3. Dorsal spinocerebellar tract

Pain and temperature in SGRitching tickling and sexual sensations are carried by the spino thalamic pathway

Ventral column tracts

• Ventral/anterior spinothalamic tract (chief sensory nucleus)

• Crude touch

Spinal cord syndromes

• Complete transverse cord lesions• Hemi section of spinal cord• Central spinal cord lesion• Posterior column syndrome • Anterior spinal syndrome + Disseminated/ multiple sclerosisSub acute combined degeneration of

spinal cord

Complete transverse cord lesion

• Features• Loss of al forms of sensations below

the segmental level of lesion• Narrow band of hyperesthesia or

paresthesia at the upper margin of level of sensory loss

• Radicular pain or segmental paresthesia may occur at the level of lesion

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• In cervical lesion the pain radiate to arm, in thoracic lesion the pain is circumferential to chest or abdomen and in lumbar and sacral lesions pain radiate to legs

causes

• Infection• Trauma• Compression by tumour• Cervical spondylosis• Transverse myelitis• Multiple sclerosis

hemisection- brown sequard syndrome

• Features• Loss of pain and temperature on the

opposite side and the upper margin is usually 2 or 3 segments below the level of lesion

• Loss of propriceptive sensation and motor deficit occur on the same side of lesion

• Touch is not affected because it passes through the lateral column and dorsal column of both sided of the cord

causes

• Infection• Trauma• Compression by tumour• Cervical spondylosis• Transverse myelitis• Multiple sclerosis

Central spinal cord lesions (syringomyelic lesion)

• Features• Dissociated sensory loss or suspended

sensory loss is loss of pain and temperature at the level of lesion where the spinothalamic fibers cross in the cord. There is loss of pain and temperature on one or both sides over a number of dermatomes with normal sensation above and below and this is called suspended sensory loss because is has upper and lower level.

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• Touch is preserved • There is sacral sparing in

intramedullary lesion

causes

• Syringomyelia• Trauma leading to hematomyelia

Posterior column syndrome (tabetic syndrome)

• Features• Common complaints are paraesthesias

in the form of tingling pins and needles, girdle and band like sensation

• Unpleasant tight feeling over limb • Loss of position and vibration sense

below the level of lesion• Pain touch and temperature is preserved

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• Sensory ataxia• Positive romberg’s sign• Lightening pain occur which is

penetrating occurring at right angle to skin

• Lhermitte’s sign – electric shock like sensation from the neck travelling down along spine when the neck is suddenly flexed or extended this occurs in lesion of posterior column of cervical region

causes

• Neurosyphilis• DM• Sub acute combined degeneration• Friedreich’s ataxia• Carcinoma• Multiple sclerosis• Mercury poisoning

Anterior spinal syndrome

• Features• Loss of pain and temperature below

the level of lesion • Preserved joint and vibration sense

causes

• Anterior spinal artery emboli• Thrombosis

Disseminated/ multiple sclerosis

-means widespread increase of connective tissue in the nervous system

FEATURES – widespread demyelinating disease of

CNS- Nerve cells replaced by neuroglial cells- Delayed or blocked conduction

Sub acute combined degeneration of spinal cord

• Demyelination of white fibers of spinal cord

• Dorsal and lateral columns are affected

• Seen in pernicious anemia patients

Complications of spinal cord transection

• Patients develop negative nitrogen balance and catabolize large amounts of body proteins is due to immobilization

1. Decubitus (postural ulcers) develop. 2. Hypercalcemia/hypercalciurea and

calcium stones in urinary tracts.3. Urinary stasis with paralysis of bladder.

• Therefore the prognosis in patients with transected spinal cord used to be very poor and death from septicemia uremia or inanition, coma and finally death.

treatment

• Faster recovery and minimal loss of function after spinal cord injury is acquired by administration of large doses of glucocorticoids

• As early as possible after injury• Administration of neurotropins • Implantation of embryonal stem cells

at the site of injury

• Another possibility being explored is bypassing the site of cord injury with brain computer interfaces devices.

• However these approaches are still a long way from routine clinical use.

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