human spinal cord continuation, Lecture notes of Orthopedics

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Afferent Sensory Tracts in the Spinal Cord

Clinical Syndromes resulting from Incomplete Spinal Cord Injury

• Central Cord Syndrome

• Brown-Sequard Syndrome

• Anterior Cord Syndrome

• Conus Medullaris Syndrome

• Cauda Equina Syndrome

• Posterior Cord Syndrome

• Central Cord Syndrome

• Motor>Sensory Loss

• Upper>Lower Extremity Loss

• Distal >Proximal Muscle Weakness

• Pneumonic: MUD

• Classically occurs with hyperextension injuries of the cervical spine

SN:

• Most common of the incomplete cord syndrome, which occurs more frequently in elderly people

with underlying degenerative spondylosis but can also be found in younger people who have had a severe hyperextension injury with or without evidence of a fracture.

• Clinical presentation is characterized by dissociation in degree of motor weakness with the lower

limbs stronger than the upper limbs and sacral sensory sparing.

• The syndrome typically occurs following a hyperextension injury and is thought to be caused by

an expanding hematoma or edema forming in the central aspect of the spinal cord.

• Anterior Cord Syndrome

• Loss of Motor function, Pain and Temperature Sensation

• Preservation of Light touch, Vibratory Sensation and Proprioception

SN:

• The patient with an ant cord syn typically present with immediate paralysis and loss of pain and

temperature sensation.

• Both the spinothalamic and corticospinal tracts are located in the anterior aspect of the spinal

cord and are therefore involved, with the dorsal columns preserved, the patient still has intact proprioception and vibratory sense as well as intact sensation to deep pressure.

• Brown-Sequard Syndrome

SN:

• Patients with brown-sequard syndrome have a motor weakness on the ipsilateral side of the

lesion and a sensory deficit on the contralateral side.

• This is caused by a functional hemi section of the spinal cord.

• It may result from a closed rotational injury such as a fracture-dislocation or may result from a

penetrating trauma such as a stab wound.

• The prognosis in cases resulting from a closed injury is quite favorable, with 90% of patients

regaining function of the bowel as well as ability to walk.

• Posterior cord syndrome

• Posterior cord syndrome is the least common of the incomplete syndromes and is typically a

result of an extension type injury.

• Its clinical presentation is one of loss of position and vibratory sense below the level of injury

secondary to the disruption of the dorsal columns.

• With these deficits as isolated findings, the prognosis for recovery of ambulation and function of

the bowel and bladder is excellent.

• Conus Medullaris Syndrome

• Injury to sacral cord, lumbar nerve roots causing

• Areflexic bladder

• Loss of control of bowels

• Knee jerk relexes preserved, ankle jerk absent

• Signs similar to cauda equina syndrome except more likely to be bilateral

• Cauda Equina Syndrome

• Injury to nerve roots and not spinal cord itself

• Muscle weakness and decreased sensation in affected dermatomes

• Decreased bowel and bladder control

Treatment of Acute Spinal Cord Injury

• Methylprednisolone 30mg/kg as soon as possible

(Within the first 8 hours after injury) for proven NON-PENETRATING spinal cord injury

• 5.4 mg/kg/hr for the next 23 hours

Important Adjunct Measures

• Frequent turning

• Special bed to prevent pressure sores

• Splint extremities to prevent flexion contractures—splints MUST be well padded to protect

skin

• Range of motion of joints

• A genital exam should be performed because a sustained penile erection may be indicative of

severe spinal cord injury.

Cervical Spine Injury

• Cervical Spine poorly protected

• Suspect if:

• Supraclavicular injury

• Maxillofacial trauma

• Head injury

• High speed injury

Initial Treatment of Possible Cervical Spine Injury

• Immobilization

• Imaging studies

• AP, lateral and open mouth spine films

• Consider CT

• MRI to view ligaments and spinal cord

• Search for occult injury in patient with a neurologic deficit

• DOCUMENT FINDINGS

• Early neurosurgical/orthopedic consultation

Neurological Examination

• Motor examination of upper and lower extremities

• Sensory Examination of upper and lower extremities

• Examine perianal sensation to pinprick (S3,S4)

• Distinguishes between a complete and incomplete spinal cord injury

• Reflexes

• DOCUMENT FINDINGS

SN:

• Neurological evaluation should start with documentation of the function of the cranial nerves,

working proximally to distally.

Clinical Signs of Cervical Spinal Cord Injury

• Areflexia

• Diaphragmatic Breathing

• Forearm flexion

• Response to pain above the clavicle

• Hypotension and bradycardia (sympathetic nervous system paralysis

• Priapism (paralysis of parasympathetics)

• Spinal Shock

• Temporary COMPLETE cessation of spinal cord function

• Occurs IMMEDIATELY after injury

• Complete loss of all reflexes– including the bulbocavernosus

• Flaccidity of all muscles

SN:

• Presence of spinal shock causes the absence of all reflexes and typically last up to 24h after the

injury, bulbocavernosus reflex is the reflex that returns first thus marking the end of the spinal shock.

• This point has a prognostic importance because recovery from a complete neurologic deficit that

is still present at the end spinal shock is extremely unlikely.

• Neurogenic Shock

• Caused by high spinal cord injury

• Slow pulse

• Low blood Pressure

Treatment

• R/O Hemorrhage and other causes of hypotension

• Fluids, Trendelenburg

• Alpha adrenergic drugs

Other problems

• Inadequate ventilation

• Change in clinical signs due to absent sensation

Frankel Classification of Spinal Cord Injury

A. Complete: no motor or sensory function

B. Sensory Only: Some sensation preserved, no motor function

C. Motor Useless: Some sensory and motor function but motor function not useful

D. Motor Useful: Sensory function preserved. Motor function weak but useful

E. Intact: Normal Sensory and Motor function

American Spinal Injury Association (ASIA) Classification

• Multi-factorial

• Genetic predisposition

• Age-related

• Some environmental factors:

• Smoking

• Obesity

• Previous injury, fracture or subluxation

• Deformity

• Operating heavy machinery, such as a tractor

SN:

• Although smoking is a general risk factor for disc degeneration and herniation occupational risk

factors’ INCLUDE sedentary work and motor vehicle driving.

Pathology

The inter-vertebral disc

• The first component of the 3 joint complex

• “Motion segment”

• It is primarily loaded in FLEXION

• Composed of “annulus fibrosus” and “nucleus pulposus”

• Degeneration of the nucleus:

• Loss of cellular material, loss of hydration

• →Pain!

• Disc degeneration will also cause

• Bulging of the disc

■ →”Spinal” stenosis

• Loss of disc height

■ →”Foraminal” stenosi

• –Herniation of the nucleus

■ →”Radiculopathy”

■ (e.g. sciatica in the lumbar spine)

Pathology:

The facet joints

• Scientific name: “zygapophysial joints”

• Synovial joints

• 2 in each motion segment

• Are primarily loaded in EXTENSION

• Pattern of degeneration similar to other synovial joints

• Loss of hyaline cartilage, formation of osteophytes, laxity in the joint capsule

• Facet degeneration will cause:

• Hypertrophy, osteophyte formation

• Contributing to spinal stenosis or foraminal stenosis

• Laxity in the joint capsule

• Leading to instability (degenerative spondylolisthesis)

Presentation

Falls into 2 categories:

• Mechanical pain: due to joint degeneration or instability

• “Axial pain” in the neck or back

• Activity related-not present at rest

• Neurologic symptoms : due to neurologic impingement

• Spinal cord

• Presents as myelopathy, spinal cord injury

• Cauda equina & Nerve roots

• Presents as radiculopathy (e.g. sciatica) or neurogenic claudication

Mechanical pain

• Associated with movement

• Sitting, bending forward ( flexion ):

• Originating from the disc

• “Discogenic pain”

• Standing, bending backward ( extension )

• Originating from the facet joints

• “Facet syndrome”

Neurologic symptoms : Spinal cord

Myelopathy:

• Loss of motor power and balance

• Loss of dexterity

• Objects slipping from hands

• UMN deficit (rigidity, hyper-reflexia, positive Babinski..)

• Slowly progressive “step-wise” deterioration.

Spinal cord injury

• Spinal stenosis associated with a higher risk of spinal cord injury

• Spinal stenosis causing myelopathy

• Disc herniation causing severe radiculopathy and weakness

• Failure of conservative treatment of axial neck pain or mild radiculopathy

Procedures:

• Anterior discectomy and fusion

• Posterior laminectomy

• Anterior Discectomy and fusion

The Lumbar spine

• Degenerative changes typically occur in L3-S

• Presents with axial pain, Sciatica, neurogenic claudication

• Physical examination:

• Stiffness (loss of ROM)

• Neurologic exam

• Weakness

• Loss of sensation

• Hypo-reflexia, hypo-tonia

• Special tests: SLRT

SN:

• Stenosis of the lumbar spine is a clinical entity that is responsible for a variety of complaints

ranging from low back pain to lower extremity dysfunction.

• Some physiologic narrowing of the canal occur with age.

The Lumbar spine: management

• Axial low back pain

• Conservative treatment if first-line and mainstay of treatment

• Physiotherapy: core muscle strengthening, posture training

• NSAID

Surgical treatment indicated for:

• Instability or deformity

• e.g. high-grade spondylolisthesis

• Failure of conservative treatment

• Lumbar Spondylosis

The Lumbar spine: management

• Spinal stenosis

• Conservative treatment is first line of treatment

• Activity modification, analgesics, epidural cortico-steroid injections

• Surgical treatment

• Indicated for:

• Acute Motor weakness e.g. drop foot

• Failure of –minimum-6 months of conservative treatment

• Spinal decompression (laminectomy) is the commonest procedure

• Spinal stenosis

• Narrowing of the canal can further occur by bulging of the disc anteriorly and by buckling of the

ligamentum flavum posteriorly, and by encroachment of the articular facets.

• Disc herniation

• Conservative treatment is first line of treatment for mild sciatica without motor deficit

• Short (2-3 day) period of rest, NSAID, physiotherapy, epidural cortico-steroid injection

• 95% of sciatica resolves within the first 3 months without surgery

• Surgical treatment:

• Indicated for cauda-equina syndrome, motor deficit, failure of 2 months of conservative

treatment

• Procedure: Discectomy (only the herniated part)

SN:

• The pain may be caused by direct pressure on the nerve root or may be caused by breakdown

products from degenerated nucleus pulposusor by an autoimmune reaction.

Discectomy

Spinal fusion

• Osteoporotic Vertebral Fractures

• Usually noticed by parents/others

• Examination:

• Neurologically normal, positive Adams test

• Management:

• Depends on age & degree of deformity

Spondylolisthesis

• Conservative treatment first

• Surgery if Grade 3 or more or failed conservative management.

• Types:

• “Degenerative” Spondylolisthesis

• “Isthmic” spondylolisthesis

• Caused by inter-articularis defect (spondylolysis)

Grades of spondylolisthesis

Destructive Spinal Lesions

• Present with pain at rest or pain at night

• Associated with constitutional symptoms

• Most common causes

• Infection

• Tumors

• Vertebral body and pedicle are the commonest sites of pathology

Spinal Tumors

Primary Spinal tumors:

• Rare

• Benign (e.g. osteoid osteoma) or malignant (e.g. chordoma)

• Management depends on pathology

Spinal metastasis

• Very common

• Biopsy required if primary unknown

SN:

• Benign tumors:

• Osteoid osteoma, osteoblastoma, osteochondroma, aneurysmal bone cyst hemangioma,

gct.

• Malignant:

• Multiple myeloma, osteosarcoma, ewing’s sarcoma, chondrsarcoma, chordoma

(notochordal cells from the vertebral body)

Spinal infections

• Most common is TB and Brucellosis

• History of contact with TB patient, raw milk ingestion

• Potentially treatable diseases once diagnosis is established and antimicrobials administered

Spinal Tuberculosis (with psoas abscess)