أسئلة الثانية جراحة رابعة دمياط (نيورو)

• Spinal Cord Injury (SCI) involves damage to the spinal cord, potentially causing temporary or permanent changes in its function.
• Neurosurgery is a common treatment.
• Understanding anatomy, classification, function and management related to spinal injuries is essential in neurosurgery

Anatomical Background

• The nervous system is divided into the central and peripheral systems.
• The central nervous system consists of the brain and spinal cord.
• The peripheral nervous system includes cranial and spinal nerves, as well as the autonomic nervous system (sympathetic and parasympathetic).

Function and Anatomy of the Spinal Cord

• Acts as a conduit for motor commands from the brain to the body
• Acts as a conduit for sensory information from the body to the brain.
• Facilitates locomotion through repetitive, coordinated muscle actions controlled by central pattern generators.
• Mediates reflexes, which are involuntary, stereotyped responses to stimuli.
• A long, thin, tubular bundle of nervous tissue connects the brain to the peripheral nervous system.
• Extends from the medulla oblongata to between vertebrae L1 and L2.
• Nerves exit through intervertebral foramina, as they did during embryonic development.
• The spinal cord is shorter than the vertebral column, leading to discrepancies between cord segments and vertebrae.
• Length is approximately 45 cm.
• Width varies, measuring 1.25 cm in the cervical and lumbar regions and 0.6 cm in the thoracic area.
• Has 31 segments: 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal.
• Each spinal segment gives rise to pairs of spinal nerves via ventral and dorsal roots.
• Blood supply comes from the anterior spinal artery, posterior spinal arteries, and radicular arteries.

Protection and Enlargements

• It is protected by the vertebral column, spinal meninges (dura mater, arachnoid mater, pia mater), denticulate ligaments, and filum terminale.
• The vertebral column consists of 33 vertebrae: 7 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 4 coccygeal.
• Contains two enlargements: cervical and lumbar.
• The cervical enlargement (C4-T1) gives rise to the brachial nerve plexus for the upper limbs.
• The Lumbar enlargement (L2-S3) gives rise to the lumbar nerve plexus for the lower limbs.
• The conus medullaris is the tapered end of the spinal cord, located at the L2 level in adults.
• The cauda equina is a collection of nerve roots at the base of the spinal column.
• The filum terminale, a 20 cm fibrous strand, provides longitudinal support.

Internal Features

• Composed of gray matter (cell bodies of motor and sensory neurons, interneurons) and white matter (fiber tracts).
• Cross-sectionally, presents as an H-shaped gray matter surrounded by white matter.
• Containing posterior, lateral, and anterior gray horns, as well as a gray commissure.
• Ascending tracts (sensory tracts) carry information from sensory receptors to the brain.
• Descending tracts (motor tracts) carry information from the CNS to the periphery.

Spinal Nerves and Autonomic System

• Motor and sensory roots combine to form spinal nerves, which are mixed (motor and sensory).
• Autonomic nerves are carried in the lateral column of the spinal cord.
• Sympathetic nerves exit via thoraco-lumbar spinal nerves.
• Parasympathetic nerves exit via cranio-sacral spinal nerves.
• Spinal plexi include cervical (C1-C5), brachial (C5-T1), lumbar (L1-L4), sacral (L4-S4), and coccygeal (S4-Co) plexuses
• These plexuses innervate various regions and control movement and sensation.

Classification of Spinal Cord Injuries

• Upper motor neuron lesions involve axons within the spinal cord.
• Lower motor neuron lesions involve axons outside the spinal cord.

Characteristics of Upper and Lower Motor Neuron Lesions

• Upper neuron lesions: hypertonia, hyperreflexia, and muscle weakness.
• Lower neuron lesions: hypotonia, hyporeflexia, muscle weakness, and atrophy.
• Stages commonly involve "shock flaccid stage & spastic stage"

Spinal Cord Injury (SCI)

• SCI is defined as damage to the spinal cord resulting in temporary or permanent changes in its function.
• Symptoms can include loss of muscle function, sensation, or autonomic function below the injury level.
• The incidence is 23-27 per million in the Middle East and North Africa.

Etiology of Spinal Cord Injury

• Traumatic is most common
• This can include motor vehicle accidents, falls, penetrating injuries or gunshot wounds.
• Non-traumatic causes are degenerative (e.g., cervical or dorsal disc prolapse), inflammatory, or neoplastic conditions.

Pathophysiology of SCI

• Primary SCI occurs due to local deformation of the spine and direct compression.
• Secondary SCI involves biochemical and cellular cascades, including electrolyte disturbances, free radical damage, edema, ischemia, and inflammation.
• Acute phase lasts up to 48 hours and involves hemorrhage and ischemia, leading to ion balance disruption, excitotoxicity, and inflammation.
• Subacute phase lasts up to 2 weeks, characterized by a phagocytic response and astrocyte proliferation, resulting in a glial scar.
• Chronic phase occurs over 6 months, during which the scarification process is completed.

Spinal Shock

• Involves hypotension and a transient loss of all neurologic function below the level of injury.
• Hypotension features SBP ~ 80 mm Hg and bradycardia.
• Factors include interruption of sympathetic pathways, loss of muscle tone, and blood loss.
• Transient loss leads to flaccid paralysis and areflexia.
• Duration: 1-2 weeks, sometimes months.
• Characterized by loss of the bulbo-cavernosus reflex.
• Spasticity and return of the reflex after spinal shock resolves.
• Prognosis is generally poor.

Assessment of SCI

• Assessed by level and severity of injury.
• Level: the lowest level of completely normal function.
• Utilizes the most caudal segment with motor function of at least 3/5 (on a scale of 0-5) and preserved pain/temperature sensation.
• Level of cord injury: Add 2 to the number vertebra from T2-T10
• The level of cord injury for the lumbar, sacral, and coccygeal regions are T11, T12, and L1, respectively.

Clinical Assessment

• Includes myotomal level (motor level), dermatomal level (sensory level), and reflex level.
• Segments and muscles for motor assessment:
  • C5: biceps (elbow flexion)
  • C6: wrist extensors (cock-up wrist)
  • C7: triceps (elbow extension)
  • C8: finger flexors (flex middle distal phalanx)
  • T1: hand intrinsics (finger abduction)
  • L2: iliopsoas (hip flexion)
  • L3: quadriceps (knee extension)
  • L4: tibialis anterior (dorsiflexion)
  • L5: EHL (great toe dorsiflexion)
  • S1: gastrocnemius (plantarflexion)

Sensory and Reflex Assessments

• Dermatomal sensory level assessment is mapped to specific regions of the body.
• Reflexes are assessed via biceps, brachioradialis, triceps, knee-jerk, and ankle-jerk reflexes.
  • Biceps is innervated by C5
  • Brachioradialis is innervated by C6
  • Triceps is innervated by C7
  • Knee-jerk is innervated by L4
  • Ankle-jerk is innervated by S1
• DTR (Deep Tendon Reflex) grading ranges from 0 (no response) to +4 (very brisk, hyperactive with clonus).
• Determined by if injury is complete or incomplete.
• Complete lesion: loss of voluntary movement, sphincter control, and sensation below the injury level.
  • Potential features may include priapism and spinal shock.
  • Incomplete lesion: any sensorimotor function >3 segments below implies an incomplete injury.

Signs and Types of Incomplete Lesions

• Incomplete is characterized by residual sensation, sacral sparing, and preserved sacral reflexes.
• Characterized by residual sensation, sacral sparing (preserved sensation around the anus, rectal sphincter contraction, and toe flexion), and preserved sacral reflexes/function.
• Types of Incomplete SCI can be:
  • Central Cord Syndrome: disproportionate weakness in upper extremities
  • Anterior Cord Syndrome: loss of motor function, pain, and temperature sensation
  • Brown-Séquard Syndrome: ipsilateral motor paralysis, ipsilateral loss of proprioception/vibration, and contralateral loss of pain/temperature sensation
  • Posterior Cord Syndrome loss of proprioception
  • Conus Medullaris Syndrome: injury to the end of the spinal cord

Central Cord Syndrome

• Occurs primarily due to acute hyperextension injury in older patients with pre-existing stenosis.
• Potential associations include cervical fracture/dislocation, acute traumatic cervical disc herniation, or rheumatoid arthritis.
• Results in a vascular watershed zone and is susceptible to edema.
• Motor fibers are somatotopically organized

Clinical Presentation and Diagnosis

• Weakness in upper limbs with lesser effect on lower limbs.
• Varying degrees of sensory disturbance below the lesion level.
• Sphincter dysfunction (usually urinary retention).
• Lhermitte's sign occurs in 7% of cases.

Natural History and diagnosis

• Initial phase: lower limbs recover first, then bladder function, and upper limb strength returns last.
• Sensory recovery has no pattern.
• Plateau phase is followed by a late deterioration phase.
• It is typically diagnosed using cervical X-rays, CT scans, and MRI to identify congenital narrowing, fractures, or spinal cord edema.

Treatment for Trauma SCI

• ICU admission
• Respiratory care.
• Maintenance of blood pressure is essential.
• Surgical management:
  • Indicated for persistent compression/motor deficit, deteriorating neurological function, and spinal instability.
• Timing for surgical intervention:
  • Early surgery (within 24 hrs) is for patients improving/deteriorating or with spinal instability.
  • Delayed surgery (within 2-3 weeks) is for patients that fail to progress.
• Surgical techniques:
  • Decompression and fusion, which may be posterior (laminectomy/lateral mass screws/rods) or anterior (discectomy/corpectomy/cages/plating).

Anterior Cord Syndrome

• Occurs due to infarction by the anterior spinal artery or compression by a dislocated bone fragment or herniated disc.
• Results in paraplegia or quadriplegia, dissociated sensory loss (loss of pain/temperature sensation)
• There is maintained joint position and deep-pressure sensation
• Diagnosis involves differentiating non-surgical conditions from surgical ones .
• Treatment needs surgical indications for large central disc herniations or instability.
• It features the worst prognosis of the incomplete injuries, with only 10-20% recovering motor control.

Brown-Séquard Syndrome

• Results from spinal cord hemi-section and is estimated to involve 2-4% of traumatic SCIs.
• Causes include penetrating trauma, radiation, cord compression hematoma, or spinal cord tumors .
• Ipsilateral paralysis
• A loss of proprioception and vibratory sense is felt on one side
• The opposite (contralateral) side would feel a loss of pain and temperature
• Diagnosis is best made to exclude all other conditions.
• The best prognosis is made, since most patients regain the ability to walk.

Posterior Cord Syndrome

• Presents clinically features due to the posterior Column.
• Has pain and paresthesia
• Long tract findings are minimal

Conus Medullaris Syndrome and Spinal Cord Injury management

• Conus Medullaris Syndrome is an injury to the end of the spinal cord.
• Located at about vertebrae T12-L2.
• Can be diagnosed from normal muscle function
• Management includes treatment to patients who have a significant trauma.
• Maintain blood pressure
• Provide the high ventilation

Other important points for Management of SCI

• Spinal should be immobilized from the neck down to prevent injury to other areas.
• The goals of prehospital treatment include spine immobilization and maintaining blood pressure and oxygenation.
• Vasopressors (dopamine) and IV fluids help maintain blood pressure with a SBP >90 mmHg.
• Use military anti-shock trousers (MAST) to immobilize the lower spine and counteract venous pooling.
• Oxygenation can be maintained using a nasal canula, face mask, or intubation, while considering C-spine precautions.
• A brief motor exam helps identify possible deficits.
• In hospital, treatment for spinal shock includes treatment of hypotension and the maintenance of oxygenation.
• Hospital management involves immobilization, addressing hypotension with fluids and vasopressors, maintaining oxygenation, using urinary catheters, DVT prophylaxis, and temperature regulation.
• Evaluation:
  • Electrolytes: hypokalemia due to hypovolemia/hypotension ↑ plasma aldosterone
  • More detailed neuro evaluation: ASIA scale is recommended
  • Functional outcome assessment to provide functional Impairment Measure and Modified Barthel index.
  • Helpful in identifying bony injuries or ligamentous injury
  • A cervical spine, thoracic spine and lumbar spine would be indicated.

Spinal Cord Injury management specifics

• Diagnostic testing (CT scan, Plain X-Ray and emergently MRI) by a health professional is recommend, and will require a long term care plan and therapy.
• Medical management may involve:
  • Methylprednisolone
  • Investigational Drugs
  • Surgical treatment
• It should be followed by a long plan of physical and occupational therapy
• Long term physical and occupational therapy:
  • Minimizing muscle atrophy
  • Improving breathing and circulation
  • Increasing mobility
  • Reducing feelings of depression and anxiety
  • Empowering patients to make a positive impact on their health
  • Range of motion exercises
  • Stretches exercises
  • Strengthening exercises
  • Gait training at home physiotherapy program
• Complications can include
  • Muscle atrophy
  • Loss of voluntary motor control
  • Spasticity
  • Pressure sores
  • Breathing problems
  • Automatic dysreflexia
• Timing of the injury will affect timing for surgical intervention.
  • Late surgery: reserved for those lesions in order to relieve pressure.
  • Early surgery: reserved for incomplete spinal lesions.