Anatomy Spinal cord ends as conus medullaris at level of first lumbar vertebra lumbar and sacral nerve roots exit below this and form the cauda equina 1

Neuroanatomy Corticospinal tracts Spinothalamic tracts Dorsal (posterior) columns 2

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Corticospinal Tract Descending motor pathway Forms the pyramid of the medulla In the lower medulla, 90% of fibers decussate and descend as the lateral corticospinal tract Synapse on LMN in the spinal cord 10% that do not cross descend as the ventral corticospinal tract Damage to this part cause ipsilateral UMN findings 4

Spinothalmic Tract Ascending sensory tract from skin and muscle via dorsal root ganglia to cerebral cortex Temperature and pain sensation Damage to this part of the spinal cord causes: Loss of pain and temperature sensation in the contralateral side Loss begins 1-2 segments below the level of the lesion 5

Dorsal (Posterior) Columns Ascending neurons that do not synapse until they reach the medulla at which point they cross the midline to the thalamus Transmits vibration and proprioceptive information Damage will cause ipsilateral loss of vibration and position sense at the level of the lesion 6

Complete vs Incomplete Sensory, motor or both functions are partially present below the neurologic level of injury Some degree of recovery Complete: Absence of sensory and motor function below the level of injury Loss of function to lowest sacral segment Minimal chance of functional motor recovery 7

Light touch… Transmitted through both the dorsal columns and the spinothalamic tracts Lost entirely ONLY if both tracts are damaged 8

Upper vs. Lower Motor Neuron Upper motor neuron lesion Motor cortex internal capsule brainstem spinal cord Lower motor neuron lesion Anterior horn cell nerve root plexus peripheral nerve

Basic Features of Spinal Cord Disease UMN findings below the lesion Hyperreflexia and Babinski’s Sensory and motor involvement that localizes to a spinal cord level Bowel and Bladder dysfunction common Remember that the spinal cord ends at about T12-L1

Motor Exam Strength - helps to localize the lesion Tone Upper cervical Quadriplegia with impaired respiration Lower cervical Proximal arm strength preserved Hand weakness and leg weakness Thoracic Paraplegia Can also see paraplegia with a midline lesion in the brain Tone Increased distal to the lesion

Sensory Exam Establish a sensory level Posterior columns Dermatomes Nipples: T4-5 Umbilicus: T8-9 Posterior columns Vibration Joint position sense (proprioception) Spinothalamic tracts Pain Temperature

Autonomic disturbances Neurogenic bladder Urgency, incontinence, retention Bowel dysfunction Constipation more frequent than incontinence With a high cord lesion, loss of blood pressure control Alteration in sweating

Total transsection Injuries Tumors infection

Total transsection Below the lesion: first stage Loss of motor function Loss of sensory Areflexion Decreased tension of muscles

Total transsection Below the lesion: second stage Normal reflexesincreased Normal tensionincreasedspasticity

Total transsection Bladder: Areflexion Ischuria paradoxa Automatic or autonomic

Spinal Shock Loss of neurological function and autonomic tone below level of lesion Loss of all reflexes Resolves over 24-48h but may last for days 18

Spinal Shock Symptoms: Flaccid paralysis Loss of sensation Bladder incontinence Bradycardia Hypotension Hypothermia 19

Hypotension Must determine cause: Spinal cord injury Blood loss Cardiac injury Combination of above 20

Neurogenic Shock Neurogenic Shock: Warm Peripherally vasodilated Bradycardic Bradycardia may be caused by something other than neurogenic shock Cervical spine injury may cause sympathetic denervation 21

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Brown-Séquard Syndrome Hemisection of the cord Ipsilateral loss of: Motor function Proprioception and vibration sense Contralateral loss of: Pain and temperature sensation 23

BSS Caused by: Prognosis: GOOD Penetrating injury Lateral cord compression from: Disk protrusion Hematomas Bone injury Tumours Prognosis: GOOD 24

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Central Cord Syndrome Older patients Preexisting central spondylosis Hyperextension injury Injury affects central cord> peripheral cord Damage to corticospinal and spinothalamic tracts Upper extremities>thoracic >lower extremities>sacral 26

CCS Present with: Prognosis: GOOD Decreased strength Decreased pain and temperature sensation Upper>lower extremities Spastic paraparesis/quadriparesis Maintain bladder and bowel control Prognosis: GOOD Although fine motor recovery of the upper extremities is rare 27

signs intramedullary extramedullary Radicular pain unusual common Vertebral pain Funicular pain Less common Umn Sign +, late +, early Lmn sign +++, diffuse Unusual, segmental Paraesthe sia progr descending ascending sphincter early late Trophic

Conus medullaris lesion Pelvic floor weakness, early sphincter dysfunction Autonomous neurogenic bladder Constipation, impaired ejeculation and errection Symmetric saddle anaesthesia Pain Tethered spinal cord: numbness feet asymmetric muscle atrophy of calf and thigh, UMN signs, bowel bladder dysfunction,foot deformities, cutaneous manifestations of spinal dysraphism

Cauda equina lesion Compression lumbar sacral roots below L3 vertebra U/L early radicular pain, worse at night Flaccid hypotonic areflexic paralysis producing peripheral paraplegia Asymmetrical sensory loss in saddle area KJ variable, ankle ↓↓ Sphincter dysfunction similar to conus lesion but late

Cauda Equina Syndrome Peripheral nerve injury to lumbar, sacral and coccygeal nerve roots Symptoms: Variable motor and sensory loss in lower extremities Bowel and bladder dysfunction Saddle anaesthesia Prognosis: GOOD 31

Conus Medullaris vs. Cauda Equina Lesion Finding Conus CE Pain Uncommon Common Reflexes Increased Decreased Bowel/bladder Common Uncommon

Stretch signs -Laseque -Fajersztajn-Krzemicki -Mackiewicz -Neri -Naffziger -Bikeles

Vascular syndromes of spinal cord Anterior spinal artery syndrome: Territory – anterior funiculi, anterior horn, base of the dorsal horn, peri ependymal area, antero medial aspect of lateral funiculi Lower thoracic sement and conus- vulnerable Abrupt onset of radicular pain, girdle pain Flaccid quadriplegia, paraplegia Bowel bladder dysfunction Thermo anaesthesia analgesia Position vibration light touch preserved

Posterior spinal artery syndrome: Uncommon Loss of position , proprioception, vibration Loss of segmental reflexes Pain , temperature – preserved Motor function- preserved spinal cord claudication