Spinal Cord Injuries PDF

Spinal Cord Injuries  Session objectives Discuss deficits characteristic of spinal cord lesions: Lesion of the anterior, lateral, and posterior column, Anterior spinal cord syndrome, Syringomyelia, Brown-séquard syndrome. What are the clinically important ascending tracts and...

Spinal Cord Injuries  Session objectives Discuss deficits characteristic of spinal cord lesions: Lesion of the anterior, lateral, and posterior column, Anterior spinal cord syndrome, Syringomyelia, Brown-séquard syndrome. What are the clinically important ascending tracts and where do they cross over? What are the clinically important descending tracts and where do they cross over? At what level does the spinal cord end and why is it important?  BasicFeatureso fSpinalCord Disease UMN fi n d i n g s b e l o w t h e lesion - Hyp erre flex ia and Bab insk i's S e n s o r ya n dm o t o r involvement that l o c a l i z e s t o a s p i n a l c o r d level Bowela n dBladderdysfunction c o m m o n What are the differences between UMN and LMN? (e.g., cauda equina vs. myelopathy) Weakness/paralysis  Motor Symptoms Below the lesion Plegia = complete lesion Paresis = some muscle strength is preserved Tetraplegia (or quadriplegia) – Injury of the cervical spinal cord – Patient can usually still move his arms using the segments above the injury (e.g., in a C7 injury, the patient can still flex his forearms, using the C5 segment) Paraplegia – Injury of the thoracic or lumbo-sacral cord, or cauda equina Hemiplegia – Paralysis of one half of the body – Usually in brain injuries (e.g., stroke) Below the lesion Motor symptoms (paralysis)  M o t o rE x a m S t r e n g t h - h e l p s to localize t h e lesion - U p p e rcervical Quadriplegia with impaired respiration - L o w e rc e r v i c a l Proximal a r m s t r e n g t h p r e s e r v e d Hand w e a k n e s s a n d leg w e a k n e s s - Thoracic Paraplegia - C a n a l s o s e e p a r a p l e g i a with a midline l e s i o n in t h e b r a i n To n e - I n c r e a s e d distal to the lesion Babinski sign=UMN syndrome  Sensory symptoms (pain and temperature, proprioception) Below the lesion  S e n s o r y Exam Establish a sensory level - Dermatomes Nipples: T4-5 U m b i l i c u s : T8-9 Posterior c o l u m n s - Vi b r a t i o n - J o i n t position s e n s e ( p r o p r i o c e p t i o n ) Spinothalamic tracts - Pain - Te m p e r a t u r e  Spinal Cord Injuries Spinal Shock Flaccid paralysis Loss of autonomic reflexes (injury above T6) Bowel &bladder dysfunction  A u t o n o m i cd i s t u r b a n c e s Neurogenicb l a d d e r - Urgency, incontinence, retention Boweldysfunction - Constipation m o r e f r e q u e n t t h a n incontinence With a high cord lesion, loss of blood pressure control Alteration in sweating A s c e n d i n g a n d D e s c e n d i n g Tracts Dorsal root Posterior (dorsal) columns Lateral corticospinal tract Spinothalamic tract Ventral root C A S E STUDY 1 The following image shows the spinal cord regions a f f e c t e d in C e n t r a l C o r d m o:rednS y Questions:.1 What ascending and/or descending tracts are involved? 2. D e s c r i b e t h e d e fi c i t s that r e s u l t f r o m C e n t r a l C o r d Syndrome. Answers1 : 1. W h a t a s c e n d i n g a n d / o r d e s c e n d i n g t r a c t s a r einvolved? With small lesions, the Anterolateral Spinothalamic t r a c t s a r e a ff e c t e d ( d u e t o i n t e r r u p t i o n of d e c u s s a t i n g fibers). With larger lesions, additional tracts affected are the C u n e a t u s Fasciculus of the D o r s a l C o l u m n a n d the medial a s p e c t of t h e Lateral C o r t i c o s p i n a l tracts. Dorsal root Posterior (dorsal) columns Lateral corticospinal tract Spinothalamic tract Ventral root  Answers 2 : 2. D e s c r i b e t h e d e fi c i t s t h a t r e s u l t f r o m C e n t r a l C o r dSyndrome. Somatotopic organization of the spinal tracts are, from medial to lateral, cervical thoracic lumbar and sacral. Therefore, in Central Cord Syndrome, the upper extremities are more affected than the lower extremities. Since the periphery of the cord is unaffected, thoracic, lumbar, and sacral function is retained. There is bilateral loss of discriminative pain and temperature in the upper extremitites and superior portion of the trunk. With larger lesions, may see loss of discriminative touch and c o n s c i o u s proprioception d u e to involvement of cuneatus fasciculus and motor impairments due to invol veme nt of latera l cortic ospin al tracts.  Central Cord Syndrome Posterior (dorsal) columns Lateral corticospinal Dorsal tract root Intermedio- lateral columns Dorsal root ganglion Spinothalamic tract Ventral root The lesion interrupts fibers crossing to enter the spino- thalamic tracts, and fibers mediating the tendon stretch reflex. As it enlarges, it affects the intermediolateral c o l u m n s (autonomic function), and the lateral corticospinal tracts.  Syringomyelia F l u i d fi l l e d c a v i t a t i o n i n t h e c e n t e r o f t h e c o r d C e r v i c a lc o r d m o s t c o m m o n s i t e - L o s s of pain a n d t e m p e r a t u r e related to t h e crossing fibers o c c u r s early c a p e like s e n s o r y l o s s - We a k n e s s of m u s c l e s in a r m s with atro phy and hyporeflexia (Anterior Horn Cervical ) - L a t e r - C S T i n v o l v e m e n t w i t h b r i s k r e fl e x e s in the legs, spasticity, and weakness May o c c u r a s a late s e q u e l a e to t r a u m a o r malformation  15 m m Chiari Malformation Syrinx, or Syringomyelia CASE STUDY 2 The following image s h o w s the spinal cord regions affected in Anterior Cord Syndrome: Questions:.1 What a s c e n d i n g and/or d e s c e n d i n g tracts are involved? D e s c r i b e t h e d e fi c i t s t h a t r e s u l t f r o m A n t e r i o r Cord Syndrome. Answer 1: 1. What ascending a n d / o r descending t r a c t s a r e involved? Essentially, all ascending and descending tracts are involved except those of the Dorsal m u.nC lo Dorsal root Posterior (dorsal) columns Lateral corticospinal tract Spinothalamic tract Ventral root SPINAL CORD ARTERIES ANTERIOR SPINAL ARTERY Vertebral artery branches join to form the anterior spinal artery, which descends the anterior median fissure and supplies the anterior two-thirds of the spinal cord. POSTERIOR SPINAL ARTERIES Each vertebral artery produces a single posterior spinal artery that descends the posterior spinal cord and supplies the posterior one-third of the spinal cord. Note that often the posterior spinal arteries originate from the posterior inferior cerebellar arteries (PICAs). Also, note that posteromedial spinal arteries can also exist. ARTERY OF ADAMKIEWICZ: * The most important radiculomedullary artery. Arises from T9 to T12, most commonly, but can originate anywhere from T8 to L3. It most commonly originates from the left side. Injury to this artery can lead to paraplegia. A n s w e r 2: 2. D e s c r i b e t h e d e fi c i t s t h a t r e s u l t f r o m A n t e r i o r Cord m o.rednS y Bilateral l o s s o f d i s c r i m i n a t i v e p a i n a n d temperature and paralysis below level of lesion. Proprioception and discriniminative t o u c h r e m a i n intact. CASE STUDY 3 The following i m a g e s h o w s the spinal c o r d r e g i o n s affected in Br ow n-S eq ua rd Sy nd rom e: Questions: 1.What a s c e n d i n g and/or d e s c e n d i n g tracts are involved? 2. D e s c r i b e t h e d e fi c i t s t h a t r e s u l t f r o m B r o w n - Sequard Syndrome. A n s w e r 1: 1. What a s c e n d i n g a n d / o r descending t r a c t s a r e involved? 1.Al ascending and descending tracts on one side of t h e s p i n a l c o r d a r e a ff e c t e d. D o r s a l root Posterior (dorsal) Lateral corticospinal tract Spinothalamic tract Ans wer 2 2. D e s c r i b e t h e d e fi c i t s t h a t r e s u l t f r o m B r o w n - S e q u a r dSyndrome. 2. Involvement of the Dorsal Column causes loss of proprioception and discriminative touch ipsilaterally (below lession). Involvement of the Anteriorlateral S p i n o t h a l a m i c t r a c t c a u s e s l o s s of crude t o u c h and discriminative pain and t e m p e r a t u r e o n t h e c o n t r a l a t e r a l s i d e a few levels below the lesion. The difference in a ff e c t e d level is d u e to t h e fact t h a t t h e anteriolateral s p i n o t h a l a m i c t r a c t s a s c e n d ipsilaterally several s e g m e n t s before decussating. Involvement of the d e s c e n d i n g tracts causes paralysis ipsilaterally below the level of the lesion.  Brown-SequardSyndrome C o r dh e m i s e c t i o n T r a u m a or tumor D i s s o c i a t e ds e n s o r yl o s s - loss of pain a n d temperature contralateral t o lesion, one or 2 levels below c r o s s i n g of s p i n o t h a l a m i c t r a c t s 1-2 s e g m e n t s a b o v e w h e r e they enter - l o s s of vibration/proprioception ipsilateral to the lesion t h e s e pathways c r o s s at the level of the brainstem W e a k n e s s a n d UMN fi n d i n g s ipsilateral t o l e s i o n  Brown-Sequard Syndrome of Spinal Cord Hemisection Posterior (dorsal) columns Lateral c o r t i c o s pinal tract Spinothalamic tract S a m e s i d e a s lesion: Side opposite lesion: UMN w e a k n e s s Loss of pain & temp. Loss of position &vibration MRI-intramedullary a s t r o c y t o m a  Myelitis Complete t r a n s s e c t i o n Trauma Hemisection Brown-Sequard syndrome Syringomyelia Central structures Hydromyelia Tumor Ventral two- Occlusion o f t h e thirds anterior spinal artery