Anatomy of the spinal cord, The Spinal Cord spinal nerves and If all the nerves exited directly from the brain, autonomous nervous system the brain would be bigger. God created the spinal cord below the brain. The spinal cord is like a channel coming out of a Majda M Thurnher1 fountain in the way that nerves emerge from Johan van Goethem2 both sides and go down, thus putting the organs closer to the brain. 1Medical University of Vienna | University Hospital Vienna | Department of Biomedical Imaging and Image- That is why God placed the spinal cord into a Guided Therapy Vienna | Austria CEO of the European Board of Neuroradiology (EBNR) hard bony channel called the spine to protect it Past President of the European Society of Neuroradiology (ESNR) from injury. 2 University of Antwerp | Belgium President of the European Society of Neuroradiology (ESNR) Ibn Sina (Avicenna) 980-1037 SPINAL CORD SPINAL CORD • The spinal cord is part of the central nervous system (CNS) • It is situated inside the vertebral canal of the vertebral column. • During development, there’s a disproportion between spinal cord growth and vertebral column growth. The spinal cord finishes growing at the age of 4, while the vertebral column finishes growing at age 14-18. 35 / 38 mm • Cervical, thoracic, lumbar, pelvic 13 mm thick in the cervical and lumbar regions 6.4 mm thick on the thoracic area 43 / 45 cm SPINAL CORD Posterior median sulcus • The spinal cord is made of Dorsal horns gray and white matter just like other parts of the CNS. • It shows four SURFACES: anterior, posterior, and Blasius G: Anatome Medullae Spinalis Nervorum 1666 White matter two lateral. Central canal • They feature FISSURES (anterior) and sulci (anterolateral, posterolateral, and posterior). Ventral horns Courtesy of Eric Schwartz Ventral median fissure 1 Gray matter Gray matter posterior grey column • anterior grey column The dorsal horn (posterior horn) contains neurons that receive somatosensory information from the lateral grey column body • The ventral horn (anterior horn) largely contains motor neurons that exit the spinal cord to innervate skeletal muscle No lateral gray matter in the cervical region! • The intermediate column and lateral horn contains neurons that innervate visceral and pelvic organs Gray matter The “Lamination” of the gray matter Anterior Cell Columns • The distribution of cells – Ventromedial (Vm) and fibers within the gray – Ventrolateral (Vl) matter of the spinal cord exhibits a pattern – Dorsomedial (Dm) of lamination. – Dorsolateral (Dl) • The cellular pattern of – Accessory (A) each lamina is composed Intermediate Gray Matter of various sizes or shapes – Intermediolateral (Iml) of neurons which led – Intermediomedial (Imm) Rexed to propose a new Posterior Cell Columns classification based on 10 layers (laminae). – Substantia gelatinosa (Sg) – Nucleus proprius (Np)80 – Nucleus dorsalis (Nd) A cytoarchitectonic atlas of the spinal cord in the cat. J Comp Neurol 1954; 100:297-351 High Resolution MR Microscopy of the Human Spinal Cord at 9.4 T 3T Spatial Resolution Postmortem Anatomy & DTI Courtesy of Thomas Naidich, New York, USA 2 Courtesy of Thomas Naidich, New York, USA Rexed Laminae I -X Dorsal Root Entry Zone Nucleus Proprius Dorsal Column of Clarke Intermediolateral Column of Terni Courtesy of Thomas Naidich, New York, USA MR Microscopy of the Human Spinal Cord at 7 T 3 White matter Coloured scanning electron micrograph (SEM) Ascending tracts convey information from the periphery to the brain (sensory information) Descending tracts carry information from the brain to the periphery (motor information). Spinal Pathways Pathway for sensation of pain and reaction to pain • Sensory neurons finger • Ascending pathway • Thalamus • Sensory cortex • Motor cortex • Thalamus • Descending pathway • Muscles 4 Ascending tracts (sensory) Fasciculus gracilis and cuneatus Pain • Fine touch Temperature • Proprioception Coarse touch • Vibration Fine touch Fasciculus cuneatus – upper limbs Vibration Faciculus gracilis – lower limbs Proprioception Conscious sensory information cortex Subconsciousinformation cerebellum Spinothalamic tract Spinocerebellar tract (anterolateral tracts) • Crude touch • Pain • Temperature • Proprioception Descending tracts (motor) Corticospinal tracts (pyramidal) (pyramidal and extra-pyramidal) Movement Muscle tone Spinal reflexes • Voluntary movements 5 Extrapyramidal tracts • rubrospinalis • reticulospinalis anterior • tectospinalis • vestibulospinalis Fasciculus gracilis • Fine touch Fasciculus cuneatus • Fine touch • Proprioception • Proprioception • Vibration • Vibration Spinothalamic tract • Pain Spinocerebellar tract • Proprioception • Temperature (subsconscious) • Crude touch 6 Corticospinal tracts (lateral and anterior) Rubrospinal tract (extra-pyramidal) • Skilled voluntary movements Tectospinal tract (extra-pyramidal) Vestibulospinal tract (extra-pyramidal) Reticulospinal tract (extra-pyramidal) Autonomic nervous system • a component of the peripheral nervous system that Heart rate regulates involuntary physiologic processes Blood pressure Respiration • It contains three anatomically Digestion distinct divisions: sympathetic, Sexual arousal parasympathetic and enteric. 7 Autonomic nervous system COVERINGS Spinal meninges • Three layers of meninges envelop the spinal cord and the roots of spinal nerves Dura mater Arachnoid Pia mater Leptomeninges The spinal dura mater The spinal arachnoid The spinal pia • Around the margin of the foramen magnum cranial dura mater is closely adherent to the bone, and is continuous • Thin (avascular) layer lining the • Directly covering the spinal cord and spinal nerve roots with the spinal dura mater dural sac and nerves root sheaths • Separated form the dura • Continuous with the lig. • The Spinal Dura Mater (dura mater denticulatum spinalis) forms a loose sheath around the medulla spinalis • represents only the meningeal layer of the cranial dura mater (the endosteal layer ceases at the foramen magnum) • its place is taken by the periosteum lining the vertebral canal 8 Spinal spaces Epidural Subarachnoid • Space between the dura and the • Space between the arachnoid periosteum and pia • Content: fat, venous plexus, • Continuous with cerebral spinal nerve roots below S2 subarachnoid space • Content: CSF, arachnoid trabeculae, veins, arteries Internal vertebral venous plexus Internal vertebral venous plexus • It sits within the spinal canal within a layer of fat containing the internal vertebral venous plexus. • The vertebral venous plexus is a highly anastomotic network of valveless veins running along the entire length of the spinal canal. Spinal epidural extramedullary hematopoiesis • sudden stabbing back pain that Spontaneous spinal epidural hematoma progressed toward paraparesis 9 Tuberculous Radiculitis How much anatomy do you need to report? Spinal cord lesion Long T2 lesion Short T2 lesion Anterior Posterior Lateral Central Enhancement pattern Bilat ventral Marginal Central Anterior Posterior Compression Multiple sclerosis Syringomyelia Infarct B12 deficiency CASE #1 10 Myelopathy Sagittal Short T2 lesions Axial Posterior/Lateral anterior Enhancement YES NO Nodular or ring Other clues Brain lesions Diagnosis Multiple Sclerosis CASE #2 11 Spinal cord lesion Sagittal Short T2 lesion Axial Central Enhancement YES Other clues Cyst DTI: central with spreading fibers lateral Diagnosis Ependymoma Myelopathy Myelopathy Long T2 lesion Sagittal Short T2 lesion Sagittal Axial lateral central Posterior/Lateral Anterior/lateral/ Anterior/lateral/ Central Anterior gray Symmetrical Central Axial posterior posterior matter dorsal columns Enhancement NO YES YES YES YES YES + leptomeningeal Nodular or ring Enhancement „Pancake-like“ Nodular or ring NO YES NO YES NO YES YES YES Black butterfly „Missing piece „Shaggy ring“ “Trident sign“ sign“ Other clues Degenerative Degenerative disease disease Brain lesions Brain lesions Eccentric Cysts, syrinx Bright spotty Subpial Other clues + edema Dilated vessels lesions enhancement Diagnosis Chronic Acute MS Vasculitis Tumor spondylotic spondylotic Mets myelopathy myelopathy Ischemia Polio SCD Paraneoplastic ATM sDAVF NMO Sarcoidosis Diagnosis Infection HIV ADEM 12.