Overview. Spinal Anatomy Spaces & Meninges Spinal Cord. Anatomy of the dura. Anatomy of the arachnoid. Anatomy of the spinal meninges

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1 European Course in Neuroradiology Module 1 - Anatomy and Embryology Dubrovnik, October 2018 Spinal Anatomy Spaces & Meninges Spinal Cord Johan Van Goethem Overview spinal meninges & spaces spinal cord Anatomy of the spinal meninges three layers (outer to inner) Anatomy of the spinal meninges dura mater (also known as theca or pachymeninx) arachnoid mater pia mater collectively the arachnoid and pia mater together are known as the leptomeninges there are two actual spaces: epidural and subarachnoid Anatomy of the dura Anatomy of the arachnoid stratum periostale stratum meningeale: extension of the dura mater from the posterior cranial fossa lies free apart from attachments to the tectorial membrane and posterior longitudinal ligament on the body of the axis stabilised by anterior and posterior spinal nerve roots, which pierce it segmentally in between: a layer of fat containing the internal vertebral venous plexus separated from the dura by a thin film of lymph thin avascular membrane lining the dural sac and nerve root sheaths a posterior median septum lies over the spinal cord, formed by web-like arachnoid processes

2 Anatomy of the pia invests the spinal cord and the spinal nerve roots, blending in with the epineurium continuous with the ligamentum denticulatum, which at its lateral border has a series of triangular processes that are fixed to the dura mater Epidural space space between the dura mater and the periosteum and ligaments of the vertebral canal superiorly bounded by the fusion of the dura with the foramen magnum content fat internal vertebral venous plexus spinal nerve roots below S2 Subarachnoid space thin cell layer between the closely apposed arachnoid and pia mater content: arachnoid trabeculae CSF veins arteries: radicular, segmental, medullary and spinal Cranium Space Typical? Example Epidural Potential No traumatic hematoma (arterial) Subdural Potential Yes traumatic hematoma (bridging veins) Subarachnoid Actual Yes haemorrhage (aneurysm, CAA), infection

3 Cranium Spine Myelography Space Typical? Example Space Typical? Example Epidural Potential No Subdural Potential Yes traumatic hematoma (arterial) traumatic hematoma (bridging veins) Actual Yes hematoma, infection, neoplasia, disc herniation Potential No - occasional direct puncture of epidural or subdural space leakage after subarachnoid puncture 35% in epidural space Subarachnoid Actual Yes haemorrhage (aneurysm, CAA), infection Actual Yes continuous w/ cranium 2% in subdural space Myelography Myelography Milants et al. European Journal of Radiology 1993 Milants et al. European Journal of Radiology 1993

4 Epidural space Spinal Cord vertebral canal conus medullaris: adult Th12- L1 filum terminale cauda equina gray matter: anterior and posterior horns white matter: anterior, lateral and posterior tracts Spinal nerves ventral and dorsal roots intervertebral foramen each pair (31) innervates a body segment: dermatomes cervical (8 p.), thoracic (12 p.), lumbar (5 p.), sacral (5 p.) and coccygeal (1 p.)

5 40-year-old woman So what is this? gradual and uniform onset of diminished pressure, vibration and touch sense tingling and numbness of legs, arms and trunk that progressively worsens pain and temperature sense are normal Lichtheim's disease Lou Gehrig's disease Lyme disease Devic s disease motor function is preserved, but slight ataxia And the answer is... Let s go back... gradual and uniform onset of Lichtheim's disease Lou Gehrig's disease Lyme disease Devic s disease diminished pressure, vibration and touch sense tingling and numbness of legs, arms and trunk that progressively worsens pain and temperature sense are normal motor function is preserved, but slight ataxia Some anatomy Spinothalamic tract 3 ascending pathways 2 descending pathways anterior coarse touch and pressure lateral pain temperature itch sexual

6 Spinocerebellar tract Fasciculus gracilis & cuneatus unconscious proprioception walking running biking... posterior or dorsal columns tracts of Goll and Burdach conscious proprioception fine touch, fine pressure and vibration 2-point discrimination Fasciculus gracilis & cuneatus Fasciculus gracilis & cuneatus Fasciculus gracilis & cuneatus Subacute combined degeneration degeneration of the posterior (and lateral) columns as a result of vitamin B12 deficiency dietary deficiency of B12, malabsorption of B12 in the terminal ileum, lack of intrinsic factor

7 So what is this? 52-year-old woman Lichtheim's subacute combined disease degeneration Lou amyotrophic Gehrig's disease lateral sclerosis Lyme neuroborreliosis disease Devic s neuromyelitis diseaseoptica unable to move her legs after abdominal procedure areflexic in the lower extremities with negative Babinski testing bilaterally sensory level to pain and temperature extended up to Th10 other intact Corticospinal tract Extrapyramidal tracts lateral conscious motor anterior 20% cervical unconscious motor automated lateral rubrospinalis arm and hands fine motor medial reticulospinalis anterior, tectospinalis, vestibulospinalis legs and trunk Back to our case Back to our case lesions of pyramid tracts or extrapyramid tracts are always combined due to their close proximity lesions of these tracts may cause Babinski sign no reflex = no α-motorneuron function

8 Back to our case Spinal cord infarction 9-year-old girl acute flaccid paresis AFP is the most common sign of acute polio, and used for surveillance during polio outbreaks Anatomy revisited Source: Wikipedia What is all the other stuff? What is all the other stuff? interneuron coordination (reflexes, proprioception) autonomic nervous system mostly diffuse

9 Conclusion spinal meninges & spaces spinal cord anatomy revisited