CAUDA EQUINA: EMBROYOLOGY, ANATOMY & PATHOLOGY: A SYSTEMATIC APPROACH

1. Control #: 2527 eEdE#: eEdE-222 (Shared Display) CAUDA EQUINA: EMBROYOLOGY, ANATOMY & PATHOLOGY: A SYSTEMATIC APPROACH PARVEZ MASOOD, MD JAWAD TSAY, MD VIRGINIA HILL, MD CLEVELAND CLINIC FOUNDATION

2. No disclosures • Parvez Masood, MD, Jawad Tsay, MD, and Virginia Hill, MD, have nothing to disclose.

3. ANATOMY Cauda equina = “horse’s tail” of lumbar, sacral, coccygeal nerve roots below conus More lumbar nerve roots are lateral More sacral/coccygeal nerve roots are medial Lumbosacral nerve roots exit under same numbered pedicle: eg, L5 exits under L5 pedicle

4. ANATOMY Nerve roots exiting conus: Ventral: efferent somatic, some sympathetic Dorsal: afferent somatic, visceral Filum terminale connects conus and dura of coccyx Intrathecal roots don’t enhance, dorsal root ganglion does enhance

5. EMBROYOLOGY Differential elongation of the spinal cord and the vertebral column resulting in superior migration of the terminal spinal cord and elongation of the nerve roots. This secondarily causes a “horse-tail” appearance of those nerves results in the formation of the cauda equina

6. CONGENITAL ABNORMALITIES

7. QUESTION 45 Y/O MALE WITH BOWEL & BLADDER COMPLAINTS

8. ANSWER OPTIONS MOST COMMON MATERNAL FACTOR ASSOCIATED WITH THIS ENTITY IS? • FOLATE DEFICIENCY • ALCOHOL ABUSE • MATERNAL DIABETES • TORCH INFECTION

9. ANSWER MATERNAL DIABETES: • 15-20% OF CHILDREN WITH CAUDAL REGRESSION SYNDROME ARE BORN TO DAIBATIC MOTHERS. ALSO B. 1% OF INFANTS OF DIABETIC MOTHERS ARE AFFECTED

10. CAUDAL REGRESSION SYNDROME High lying club shaped cord terminus (amputation of the terminal spinal cord) Sacral dysgenesis Sacral dysgenesis

11. CAUDAL REGRESSION SYNDROME INTRODUCTION: A rare congenital anomaly assocaited with absent lower vertebral bodies, malformed genitalia, anal atresia and potential lower extremity anomaly (worst case scenario – sirenomyelia). CLINICAL PRESENTATION: Neurogenic urinary bladder dysfunction. Structural anomaly of lower extremity & sacrum Sacral dysgensis with high lying club shaped cord (Group I) CLASSIFICATION: Sacral dysgensis with low lying cord with associated tethered anomalies and lipo-myelo-meningo anomalies (Group II)

12. IMAGING HALLMARKS: • Lumbosacral dysgenesis (both with group I & II) • Amputated high lying spinal cord (Group I) • Tethered low lying cord with variable associated anomalies of the meninges – fat – skin. IMAGING GOLD STANDARD/DIAGNOSIS: MRI imaging TREATMENT PROGNOSIS: • With group II: Untethering with repair of associated anomalies • Surgery to improve lower extremity & bowel bladder function

13. QUESTION NEWBORN WITH DORSAL MENINGOCELE

14. ANSWER OPTIONS WHAT IS THE MOST COMMON MALFORMATION ASSOCIATED WITH THIS ENTITY? • CHIARI • DANDY WALKER • CARDIAC SEPTAL DEFECTS • SEPTO-OPTIC DYSPLASIA

15. ANSWER CHAIRI II: • 15-20% OF CHIARI MALFORMATION PATIENTS ARE ASSOCIATED WITH DIASTOMETAMYELIA.

16. DIASTOMETAMYELIA Low lying spinal cord (tethered) No imaging identifiable spur Split spinal cord (each side has its own unilateral nerve roots)

17. DIASTOMETAMYELIA INTRODUCTION: Split cord malformation with 2 hemi-cords. Each has a single dorsal horn and ventral horn as well as central canal. CLINICAL PRESENTATION: Neurologic dysfunction. Later on progressive vertebral body (kypho-scoliotic) changes and orthopedic issues. Bony or fibrous or fat band separating the two hemi-cords (Type I). Extends from posterior Elements to merge with the vertebral body CLASSIFICATION: No mesenchymal band seperation. Just spinal cord splitting (Type II)

18. IMAGING HALLMARKS: • Two hemi-cords. • May appreciate a bony or fibrous separation (Type I) • Each hemi-cord has its own central canal and dorsal and ventral horns IMAGING GOLD STANDARD/DIAGNOSIS: MRI imaging TREATMENT PROGNOSIS: • Untethering of cord with resection of spur • Orthopedic procedures for spine alignment issues (kypho-scoliosis)

19. QUESTION 6 Y/O MALE WITH ABDOMINAL PAIN

20. ANSWER OPTIONS ALL OF THE FOLLOWING ARE CHARACTERSTIC FOR NF-1 EXCEPT? • PSEUDOARTHROSIS • LATERAL MENINGOCELE • PLEXIFORM NEUROFIBROMA • SACRAL DYSPLASIA • SPHENOID WING DYSPLASIA

21. ANSWER SACRAL DYSPLASIA: • ALL OF THE AFOREMENTIONED ARE CHARACHTERSTICS OF NF-1 EXCEPT SACRAL DYSPLASIA. B. HALLMARK OF NF-1 IS PLEXIFORM NEUROFIBROMA. C. HALLMARK OFNF-2 IS VESTIBULAR SCHWANNOMA (BILATERAL).

22. NEUROFIBROMATOSIS Multiple separate enhancing nodules (along the entire cauda equina)

23. NEUROFIBROMATOSIS INTRODUCTION: NF-1 is a chromosomal disorder (#17) mesodermal dysplasia disorder. Whereas NF-2 is an chromosomal anomaly (#22) predisposing to multiple schwannomas and meningiomas or ependymomas (MISME tumors) with both of them although being completely unrelated present with nerve tumors on imaging as the most common presentation. CLINICAL PRESENTATION: NF-2 presents typically (greater than 50% patients) with hearing loss. Patients with cord lesions (almost 50% present with cord compression symptoms). NF-1 presents typically with cutaneous or skeletal deformities.

24. NF-1 (associated with chromosome 17) typically mesodermal pathologies. Hallmark is a plexiform neurofibroma. NF-1 (associated with chromosome 17) typically mesodermal pathologies. Hallmark is a plexiform neurofibroma. CLASSIFICATION: CLASSIFICATION: CLASSIFICATION: CLASSIFICATION: CLASSIFICATION: NF-2 (associated with chromosome 22) typically with MISME lesions (detailed above). Hallmark is bilateral vestibular schwannomas. NF-2 (associated with chromosome 22) typically with MISME lesions (detailed above). Hallmark is bilateral vestibular schwannomas. NF-2 (associated with chromosome 22) typically with MISME lesions (detailed above). Hallmark is bilateral vestibular schwannomas. IMAGING HALLMARKS: • NF-1: • Plexiform neurofibroma • Intracranial and optic nerve glioma • Sphenoid wing and other osseous dysplasias • Cervical kyphosis • NF-2: • MISME lesions (detailed above)

25. IMAGING GOLD STANDARD/DIAGNOSIS: MRI imaging of brain and spine TREATMENT PROGNOSIS: • Resection of symptomatic tumors • Orthopedic procedures for spine alignment issues (kypho-scoliosis)

26. QUESTION 1 Y/O MALE WITH INCONTINENCE

27. ANSWER OPTIONS NORMAL LOCATION OF CONUS? • L1 • L1-2 • L2 • L2-3 • L3

28. ANSWER AT OR ABOVE L2-3 LEVEL:

29. TETHERED CORD Low lying spinal cord Fat along the terminal cord (lipomeningocele)

30. TETHERED CORD INTRODUCTION: Low lying terminal spinal cord below inferior L2 which may or may not be associated with a soft tissue – fatty mass or may or may not be adherent to the posterior spinal canal. CLINICAL PRESENTATION: Neurologic dysfunction. Low back and leg pain. May be associated with gait disturbance. IMAGING GOLD STANDARD/DIAGNOSIS: MRI imaging

31. IMAGING HALLMARKS: • Conus ends below inferior L2. • Thickened filum (greater than 2 mm at L5-S1 on MRI). • May or may not be associated with spectrum of spinal dysraphisms TREATMENT PROGNOSIS: • Untethering of cord • May be followed with CSF flow study to look for re-tethering (Caveat: return of normal CSF flow is seen in less 1/3 of patients even if symptoms resolve) 3. Re-tethering is based mainly on clinical grounds

32. QUESTION 5 MONTH FEMALE WITH DORSAL SINUS

33. ANSWER OPTIONS WHICH NEUTRITIONAL DEFICIENCY IS ASSOCIATED WITH THIS ENTITY? • Thiamine • Riboflavin • Folic acid • Leucine • Cholecalciferol

34. ANSWER FOLIC ACID:

35. MYELOMENINGOCELE Sina bifida with outpouching of the meninges Fetal ultrasound

36. MYELOMENINGOCELE INTRODUCTION: Dorsal spinal defect without skin covering exposing meninges with or without neural tissue and or CSF. CLINICAL PRESENTATION: New born with exposed midline neural tissue. Level of abnormality reflects neurological deficits. ASSOCIATIONS: Chiari malformation. (type II with lumbar and type II with cranio-cervical)

37. IMAGING HALLMARKS: • Open spinal dysraphism • Low lying spinal cord • Open neural arch • Intracranial Chiari findings IMAGING GOLD STANDARD/DIAGNOSIS: MRI imaging TREATMENT PROGNOSIS: • Prevention (Folate supplementation for conceiving & pregnant women) • In-utero surgery if possible 3. Repair of the meningomyelocele in early neonate period

38. QUESTION 50 Y/O MALE WITH LOW BACK PAIN – INCIDENTAL FINDING

39. ANSWER OPTIONS ALL THE FOLLOWNG RESTRIC DIFFUSION EXCEPT? • EPIDERMOID • ARACHNOID CYST • ABSCESS • INTRACRANIAL PNET

40. ANSWER ARACHNOID CYST: Follows CSF intensity (density) on all imaging parameters

41. ARACHNOID CYST CSF intensity collection without restricted diffusion with associated mass effect and bone remodeling

42. ARACHNOID CYST INTRODUCTION: Extramedullary intraspinal CSF collection. CLINICAL PRESENTATION: Most patients are incidentally detected. Presentation may be in relation to mass effect and compression of cauda equina, especially if present in sacral region. Intradural. CLASSIFICATION: Extradural (herniating thru the dura)

43. IMAGING HALLMARKS: • CSF intensity circumscribed collection • Mass effect (bone scalloping & compression of cauda equina – thecal sac) (bone remodeling is more common with extradural form) 3. Cap sign: Seen with extradural type – epidural fat at superior & inferior aspect IMAGING GOLD STANDARD/DIAGNOSIS: MRI imaging TREATMENT - PROGNOSIS: • Only if symptomatic (nerve or cord compression) • Decompression – fenestration of the arachnoid cyst

44. TRAUMA - IATROGENIC ABNORMALITIES

45. QUESTION MOST COMMON PRESENTATION OF CHRONIC SPINE SUBARACHNOID HEMORRHAGE IS? MOST COMMON PRESENTATION OF CHRONIC SPINE SUBARACHNOID HEMORRHAGE IS? • Headache • Hearing loss • Vomiting • Back pain • Headache • Hearing loss • Vomiting • Back pain

46. ANSWER HEARING LOSS: Due to cortical superficial siderosis (most common extra spinal presentation of myxopapillary ependymoma).

47. QUESTION MOST COMMON CAUSE OF EPIDURAL HEMATOMA IN SPINE IS? • Coagulopathies • Trauma • Spontaneous • Iatrogenic

48. ANSWER SPONTANEOUS EPIDURAL HEMTOMA:

49. QUESTION DESIRED LOCATION OF COLLECTION IN CSF LEAK BLOOD PATCH IS: • Subdural • Epidural • Subarachnoid

50. ANSWER EPIDURAL - BLOOD PATCH