Conus Medullaris and Cauda Equina Syndromes

Temple University HospitalNovember 22, 2006

Presented by Darric E. Baty, M.D.

Outline of Discussion• Introduction• Anatomical Overview• Conus Medullaris Syndrome• Trauma As An Etiology• Cauda Equina Syndrome• Questions

Introduction• Conus medullaris and cauda equina

syndromes are clinical entities– Diagnosis based on clinical findings

• History and Physical Examination– Diagnosis prompts emergent acquisition of

appropriate radiographic workup• Exclude psychogenic causes• Identify the pathology to aid in formulation of a

treatment plan– Etiology is variable

Introduction• What’s the Difference?

– Idealistically• Patients with conus medullaris syndrome typically present

with symptoms consistent with:– Spinal cord compression– Spinal cord dysfunction– “Intrinsic pathology”

• Patients with cauda equina syndrome typically present with symptoms consistent with:

– Lumbosacral radiculopathies– “Extrinsic pathology”

– Practically• There is much overlap in symptomatology• Both require complete evaluation, including imaging, to

manage appropriately

Anatomical Overview• For Zak • For Bong Soo

Anatomical Overview

Conus Medullaris Syndrome• Definitions

– Historically (i.e., in the “pure, classic” syndrome) defined as signs consisting of:

• Paralytic bladder incontinence• Bowel incontinence• Impotence• Perineal sensory changes• Absence of lower extremity weakness

– Presently, a constellation of signs and symptoms including:• Bowel dysfunction• Bladder dysfunction• Sexual dysfunction• Poor rectal tone• Perianal sensory changes• Sometimes, lower extremity weakness

Conus Medullaris Syndrome• Etiologies

– Tumor– Vascular lesion– Diabetic neuropathy– Trauma– Disc herniation

Conus Medullaris Syndrome• Symptoms

– Back pain– Unilateral or bilateral leg pain– Bladder dysfunction– Bowel dysfunction– Sexual dysfunction– Diminished rectal tone– Perianal sensory loss– Lower extremity weakness

Trauma As An Etiology

Trauma As An Etiology• Acute Spinal Cord Injury Syndromes in Trauma Patients

– Complete spinal cord injury• ASIA/IMSOP Grade A• Unilevel: no zone of partial preservation• Multiple level: zone of partial preservation

– Incomplete spinal cord injury• ASIA/IMSOP Grades B, C, and D• Cervicomedullary syndrome• Central cord syndrome• Anterior cord syndrome• Posterior cord syndrome• Brown-Séquard syndrome• Conus medullaris syndrome

– Complete cauda equina injury• ASIA/IMSOP Grade A

– Incomplete cauda equina injury• ASIA/IMSOP Grade B, C, and D

– Reversible or transient syndromes• Cord concussion• Burning hands syndrome• Contusio cervicalis• Hysteria

Trauma As An Etiology• Conus Medullaris Syndrome: Trauma

Definition– Combination of upper and lower motor neuron

deficits, with initial flaccid paralysis of the legs and anal sphincter

Trauma As An Etiology• Conus Medullaris Syndrome: Trauma

Symptoms– Acute Phase

• Flaccid paralysis of the legs• Paralysis of the anal sphincter

– Chronic Phase• Muscle atrophy of the legs• Lower extremity spasticity• Lower extremity hyperreflexia

– Extensor plantar response may be present• Development of a low-pressure, high-capacity neurogenic

bladder– Sensory deficits are variable

Cauda Equina Syndrome• Definitions

– Historically• Bilateral sciatica

– Expanded to include unilateral sciatica• What about a central disc herniation at L5-S1 sparing the

motor and sensory roots of the lower extremities but affecting bowel and/or bladder function?

• The frequency of daily urination is much greater than bowel evacuation, so…

– Presently• Bladder dysfunction with a decrease in perianal sensation

Cauda Equina Syndrome• Etiologies

– Disc herniation– Disc fragment migration– Iatrogenic epidural hematoma

• Post LP or spinal anesthesia• Postoperatively

– Infection– Tumor– Trauma

Cauda Equina Syndrome• Symptoms

– Back pain– Radicular pain

• Bilateral• Unilateral

– Motor loss– Sensory loss– Urinary dysfunction

• Overflow incontinence• Inability to void• Inability to evacuate the bladder completely

– Decrease in perianal sensation

Cauda Equina Syndrome• Avoid the Trap

– Acute central disc herniation at L4-5 or L5-S1• The sacral roots lie centrally within the dural sac• Sparing of the lumbar, and even S1, roots may be

present– Total preservation of leg strength possible– Bowel and bladder may be completely paralyzed– Perineal anesthesia present

• The sacral roots are very delicate– Recovery may not occur, even with relatively expeditious

decompression

Questions• Please give two etiologies of conus

medullaris and/or cauda equina syndrome• Please recall the most common location

for the end of the spinal cord in the adult human