Brown-Sequard syndrome/hemisection of the cord

Central cord syndrome (syringomyelia)

Posterior column syndrome (tabes dorsalis)

Posterolateral cord syndrome (SACDC)

Combined AHC—pyramidal tract syndrome (ALS)

AHC syndrome

Anterior spinal artery occlusion.

Complete Cord Transection

Causes Features

Trauma

Metastatic carcinoma

Multiple sclerosis

Spinal epidural hematoma

Autoimmune disorders

Postvaccinial syndromes

Sensory:

All sensations are affected

Sensory level is usually 2 segments below the level of lesion

Segmental paresthesia occurs at the level of lesion

Motor:

Paraplegia due to corticospinal tract involvement

First spinal shock followed by hypertonic hyperreflexia paraplegia

Loss of abdominal and cremasteric reflexes

At the level of lesion LMN signs occur

Autonomic:

Urinary retention and constipation

Anhidrosis, trophic skin changes, vasomotor instability below the level of lesion

Sexual dysfunction can occur

Brown-Sequard Syndrome

Due to damage to one lateral half of spinal cord.

Causes Features

Caused by extramedullary lesions

Usually caused by penetrating injuries

(gunshot) or tumor

Sensory:

Ipsilateral loss of proprioception due to posterior column involvement

Contralateral loss of pain and temperature due to involvement of lateral

spinothalamic tract 1 or 2 segments below

Motor:

Ipsilateral spastic weakness due to descending corticospinal tract involvement

Lower motor neuron signs at the level of lesion

Central Cord Syndrome

Causes Features

Most common cause is syringomyelia

Other causes are hyperextension, injuries of neck, intramedullary tumors

and trauma

Associated with Arnold Chiari type 1 and 2 and Dandy Walker malformation

Sensory:

Pain and temperature are affected

Touch and proprioception are preserved

Dissociative anesthesia

Shawl like distribution of sensory loss

Motor:

Upper limb weakness > Lower limb

weakness

Other features include:

Horner’s syndrome

Kyphoscoliosis

Sacral sparing

Neuropathic arthropathy of shoulder and

elbow joint

Early bladder involvement (exception—

syringomyelia)

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Posterior Column Syndrome

Cause Features

Occurs due to neurosyphilis, diabetes mellitus Sensory:

Impaired position and vibration sense in lower limb

Sensory ataxia

Positive Romberg’s sign, sink sign and Lhermitte’s sign

Abadie’s sign positive

Urinary incontinence

Absent knee and ankle jerk (areflexia and hypotonia)

Charcot’s joint

Miotic and irregular pupil not reacting to light—Argyll Robertson pupil

Posterolateral Column Disease

Causes Features

Vitamin B12 deficiency

AIDS

HTLV associated myelopathy

Cervical spondylosis

Sensory:

Paresthesia in feet

Loss of proprioception and vibration in legs

Sensory ataxia

Positive Romberg’s sign

Bladder atonia

Motor:

Corticospinal tract involvement—spasticity, hyperreflexia, bilateral Babinski sign

AIDS-associated dementia and spastic bladder is present

HTLV associated myelopathy—slowly progressive paraparesis and an increase in CSF IgG

antibodies to HTLV1

(AIDS: acquired immunodeficiency syndrome; HTLV: human T-cell lymphotropic virus; CSF:

cerebrospinal fluid; IgG: immunoglobulin G)

Anterior Horn Cell Syndromes

Cause Features

Spinal muscular atrophy (SMA) Motor: Weakness, atrophy, and fasciculations

Hypotonia with depressed reflexes

Muscles of trunk and extremities are affected

Sensory system is not affected

Anterior Spinal Artery Syndrome

Cause Features

Occurs due to syphilitic arteritis, aortic dissection, atherosclerosis of aorta,

SLE, AIDS, and AV malformation

Motor:

Flaccid and areflexic paraplegia

Sensory:

Loss of pain and temperature

Preservation of position and vibration

Autonomic:

Urinary incontinence

Spinal cord infarction usually occurs in T1 to

T4 and L1 segment

Abrupt onset, radicular, or girdle pain

Postspinal Artery Syndrome

Cause Features

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Rare Loss of proprioception and vibratory sense

Pain and temperature is preserved

Absence of motor deficit

Anterior Horn Cell and Pyramidal Tract

Cause Features

ALS—amyotrophic lateral sclerosis LMN signs

UMN signs

Sensations preserved

Onuf’s nucleus spared—hence no bladder and bowel involvement

Fig. 6E.8: Spinal cord syndromes 1.

Fig. 6E.9: Spinal cord syndromes 2.

Difference Between Paraplegia in Flexion and Paraplegia in Extension

Features Paraplegia in extension Paraplegia in flexion

Definition Lower limb takes an extension attitude and

extensor muscles are spastic

Lower limb muscles take an attitude of flexion

Pathology Only pyramidal tract involved Both pyramidal and extrapyramidal tract involved (reticulospinal

tracts). Occurs in late stage of paraplegia

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Evolution Early Late

Tone Clasp knife spasticity in extensor group Tone is increased in flexor groups

Deep tendon

reflex (DTR)

Deep tendon reflexes are exaggerated

Clonus may be present

DTR’s are present but diminished

No clonus

Plantar reflex Extensor plantar response Extensor plantar associated with flexor spasm

Mass reflex** Absent Present

Note: **Mass reflex: Any stimulation (scratching of skin) below the level of lesion produces an

interoceptive response resulting in flexor spasms, spontaneous emptying of bowel and bladder, profuse

sweating and piloerection and seminal emission.

Cord Involvement at Multiple Sites

Arachnoiditis (in tubercular, there is patchy involvement)

Neurofibromatosis

Multiple sclerosis

Secondary deposits

Cervical spondylitis.

Causes of Spastic Paraplegia (UMN Type Lesion)

A. Gradual onset

Cerebral causes—parasagittal meningioma, hydrocephalus, etc.

Spinal causes:

Compressive or transverse lesion in the spinal cord

Noncompressive or longitudinal lesion or systemic disease of the spinal cord.

Motor neuron disease (MND), e.g. amyotrophic lateral sclerosis

Multiple sclerosis, Devic’s disease

Friedreich’s ataxia

Subacute combined degeneration (i.e. from vitamin B12 deficiency)

Lathyrism

Syringomyelia

Hereditary spastic paraplegia

Erb’s spastic paraplegia

Tropical spastic paraplegia

Radiation myelopathy.

B. Sudden onset

Cerebral causes—thrombosis of unpaired anterior cerebral artery, superior sagittal sinus thrombosis

Spinal causes:

Compressive causes:

Injury to the spinal cord (fracture-dislocation or collapse of the vertebra)

Prolapsed intervertebral disc

Spinal epidural abscess or hematoma.

Noncompressive causes:

Acute transverse myelitis

Thrombosis of anterior spinal artery

Hematomyelia (from arteriovenous malformation, angiomas, or endarteritis)

Radiation myelopathy electrical injury.

Causes of Flaccid Paraplegia (LMN Type)

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UMN lesion in shock stage, transverse myelitis, spinal injury

Lesion involving anterior horn cells:

Acute anterior poliomyelitis

Progressive muscular atrophy (variety of MND).

Diseases affecting nerve root—tabes dorsalis, radiculitis, Guillain-Barré (GB) syndrome

Diseases affecting peripheral nerves:

Acute infective polyneuropathy (GB syndrome)

High cauda equina syndrome

Disease of peripheral nerves involving both the lower limbs

Lumbar plexus injury (psoas abscess or hematoma).

Diseases affecting myoneural junction:

Myasthenia gravis, Lambert-Eaton syndrome

Periodic paralysis due to hypo- or hyperkalemia.

Diseases affecting muscles—myopathy.

Causes of Quadriplegia

Weakness of all the 4 limbs can occur in the lesions from cortex to C5 level of spinal cord and various

LMN lesion affecting anterior horn cells, roots, peripheral nerve, NM junction, and muscles.

Upper motor neuron causes Lower motor neuron causes

Cerebral palsy

Bilateral brainstem lesion (glioma)

Craniovertebral anomaly

High cervical cord compression

Multiple sclerosis

Motor neuron disease

Acute anterior poliomyelitis

Guillain-Barré syndrome

Peripheral neuropathy

Myopathy or polymyositis

Myasthenia gravis and crisis

Periodic paralysis

Snake bite, organophosphate poisoning, etc.

SPECIFIC LOCALIZING SIGNS AT VARIOUS LEVELS

Features of Cervical Signs at Cord Lesion

In general, cervical cord disorders are best localized by the pattern of weakness that ensues, whereas

sensory deficits have less localizing value.

High cervical cord lesions (lesions above C5) are frequently life threatening, produce quadriplegia and

weakness of diaphragm, the main respiratory muscle innervated by the phrenic nerve (C3-C5).

Extensive lesions near the junction of the cervical cord and medulla are usually fatal owing to

involvement of adjacent medullary centers, which results in vasomotor and respiratory collapse.

Compressive lesions near the foramen magnum may produce weakness of the ipsilateral shoulder

and arm followed by weakness of the ipsilateral leg, then the contralateral leg, and finally the

contralateral arm (cartwheel pattern or Ellsberg phenomenon).

Lesions at C4-C5 produce quadriplegia with preserved respiratory function.

At the midcervical (C5-C6) level, there is relative sparing of shoulder muscles and loss of biceps and

brachioradialis reflexes.

Lesions at C7 spare the biceps but produce weakness of finger and wrist extensors and loss of the

triceps reflex.

Lesions at C8 paralyze finger and wrist flexion, and the finger flexor reflex is lost.

Horner’s syndrome (miosis, ptosis, and facial hypohidrosis) may also occur ipsilateral to cervical

lesions at any level.

Features of Thoracic Cord Lesion

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Lesions of the thoracic cord are best localized by identification of a sensory level on the trunk.

Useful markers in terms of sensory dermatomes are at the nipples (T4), xiphisternum (T6), subcostal

margins (T8), umbilicus (T10), and pubic symphysis (T12)

The abdominal wall musculature, supplied by the lower thoracic nerves is observed during

movements of respiration or coughing or by asking the patient to interlock the fingers behind the head

in the supine position and attempt to sit up.

Lesions at T9-T10 paralyze the lower, but spare the upper, abdominal muscles, resulting in upward

movement of the umbilicus when the abdominal wall contracts (Beevor’s sign) and in loss of lower, but

not upper, superficial abdominal reflexes. With unilateral lesions, attempts to contract the abdominal wall produce movement of the umbilicus to

the normal side; superficial abdominal reflexes are absent on the involved side.

Midline back pain is a useful localizing sign in the thoracic region.

Feature of Lumbar Cord

Effect of various root lesions in lumbar region:

Roots Motor deficit (most rapidly demonstrated)

L2 Hip flexion and thigh adduction

L3 Knee extension and thigh adduction

L4 Inversion of foot

L5 Dorsiflexion to toes and foot

S1 Plantar flexion and eversion of foot

Lesions at L2-L4 paralyze flexion and abduction of the thigh, weaken leg extension at the knee, and

abolish the patellar reflex.

Lesions at L5-S1 paralyze movements of the foot and ankle, flexion at the knee, and extension of the

thigh, and abolish the ankle jerk (S1).

A cutaneous reflex useful in localization of lumbar cord disease is the cremasteric reflex, which is

segmentally innervated at L1-L2.

Features of Sacral Cord/Conus Medullaris

The conus medullaris is the tapered caudal termination of the spinal cord, comprising the lower sacral

and single coccygeal segments. Isolated lesions of the conus medullaris spare motor and reflex

functions in the legs.

The Conus Syndrome (Fig. 6E.10)

Bilateral saddle anesthesia (S3-S5), prominent bladder and bowel dysfunction (urinary retention and

incontinence with lax anal tone), and impotence

The bulbocavernous (S2-S4) and anal (S4-S5) reflexes are absent

Muscle strength is largely preserved.

Cauda Equina Syndrome—Asymmetric, Atrophic, and Areflexic Paralysis of Lower Limbs (Fig.

6E.10)

The cluster of nerves derived from the lower cord as they descend to their exits in the intervertebral

foramina (L2-3 to coccygeal nerve roots).

Cauda equina lesions are characterized by severe low back or radicular pain, asymmetric leg

weakness or sensory loss, variable areflexia in the lower extremities, and relative sparing of bowel

and bladder function.

Mass lesions in the lower spinal canal may produce mixed clinical picture in which elements of both

cauda equina and conus medullaris syndromes coexist.

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Fig. 6E.10: Conus-cauda equina syndrome.

Conus medullaris syndrome (S2-4) Cauda equina syndrome (L3 root and

below)

Presentation Sudden and bilateral Gradual and unilateral

Reflexes Knee jerk is preserved but ankle jerk is affected Both knee and ankle jerks are affected

Radicular pain Less severe More severe

Low back pain More Less

Sensory

symptoms and

sings

Numbness is symmetrical and bilateral, sensory

dissociation occurs, saddle anesthesia present

Numbness is asymmetrical, may be

unilateral, no necessary dissociation

Motor strength Typically symmetric hyperreflexia, distal paresis of lower

limbs

Asymmetric areflexic paraplegia

Impotence Frequent Less frequent

Sphincter

dysfunction

Overflow urinary incontinence and fecal incontinence, tend

to present early in course of disease

Urinary retention tends to present late in

course of disease

Trophic changes Common Less marked

Epiconus: Lesion of lumbar cord at the level of L4-S2 characterized by a flaccid paralysis of legs (only

the roots are affected causing peripheral paralysis, i.e. distal paraplegia). Reflex but not conscious

evacuation of the bladder is present, and rectum is preserved. Sexual potency is lost.

What are the Different Types of Spinal Pain?

Radicular pain is characterized as a unilateral, lancinating, dermatomal pain often exacerbated by

cough, sneeze, or Valsalva’s maneuver. Radicular pain is common with extradural growths and rare

with intramedullary lesions. An example of an extramedullary tumor causing radicular pain is the

neurilemmoma (usually an intradural extramedullary lesion).

Vertebral pain is characterized by an aching pain localized to the point of the spine involved in the

compressive process and often accompanied by point tenderness. Spinal pain is common with

neoplastic or inflammatory extradural lesions and infrequent with intramedullary or intradural

extramedullary lesions.

Funicular (central) pain is common with intramedullary lesions and very unusual with extradural

lesions. It is described as deep, ill-defined painful dysesthesias, usually distant from the affected

spinal cord level (and therefore of poor localizing value), probably related to dysfunction of the

spinothalamic tract or posterior columns.

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