This document discusses diseases affecting the spinal cord (myelopathy). It begins by describing the anatomy of the spinal cord and defines myelopathy as any lesion involving the spinal cord. It then outlines the major sensory and motor pathways in the spinal cord. The main clinical syndromes of spinal cord disease discussed are paraparesis, tetraparesis, and Brown-Sequard syndrome. Causes of spinal cord disease mentioned include transection, compression, and disc protrusion. Signs of upper and lower motor neuron lesions are defined. The document concludes by providing overviews of multiple sclerosis and amyotrophic lateral sclerosis, including their pathophysiology, clinical signs, and subtypes.
2. INTRODUCTION
⢠The spinal cord extends from the top of the C1
vertebra to the bottom of the body of the L1
⢠There is an expansion in the diameter of the cord
in the cervical & lumbar region (increase number
of AHC to arms and legs)
⢠The spinal cord, cauda equina and filum
terminale down to S2 level, surrounded by thick
covering of duramater
⢠Any lesion involving the spinal cord result a
syndrome called a âmyelopathyâ
3. THE MAJOR PATHWAYS WITHIN SPINAL CORD
⢠Sensory pathways
oAntero-lateral system, dorsum
column (medial lemniscal)
ďźTouch, vibration, pain, itch,
temperature
⢠Motor pathways
ďźThe axons in the tracts enter the
anterior horn of the spinal cord
and synapse on the lower motor
neuron cell body
4. THE CLINICAL SYNDROMES OF SPINAL CORD
DISEASE
⢠There are tree main motor syndromes associated with spinal cord disease
ďźParaparesis (UMN involvement of legs only)
ďźTetraparesis (UMN involvement of all four limbs)
ďźBrown-Sequard syndrome (Unilateral lesion causing UMN involvement of
one side)
Paralysis is the complete loss of voluntary movement
The words âplegiaâ âpalsyâ and âparesisâ are sometimes used
interchangeably to describe weakness
Paresis is the correct term to describe incomplete paralysis, Plegia means
complete paralysis and Palsy used when the paralysis affects cranial motor
nerve (bellâs palsy, pseudobulbar palsy) or a static weakness (cerebral palsy)
5. PARAPARESIS (SPASTIC PARAPARESIS OR
PARAPLEGIA)
⢠Paraparesis indicates bilateral UMN
damage involving the axons that
innervate the legs from both
corticospinal tracts
⢠The clinical signs include :
ďźIncreased tone with spasticity
ďźIncreased reflexes with clonus
ďźExtensor plantar response (Babinski
sign)
ďźSphincter dysfunction
6. TETRAPARESIS (SPASTIC TETRAPARESIS,
TETRAPLEGIA, QUADRIPARESIS, QUADRIPLEGIA)
⢠Spastic tetraparesis produces the
same clinical picture as paraparesis
but involves both arms and legs
⢠It is usually caused by lesion in the
high cervical cord, occasionally due to
brainstem
7. BROWN SEQUARD SYNDROME (UNILATERAL CORD LESION)
⢠Brown Sequard syndrome is rare in its pure form but partial forms
are more common
⢠The pure brown Sequard syndrome clinical picture consist of :
⢠Ipsilateral spastic leg and sometimes arm if the lesion above C5,
with bisk reflexes and an extensor plantar response
⢠Ipsilateral loss of joint position sense and vibration or touch (dorsal
column), contralateral loss of pain and temperature
o Pain fibers ascend a few spinal segments before entering the dorsal horn
to synapse
o If the lesion damages the anterior horn cell as well as the white matter
tracts then the patient will have UMN signs below the level of the lesion
and LMN signs at and about the level of the lesion
8.
9. CAUSE OF SPINAL CORD DISEASE
⢠Transection of the cord
⢠Usually the result of trauma following anterior dislocation of one
vertebra on another
⢠It causes loss of all motor, sensory and autonomic functions
⢠If transection is complete often include sphincter dysfunction
⢠With any severe acute spinal cord lesion there are two clinical stages:
⢠Spinal shock : loss of all reflex activity below the level of lesion,
flaccid limbs, atonic bladder with incontinence, atonic bowel, loss of
genital reflexes and vasomotor control
⢠Heightened reflex activity : after 1-2 weeks associated with spasticity
of the limbs, brisk reflexes and extensor plantar response, spastic
bladder and hyperactive autonomic function (sweating)
10. SPINAL CORD COMPRESSION
⢠The clinical feature is determined by the site of
compression
⢠Lesion affecting the cord below T1 will not involve the
arms
⢠Lesion between C5 and T1 cause LMN and sometime
UMN signs in the arm and UMN signs in the legs
⢠Lesion above C5 cause UMN signs in the arms and legs
⢠Compressive lesions may spare sphincter function until
the patient has severe disease
11. DISC PROTRUSION
⢠The most common cause of disc disease is spondylosis (degenerative
change)
⢠Damaged disc usually protrude laterally and cause compression of
the nerve roots (LMN)
⢠However disc can protrude centrally or posteriorly, when it occurs
above the level L1 causes spastic paraparesis or tetraparesis at
high cervical level
⢠When central disc protrusion occurs below L1 level, the cauda
equina will be affected and the patient will have LMN syndrome
affecting the leg and bladder
18. UPPER MOTOR NEURON LESION
⢠Increased tone (spasticity)
⢠Pyramidal-pattern weakness
ďźThe anti gravity muscle are preferentially spared and
stronger (flexors of the upper limbs and extensors of the
lower limbs)
⢠Absence of muscle wasting and fasciculations (focal muscle
wasting and fasculations are features of LMN lesion)
⢠Brisk tendon reflexes and extensor plantar response
(Babinski sign)
19. MULTIPLE SCLEROSIS
⢠Multiple sclerosis (MS) is a progressive demyelinating and
neurodegenerative disease of the central nervous system (CNS)
which gradually results in severe neurological deficits.
⢠MS is thought to involve an interplay between genetic and
environmental factors, which result in an immunologically
mediated inflammatory response within the CNS
20. PATOPHYSIOLOGY
⢠Demyelination is a disintegration
of the myelin sheath caused by an
inflammatory and destructive
process, the axon being partly or
completely denuded
⢠Destruction of the myelin sheath
disrupts the normal transmission
of nerve impulses resulting in
neurological signs and symptoms
The immune system causes inflammation that
damages myelin
21. PATOPHYSIOLOGY
⢠The most common sites of MS lesion are in the greyâwhite matter in the
cerebrum, the periventricular region, cerebellar white matter, optic
nerves and cervical portion of the spinal cord and brainstem, but the
disease can involve any part of the CNS
⢠Until recently MS had been widely considered as a disease of âwhite
matterâ of the CNS
22. CLINICAL SIGNS
⢠The pattern of symptoms of MS is complex, variable and unpredictable
⢠People with MS who suffer from loss of muscle activation
⢠Spasticity (along with fatigue and weakness) is one of the three most
common physical signs and symptoms experienced by MS patients
⢠Altered sensation occurs at some stage in almost every individual with
MS. Sensory symptoms, such as paraesthesia of a limb or of the face,
with numbness, tingling or burning
⢠The involvement of the visual pathways is very common, the episodic
visual blurring so often described by patients
⢠Acute vestibular symptoms with severe positional vertigo (an illusion of
movement in the personâs relationship with the environment)
23. The disease can be divided into four clinical
subtypes
⢠Relapsing-remitting MS (RRMS) is the most common subtype, affecting 85%
of people with MS and is characterized by short attacks to the CNS followed
by a complete or partial return to normal functioning
⢠Secondary-progressive MS (SPMS) is a subgroup that begins as a relapsing-
remitting course accompanied by a steady decline in function and is often
developed by patient
⢠Primary-Progressive MS (PPMS) is a progression of the disease where a
steady decline in function experienced from the onset of the disease
⢠Progressive-Relapsing MS (PRMS) is similar to PPMS but has the additional
characteristic of acute attacks
24.
25. AMYOTROPHIC LATERAL SCLEROSIS
⢠Progressive nervous system disease that affects nerve cells in the
brain and spinal cord, causing loss of muscle control
⢠The disease is progressive, meaning the symptoms get worse over
time
⢠In ALS, both the upper motor neurons and the lower motor neurons
degenerate or die, and stop sending messages to the muscles
⢠Unable to function, the muscles gradually weaken, start to twitch
(called fasciculations), and waste away (atrophy), eventually, the
brain loses its ability to initiate and control voluntary movements
26. CLINICAL SIGNS
⢠Fasciculations (muscle twitches) in the arm, leg, shoulder, or tongue
⢠Muscle cramps
⢠Tight and stiff muscles (spasticity)
⢠Muscle weakness affecting an arm, a leg, neck or diaphragm
⢠Slurred and nasal speech
⢠Difficulty chewing or swallowing
⢠For many individuals the first sign of ALS may appear in the hand or
arm as they experience difficulty with simple tasks such as buttoning
a shirt, writing, or turning a key in a lock