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TOPIC 35. Congenital defects of the spine and spinal cord.
Syringomyelia.
Topic questionsI. Craniovertebral anomalies1. Dandy-Walker
syndrome2. Chiari syndrome* Malformation type I* Malformation type
II
II. Anomalies and secondary spinal deformityKlippel Feil
syndrome
III. Spine and spinal cord dysraphia, spinal hernias1. Spinal
dysraphia2. Spine and spinal cord dysraphia* Spina bifida occulta*
Full rahiskhizis* Spina bifida anterior* Spina bifida complicata*
Spinal hernias
IV. Syringomyelia1. Pathology2. Pathogenesis3. Classification4.
Clinic5. Diagnostics6. Treatment7. Forecast
Terms definition:
Atlas assimilation - a partial orcomplete fusion of the
cervicalvertebrae and I occipital bone of theskull, which may not
be accompaniedby clinically significant impairment,while in other
cases leads tocompression of the craniovertebralstructures (upper
cervical spinal cordand medulla oblongata), limiting theupper
cervical spine mobility, spineinstability and lower cervical
spinesegments development.
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Basilar impression - funnelimpression in the occipital
Blumenbachstingray, occipital-vertebral joints andthe foramen
magnum, in which there issome replacement of the spine in
thecranial direction with decreasing of theposterior fossa size, II
cervical vertebraodontoid bone is higher than normal -at foramen
magnum or even includedin the cranial cavity. Basilar impression -
lower
stingray divisions, anterior divisions ofthe I and odontoid bone
of II cervicalvertebra introduction into the cranialcavity, (MRI,
T1-weighted image)
Hydromyelia - expansion of thespinal cord central canal, the
cause ofwhich can be the channel congenitalanomaly, usually
observedsimultaneously with spina bifida andhydrocephalus internus,
or secondarydeveloping in vivo because of variouspathological
conditions (compressionof the spinal cord, cerebellar tumor)when an
excessive amount of fluid canstretch central channel.
Cavernous hemangioma of thethoracic spinal cord, hydromyelia
Platybasia - interrelationchanges between the skull base
bonesand the upper cervical vertebrae, whichis characterized by an
increase inbasilar skull angle, ie the anglebetween the planum
sphenoideum andBlumenbach stingray, which normallyranges from 135
to 143 .
The angle between lines drawnon the base of the anterior cranial
fossaand stingray is typically less than orequal to 105 (a).
Increasing this angleover 105 is called platybasia (b)
Chiromegaly - excessive length of the upper extremities with an
increase ofthe hands and fingers.
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Status dysraphicus includesthose anomalies of the
anatomicalstructure of the human body that can bedetected at birth
or in early childhood,which may increase with age ordisappear:
chonechondrosternon orfunnel chest, kyphoscoliosis,lengthening or
shortening of the upperlimbs, peculiar bending of the
fingers("monkey 's paw"), various size andlocation of the breasts,
sensitivitydisorders, often segmental type,acrocyanosis,
bedwetting, mainly incombination with spina bifida, and anumber of
degenerative signs (highpalate, abnormal body hairing,abnormal
teeth development).
Chonechondrosternon
Kyphoscoliosis
Syringomyelia - a cavity in thespinal cord.
Synostosis - continuousconnection between bones.Pathological
synostosis are formed inunusual place and can lead to
seriousillness: craniostenosis, congenitalradioulnar synostosis,
foot little fingerjoint, wrist, vertebrae blocking, etc.
Multiple synostosis of the cranialsutures with the tower
skulldevelopment (oxycephaly)
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Meningocele - spinal or craniocele at which hernia consisting of
skinnedmodified arachnoid and pia mater, filled with cerebrospinal
fluid, protrudes throughthe bone defect.
I. Craniovertebral anomalies are characterized by defects of the
occipitalbone and structures located in the posterior fossa and
upper spine and spinal corddevelopment.
1. Dandy-Walker syndrome is a congenital malformation of the
trunk andcaudal cerebellar vermis, leading to incomplete IV
ventricle median (Magendie) andlateral (Luschka's) apertures
disclosure. Is manifested with hydrocephalus and oftenhydromyelia
signs. The last one can cause the development of
syringomyelia,syringobulbia in accordance with the hydrodynamic
Gardner theory. Gardner theory:due to Magendie hole incomplete
disclosure CSF pressure is higher in the ventricularsystem of the
brain, which contributes to reduced drainage and expansion of
thespinal cord central canal and hydromyelia development
accompanied by degenerativechanges in central gray matter of the
channel wich is adjacent to the expansion.Dandy-Walker syndrome is
characterized by functional insufficiency of thecerebellum and the
medulla oblongata manifestations, the symptoms ofhydrocephalus,
intracranial hypertension.
Fig. 1. MRI of a patient withDandy-Walker syndrome.
Cystoidmasses in the posterior fossa,hypoplasia of the cerebellar,
tentoriumcerebellum high standing.
Diagnostics - CT and MRI studies. Signs of hydrocephalus are
revealed,pronounced particularly with widening of the brain IV
ventricle, MRI can detectdeformation of these brain structures.
2. Arnold-Chiari anomaly - a congenital abnormality of
hindbraindevelopment been the posterior fossa and this area brain
structures size discrepancy,wich leads to the the brain stem and
cerebellar tonsils omission into the foramenmagnum and their denial
at this level.
There are 4 types of Chiari malformation.Chiari malformation I
(adult type) (Fig. 2.) The most common form of
cerebellar abnormalities. This symptom is a mono- or bilateral
ptosis of the cerebellartonsils through the foramen magnum into the
spinal canal (the tonsils, the lower partof the cerebellum,
normally located above the foramen magnum). The most
importantfactor is the fact that the clinical manifestations appear
only on the 3 - 4th life decade,being a random finding on MRI.
Clinic: headache, neck pain, weakness, numbness of the hands,
loss of pain andtemperature sensitivity in them, staggering,
dizziness, "beating down nystagmus".
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Fig. 2. Anomaly Chiari type 1.Amygdala I omitted to
cervicalvertebra: MRI T2-weighted image
Chiari malformation II (children type) (Fig. 3.). Consists of
not only thecerebellum and brain stem displacement through the
foramen magnum but also theIV ventricle. Characteristic features -
the presence of meningomyelocele in thelumbar region. Neurological
defects occur on the background of the occipital boneand cervical
spine abnormalities. There is always a hydrocephalus, often
cerebralaqueduct stenosis. Neurological symptoms are present at
birth.
The typical clinical picture: pain in the nape area aggravated
by coughing,sneezing, fainting, dizziness, blurred vision,
decreased pain and temperaturesensitivity, as well as muscle
strength in the upper extremities, spasticity of the upperand lower
extremities. Sometimes episodes of apnea join (cessation of
breathing for ashort period), the weakening of gag reflex,
involuntary rapid eye movements.
Fig. 3. Anomaly Chiari type 2.MRI, T1-weighted image. The
brainstem and cerebellum are displacedcaudally, IV ventricle
compressed atcraniovertebral junction, hardlydifferentiated, also
cerebrospinal herniais determined at upper thoracic leveland
syringomyelia (below)
Chiari malformation II is the cerebellum part and brain stem
with meningesshifting into the meningocele, located in the nape
area.
When Chiari malformation IV hypoplasia of the cerebellum is
marked andcaused its total hernia; cerebellum can not be
distinguished. Chiari malformation typeIII and IV are found only
rarely.
The pathogenesis of the disease is not completely established.
In all likelihood,there are three pathogenetic factors: (1) due to
congenital hereditary osteoneuropaty,(2) traumatic lesions of
sphenoid - ethmoid and sphenoid - occipital part of the rampdue to
birth trauma, (3) hydrodynamic liquor shock into the wall of the
spinal cordcentral canal.
Diagnosis: MRI of the brain, cervical and thoracic spinal cord
(forsyringomyelia exceptions). Ultrasound diagnosis of
Arnold-Chiari anomaly in thefetus is available.
Treatment. When "asymptomatic variant" dynamic monitoring with
annualsurvey is performed. If low intensity pain is the only
symptom, conservative therapy
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is used for the treatment: the use of nonsteroidal
anti-inflammatory drugs and musclerelaxants. If there is
neurological deficit (numbness, paresis, etc.) the
surgicaltreatment is performed ( laminectomy, expanding the foramen
magnum, etc.). Insome cases the final diagnosis is established
during surgical revision. The goal ofsurgery is to eliminate nerve
structures compression and cerebrospinal fluid
currentnormalization, for which an increase of the posterior
cranial fossa is performed.
II. Anomalies and secondary spinal deformityKlippel - Feil
syndrome (short neck) is a cervical vertebrae congenital
anomalies and fusion. It can be the cervical vertebrae
incomplete differentiation andreducing of their number, sometimes
their number is no more than four. The clinicalpicture is
characterized by a triad: short neck ("the man with no neck", "frog
neck"),low hairline at the neck, a significant limitation of the
head mobility. In severe cases,the chin rests to the sternum,
earlobes relate to shoulder girdle, sometimes - the foldsof skin
come from the ears to the shoulders (Fig. 4.). The syndrome may
occur inconjunction with other cervical congenital abnormalities;
for example, the basilarimpression and atlanto - occipital fusion.
In addition, there may be scoliosis, facialasymmetry, torticollis
(a neck strain, characterized by the head inclination to
theaffected side, and face turn in a healthy side), wrinkling of
the neck skin, synkinesias(mirror movements, mainly in hands, but
sometimes in whole hand) and lessfrequently facial muscles
paralyzes, ptosis, cleft or high palate. Systemic
congenitalanomalies are also possible: the genitourinary system
(eg, unilateral absence ofkidney), cardiovascular, central nervous
system, deafness due to defects of the innerear bones development.
According to the radiographic studies there are two forms
ofKlippel- Feil syndrome: 1) atlas is fused with other cervical
vertebrae, the totalnumber of which is reduced in this connection,
there are usually no more than 4 ofthem; 2) cervical vertebrae
synostosis, the height of their bodies reduced. Oftencombined with
platybasia.
Fig. 4. Klippel-Feil syndrome
III. Spine and spinal cord dysraphia, spinal hernias1. Spinal
dysraphia is a malformation associated with tissues of
mesodermal
and ectodermal origin incomplete closure along the median suture
(from the Greek.Rhaphe seam) - midline of the spine. Manifestations
of spinal dysraphias aresplitting arches of the vertebrae (spina
bifida) and soft tissue located sagittally, aswell as different
variants of spinal hernias emerging, sometimes dermoid cyst
(cystcontaining hair, hair follicles and sebaceous glands), lipoma,
a syndrome of "hard"end filament.
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2. Spine and spinal cord dysraphia (Fig. 5.) There are following
optionsdepending on their degree of underdevelopment: 1) spina
bifida occulta; 2) spinabifida complicata; 3) spina bifida
anterior; 4) spinal hernias: meningocele,meningoradikulocele ,
myelomeningocele mielotsistotsele ; 5) rahiskhizis partial
andfull.
Fig. 5. Spine and spinal cord dysraphia* Hidden spina bifida -
spina bifida occulta (from Lat. Spina - awn, bifidus -
split in half). The most common form of the spine anomalies -
the splitting ofvertebrae arches (spina bifida occulta). There can
be 1-2 cleft vertebra, but sometimesmost of them are cleft. Cleft
arcs ends are often pressed into the lumen of the spinalcanal and
cause compression of the dura mater, subdural space and cauda
equinaroots, while the bone defect which is covered with soft
tissue is intact. This form ofanomalies is detected during
spondylography, usually on low-lumbar upper-sacrallevels. Retracted
and atrophied skin sometimes is marked in the area of arc
splitting,tissue swelling, scarring, pigmentation, hypertrichosis
is also possible.
* Full rahiskhizis - severe dysraphia manifested not only by
splitting arcs andthe vertebral bodies, but also the adjoining soft
tissue. spinal cord can be seenthrough a cleft in the soft tissues
immediately after birth. Hernial protrusion is absent.Vertebral
bodies can coalesce in the ventral cleft. Malformations of other
vertebrae,ribs are possible.
* Spina bifida anterior - cleft of the vertebral bodies. It is
mainly a randomfinding on spondylograms, but can be combined with
other developmental defects.
* Spina bifida complicata - cleft of the vertebral arches in
combination withtumor-like growths, representing only by fat or
fibrous tissue beneath the skin andfilling vertebrae arcs bone
defects, growing together with meninges, roots and thespinal cord.
It is often localized on the lumbosacral level of the spinal
column.
* Spinal hernia, arising from vertebrae cleft arches and the
soft tissuessplitting, are congenital hernial protrusion of the
spinal canal contents: meningocele -hernial protrusion of the
meninges, filled with CSF; meningoradikulocele - hernia,consisting
of the meninges, spinal roots and CSF; mieloradikulomeningocele -
hernia,including the structure of the spinal cord, spinal roots,
meninges and cerebrospinalfluid; myelocystocele - hernial sac
containing a portion of the spinal cord with signshydromyelia (Fig.
6, 7.).
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Fig. 6. Types of spinal herniasA - Meningocele,B, C -
Myelocystocele
B C
Fig. 7. Localization of spinalhernias
a - typical localization; b - nontypical localization (in
thoracic); c -giant spinal hernia; d - rahiskhizis,lower
paraplegia
Diagnostics. Diagnosis is not difficult when spinal hernia.
Neurological statusstudy can tell about hernia sac contents.
Precise diagnosis can be achieved byperformaing spondylography and
MRI studies.
Only surgical treatment is possible possible.IV. Syringomyelia -
a chronic, slowly progressing disease of the young and
middle age, which is based on the cavities in the spinal cord
formation, mainly at thecervical enlargement level.
1. Pathomorphology. At syringomyelia spinal cord is deformed in
theanteroposterior direction. Cavities of different diameters
(1-1.5 cm and barelynoticeable) are visible on cross sections in
most cases.
They are located in the central channel, distributes in the side
sections to theposterior horns of the spinal cord. In the case of
the large cavities formation spinalcord is compressed to narrow
plate that surrounds syringomyelitic cavity, if smallercavities
than spinal cord is deformed, asymmetric. Posterior horns and
posterior cordsare often deformated. Sometimes cavity revealed only
in the spinal cord lateralfuniculus, and the center channel is of
normal size or absent (Fig. 8.).
Fig. 8. Spinal cordA - with syringomyelitic cavityB - normal
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B2. Pathogenesis. Dysonthogenetic theory links the gliosis
occurrence and the
pathological cavities in the spinal cord tissue formation with
embryonic developmentviolation in the early stages (3-6 week) and
is due to incomplete or incorrect closureof neural tube with
violation of posterior suture formation (dysraphia) which leadsnot
only to the spinal cord central channel expansion with diverticula
formation, butalso to the fetal tissue accumulation behind the
central channel.
Hydrodynamic theory. Increased production of cerebrospinal
fluid, which isnormal in the first 6-8 weeks of embryonic
development, increases its pressure in theneural tube , which leads
to the Magendie and Luschka holes opening, ie, there is aconnection
with the ventricular system and subarachnoid space and central
channelobliteration. In the case of draining holes stenosis or
occlusion cerebrospinal fluidgoes into the central channel under
pressure, extends it and forms a cavity.
Arnold-Chiari anomaly is combined with syringomyelia in 40% of
casesbecause of onthogenesis pathology.
Malformations of the spinal cord may also be accompanied with
other organsand tissues impaired development. These are manifested
signs of dysraphic status(Fig. 9.). These include malformations of
the skin, muscles, bones, internal organs,the nervous system: spine
curvature, funnel sternum, deformity of the hands and feet,extra
nipples, vertical crease between the eyebrows, split tip of the
tongue and upperlip, high palate, dental anomalies, excessive hair
growth, facial asymmetry, eyelidhypertrophy, akromegaloid features,
short neck, enuresis, short stature, long arms, etc.
Fig. 9. Deformation of the upperlimbs when dysraphic status
However, unlike true syringomyelia, various necrotic, and
ischemic adhesionscan lead to gliomatosis with cavities formation
that is called secondary syringomyelia.It is possible after
hemorrhachis (hemorrhage into the spinal cord), spinal cord
injury,necrotizing myelitis, a spinal cord benign tumor, etc.
3 . Classification:1. According etiologic and pathogenetic
mechanisms: Idiopathic (true); secondary.2. Syringomyelitic process
localization: spinal (cervical-thoracic, cervical, thoracic,
lumbar, sacral, total); stem; spinal stem.3. According to clinical
manifestations: posterior horns; anterior horns;
vegetative-trophic;
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mixed; bulbar.4. Clinic. Syringomyelia is a classic version of
the gray matter entire lesion at
the level of the cervical-thoracic spinal cord. This presupposes
the development of atypical triad of symptoms:
1. Sensitive violations: segmental dissociated posterior horns -
type ofsensitivity violations.
2. Movement disorders: peripheral (flaccid, atrophic) upper
limbs paresis.3. Autonomic dysfunction: trophic and
vascular.Sensory disorders are the main characteristic of the
disease. This type of
violation is also called "syringomyelitic". It is characterized
by pain and temperaturesensitivity loss while maintaining the
tactile and musculoarticular on the upper limbsand upper torso
("jacket type") (Fig. 10.) .
Fig. 10. Loss of pain andtemperature sensitivity atsyringomyelia
as a "jacket" whencavities are formated at the cervical,thoracic
segments of the spinal cordand brainstem.
Sometimes the first time patients go to a surgeon or
traumatologistcomplaining about painless chronic wounds, burns.
Deep pain of different locations is common. It has a nagging,
unscrewscharacter, sometimes accompanied by paresthesias, often
with hyperpathiccomponent. Pain may occur long before any objective
evidence of disease.
Movement disorders in the upper extremities are represented by
sluggish,atrophic paresis appearing, which are located mainly in
the distal parts. They arecharacterized by small muscles of the
hand malnutrition with the formation of"clawed hand" or "monkey's
paw". Fibrillary twitching are observed in atrophicmuscles. Tendon
and periosteal reflexes are reduced or absent.
With the defeat spreading to the lateral spinal cords there are
signs ofconducting motor and sensation pathways vilation. Spastic
paraparesis of feet appears,conductor sensitivity violation.
Quite rare is lumbosacral form of the disease, which is
characterized by thesame sensory and motor violation of the lower
extremities.
Syringomyelia often accompanies syringobulbia, which may be an
independentmanifestation of the disease. Thus the cavity formed in
the medulla oblongata and / orvarolevom bridge. V, VII, VIII, IX,
X, XII cranial nerves nuclei are affected. In thiscase, patients
have facial pain, temperature and pain hypoesthesia on the face
inZelder areas while maintaining tactile sense, peripheral paresis
of the facial muscles,hearing loss is detected, nystagmus, bulbar
syndrome: dysphonia, dysphagia,dysarthria, tongue atrophy appears,
fibrillar twitching in its muscles.
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Vegetative-trophic disorders are extremely polymorphic. This may
be aviolation of sweating, hyperhydrosis manifests itself (less
anhidrosis) on the face,upper limbs, trunk. Peripheral circulatory
disorders are also possible that manifestlike hyperemia,
acrocyanosis. Over time, vegetative-trophic disorders
increase.Appears dry, flaky skin, hyperkeratosis with deep cracks
or sores that do not heal,there may be hypo-or hyperpigmentation,
eczematous processes. Nail changes aremarked that are easy to
crumble, break. Trophic disorders of osteoarticular system
ismanifested: kyphoscoliosis of the thoracic spine, arthrosis,
osteoarthropathy,pathological dislocation of joints, chiromegaly
(increasing of hands and fingers of theupper extremities). The
disease is often accompanied by stomach ulcer, myocardialhypoxia,
failure of the pituitary-adrenal system, sexual dysfunction.
5. Diagnostics. The most informative method is the MRI study:
typically thereare increasing in spinal cord diameter, presence of
cysts filled with cerebrospinalfluid, which are often localized in
the thoracic and cervical spine. Increased cysticformations in some
cases leads to the development of spinal deformities, such
asscoliosis (Fig. 11.).
Fig. 11. Syringomyelitic cavityat MRI examination
6. Treatment. Surgery. Indications for neurosurgical treatment
are: rapidprogression of the disease, liquorodynamic violations
increasing, craniovertebralanomalies. The surgery means withdrawal
of cerebrospinal fluid in the other cavitiesand craniovertebral
junction decompression.
7. Forecast for life is relatively favorable, for recovery is
unfavorable
III.Spineandspinalcord1.Spinal2.Spineandspinalcord*Spinabifidaocculta*Fullrahiskhizis*Spinabifidaanterior*Spinabifidacomplicata*SpinalherniasIV.Syringomyelia1.Pathology2.Pathogenesis3.Classification4.Clinic5.Diagnostics6.Treatment7.Forecast