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.

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.

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)

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".

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

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.

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.).

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

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;

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.

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