Spinal Cord Disease and myopathies
Intrinsic Spinal cord disease (Myelopathies)
- Suspect when there are bilateral signs involving arms and legs
- The cord lies within the spinal canal surrounded by the Vertebral bodies : Cervical 7 Thoracic 12 Lumbar 5 Sacral 1
- Spinal nerves 31 in total : Cervical 8 Thoracic 12 Lumbar 5 Sacral 5 Coccygeal 1 ????
- First 7 cervical nerves roots exit above their reference vertebrae, the rest below
- The nerve roots exit via several levels below through the intervertebral foramina where they are formed due to vertebrae outgrowing the cord
- Notes that the spinal cord level does not equal that of the vertebral level indeed
- The cord is much shorter than the space
- Below L1 lies the cauda equina made of of motor and sensory roots
- Spinal cord runs from the foramen magnum to the lower border of L
- The cord is thicker at cervical and lumbar regions where fibres pass to/from arms and legs and so more vulnerable to compression
- Below that the remaining lower motor neurone fibres form the cauda equina and are susceptible to compression with extrinsic lesions that impinge on the space below L
- Intrinsic vascular and neoplastic lesions can also cause cord compression
- The common feature is the presence of neurological signs and symptoms in both legs and /or arms
- Look for a sensory level staring distally and moving up legs and trunk
- Document reflexes and plantars
- C5: Biceps - Shoulder tip, Shoulder abduction
- C6: Biceps, Brachioradialis, Sensory Lateral arm and forearm, Motor Elbow flexion
- C7: Triceps, Dorsal arm and forearm and middle finger, Elbow extension
- C8: Finger flexion, Sensory Medial forearm, little finger, Finger flexion
- L3: Adductor, patellar, Sensory Anterior and medial thigh, Thigh adduction
- L4: Patellar, sensory Medial leg. Patellar
- L5: Hamstring, sensory Lateral calf and leg. Ankle dorsiflexion
- S1: Achilles
- Posterior calf and sole of foot. Ankle plantar flexion
- S4,5: Anal - sensory Saddle distribution around anus. Anal reflex
- Lesion at C4-C5 : Complete quadriplegia and some diaphragm weakness
- Lesion below T1 - normal Upper limb function and bilateral lower limb weakness
- At C7 level the roots to T1 are formed and exit
- At T10 level the roots to T12 are formed exit
- At L1 the roots to S1 are formed and exit.
- This should immediately suggest cord disease and the next question is to determine at what level of the cord.
- Back pain if present may help to identify the level of disease.
- MRI is the imaging strategy of choice In practice the whole cord should be imaged as there are often additional metastases or disease present at other sites.
- Other more medical diseases to consider are B12 deficiency, transverse myelitis and vascular events.
- MRI is the gold standard nowadays and has replaced myelography
- Newer CT imaging has improved and may be useful when MR not possible or unavailable
- Plain X-Ray films should also be considered
- If there is no evidence of cord compression then consider CSF analysis (MS), EMG (Motor neurone disease, B12 levels etc
- In the differential diagnosis of spastic paraparesis - don't the rare parasagittal meningioma or motor neurone disease
- However most of the time bilateral weak legs is a cord problem or below
- Brain imaging is still however useful as other lesions may exist e.g. MS, ADEM, metastases
- Skin care - needs to be inspected as patient unaware to prevent pressure ulcers and problems.
- Passive movement of limbs to prevent contractures and joint stiffness
- TED stockings and LMWH to prevent DVT/PE
- Urinary catheterisation to prevent retention initially
- May use reflex bladder drainage and conveen or intermittent self catheterisation
- Hydration and fluids.
- Dietary fibre, laxatives and suppositories and manual evacuation to manage bowels
- Avoid weight gain.
- Spasticity - often variable and baclofen can be useful
- Sexual dysfunction often difficult to improve though fertility preserved
- Expert help
- Long term mobility aids and wheelchair.
- OT assessment and equipment to help at home
- House adaptation
- Access to respite care
Spinal Cord Compression
- Cervical spondylosis
- Vertebral body collapse (tumour, rarely osteoporosis)
- Central Disc prolapsed
- Abscess - TB, Haematoma (trauma, warfarin, haemophila, LP)
- Paget's disease, Cervical stenosis
- Neurofibromas, Meningiomas, Gliomas, Ependymomas
- Localised back pain is a useful sign
- Bilateral UMN loss - spastic paraparesis however initially may be flaccid weakness
- Loss of bowel and bladder and sexual function
- Sensory level below lesion
- Loss of autonomic supply
- Priapism may be initial finding due to loss of inhibition from higher centres
- All modalities are on the same side as their motor/sensory except spinothalamic pain and temperature
- Incomplete cord compression can give any variation of above
- MRI is modality of choice and important to view whole cord as metasynchronous lesions may be found
- Look for tumours of lung (CXR), breast (Breast exam and mammogram), prostate (DRA and PSA), thyroid (examine for nodules) and kidney (Dipstick urine for blood + renal USS) and Myeloma screen
- Biopsy of extradural compressive lesions
- Urgent imaging and Discussion with neurosurgeons (high lesions) and Orthopaedic surgeons (lower lesions) need for urgent decompression.
- Speed is of the essence
- Role for steroids acutely unclear - evidence not great but IV dexamethasone often given in attempt to reduce oedema and cord compression
- Discuss with oncologists if tumour suspected
- Developmental abnormality with an enlarged cavity in the cord begins in adolescence
- May be part of other developmental structural abnormalities that affect CSF drainage.
- Lower cervical and high thoracic longitudinal cyst or syrinx in the cervical cord anterior to central canal
- Expanding cyst damages area around central canal where the spinothalamic tracts cross
- Syrinx slowly enlarges with time
- May be due to blockage of outflow from IVth ventricle with Arnold-Chiari malformation - cerebellar tonsils herniate through FM into cervical canal or in rare cases may be due to an acquired obstruction e.g. a tumour.
- Clinically a central cord syndrome with dissociated sensory loss
- Classically burns on fingers due to loss of pain sensation.
- Central sensory impairment has a cape like distribution over the patients shoulders
- Preservation of the dorsal columns proprioception and vibration.
- Hand and arm muscle LMN weakness and wasting as cord grey matter damaged as cavity expands.
- Upper motor neurone lesions below lesion
- Bladder and bowels usually spared
- Horner's syndrome due to cervical cord damage
- Facial numbness (Trigeminal nerve nucleus down to C2)
- Extension into medulla causes syringobulbia with brainstem and even cerebellar signs
- Can be asymmetrical
- Diagnosis by MRI scan of brain and cord
- Surgical decompression and aspiration of cysts
- Surgery to correct Chiari defect may improve matters such as removal of posterior margin of the foramen magnum
Central Cord syndrome
- Not a particular disease but a pattern of disease
- Syringomyelia is not the only cause.
- Pattern of injury also seen in traumatic spinal injuries where a central canal destructive lesion will cause damage to the crossing spinothalamic tracts and other modalities.
- May be due to Syringomyelia, trauma, tumours, anterior spinal artery occlusion.
- Causes a cape like loss of dissociated sensory loss of pain and temperature over the shoulders
- There will be weakness of upper limbs > Lower limbs.
- MRI scan
- Treat underlying cause
Subacute combined degeneration of the cord
- Damage to posterior columns and corticospinal tracts usually due to B12 deficiency - also see Dementia and Peripheral neuropathy.
- B12 deficiency due to Pernicious anaemia, Gastrectomy (Loses intrinsic factor), Terminal ileal disease (absorbs B12) eg Crohn's disease
- UMN signs from pyramidal tract damage - rarely leads to spastic paraparesis, upgoing plantars and brisk reflexes.
- Dorsal column loss of vibration and proprioception - positive Romberg's sign
- Sensory peripheral neuropathy - LMN reduced jerks and touch sense
- FBC - megaloblastic anaemia due to Low B12 and also check Folate levels.
- Elevated methylmalonic acid and homocysteine.
- Positive Anti-parietal and intrinsic factor antibodies
- Schilling test rarely done
- Treat with Vitamin B12 1 mg x 5 over 2 weeks and then every 3 months for life
- Acute demyelination of the spinal cord
- Transverse suggests whole cross section of cord affected
- May be partial. Causes
- Infection : HTLV-1, HIV, HZV, HCV, HSV, Mycoplasmal infection, CMV, Poliomyelitis
- Multiple sclerosis/Devic's, Paraneoplastic
- Sarcoid, ADEM, SLE
- Onset of Symptoms of weakness and sensory loss and sphincter loss over hours
- Possible Fever
- Mild to Severe back or neck pain.
- Sensory level and motor weakness- paraparesis, tetraparesis
- May cause a spastic paraparesis below the level, Lhermitte's signs when flexion of the neck causes pains can be seen in some cases.
- MRI excludes compressive lesions
- Plaques of demyelination in the cervical cord and lower.
- Lumbar puncture - Elevated CSF Protein and Lymphocytes
- CSF PCR for viruses
- High dose IV Methylprednisolone for ADEM/MS.
- Acyclovir for HZV
- Ganciclovir for CMV.
- Near complete recovery can occur even with severe cases
- A small proportion go on to develop Multiple sclerosis.
- Skin, Bowel and bladder care and rehabilitation
- Medication for spasticity
Acute spinal cord infarction
- Occlusion of anterior spinal artery often in elderly patients
- Dorsal columns preserved - light touch, vibration, proprioception
- Spinothalamic damage with loss of pain and temperature.
- ECG - AF or New MI
- MRI scan
- Oxygen, resuscitation
- Anticoagulation for embolic causes
Spinal cord arteriovenous malformations
- Direct connection between arteries and veins
- Root pain, sensory level, sphincter involved
- Look for overlying angioma
- MRI and MRA
- Embolisation or surgery
- Neurosyphilis damage to dorsal (sensory) nerve roots and degeneration of the posterior columns (ataxia)
- General paralysis of the insane with a dementia type picture, cortical atrophy, delusions of grandeur famously and epilepsy
- Meningovascular syphilis produces an endarteritis and fibrosis affecting II, III and IV cranial nerves
- Result in stroke like episodes.
- Shooting "lancinating" pains from sensory root irritation
- Positive Romberg's sign and broad based ataxic gait from posterior column loss.
- Neurosyphilis - Argyll Robertson pupil - small irregular, optic atrophy, loss of deep pain sensation.
- Charcot's type joints due to loss of protective pain sensation
- Down going plantars
- TPHA FTAA
- Penicillin - Beware of Herxheimer reaction due to release of toxins from spirochaetes
- May be ameliorated with steroids
- Uncommon in those under 50
- Degeneration of cervical spine
- Affects mostly C5/6 and C6/7 Osteophytes and narrowing of spinal canal in older patients
- Hyperrtrophy of ligamentum flavum and subperiosteal new bone formation.
- Radiculopathy and even myelopathy
- Neck pain
- Radiculopathy Lower motor neuron motor in hands - wasting and fasciculations and upper motor neurone in legs in root affected
- Dermatomal Sensory loss
- Rare C3 root compression - occipital pain
- Myelopathy - C5/6 or C6/7
- brisk reflexes arms and UMN signs in legs
- Lhermitte sign
- Proximal leg weakness and loss of vibration sense in feet
- Cervical spine films can show degeneration and foraminal narrowing (< 13 mm is significant) and osteophytes
- MRI is imaging of choice
- Electromyography (EMG) can help diagnose cervical radiculopathy
- Most commonly conservative with physiotherapy and pain relief NSAIDs
- Radiculopathy tends to settle spontaneously
- Surgical decompression for intractable pain or weakness and radiculopathy by anterior cervical diskectomy and fusion
- Moderate to severe myelopathy - Laminectomy or laminoplasty
Hereditary spastic paraparesis
- Autosomal Dominant - so a family history is typical.
- Rarely other forms exist with XLR and AR inheritance
- Sensation and sphincters usually well preserved and degeneration isolated to the corticospinal tracts.
- Progressive spastic paraparesis from childhood with characterised "scissors" gait with associated skeletal deformities such as pes cavus
- Exclude other causes
- MRI spine
- Genetic analysis
Motor Neuron Disease (Amyotrophic lateral sclerosis)
- A severe and progressive degenerative neurological disease with mixed upper and motor neurone weakness - wasting and hyperreflexia
- No sensory involvement
- Exclude other treatable causes
- Often Age > 60 years but also seen in younger
- Familial cases (10% of cases) have impaired superoxide dismutase (SOD1) activity suggesting a possible oxidative damage hypothesis.
- Degeneration of corticospinal and corticobulbar neurones and anterior horn spinal nerves too.
- Wasting + hyperreflexia + no sensory, spared eyes, sphincters intact
- Following are classically not seen in MND - sensory Symptoms, weakness of extraocular muscles, bladder or bowel dysfunction
- Dementia is rare and unusual
- El-escorial guidelines may be used for diagnosis especially for clinical trials but not covered here
- Classically an elderly patient with progressive limb weakness with visible fasciculations and wasting and increased reflexes, tone and clonus
- Head ptosis - weakness due to atrophy of neck extensors
- Can be differentiated into
- Amyotrophic lateral sclerosis LMN + UMN
- Progressive bulbar palsy with Bovine cough, dysphagia, dysarthria
- Progressive muscular atrophy - LMN predominant
- Primary Lateral sclerosis - UMN only.
- Weakness of respiratory muscles can lead to Type 2 respiratory failure.
Investigations very much to exclude other diagnoses
- MRI of head and neck to exclude a high cord lesion and other pathology such as cervical spondylosis
- Nerve conduction studies - may be reduced amplitude in late disease
- EMG - fasciculations and fibrillation potentials (exclude motor neuropathy)
- Mild Raised CK with cramps and spasticity
- Holistic Support and General nursing care
- Skin care and hydration.
- Riluzole may have some value - trials suggest adds 2 months has been approved by NICE
- Riluzole blocks release of glutamic acid
- PEG feeding in some cases.
- Mean Prognosis is 2 years survival after diagnosis
- Terminal care and palliation
- Uncommon now due to polio vaccination
- Previous epidemics stimulated the development of respiratory support and and intensive care management.
- Acute illness due to Polio type 1,2, or 3 which invades the GI tract.
- Has a propensity for nervous tissue and may have bulbospinal disease.
- Fever, headache, backache, lethargy.
- Acute flaccid muscle weakness and wasting
- Brainstem bulbar Symptoms and signs - diplopia, dysphagia.
- Quadriplegia seen in adult forms
- Single lower limb weakness in children.
- Post polio syndrome - weakness and severe fatigue in later life but not due to new infection
- Aseptic meningitis
- IgM Ab to Polio
- CSF - raised protein and lymphocytes
- Supportive therapy
- Prevention is the key.
- Respiratory support may be needed with respiratory muscle weakness. Management of long term disability e.g foot drop with splints
Spinal Muscular atrophy
- Autosomal recessive degeneration of the anterior horn cells, spinal interneurons and in some the bulbar nuclei can be affected
- Sphincters and sensation unaffected
- Type 1: Werdnig Hoffman disease - wasting, hyporeflexia, tongue fasciculations, hand tremor Early hypotonia and muscle wasting at 6 months and death by 2 years old.
- Type 2: Intermediate form in terms of prognosis
- Type 3: Kugelberg-Welander disease - Onset at 18 months and can survive into adulthood
- EMG - denervation
- Genetic studies
Bulbospinal muscular atrophy (Kennedy's syndrome)
- X linked recessive with CAG trinucleotide repeat.
- Involves androgen receptor gene on X chromosome.
- Commonest form of SMA onset in an adult
- Brain stem and cord atrophy
- Age of onset 15-60
- Gynaecomastia 50%, Tongue and face and proximal weakness
- Progressive LMN signs, NO UMN lesions which helps exclude MND
- Genetic testing, Elevated CK
- Supportive, Usually a normal lifespan
Cauda Equina lesions
- The nerve roots are formed at a much higher level than where they exit the spinal canal The cord ends at L1 and the space is just full of the remaining roots waiting to exit.
- A central cord prolapse is unusual but will cause pressure on the fibres of the cauda equina as will trauma, tumours etc
- There will be localised back pain, flaccid weakness, loss of saddle area sensation and loss of sphincter control.
- Rapid diagnosis and treatment is recommended
- Radiculopathies are dealt with below
- Damage to the bundle of nerve roots which are lower motor neurones which lie in the canal below the end of the cord at level L1 Causes
- Vertebral body destruction from tumour (metastases, myeloma), osteoporosis (rarely causes neurology), Central Disc prolapse
- Fluid compressing nerves : Abscess - TB Haematoma - warfarin
- Boney overgrowth Paget's disease, Lumbar stenosis, Ankyloisng spondylitis
- Tumours: Neurofibromas, Meningiomas, Gliomas, Ependymomas
- Lower back pain, Flaccid Weakness in legs, Sensory loss over genitalia around the perineum and buttocks - saddle area
- Loss of sphincter control - urine and faecal incontinence
- MRI is modality of choice but High resolution CT is second best but newer machines with improved imaging might help to identify likelihoods of aeiology if MRI not available or contraindicated.
- Look for tumours of lung (CXR), breast (Breast exam and mammogram), prostate (DRA and PSA), thyroid (examine for nodules) and kidney (Dipstick urine for blood + renal uss) and Myeloma screen
- Discussion with neurosurgeons (high lesions) and Orthopaedic surgeons (lower lesions) need for urgent decompression
- Urgent discectomy for central prolapsed disc
- Role for steroids acutely unclear - evidence not great but Dexamethasone 8 mg bd often given.
- Discuss with oncologists if tumour suspected
- Urgent radiotherapy may be indicated
- Otherwise manage Skin protection, prevent DVT, passive exercises, catheterise etc as spinal cord compression
- Usually L4/L5/S1 below level of cord
- May cause compression of the fibres of the cauda equina
- The annulus fibrosis surrounds softer nucleus pulposus
- This can prolapse normally posterolaterally to cause pressure on the nerve root or centrally to affect the cauda equina
- Acute prolapse - Usually unilateral pain in distribution of dermatome and locally
- Loss of corresponding reflex as well as weakness and wasting
- Reduced straight leg raising if lumbar area
- Pain worse with movement, coughing
- Reduced straight leg raising suggest a lesion beyond L5, more proximal lesions such as positive femoral stretch test suggests roots L1,L
- L3, L4 are involved.
- Central compression of the cauda equina below L
- Sensory loss and weakness in legs
- Impaired sphincters and saddle anaesthesia.
- MRI scan
- EMG may be useful
- Most prolapsed discs settled spontaneously with rest.
- Those with severe compression can have surgical removal of prolapsed material
- Cervical central compression or cauda equina compression requires lumbar laminectomy
- Surgical results are poor and patients must be selected carefully
- Conservative treatment is the modality of choice in most patients
- Compression from Metastases or extradural tumour
- Compression of nerve due to expanding tumour
- As above
- Other evidence of malignancy - lung, prostate, breast
- Extrinsic local malignant lesion e.g. pelvic or retroperitoneal lesion
Lumbar spinal stenosis
- Often predisposed by a congenitally small canal and can affect the central canal or lateral recesses
- Weakness, numbness and paraesthesia of legs with walking
- Pain in calves and legs on walking and relieved by rest similar to intermittent claudication but there is no evidence of vascular compromise
- MRI or High resolution CT confims diagnosis
- Decompression of canal or foramen
Nerve root lesions - Radiculopathies
- The anterior (motor) and posterior (sensory) roots fuse to form a single nerve root which passes laterally and forwards between the body of the vertebra and the through the intervertebral foramen
- Here it is prone to damage from a laterally
displaced disc prolapse or simple degeneration and spondylosis of the
Clinical syndrome of root disease
- loss of the relevant reflex
- shooting pain down limb or across trunk in dermatomal pattern
- Weakness in the distribution in myotomal pattern
- sensory loss in dermatomal pattern
- Nerve root damage causes sensory or motor symptoms in corresponding myotome and dermatome. Causes
- Disc degeneration, osteophytes, tumour, infection or diabetes can lead to demyelinating or axonal damage
- Most commonly seen related to cervical spondylosis
- Prolapsed discs are seen usually between C6 and T1 in the cervical region
- C5 - radial side of forearm and reduced biceps reflex and power
- C6 - deficit in thumb and first finger and decreased bicep and brachioradialis
- C7 - deficit in middle and ring finger and reduced triceps jerk
- C8 - Deficit in little finger and reflexes are normal
- T1 - T12 - pain in distribution but no weakness
- Can cause chest wall pain and be mistaken as cardiac pain
- T1 lesion can cause Horner's syndrome.
- LMN lesion affecting that myotome
- X-Ray Cervical spine - osteoarthritis
- MRI - shows nerve root impingement
- NCS is normal
- EMG - denervation of affected muscles
- Physiotherapy, NSAIDs, Surgical decompression with weakness and pain
- A tear in the annulus fibrosis of an intervertebral disc and cause posterolateral herniation of the nucleus pulposus and pressure on adjacent nerve roots
- Pathology of nerve roots causes sensory or motor Symptoms in corresponding myotome and dermatome
- Damage to roots with Disc, osteophytes, tumour, infection or diabetes can lead to demyelinating or axonal damage
- L2 - sensory deficit lateral and anterior thigh weak psoas and quadriceps. Reflexes normal
- L3 - sensory deficit lower medial thigh weak psoas and quadriceps. Reduced knee jerk.
- L4 - sensory deficit medial lower leg. Decreased knee jerk
- L5 - Lateral lower leg. Weak. No reflex abnormality
- S1 - lateral foot and with weak gastronemius. Reduced ankle jerk
- MRI-shows nerve root impingement
- NCS is normal
- EMG denervation of affected muscles
- Physiotherapy, NSAIDs, Surgical decompression with weakness and pain
- Localised pressure on nerve root
- Benign tumour May have Neurofibromatosis
Brachial plexus lesions
- Roots from C5 to T1
- Apical lung malignancies (Pancoast tumour)
- Trauma e.g. motor cycle accident, Birth trauma
- Cervical rib, Neuralgic amyotrophy
- Pain over the shoulder (in a smoker always CXR)
- Cervical rib may also impair vascular supply and made worse by carrying or lifting
- Commoner in women
- CXR, FBC, ESR MRI can help differentiate inflammatory of neoplastic
Brachial neuritis (neuralgic amyotrophy)
- Inflammation of brachial plexus ? infective
- Severe pain in shoulder for 1-3 days followed by weakness and wasting of shoulder as settles.
- CXR and CT may be needed if infiltrative process.
- Differentiate from other causes of a weak arm
- Steroids have been used
- Conservative, physiotherapy
- Roots from L2 to S2
- Pelvic malignancies