Approach to bilateral UMN or mixed lesion - spastic paraparesis plus (inc HSP, TM) Flashcards
Examination dance for bilateral UMN spastic paraparesis
Inspection
1. Chronicity: wasting (LMNL) vs contracture (UMNL) or both
- Wasting is often not a feature of UMNL, however in longstanding cases there will be disuse atrophy wasting
- Contracture in chronic immobility
2. Mobility
- Wheelchair immobility
- Walking aid with scissors gait
(or rarely high steppage gait in foot drop)
3. Surgical scars
- Spinal level
- Deformity correction over ankle, or pes cavus
4. IDC - bladder involvement
Examination
1. Bilateral pyramidal weakness
- flexors: hip flexion, knee flexion, ankle dorsiflexion, eversion
2. Hypertonia - foot jump off from couch
(Look for hypotonia LMNL signs below UMNL level)
3. Hyperreflexia and crossed adductor response (pyramidal lesion)
- Opposite adductors contract during knee jerk
(Look for hyporeflexia LMNL signs below UMNL level)
4. Ankle clonus > 3 beats
5. Extensor plantar response on Babinski
5A. Oppenheim sign: extensor plantar response on pressing inner border of tibia
5B. Gordon sign: extensor plantar response on pinching Archilles tendon
6. Is there a sensation loss?
- Patchy: cervical myelopathy
- Peripheral neuropathy: FA, SCA, cervical myelopathy, multiple sclerosis
- DCML: tabes dorsalis (neurosyphilis)
- Pinprick in cape distribution: syringomyelia
- Sensory level: transverse myelitis, spinal cord lesion tumour/compression/trauma
7. Is there ataxia on heel shin test/dysdiadochokinesia?
No sensory loss
- Hereditary spastic paraparesis (10% may have sensory loss)
- Cervical myelopathy (that does not affect sensation)
- Parasagittal lesion
- Bilateral cortical lesion
Wishlist
Fundoscopy
Approach to spastic paraparesis (bilateral UMN)
Differentiating features
1. Mixed lesion - LMNL below UMNL level
2. Cerebellar signs
3. Sensation impairment
Sensory level in bilateral spastic paraparesis
What is spasticity?
What is rigidity?
Spasticity
- Increase in muscle tone due to hyperexcitability of stretch reflexes, velocity-dependent increase in tonic stretch reflex
- More marked at onset of movement, decreasing as passive movement continued (clasp knife phenomenon)
Rigidity
- Constant increased tone throughout range of motion independent of velocity
Pathophysiological basis for spasticity
Enhanced stretch reflex activity
- Increased muscle tone (tonic stretch reflexes)
- Exaggerated reflexes (phasic stretch reflexes)
Normal:
Turning off stretch reflexes to allow normal movement
Brain sends inhibitory inputs from reticulospinal and other descending pathways to motor neurons
UMNL
Loss of inhibitory inputs from spinal cord
Alpha motor neurone hyperexcitability
Denervation supersensitivity, shortening of motor neurone dendrites, sprouting of dorsal root afferents
Conus medullaris syndrome
Level: Mixed LMN (flaccid) weakness at level of lesion + UMN below (spastic)
Distribution: symmetrical, proximal > distal
Reflexes: Areflexia at level, hyperreflexia below
Sensation: saddle anaesthesia S3-S5
Additional features: back pain, lower back scar, urinary dysfunction, fecal incontinence, erectile dysfunction
Spinocerebellar ataxia and Friedreich’s ataxia
Level: Predominant UMN (cerebellar) +/- LMN (peripheral neuropathy)
Distribution: symmetrical
Reflexes: hyperreflexia
Sensation: +/- peripheral neuropathy, DCML
Additional features: cerebellar signs, scoliosis, HOCM, diabetes
Subacute combined degeneration
Level: predominant UMN +/- LMN
Distribution: symmetrical
Reflexes: hyperreflexia (areflexia in peripheral neuropathy)
Sensation: DCML loss, Romberg positive
Additional features: wide based gait, urinary retention, impotence, glossitis, megaloblastic anemia, cognitive impairment
Tabes dorsalis
Level: mixed
Distribution: symmetrical
Reflexes: areflexia
Sensation: proprioception loss, Romberg positive
Additional features: Argyll Robertson pupil (small, accommodate but no response to light), ataxia, charcot joint, optic atrophy
Think of dual pathology for mixed UMN LMN
- Cervical myelopathy + diabetic polyneuropathy
- Cervical myelopathy + lumbar radiculopathy
- Others
Motor neuron disease (anterior horn cell disease)
Level: predominant LMN +/- UMN
Distribution: asymmetrical, distal > proximal
Reflexes: predominant hyporeflexia
Sensation: NORMAL
Additional features: fasciculations, respiratory failure, emotional lability
Brainstem lesions
Example diseases:
1. Multiple sclerosis
2. Brainstem infarct (bilateral and well exceedingly rare - mostly locked-in)
3. Space occupying lesion (tumour, abscess)
Level and reflex: UMN only, hyperreflexia
Distribution: varies
Sensation: normal
Additional features: cerebellar signs, other CN involvement, lesion separated in space
Hereditary spastic paraparesis
(paresis - limited movement; plegia - complete inability)
Also known as
Familial spastic paraparesis
Stumpell-Lorrain syndrome
Definition
Progressive severe spasticity of lower limb due to degeneration of ends of corticospinal tracts within spinal cord
- X-linked, AD (most common) or AR
- Ends of longest corticospinal fibres affected
Clinical features
1. Spastic weakness - LL greatly affected than UL
2. Muscle wasting in very chronic > 10 years distal muscle group - small muscles of feet and tibialis anterior
3. Peripheral nerves normal
4. +/- Sensory impairment in 10-65% patients
5. +/- Diminished proprioception and vibration (central axonopathy)
6. Pes cavus
7. Some variants cerebellar signs
Complications
1. Cataracts or optic nerve atrophy/retinopathy
2. Ataxia - lack of coordination
3. Epilepsy
4. Cognitive impairment
5. Deafness
6. Bladder and urinary incontinence
7. Respiratory muscle weakness
8. Peripheral neuropathy (rarely)
Tropical spastic paraparesis
Definition
HTLV-1 associated myelopathy
Characterised by chronic progressive spastic paraparesis
Incubation months to years
Features
1. Progressive spastic weakness, proximal > distal
2. Sphincter disturbance
3. Mild sensory involvement
Epidemiology
Caribbean, Africa, Japan, South America
Mode of transmission
1. Sexual contact
2. Sharing of needles, blood products
3. Vertical transmission
1-4% develop
Transverse spinal cord lesion
Level: Pure UMN spastic paraparesis
Sensation: Bilateral sensory loss from below until even T10 (umbilical)
Additional features: Urinary disturbance, back scar
Causes of transverse spinal cord lesion:
1. Trauma
2. Neoplastic (mets, lymphoma, meningioma)
3. Infective (abscess)
4. Inflammatory (transverse myelitis, multiple sclerosis, viral infection)
5. Vascular (vasculitis, spinal artery thrombosis)
6. Degenerative spine in cervical or lumbar
Transverse myelitis
Definition of transverse myelitis
Acute inflammation of cord, affecting diffusely at 1 or more levels, affecting all spinal cord function
- Resultant PAIN, bilateral motor, sensory and sphincter deficit below level of lesion
- Progresses rapidly within hours to days
Causes:
1. Bacteria - lyme, mycoplasma, tuberculosis, syphilis
2. Viral - HSV, VZV, CMV, EBV, HIV, HAV, influenza, echovirus
3. Demyelination (MS, Devic’s disease)
4. Radiation myelopathy
5. Anterior spinal artery occlusion
6. Vasculitis
7. Autoimmune
8. Vaccination
Treatment: corticosteroid
Cervical myelopathy
Level: mixed LMN (if at level) with UMN (below) - but we do not know which level!!
Distribution: asymmetrical
Sensation: patchy, non-specific, gloves and socks distribution
Gait: sensory ataxia (DCML)
Additional features: finger escape (deficient adduction of ulnar 2 fingers), positive Hoffman, slow grip and release
Cervical myelopathy vs cervical radiculopathy
Syringomyelia
Level: mixed LMN (level) and UMN (below)
Distribution: symmetrical
Sensation: cape-like, pure DCML, pure spinothalamic, or pansensory loss
Additional features: syringobulbia extension causing Horner’s syndrome, bulbar palsy, facial numbness, ataxia
Pure bilateral spastic paraparesis without sensory loss
- Parasagittal meningioma (lower limbs in parasagittal region of motor homunculus)
- HSP without sensory involvement
- Multifocal strokes
- Multiple sclerosis demyelination without sensory involvement
- Cerebral palsy
- Cervical myelopathy with patchy sensory loss that failed to pick up
Investigations for bilateral spastic paraparesis
- Relevant blood tests
- Full blood count - anaemia, infection
- B12 and folate - SCD - Imaging - magnetic resonance imaging of brain and spinal cord
- Lumbar puncture - if suspecting multiple sclerosis, transverse myelitis
- Nerve conduction studies and electromyography
- Genetic testing and counseling
Management of spasticity
Non-pharmacological
1. Physiotherapy - stretching, strengthening
2. OT - orthoses, casts, braces
3. Cold packs
4. Electrical stimulation
Pharmacotherapy: for spasticity and neuropathic pain
1. Benzodiazepines
2. Baclofen
3. Tizanidine
4. Dantrolene
5. Clonidine
6.Gabapentin
7. Intrathecal - baclofen, phenol
8. Botulinum toxin injection
Neurosurgery
- selective dorsal rhizotomy (between L2 and S2)
Orthopaedics
- Contracture release
- Tendon transfer
- Osteotomy
