Scenarios: Difficulty walking, falls, back pain.
Examination of spastic paraparesis: Look around the bed for walking aids or wheelchairs, and check for the presence of a catheter. If the patient can walk, look for a spastic gait with bilateral circumduction described as “scissoring”, and whilst they are standing inspect the spine for scars. If not able to walk, ask them to sit forward so you can see the spine whilst doing your inspection – you may want to palpate down the spine to asses for any tender points. If you see a scar think of your surface landmarks to help localise it – T3 at spine of scapula, T7 and lower tip of scapula, and L4 at posterior superior iliac spine. Move down to the feet looking for neuropathic joints, high foot arches, and disuse wasting. There will be increased tone, clonus, spasms, weakness in a pyramidal pattern (extensors stronger than flexors), hypereflexia, and upgoing plantars. There may or may not be sensory involvement depending on the underlying cause, but if absent you should consider diagnoses like MND and HSP, whilst if present you should see if you can find a sensory level to localise the lesion – by definition the lesion must be above L1 as this is where the pyramidal tracts (i.e.: spinal cord) end. If you have time and the examiners allow, do a limited further examination including upper limb reflexes, checking for past pointing and intention tremor, and eye movements for nystagmus or an INO. I would like to complete my examination by:
- Taking a history in particular focusing on symptoms affecting other body sites such as bowel and bladder function and the bulbar area, past medical history, and family history.
- Perform a digital rectal examination to asses for anal tone and check for saddle anaesthesia.
- Complete a neurological examination of the arms and cranial nerves, including fundoscopy and eliciting any cerebellar signs.
- Cerebral palsy: Scenario describing birth injury or illness around the neonatal period, intellectual impairment, spastic paraparesis, brisk reflexes, upgoing plantars.
- Hereditary spastic paraparesis: Spastic paraparesis, brisk reflexes, upgoing plantars. Absence of sensory signs.
- Friedrich’s ataxia: Pes cavus, cerebellar signs, wasting, spastic paraparesis, reflexes may be absent. Peripheral sensory neuropathy including dorsal column loss.
- Multiple sclerosis: Spastic paraparesis, brisk reflexes, upgoing plantars, cerebellar signs, and a history of visual or sphincter disturbance. There may be sensory signs, dorsal column more commonly than spinothalamic.
- Anterior spinal artery occlusion: Spastic paraplegia, brisk reflexes, upgoing plantars. Loss of pain and temperature with a sensory level; dorsal columns spared.
- Motor neurone disease: Spastic paraparesis, brisk reflexes, upgoing plantars, wasting, faciculations. Absence of sensory signs.
The possible site of the lesion includes spinal cord (demyelination, trauma, cord compression due to prolapsed disc or space occupying lesion, vascular event or congenital myopathic process), anterior horn cell (motor neurone disease) or parasaggital (meningioma). In more detail…
- Congenital: Hereditary spastic paraparesis, Friedrich’s ataxia, spinocerebellar ataxia, or other childhood conditions like cerebral palsy.
- Compressive: Prolapsed disc, tumour (primary or secondary, benign or malignant), abscess, Pott’s disease, haematoma or haemorrhage; or a parasaggital meningioma.
- Demyelinating: Multiple sclerosis, neuromyelitis optica (Devic’s disease), subacute combined degeneration of the cord, transverse myelitis (HSV, VZV, HIV, paraneoplastic, autoimmune, radiation), tropical spastic paraparesis.
- Other: Motor neurone disease, syringomyelia, anterior spinal artery occlusion.
- Bedside tests: Blood pressure (autonomic involvement), vital capacity (respiratory muscle involvement).
- Bloods: Bone profile, LFTs, immunoglobulins and protein electrophoresis (malignancy); FBC, CRP, ESR (malignancy, infection, inflammation); virology and serology (HIV, HTLV-1, syphilis); anti-aquaporin 4 IgG antibodies (NMO), ANA (autoimmune causes); haematinics (B12 deficiency with SACDC).
- Imaging: MRI spine (demyelination, trauma, compression; localise site of lesion, asses for intervention).
- Special tests: Visual evoked potentials and MRI brain (multiple sclerosis for lesions disseminated in time and place), lumbar puncture (oligoclonal bands in CSF not serum, MCS, AFBs, syphilis, ACE level), EMG (fibrillation and fasiculations in MND).
- Non-pharmacological: Education, physiotherapy, occupational therapy, orthotics, social services assessment, DVLA considerations.
- Medical: Depends on underlying cause – steroids (IV methylprednisolone, PO dexamethasone), radiotherapy.
- Surgical: Depends on underlying cause – decompression, fixation.
- What malignancies commonly metastasise to bone? Solid organ ones like lung, breast, prostate, kidney and thyroid; and haematological conditions affecting bone should also be considered such as multiple myeloma.
- What is the differential diagnosis of a flaccid paraparesis? Myopathies (inflammatory, toxic, inherited), neuromuscular junction disorders (botulism, myasthenia gravis), neuropathy (hereditary motor sensory neuropathy, alcohol, lead poisoning, porphyria), anterior horn cells (motor neurone disease).