01Purpose and principlesWhat the assessment is for and the core concepts behind it.
Cord localisation uses longitudinal and cross-sectional anatomy. A cervical lesion may affect arms at the segment and legs through descending tracts; a thoracic lesion spares arms and creates a truncal level; a conus lesion combines sacral and root findings. Autonomic pathways explain retention, bowel and sexual dysfunction. Respiratory risk rises above C5 because phrenic motor output and cough can be affected. Early spinal shock can remove reflexes temporarily, so time since injury alters the expected signs.
Cross-sectional syndromes are teaching models, not rigid templates. Real infarcts, trauma, tumours and inflammation are irregular and evolve with oedema. Anterior spinal-artery injury often causes abrupt flaccid weakness that later becomes spastic, loss of pain and temperature and autonomic dysfunction, with preserved dorsal columns. A hemicord lesion produces Brown-Sequard features, while a central lesion can damage crossing spinothalamic fibres and segmental motor neurons before long tracts.
The examination should lead to imaging, not delay it. Map light touch, pinprick, temperature where safe, vibration and joint position; test motor level, reflexes, plantars and gait only when stable; ask about bladder, bowel, sexual and respiratory function. MRI of the relevant and often wider spine identifies compression and intramedullary pathology. Brain imaging, CSF, vascular, metabolic and infectious tests follow the tempo and imaging pattern.
Key points
- A spinal-cord syndrome combines upper-motor-neurone dysfunction below a lesion, segmental lower-motor-neurone signs at the level, a tract-pattern sensory disturbance and possible autonomic impairment.
- The perceived cutaneous sensory boundary can sit several segments below the structural lesion, especially for pain and temperature, so it guides but must not narrowly limit imaging.
- Corticospinal fibres have crossed in the medulla and descend ipsilaterally, so a hemicord lesion causes ipsilateral pyramidal weakness below the lesion.
- Dorsal-column fibres ascend ipsilaterally, producing ipsilateral loss of vibration and joint position below a hemicord lesion.
- Spinothalamic fibres enter, travel one or two segments and cross through the anterior white commissure, so contralateral pain and temperature loss may begin below the lesion.
- Anterior cord syndrome impairs motor and pain-temperature pathways while relatively sparing dorsal-column vibration and position; spinal-cord infarction is an important cause.
- Central cord syndrome disproportionately affects upper limbs and may add sacral sparing, classically after cervical hyperextension in an older narrowed canal, but MRI defines the actual injury.
- Brown-Sequard syndrome combines ipsilateral weakness and dorsal-column loss with contralateral pain-temperature loss below the hemicord lesion.
- Posterior cord syndrome causes sensory ataxia and impaired proprioception with relatively preserved power and pain-temperature sensation; B12 deficiency and tabes are classic causes.
- Sacral sparing indicates an incomplete lesion and has prognostic significance, but examination must include voluntary anal contraction and deep anal pressure only when clinically appropriate and consented.
02Indications, selection and cautionsWhen it is useful, when urgency changes and important limitations.
Motor and all sensory modalities are absent below the neurological level with no sacral sensory or motor preservation after spinal shock and confounders are considered.
Acute bilateral weakness and loss of pain and temperature occur below the lesion with relative preservation of vibration and position sense, often plus autonomic dysfunction.
Ipsilateral pyramidal weakness and proprioceptive loss occur below a hemicord lesion, with contralateral pain and temperature loss beginning a little lower.
Upper limbs are weaker than lower limbs after cervical injury or central expansion, with variable sensory, bladder and sacral-sparing features and possible burning hand pain.
Severe loss of vibration and joint position creates sensory ataxia, stamping gait and Romberg positivity while pain, temperature and elementary power remain relatively preserved early.
At the lesion, dermatomal sensory change, focal pain, wasting and reduced reflexes may coexist with long-tract signs below, helping locate a cervical or thoracic process.
03Method and interpretationA systematic approach to the test and its findings.
Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.
- 01
Formal neurological level examinationFirst step - Why
- Define the most caudal normal motor and sensory segments, sacral sparing and an incomplete-syndrome pattern.
- Interpretation and limitations
- Use a reproducible chart and record timing. Pain-temperature levels can start below the lesion, and sedation, shock, neuropathy and pain may make the first examination unreliable.
- 02
MRI whole or targeted spine - Why
- Identify extrinsic compression, intrinsic cord signal, haemorrhage, infarction, demyelination, tumour or a cavity.
- Interpretation and limitations
- Coverage depends on syndrome and cause, but do not terminate imaging solely at the reported cutaneous level. Add contrast for tumour, infection or inflammation as advised.
- 03
CT and vascular imaging - Why
- Define fracture and bone or investigate aortic and spinal vascular disease in sudden traumatic or infarct-like presentations.
- Interpretation and limitations
- CT does not exclude cord oedema or epidural soft tissue. Diffusion MRI and vascular studies can support infarction but early sensitivity and technical quality vary.
- 04
CSF analysis - Why
- Investigate inflammatory, infectious and malignant intramedullary syndromes after compression and procedural contraindications are excluded.
- Interpretation and limitations
- Cells, protein, glucose, microbiology, oligoclonal bands and cytology are selected by phenotype. A nonspecific protein rise must not be treated as a diagnosis.
- 05
Metabolic and systemic screen - Why
- Identify B12, copper, HIV, syphilis, systemic autoimmunity, malignancy or infection when the pattern and tempo suggest them.
- Interpretation and limitations
- Posterior-column, long-segment or slowly progressive disease particularly warrants cause-led blood tests; treatment should not wait for delayed B12 results when neurological deficiency is suspected.
- 06
Respiratory and autonomic assessment - Why
- Detect high-cord ventilatory failure and bladder or cardiovascular complications early.
- Interpretation and limitations
- Serial forced vital capacity, cough, blood gases, post-void residual and haemodynamic review provide actionable physiology that a sensory map alone cannot.
04Clinical next stepsHow the result changes management or prompts escalation.
01Acute levelExclude compression firstFirst stepA new truncal sensory boundary accompanies bilateral weakness or autonomic symptoms.+
- 1Use ABCDE, check respiratory mechanics for cervical disease, document motor, sensory and sacral status and immobilise if trauma or instability is possible.
- 2Arrange emergency MRI and spinal advice, using pain, fever, cancer, trauma, anticoagulation and onset tempo to prioritise compression, abscess, haematoma and infarction.
- 3After external compression is excluded, pursue inflammatory, infectious, vascular and metabolic causes with contrast imaging, CSF and targeted blood tests.
- 4Manage retention, pressure, thrombosis, bowel, pain and rehabilitation needs from presentation rather than after the syndrome is named.
02Cross-sectional patternUse tract dissociation intelligentlyMotor and sensory modalities are affected unequally across the body.+
- 1Compare weakness, vibration and position, pain and temperature and segmental signs on both sides and note where each change begins.
- 2Generate an anatomical hypothesis such as anterior, central, hemicord or posterior disease, then test it against onset, cause, imaging and autonomic findings.
- 3Avoid excluding disease because the pattern is incomplete: oedema, multilevel injury and evolving spinal shock frequently blur textbook boundaries.
03Ongoing reviewRepeat level and prognosisA cord lesion has been treated or stabilised and neurological evolution must be measured.+
- 1Repeat the same motor, sensory and sacral examination after resuscitation, decompression or resolution of spinal shock and record whether the lesion remains complete.
- 2Monitor ventilation, autonomic dysreflexia risk, orthostatic pressure, bladder, bowel, skin, spasticity, pain and thrombosis with a spinal rehabilitation service.
- 3Use the neurological trend, imaging and functional goals to counsel prognosis, avoiding certainty from one early sensory level or reflex pattern.
05Procedure and medicine safetyRelevant preparation, treatment and contraindications.
No syndrome-wide drug
There is no single medicine regimen for a sensory level; treatment follows the identified cause.Steroid, antimicrobial, anticoagulant reversal, vascular and nutritional therapies have conflicting indications and should not be given indiscriminately.
Cause-directed corticosteroid
Use only the relevant metastatic or inflammatory specialist protocol after urgent structural and infectious assessment.Routine traumatic steroid is not recommended, and uncontrolled infection or haemorrhage may be worsened or obscured by empirical treatment.
Bladder and bowel regimen
Individualise catheter, laxative and suppository timing from neurological level, residual volume and rehabilitation assessment.Anticholinergic burden, retention, diarrhoea, dehydration and catheter infection require review; symptom control does not replace neural diagnosis.
Venous-thromboembolism prevention
Apply mechanical and pharmacological prophylaxis according to spinal injury, bleeding and operative policy.Coordinate with haemorrhage, surgery and neuraxial procedures and adjust for renal function and thrombocytopenia.
06Risks, monitoring and follow-upComplications, safety checks and further assessment.
- Repeat motor, pinprick, light touch, vibration, proprioception, reflex, plantar and sacral findings using the same landmarks and timed documentation.
- Monitor forced vital capacity, cough and gas exchange for cervical or ascending lesions even when resting oxygen saturation is preserved.
- Follow bladder residual, bowel function, skin, pressure areas, temperature, thrombosis, pain and autonomic symptoms as core cord outcomes.
- Reassess after spinal shock resolves because reflexes, tone and the apparent completeness of injury can change substantially.
- Track functional transfers, walking, hand use, sensation-related injury risk and rehabilitation participation alongside impairment scores.
- Escalate any rising level, new weakness, respiratory decline, fever, severe spinal pain or new sphincter dysfunction immediately.
07Special situationsVariants, exceptions and circumstances that change the usual approach.
Spinothalamic loss starts lower
Fibres ascend briefly before crossing, so the contralateral pain-temperature boundary may lie one or two segments below a hemicord lesion.
Level is not a scan limit
Because sensory boundaries are imprecise and lesions can be multiple, imaging should follow clinical cause and anatomy rather than one dermatome.
Central is arm-heavy
Cervical central injury can disproportionately impair upper limbs, but modern assessment should describe the actual MRI and neurological pattern rather than rely on a label.
Posterior loss causes falls
Power may test normally in bed while severe proprioceptive loss makes standing unsafe once visual compensation is removed.
Sacral sparing means incomplete
Preserved perianal sensation, deep anal pressure or voluntary contraction indicates surviving long tracts and changes injury classification and prognosis.
Spinal shock is temporal
Flaccidity and absent reflexes immediately after a major cord lesion later evolve into spasticity, preventing premature peripheral localisation.
08Common pitfallsFrequent interpretation and management errors.
- 01
Restricting MRI to the exact dermatome reported as the sensory level.
- 02
Calling an acute flaccid areflexic paralysis peripheral without considering early spinal shock.
- 03
Treating Brown-Sequard, anterior or central cord labels as causes rather than anatomical patterns.
- 04
Testing light touch alone and missing dissociated pain-temperature or proprioceptive loss.
- 05
Omitting sacral, respiratory and autonomic assessment from a detailed limb examination.
- 06
Giving empirical corticosteroid to every sensory level before excluding compression, infection, trauma and haemorrhage.