Localization of the Cause of Weakness by Clinical Syndrome
| Localization | Syndrome(s) | Additional features | Possible pathology |
|---|---|---|---|
Brain
| Hemiplegia
| Homonymous hemianopia, ipsilateral sensory loss, dysphasia, dysphagia | Stroke, MS, tumour, migraine, post-ictal, hypoglycaemia |
| Isolated monoplegia | Typically part of limb only (‘cortical hand’), no sensory loss | Stroke, MS, tumour, post-ictal | |
| Brainstem | |||
| Weber | Ipisilateral IIIrd and contralateral hemiplegia | Stroke |
| Quadriplegia | Bulbar palsy, horizontal gaze paralysis, delirium | Stroke, central pontine myelinolysis | |
| Millard-Gubler | Ipsilateral VIth/VIIth, contralateral arm and leg weakness | Stroke, MS | |
| Djerine | Ipsilateral XIIth, contralateral hemiplegia and loss of proprioception/vibration | Stroke, MS |
| Spinal cord | Anterior cord | Para/quadriplegia, sensory level, sphincter disturbance, proprioception/vibration (relatively) spared | Anterior spinal artery thrombosis, cord compression, tumour, radiation |
| Transverse myelitis | Para/quadriplegia, sensory level, constricting/band-like pain | MS, inflammatory, tumour, post-infectious, viral, dural AVM | |
| Posterior cord | Sensory ataxia, vibration sensation loss | B12/copper deficiency, HIV, syphilis, tumour, dural metastasis, MS | |
Brown Séquard (hemi-cord) | Ipsilateral weakness and loss of proprioception/vibration, contralateral loss of pain and temperature | MS, penetrating injury, tumour | |
| Conus medullaris | Prominent sphincter involvement, saddle anaesthesia, mixed UMN/LMN signs | Disc prolapse, tumour | |
| Central cord | Suspended, dissociated sensory level | Syrinx, MS, acute compression, intramedullary tumour | |
| Spinal roots | Cauda equina | Back/radicular pain, sphincter disturbance, dermatomal sensory loss | Disc prolapse, tumour, arachnoiditis, lumbar canal stenosis |
| Polyradiculopathy | Proximal and distal weakness, areflexia in affected limbs, back/radicular pain, sensory symptoms > sensory signs | GBS/CIDP, leptomeningeal infiltration (e.g. lymphoma), Lyme, VZV/viral | |
| Monoradiculopathy | Weakness in a group of muscles in one limb, pain radiating down limb +/– sensory loss in corresponding dermatome | Degenerative, disc prolapse, tumour, VZV/viral | |
| Plexus | Brachial or lumbar-sacral plexopathy | Pain (often in groin or shoulder) before weakness, patchy/minimal sensory loss | Diabetes, idiopathic, infiltrative (cancer/lymphoma), radiation, infective |
| Peripheral nerve | Demyelinating | Proximal and distal weakness without wasting, global areflexia, early vibration loss | GBS/CIDP, paraproteinaemic |
| Axonal | Distal weakness and sensory loss, wasting, reflex loss in weak limbs/at ankles only | Alcohol, nutritional, diabetes, critical illness, paraneoplastic | |
| Mononeuropathy | Weakness in one area of one limb +/– sensory loss and wasting | Compression, trauma | |
| Multiple mononeuropathies (mononeuritis multiplex) | Pain, systemic features of vasculitis | Vasculitis, cancer, sarcoid, lymphoma, amyloid, HIV, multiple pressure palsies | |
| Neuromuscular junction (myasthenic) | Generalized | Fatigable proximal weakness, dysphagia, dysarthria, neuromuscular respiratory failure, no sensory loss | Autoimmune (myasthenia gravis) |
| Ocular | Fatigable diplopia/ptosis | Autoimmune, Botulism (if ‘descending’ weakness) | |
| Lambert-Eaton | Dry mouth/autonomic dysfunction, supressed reflexes which return post exercise | Paraneoplastic, non-paraneoplastic | |
| Muscle | Proximal myopathy | Myalgia, rash | Inflammatory (dermatomyositis), steroids, statins |
| Rhabdomyolysis | Myalgia, dark urine/myoglobinuria | Crush injury, malignant hyperthermia, neuroleptics | |
| Other | Inclusion body, limb-girdle, fascio-scapulo-humeral, distal patterns | Genetic/degenerative (rarely present acutely) |