FFinalistSouthampton · 2027
Neurology
AKT · Neurology/Movement & neurodegeneration

Motor neurone disease

Degeneration of upper AND lower motor neurons (commonest = ALS)

Overview

A progressive neurodegeneration of motor neurons with MIXED upper and lower motor neuron signs and — characteristically — NO sensory involvement and NO sphincter/eye-movement involvement until late. Amyotrophic lateral sclerosis is the commonest form. Riluzole modestly extends survival.

Recognise

  • Mixed UMN signs (spasticity, brisk reflexes, upgoing plantars) AND LMN signs (wasting, fasciculations, weakness)
  • NO sensory loss, NO sphincter disturbance, eye movements spared (key negatives)
  • Bulbar onset: dysarthria, dysphagia, tongue fasciculation/wasting; respiratory failure ultimately

Red flags

  • Respiratory compromise (FVC), bulbar dysfunction with aspiration; weight loss

Differentials & how to tell them apart

Cervical myeloradiculopathy / cord compressionmixed signs but WITH sensory level/sphincter signs and a structural cause on MRI
Myasthenia gravisfatigable weakness, ocular involvement, NO UMN signs, antibodies
Multifocal motor neuropathypure LMN, conduction block, treatable
Cervical spondylotic myelopathysensory involvement + imaging

Investigations

Clinical diagnosis supported by electromyography/nerve conduction (denervation with normal sensory conduction); MRI to exclude mimics (cord compression, myelopathy).

Management

Riluzole + multidisciplinary care; NIV for respiratory failure

  1. 1Confirm clinically + EMG; specialist MDT. Riluzole to modestly extend survival; non-invasive ventilation for respiratory insufficiency.Gate: The combination of UMN + LMN signs with NO sensory loss and NO sphincter/eye involvement is the diagnostic pattern — sensory signs should make you doubt MND and image the cord
  2. 2MDT: SALT + PEG feeding for dysphagia, respiratory support, communication aids, palliative/advance care planning.
Riluzole — glutamate antagonist — modestly prolongs survival (~months)
Non-invasive ventilation (BiPAP) — for respiratory failure — improves survival/QoL

Key points

Mixed UMN+LMN with no sensory or sphincter signs is MND. Sensory loss points elsewhere (cord compression). Riluzole and NIV are the survival-modifying interventions.

Monitor & prognosis

FVC/respiratory function, swallow/weight, function, advance care.

Median survival ~3–5 years; bulbar onset worse.

Source: NICE NG42 (motor neurone disease)