Motor Neurone Disease (MND)

Subtypes

• Amyotrophic Lateral Sclerosis (ALS): Most common; shows both UMN (hyperreflexia, spasticity) and LMN(weakness, fasciculations) features

• Progressive Muscular Atrophy: Primarily LMN signs

• Progressive Bulbar Palsy: Bulbar region involvement (speech, swallowing)

• Pseudobulbar Palsy: Predominantly UMN signs affecting bulbar region

Inheritance

• Sporadic (~90%): No known familial component; risk to first-degree relatives low (~1–3%)

• Familial (~10%): Can be autosomal dominant, autosomal recessive, or X-linked

• Genetic Testing: Usually neurology-led, mainly for prenatal counselling or confirmed familial forms

  • Negative test doesn’t exclude a genetic basis; positive test doesn’t predict precise prognosis

Symptoms

• Dysphagia (swallowing difficulty)

• Gait disturbance (foot drop, stumbling)

• Muscle fasciculations (often in limbs, tongue)

• No sensory, bladder, or bowel involvement (differentiates from MS, other conditions)

• Progression over months to years, variable from patient to patient

Examination

• Distal lower limb weakness (e.g. foot drop)

• Slurred speech/hoarseness if bulbar involvement

• Fasciculations in skeletal muscle or tongue

• Mixed UMN and LMN signs: Spasticity, hyperreflexia + muscle atrophy, fasciculations

Investigations

• Clinical Diagnosis: Exclusion of mimics (e.g. cervical spondylosis, myelopathy)

• Nerve Conduction Studies / EMG: Help confirm denervation and rule out peripheral neuropathies

• CT/MRI Cervical Spine: Exclude structural lesions

• Respiratory Function Tests: Regular checks for early ventilatory failure

Treatment

• No Cure; management is supportive and palliative

• Riluzole (sodium channel blocker) modestly prolongs survival (by a few months)

• Baclofen for muscle cramps/spasticity

• Botulinum Toxin can help reduce severe spasticity

• Early Multidisciplinary Team (MDT) input:

  • Speech therapy (swallow assessment, communication aids)

  • Dietetics (optimising nutrition)

  • Palliative care for advanced disease

• Non-Invasive Ventilation (e.g. BiPAP) may improve quality of life and prolong survival