Motor Neuron Disease
Also known as Lou Gehrig’s disease.
Paralytic disorder characterised by gradual, heterogenous, and progressive degeneration of all motor neurons. There is also a strong association with frontotemporal dementia.
Motor neuron disease is divided into four main types:
- Amyotrophic Lateral Sclerosis
Mixed UMN and LMN signs in all limbs. ALS is the most:- Common (70%)
- Malignant
Life expectancy ~3 years.
- Isolated bulbar palsy
Initial swallowing and speech difficulty; progresses to generalised disease.- ~5-10% of cases
- Life expectancy ~ 4 years
- Progressive muscular atrophy
Pure LMN signs.- ~5%
- Primary lateral sclerosis
Pure UMN signs, predominantly in lower limbs.- Slower disease progression
Epidemiology and Risk Factors
Pathophysiology
Aetiology
Clinical Manifestations
Motor findings:
- UMN
- Spasticity
- Hyperreflexia
- LMN
- Weakness
- Wasting
Diagnostic Approach and DDx
Diagnosis is made on clinical grounds.
Differential diagnoses:
- Multifocal motor neuropathy
Amenable to treatment.
Investigations
Bedside:
Laboratory:
Imaging:
Other:
Management
Resuscitation:
ABC approach. Comment on team coordination and clinical priorities. Specific therapy:
- Pharmacological
- Procedural
- Physical
Supportive care:
Disposition:
Preventative:
Marginal and Ineffective Therapies
Anaesthetic Considerations
Complications
- Death
3-5 years following diagnosis, secondary to respiratory failure. - D
- Frontotemporal dementia
Prognosis
Key Studies
References
- Bersten, A. D., & Handy, J. M. (2018). Oh’s Intensive Care Manual. Elsevier Gezondheidszorg.