Basics
- Most common cause of dementia
- Progress, neurodegenerative disorder of unknown cause that commonly first manifests as impairment in memory
- As the disease progress the patient becomes more disoriented, has increased difficulty communicating and performing activities of daily living
- Treatment options are limited though Memantine (Namenda) and a class of drugs known as acetylcholinesterase inhibitors [like Tacrine (Cognex)] have demonstrated some cognitive benefits
Symptoms and Signs
- Initially: Loss of recent memory, often noticed only by close family members
- As the disease progresses the patient becomes increasingly disoriented to both when and where they are.
- Depression and other psychiatric symptoms are common
- Late: Patients often develop difficulty effectively communicating, naming objects, and making simple calculation often causing them to leave work and give up family financial responsibilities.
- A total cessation of speach, incontinence, and a bedridden state point to terminal manifestations of the disease
Demographics
- Sporadic with about 5% of cases associated with a familial cause (Familial Alzheimer disease- secondary to a mutated amyloid precursor protein on Chr 21)
- Increased risk in people with Down’s syndrome (aka trisomy 21)
Diagnosis
- A clinical diagnosis in that test often just exclude other, possibly treatable, causes of dementia
- MRI demonstrates ex vacuo enlargement of the ventricles and atrophy of the cerebral cortex
Treatment
- Memantine
- Tacrine
- Donepezil
- Rivastigmine
- Galantamine
- Medications are also used to treat the psychiatric manifestations of the disease
Prognosis
- Death is normally seen within 5-10 years of the first symptoms often secondary to infections or inanition
Differential Diagnosis
- Alcohol induced amnestic syndrome
- Lewy body dementia
- Vascular dementia
- Creutzfeldt-Jakob disease
Basics
- A disease that affects motor neurons (both Upper and Lower motor neurons) resulting in weakness of voluntary muscles
- Rarely associated with cognitive problems (2% develop some type of dementia)
- While the exact cause is unknown, the disease attacks neurons in the cervical (neck) spine and the medulla (brainstem)
- Treatment options are currently lacking though trials with Riluzole have demonstrated some benefit
- Triad: Atrophic weakness of hands and formarms, Mild lower extremity spasticity, and diffuse hyperreflexia
Symptoms and Signs
- Classically presents with weakness and atrophy of the hands (lower motor neuron) with spasticity and hyperreflexia of the lower extremities (this picture may very depending on the type of neuron involved)
- Progressive disorder
- Difficulty speaking (dysarthria) and swallowing (dysphagia)
- Sphincter control is usually maintained
Demographics
- Prevalence: 5 per 100,000
- Familial in about 10% of cases- usually autosomal dominant (consecutive generations affected)
- Onset normal after the age of 40
Diagnosis
- Clinical features
- EMG- demonstrates fibrillations and sharp waves
- Lumbar puncture (aka spinal tap)- may demonstrate increased protein
Treatment
- Riluzole (Rilutek©) has demonstrated modest improvement in tracheostomy-free survival
- Main treatment aimed at minimizing disability: Trach, Feeding tube, etc.
- Spasticity and cramps can be treated with baclofen
Prognosis
- Median survival: 3-4 years
- Most patients die within 5 years of onset
Differential Diagnosis
- Cervical spondylotic myelopathy- will usually see neck pain and sensory findings. The diagnosis becomes easier as ALS progresses
References and Additional Reading
