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Flashcards in ALS Deck (23):
1

key findings

weakness of the legs > arms

*fasciculations* of several muscles and is

*hyperreflexic* in all 4 extremities

*both upper and lower motor neurons

2

epi

common cause of anterior horn cell disorder
M>W

3

pathophys

HALLMARK: SIMULTANEOUS UPPER AND LOWER MOTOR NEURON DISEASE
Loss of lower motor neurons in the anterior horns of spinal cord
Loss of upper motor neurons that project in corticospinal tracts

4

2 characteristics

Neuronal muscle atrophy (amyotrophy)
Hyperreflexia

5

ddx

Multifocal motor neuropathy
Polio (now “post-polio syndrome”)
“Spinal muscular atrophy”
West Nile Virus encephalitis
Demyelination diseases
CVA/TIA
Heavy metal poisoning
B12 deficiency
Syphilis
Various Endocrinopathies

6

early symptoms

Lower extremity weakness
Frequent falls
Asymmetric weakness of the hands
Difficulty with fine motor skills
Foot drop
Severe muscle cramping
Spasticity of arms and legs
Dysarthria
Dysphagia
*Cognitive dysfunction NOT a feature

7

late symptoms

Fasciculations
Recurrent bouts of pulmonary infection after respiratory muscle involvment
Respiratory failure-->death

8

signs

Diffuse hyperreflexia and spasticity (upper motor neuron)

Fasciculations, weakness, and atrophy (lower motor neuron)

+Babinski
claw hands
tongue: "can of worms"

9

rating scale

ALSFRS-R (ALS Functional rating scale-Revised)

lower score is worse

10

see charts

UMN vs LMS
*limb s/s
axial s/s

11

lab imaging: MRI

dx of exclusion
Brain and spinal MRI-done to rule out other conditions that can mimic early ALS
MR spectroscopy and CT with myelography can also be used if MRI contraindication

PET

12

lab imaging: EMG

Fibrillation and fasciculation potentials
Motor units polyphasic with high amplitude and long duration

Examine at 3 levels:

Most involved limb first
Distal muscles
Bulbar muscles

13

labs to rule out

B12/folate
HIV status
Lyme serology
Thyroid function tests
CPK

14

CSF?

gen not helpful

15

PFTs?

test in sev. disease

16

tx? support

Respiratory support
Nutritional support
Mobility support
Communication support

17

tx med

Riluzole

18

tx failures

irradiation, corticosteroids, cyclophosphamide, IVIG, gabapentin, lamotrigine, IGF-1, celecoxib

19

future tx

Stem cells
enhance survival of motor neurons

20

prognosis

VERY POOR
Relentessly progressive, involving upper and lower extremities, truncal and bulbar musculature

*terminal within 3-5 years after diagnosis

21

genetic etiology

Unknown;
Subset of familial cases: genetic locus at the copper-zinc superoxide dismutase gene (SOD1) on chromosome 21

Recessive locus on chromosome 2 has been linked to GTPase regulation

Possible evidence of glutamate toxicity and protein nitration involved in development of ALS


22

missense mutations

A4V mutation most common (up to 50% of cases, rapid course with rare upper motor neuron signs)

23

sporadic in

80-90% cases