38 - Motor Neuron Disease

Question 1

What are LMN disease signs?

Answer 1

weakness, atrophy, fasiculations, hyporeflexia.

NORMAL sensation and conduction velocity

Question 2

What is infantile form of spinal muscular atrophy?

Answer 2

Werdnig-Hoffman. autosomal recessive

Question 3

What is juvenile form of spinal muscular atrophy?

Answer 3

Wohlfart-Kugelberg Welander. Autorecessive.

Question 4

Where is mutation is present in spinal muscular atrophy?

Answer 4

mutation on ch. 5 for surival motor neuron gene.
All SMA have LOSS of SMN1
pheonotype determined by extent of SMN2 loss

Question 5

What is clinical presentation of Werdnig Hoffman?

Answer 5

signs of LMN disease:
atrophy, hypotonia, hyporeflexia, tongue fasciculations, FROG LEG POSTURING
EMG = muscle denervation
biopsy = muscle group atrophy

Question 6

What is clinical presentation of Wohlfart Kugelberg Welander?

Answer 6

resembles a myopathy mixed with a LMN disease:
-fasciculations, atrophy of PECTORALIS + thighs
-proximal muscle weakness
EMB: LMN disease, normal CK (not myopathy) and fiber denervation

Question 7

What is clinical presentation of Adult onset SMA?

Answer 7

resembles sporadic LMN disease

Question 8

What is ALS?

Answer 8

progressive loss of LMN in spinal cord/brainstem + UMMN projecting into CST.
Idea is you have too much glutamate excitement that leads to degeneration

Question 9

What are the causes of ALS?

Answer 9

most commonly idiopathic.
Familial form = mutation in AD superoxide dis gene (ch.21)
juvenile = mutation of ch.9
w/FTD = mutation of ch.17
MCC = ch.9 C90RF72 expansion

Question 10

What is differential diagnosis for ALS?

Answer 10

MSA, cerebellar disease, craniocervical tumor (always get MRI), post-polio syndrome, polyglucosan body DZ, Tay Sach, kennedy Dz, HyperPTH.

Question 11

What is gross pathology of ALS?

Answer 11

lack of myelin in corticospinal tract and loss of anterior horn neurons (pale).

Question 12

What is microscopic pathology of ALS?

Answer 12

Bunina Boday (eosinophilic inclusion bodies in anterior horn cell nuerons (high ubiquitin)

Question 13

What is clinical presentation of ALS?

Answer 13

LMN signs (weakness, atrophy, fasciculations
Early ALS shows weakness of DISTAL muscles first.
UMN signs (weakness, hyperreflexia, spastic tone, and babisnki+.
NORMAL sensation
Patients die of respiratory and dysphagia

Question 14

What is treatment of ALS?

Answer 14

glutamate antagonist Riluzoe

Question 15

How is botox used for ALS?

Answer 15

can help prevent excess salivation

Question 16

What is a bunina body?

Answer 16

dense granule inclusion in cytoplasm of ubiquitin.

present in ALS.

Question 17

What is most common cause of genetic ALS?

Answer 17

expansion of C90RF72 on chromosome 9