Neuromuscular Flashcards
Familial ALS gene (FLAS)?
Inheritance?
SOD1 and C9orf72
AD
Spinal Muscular Atrophy (SMA)
1) Gene & Chromosome?
2) What modulated the phenotype?
1) SMN1 Gene on Chromosome 5p (AR dz = 0 fucntioning SMN1 copies)
2) SNM2 copy number modulates phenotype (i.e., more SMN copies correlates with milder symptoms)
Hexosaminidase A deficiency:
1) A/w with accumulation of ________ within _____ ?
2) A/w what disease(s)?
3) T/F - Can be a/w psychiatric features?
Hexosaminidase A deficiency results in a group of neurodegenerative disorders caused by intralysosomal storage of the specific glycosphingolipid, GM2 ganglioside.
The prototype hexosaminidase A deficiency is Tay-Sachs disease, also known as the acute infantile variant. Tay-Sachs disease is characterized by progressive weakness, loss of motor skills, decreased attentiveness, and increased startle response beginning between ages three and six months with progressive evidence of neurodegeneration including: seizures, blindness, spasticity, eventual total incapacitation, and death, usually before age four years.
The juvenile (subacute), chronic, and adult-onset variants of hexosaminidase A deficiency have later onsets, slower progression, and more variable neurologic findings, including: progressive dystonia, spinocerebellar degeneration, motor neuron disease, and, in some individuals with adult-onset disease, a bipolar form of psychosis.
Kennedy’s dz:
1) Inheritance?
2) Descriptive name? (sans eponym)
3) Age of onset?
4) Other primary organ system involved?
X-Linked Spinal Bulbar Muscular Atrophy:
Individuals with SBMA have muscle cramps and progressive weakness due to degeneration of motor neurons in the brain stem and spinal cord.
Ages of onset and severity of manifestations in affected males vary from adolescence to old age, but most commonly develop in middle adult life. The syndrome has neuromuscular and endocrine manifestations (e.g., gynecomastia).
Vit B6 (Pyridoxin) TOXICITY:
1) Primarily affects the ____ within the CNS/PNS?
2) Primary exam findings (3)
1) Affects Dorsal root ganglion (Sensory Neuron dz) AKA sensory Neuronopathy:
2) Exam:
- All modality sensory loss
- Ataxia (early Ataxia—–very important finding)
- Areflexia
(normal motor exam/strength)
Vasculitis Neuropathies
Enlarged Hypoechoic nerves on US—-Pathognomonic Usually asymmetric neuropathy (Mononeuritis Multiplex) plus other systemic symptoms eg: Kidney, GI, Skin, fatigue, etc.
Foot INVERSION
- Primary nerve involved?
- Roots?
- Muscle?
Tibial Nerve
(L4-L5)
Tibialis Posterior muscle
Foot Eversion and Dorsiflexion
Primary nerve?
Peroneal Nerve
Myokymic discharges on EMG needle exam
Radiation induced Plexopathy
Patient had lung Cancer, Had XRT, now has plexopathy.
Cancer recurrence or XRT?
If there is Myokymia on EMG it is XRT
Erb’s Palsey (Waiter’s Tip):
1) Two common etiologies?
2) Trunk? Roots?
3) Weakness of ____ ?
4) Sensory loss distribution?
1)
- Most common Plexopathy in newborn
- Common in MVA eg: Motor cycle accident head goes one way and arm the other way.
2) Upper Trunk; C5, C6
3) Weakness: - Shoulder Abd (Deltoid/Axillary N.)
- Elbow flexion(Bicep/Musculocutanous N.)
- Arm Supination
4) Numbness: LATERAL forearm
Klumpke Palsey:
1) Mechanism
2) Trunk involved? Roots?
3) Weakness?
Numbness?
1) Usually occur when arm and shoulder are pulled up
2) Lower Trunk; C8, T1
3) Weakness: Intrinsic hand muscles & wrist flexors –> ‘claw hand’
4) Numbness: MEDIAL forearm (C8, T1 dermatome)
Femoral Nerve (Roots)
Lumbar Plexus; L2, L3, L4
(Same as obturator)
Sciatic Nerve (Roots)
Lumbosacral Plexus; L4, L5, S1
GABA 8 Receptor agonist
Baclofen
Stimulated by GlutamateInhibited by GABA and Glycine
Anterior horn cells
By enzyme:Glutamate Decorboxylase (GAD)GAD65 Ab blocks this enzyme in stiff person syndrome
Glutamate is broken into GABA
Blocks the release of presynaptic GABA and Glycine
Tetanus
