Neuro/Psych 1 Flashcards
Deficient enzyme in Tay Sachs
Hexosaminidase A
Accumulated enzyme in Tay Sachs
GM2 ganglioside
Tay Sachs presentation
- Cherry-red spot in macula
- Progressive neurodegeneration (hypotonia, wkness, abnormal startle reflex)
- Histo: onion skin lamellar lipid rings on EM
AR
How is Tay Sachs different from Neimann-Pick Disease
TS: no hepatosplenomagaly
Similar eye and neuro findings
Ataxia-telangiectasia
- Defect in ATM gene => can’t repair DNA ds breaks
- Therefore hypersensitive to ionizing radiation
- Repeated sinopulmonary infections
- cerebellar ataxia
- Oculocutaneous telangiectasias
- increased incidence of malignancy
Function of glycine and GABA in neurons
They’re inhibitory!
They regulate LMNs
What’s the MOA of tetanus toxin?
- Retrograde axonal transport from motor neuro to CNS
- Prevents release of glycine/GABA
Causes: ^ed muscle activation => spasms hyperreflexia
What are signs of lithium toxicity?
ACUTE:
- GI: N/V/D
- Late neuro sequela
CHRONIC
- Confusion
- Agitation
- Ataxia
- Tremors/fasciculations
What are the causes of lithium toxicity?
- Overdose
- Volume depletion (decreased GFR)
- Drug interactions
Toxicity DDIs = Lithium + ______
- Thiazide diuretics
- NSAIDs (not aspirin)
- ACEIs
Inheritance & gene of Fragile X syndrome
X-linked
FMR1
Clinical presentation of Fragile X
- Long, narrow face
- Prominent chin & forehead
- Large testes
- Large everted ears
- Hyperlaxity w/ joints
- Developmental delay (speech and motor)
What are the top 2 most common causes of genetic intellectual disability?
1) Down syndrome
2) Fragile X syndrome
What is measured to determine neural tube defects?
- alpha-fetoprotein (AFP) — maternal serum & amniotic fluid
- acetylcholinesterase — only amniotic fluid
Both increased due to leakage of fetal CSF
CSF of viral meningitis
- Normal glucose
- Increased protein
- Increased (~90%) lymphocytes
