When Things Go Wrong (55b, 66b - 77b, 79b) Flashcards
Which genetic mutation is implicated in familial ALS?
C9orf7
- Causes hexanucleotide repeat in chromosome 9
- Autosomal dominant inheritance
What are the EMG findings of small-fiber neuropathy?
None!
- EMG is normal
- Only detects abnormalities in large (A-alpha, A-beta) fibers
- Need to do skin biopsy
This can be super frustrating for patients if they are in pain, and the doctor says its in their head!
Describe the classic pattern of diabetic neuropathy
Is this characteristic of axonal or demyelinating neuropathy?
Glove and stocking pattern
Axonal
Which area of the cerebellum is damaged?
- Ataxia of the arm and leg
- Disorders of motor planning
Intermediate cerebellar hemispheres
Which area of the brain relays the major output pathway from the basal ganglia?
Ventral thalamus
Also releays major output from the cerebellum
Remember, the output nuclei of the basal ganglia are the substantia nigra pars compacta and the internal segment of globus pallidus
What are the goals of management for hemorrhagic stroke?
How is this accomplished?
- Prevent expansion of the hematoma
- Prevent compression of vital brain structures
Accomplished by:
- Lower blood pressure
- Secure ruptured vessel
- Give platelets + anticoagulants
How do you differentiate between benign essential tremor and Parkinsonism?
- Benign essential tremor
- Faster than Parkinsonism tremor
- Worse with anxiety, fatigue, temperature extremes
- Better with alcohol, sleep
- May be symmetric or asymmetric
- Parkinsonism
- Rest/pill-rolling tremor (4-6 Hz)
Typical acute CNS demyelinating symptoms include all of the following except?
- Optic neuritis
- Partial myelitis
- Abrupt onset of hemiparesis
- Double vision
- Balance impairment
c. Abrupt onset of hemiparesis
* Attacks take >1 day to develop in MS
What is the managment of primary CNS lymphoma?
- Chemotherapy (methotrexate)
- Radiation (whole brain)
- Corticosteroids can decrease edema initially, but disease will recur if other treatments are not used
Basal ganglia, direct pathway
- Receptor:
- Signals to:
- Promotes or inhibits movement?
Basal ganglia, direct pathway
- Receptor: D1 dopamine receptor
- Signals to: Globus pallidus internal segment, substantia nigra reticulata
- Promotes or inhibits movement: promotes movement
On a SPECT scan, what would you expect to see in a patient with Parkinson’s disease?
- Parkinson’s Disease = period-shaped substantia nigra
- Not normal; image B
- Not Parkinson’s Disease = comma shaped
- Normal; image A
- Patient may still have parkinsonism, but look for different etiology

A lare cyst with an “enhancing mural nodule” on MRI is most likely which kind of brain tumor?
Pliocytic astrocytoma
- Usually cerebellar
- Histology will show rosenthal fibers
Which tracts are involved in ALS?
Corticospinal and corticobulbar
How do we test for small fiber neuropathy?
- Skin biopsy
- QSART (a fancy sweat test)
- If sweating is reduced or it takes too long, indicates autonomic dysfunction
HSV-1 is associated with [meningitis/encephalitis]
HSV-2 is associated with [meningitis/encephalitis]
HSV-1 is associated with encephalitis (frontotemporal)
HSV-2 is associated with meningitis
HSV-1 generally causes worse outcomes; causes acute necrosis
How will agenesis of the corpus callosum affect intelligence, if there are no other structural brain abnormalities?
Intelligence is likely to be normal
What is myoclonus?
Brief, lightning-like muscle jerks
- Not rhythmic
- Parkinsonism tremor is rhythmic/predictable
- Most common = asterixis
- Quick flap of the hand
Which of the mechanisms is not considered to be a pathologic feature of multiple sclerosis ?
- Innate immune activation
- Axon damage due to metabolic stress
- Loss of Schwann cells
- Elaboration of increased sodium channels in demyelinated axons
c. Loss of Schwann cells
- Demyelination in MS is due to autoreactive lymphocytes and inflammation
- Will affect white AND grey matter
Which tumors are associated with “chicken wire vasculature” and “fried egg appearance”
Oligodendroglioma

A patient presents with headache is worst in the morning but diappears during the day, recurring the next day
The headache is worse with head shaking and the valsalva maneuver
They have been increasing in frequency and severity
What are you most concerned for?
Brain tumor
- Classic brain tumor headache = signs of increased intracranial pressure
Will Parkinson’s disease be symmetric or asymmetric at onset?
Asymmetric
Which tumor is associated with pseudo-rosettes and true rosettes?
Ependymoma
An infant is admitted to the NICU after imaging reveals bilaterally hypoplastic optic nerves, absent septum pellucidum, and thin corpus callosum.
What is the most likely diagnosis?
What screening tests should be ordered?
Septo-optic dysplasia
Order glucose monitoring screen and endocrine function tests
- Failure of midline prosencephalic structures
- 2/3 of the following confirm diagnosis:
- Optic nerve hypoplasia
- Pituitary defects
- Midline brain defects
A-alpha fibers are [motor/sensory]
A-beta fibers are [motor/sensory]
A-alpha fibers are motor
A-beta fibers are sensory






