Exam #3: Lesions III Flashcards
What are the four general functions of the basal ganglia?
1) Inhibiting involuntary movement at rest
2) Disinhibiting voluntary movement
3) Accelerating voluntary movements
4) Stopping movements upon completion
Once you have identified that there is a basal ganglia deficit, accompanied by behaviroal deficit, what structure is implicated?
Head of the caudate
What are the MRI signs of Huntington’s Disease?
- Atrophy of the Head of the Caudate with enlarged lateral ventricles
- Loss of corticostriatal fibers that leads to cortical atrophy
What is the name for the pathognmenoic presentation of Huntington’s Disease?
Chorea
- ***Note that patients also have:
- Dystonia
- Torticolis
- Blepharospasm
- Athetosis
- Hemiballismus
What is dystonia?
Constant contraction of a muscle
What is Torticolis?
“Twisted neck”
What is a blepharospasm?
Involuntary blinking and holding of the eyes shut
What type of tremor is seen in PD?
“pill-rolling”
What are the characteristics of PD?
- Pill-rolling tremor
- Difficulty initiating movement
- Reptilian stare–lack of blinking
What is the general sequence of structures in the basal ganglia?
Cortex
Striatum
Pallidum
Thalamus
What is a surgical intervention for PD?
Pallidotomy
What are the major functions of the cerebellum?
1) Integration of equilibrium & locomotion
2) Integration of head & eye movements (MLF)
3) Coordinating voluntary movements
What tract sends cortical information to the cerebellum (via the pons)?
Corticopontocerebellar pathway
What pathway runs from the cerebellum to the cortex?
Dentorubrothalamic tract
What are the tracts that make adjustments to ongoing movements?
Vestibulospinal
Rubrospinal
What type of deficits are seen in cerebellar lesions?
IPSILATERAL deficits
Where does the corticopontocerebellar tract cross-over?
Pons
If you lesion the cerebellum directly in the midline, which direction will the patient fall?
Equal amount of chance to fall to EITHER side
What arteries supply the cerebellum?
AICA
PICA
What part of the brain must AICA go around?
Pons
*****AICA sends a few arteries to the pons (laterally) as it goes around it–at the pontomedullary junction
What part of the brain must PICA go around?
Brainstem
**PICA sends a few arteries to the brainstem (laterally)
Where does the superior cerebellar artery send bracnhes?
Midbrain
- Supplies the superior cerebellum, but as it travels to the cerebellum, it also supplies the midbrain
What type of lesion should you suspect if you see mixed brainstem & cerebellar signs?
Infarct of the superior cerebellar artery
What are the hallmarks for SCA Syndrome?
- Ipsilateral Dysmetria
- Contralateral pain & temperature loss
- Contralateral superior oblique paralysis
- Ipsilateral Horner’s Syndrome
What are the symptoms of Horner’s Syndrome?
- Upper lid ptosis
- Constricted pupil
- Flushed, dry face
