Cerebellum Structure and Function Flashcards
Anatomically, the cerebellum is divided into the __ lobe and __ lobe, as well as the __-nodular lobe.
Anterior lobe of cerebellum; aka the __ cerebellum→ primary input is limbs via spinal connections. Function is __, __ __, axial muscle control and locomotion
Posterior lobe: aka the __ cerebellum→ primary connections with the cerebral cortex. Main function is to __ __ and fine motor control of the limbs
Flocculonodular lobe; aka the __ cerebellum → primary input with the vestibular apparatus of the __, main function is for eye movement and ___ in space
Fissures separate parts of the cerebellum;
primary fissure; separates anterior to posterior lobe.
Anatomically, the cerebellum is divided into the anterior lobe and posterior lobe, as well as the follicular-nodular lobe.
Anterior lobe of cerebellum; aka the spinal cerebellum→ primary input is limbs via spinal connections. Function is posture, muscle tone, axial muscle control and locomotion
Posterior lobe: aka the cerebral cerebellum→ primary connections with the cerebral cortex. Main function is to coordinate movements and fine motor control of the limbs
Flocculonodular lobe; aka the vestibular cerebellum → primary input with the vestibular apparatus of the ear, main function is for eye movement and orientation in space
Fissures separate parts of the cerebellum;
primary fissure; separates anterior to posterior lobe.
Cerebellum is also divided into lobules. The flesh colored middle portion is part of the cerebellum that is attached to the rest of the brain through the pons. They are known as the cerebellar peduncles (superior, middle and inferior cerebellar peduncle)
Everything that flows in and out of the cerebellum goes through the peduncles.
Different peduncles have different inputs and outputs:
superior CBL peduncle: primarily ____ from the cerebellum
Middle CBL peduncle: exclusively ___ to the cerebellum
INferior CBL peduncle: Primarily ___ to the cerebellum
superior CBL peduncle: primarily OUTPUT from the cerebellum
Middle CBL peduncle: exclusively INPUT to the cerebellum
INferior CBL peduncle: Primarily INPUT to the cerebellum
The midline of the cerebellum→ ___.
Area immediately following the vermis → __.
Lateral hemispheres flank both paravermi.
The midline of the cerebellum→ vermis.
Area immediately following the vermis → paravermis.
Lateral hemispheres flank both paravermi.
Vascular Supply of the Cerebellum
Most of the cerebellum is supplied by the __ __ __. The posterior part of the cerebellum is partially suppliked by the __ __ __ __ (PICA), and the flocculonodular lobe is supplied by ___ (the nateiror and posteiror inferior cerebellar)
Part of the cerebellum and the pons are supplied by the ___ artery, as well as some of the cerebellar arteries.
Vascular Supply of the Cerebellum
Most of the cerebellum is supplied by the superior cerebellar artery. The posterior part of the cerebellum is partially suppliked by the posterior inferior cerebellar artery (PICA), and the flocculonodular lobe is supplied by A-PICA (the nateiror and posteiror inferior cerebellar)
Part of the cerebellum and the pons are supplied by the basilar artery, as well as some of the cerebellar arteries.
Cerebellar Syndromes can be characterized as focal or diffuse cerebellar abnormalities, based on examination.
Focal lesions include :
Diffuse lesions will have more clinical manifestations, and can have a number of etiologies (___), degenerative (____), toxic, inflammatory (ex/ ___– through molecular mimicry, you develop antibodies to the tumor, but you also end up developing an immune response to the purkinje cells/other own body cells.)
Post infectious cerebellitis would show elevated cell counts in the CSF and ___ protein
Cerebellar Syndromes can be characterized as focal or diffuse cerebellar abnormalities, based on examination.
Focal lesions include tumor, traumas, stroke (look at the vascular territories), or inflammatory disorders like MS
Diffuse lesions will have more clinical manifestations, and can have a number of etiologies (post infectious cerebellitis, particularly in pediatric population), degenerative (sporadic or genetic), toxic, inflammatory (ex/ paraneoplastic– through molecular mimicry, you develop antibodies to the tumor, but you also end up developing an immune response to the purkinje cells/other own body cells.)
Post infectious cerebellitis would show elevated cell counts in the CSF and high protein
Post infectious cerebellitis would show elevated cell counts in the CSF and __ protein
Post infectious cerebellitis would show elevated cell counts in the CSF and high protein
Lesions in the cerebellum will produce ___ symptoms to the lesion
Lesions in the cerebellum will produce ipsilateral symptoms to the lesion (they already crossed over).
Anterior lobe lesions; seen more in ___ related lesions
Caudal vermis lesions affect the ___ lobe; seen more in ____.
If contained in the vermis, you might have more-normal limb coordination, compared to if the lesion affected the rostral/anterior lobe.
If the flocculonodular lobe is affected, may have more visual disturbances.
Any lobe can be affected by a stroke, and will show as a hemispheric syndrome.
Lesions in the cerebellum will produce ipsilateral symptoms to the lesion (they already crossed over).
Anterior lobe lesions; seen more in alcoholic related lesions
Caudal vermis lesions affect the flocculonodular lobe; seen more in medulloblastoma.
If contained in the vermis, you might have more-normal limb coordination, compared to if the lesion affected the rostral/anterior lobe.
If the flocculonodular lobe is affected, may have more visual disturbances.
Any lobe can be affected by a stroke, and will show as a hemispheric syndrome.
Lesions in the cerebellum will produce ipsilateral symptoms to the lesion (they already crossed over).
Most common Autosomal Recessive Spinocerebellar Ataxia is ___ ___. Common in the ___ population.
Friedreich Ataxia (FA)
- often diagnosed in the pediatric population
Friedreich Ataxia is an autosomal recessive pattern of a spinocerebellar ataxia. It’s assocaited with the FRDAI1 gene on chromosome 9, whic codes for the ___ protein, involved in iron metabolism in the mitochondria.
What symptoms are involved? systemic symptoms? Treatment?
Friedreich Ataxia is an autosomal recessive pattern of a spinocerebellar ataxia. It’s assocaited with the FRDAI1 gene on chromosome 9, whic codes for the FRATAXIN protein, involved in iron metabolism in the mitochondria.
- Hyper or Areflexic
- Visual abnormalities
- Marked axonal sensory neuropathy
- Systemic symptoms include: cardiomyopathies (inverted Twaves, ventricular hypertrophy, Diabetes, pes cavus, equinovarus, hammer toe, scoliosis).
- On MRI: signal abnormalities in the posterior and lateral columns and thinning of the spinal cord.
Treatment: Idebenone (synthetic coenzyme Q10 analogue) has been shown to help reduce cardiomyopathy. The rest of the treatment for FA is symptomatic.
Symptoms: 50-80yo at onset.
- Cerebellar: kinetic tremor, parkinsonism, cognitive decline, autonomic dysfunction, ataxia (gait).
- Systemic: soft velvety skin, broad forehead (macrocephalic), macroorchidism, hyper flexible joint, MV prolapse
What cerebellar injury could this be?
X linked Spinocerebellar Ataxia Syndromes
Fragile X tremor ataxia syndrome
Definition: X-linked disorder leading to cerebellar dysfunction
Symptoms: 50-80yo at onset.
- Cerebellar: kinetic tremor, parkinsonism, cognitive decline, autonomic dysfunction, ataxia (gait).
- Systemic: soft velvety skin, broad forehead (macrocephalic), macroorchidism, hyper flexible joint, MV prolapse
Although this is an X Linked disorder, it can still happen in women and lead to premature ovarian failure.
Investigations:
- MRI: middle cerebellar peduncle hyperintensities, white matter changes
- Genetics: X-linked expansion CGG in FMR1 gene (premutation 61-200; affected >200)
Multiple System Atrophy (MSA)
Actually a form of __ but also has cerebellar signs.
Two forms: MSA-P (__) or MSA-C (__)
__ to __ rate of progression– most become wheelchair bound within the first few years.
Dysarthria, dysphadia, pseudobulbar affect, early autonomic dysfunction
Slurring of speech, swallowing difficulties.
Pyramedial signs (cortical spasticity) in addition to the rigidity, and systemic symptoms as well– marked constipation and bladder dysfunction, cardiology and sleep problems.
__ __ sign on MRI.
Multiple System Atrophy (MSA)
Actually a form of parkinsonism but also has cerebellar signs.
Two forms: MSA-P (Parksinsonian) or MSA-C (Cerebellar)
Moderate to rapid rate of progression– most become wheelchair bound within the first few years.
Dysarthria, dysphadia, pseudobulbar affect, early autonomic dysfunction
Slurring of speech, swallowing difficulties.
Pyramedial signs (cortical spasticity) in addition to the rigidity, and systemic symptoms as well– marked constipation and bladder dysfunction, cardiology and sleep problems.
Cross bun sign on MRI.
SCI can be characterized as supraspinal, spinal, and spinal.
Suprasacaral and supraspinal is UMN pattern, Infra Sacral/spinal is more of a LMN pattern of injury.
