Cerebellar Degeneration MRI

A 41 yo female with slow progressive ataxia, slurred speech since last 15 years. Truncal ataxia on neurological examination. Family history of similar complains was present. 

MRI sagittal T1 and T2w images show:
Marked atrophy of the cerebellum.

Normal brain stem (midbrain, pons and medulla are spared)

Cerebellar Degeneration: 
Atrophy of the cerebellum is associated with many genetic conditions.
Non genetic causes include chronic severe alcohol intake, paraneoplastic syndromes, drugs like Phenytoin.
The nomenclature of genetic disorders associated with cerebellar atrophy is complex. Most are classified by the chromosomal location and pattern of inheritance. In many, a specific gene mutation or defective protein has been found. In the past, these disorders were referred to as cerebellar degeneration, spinocerebellar degeneration and olivopontocerebellar atrophy (OPCA) depending on whether the cerebellum, spinal cord, brainstem or a combination of any of the above affected.

Spino Cerebellar Degeneration MRI

A 28 yo male, C/o slow progressive ataxia and slurred speech. On neurological examination nystagmus, altered cognition. Family history significant.

MRI sagittal T1 and T2w images show:

Marked atrophy of the cerebellum and Brain stem, compensatory enlargement of adjacent Cp angle cisterns and fourth ventricle.

Imaging findings and history is consistent with a clinical diagnosis of Spinocerebellar Degeneration - Spino Cerebellar Ataxia.


Spino Cerebellar Ataxia (SCA)
Atrophy confined to cerebellum and Pons is an imaging wise diagnostic clue.
These neurodegenerative disorders, once termed Olivo Ponto Cerebellar Atrophy (OPCA), comprise a large group of inherited disorders characterized by progressive ataxia and brainstem signs.
DNA analysis in this patient demonstrated SCA Type 2; typically manifests with progressive gait and limb ataxia, dysarthria and slow saccadic eye movements.
The SCA-2 mutation is an expansion of an unstable CAG repeat located in the ataxin-2 gene on chromosome 12q24.1.

Huntington's Disease MRI

A 51 yo male under psychiatric treatment over several years. Relative complaining of his dementia. On neurological examination noticed Chorea. Family history was significant; father had a milder but similar illness.

Coronal MRI T1w image show:
Marked atrophy of caudate nuclei with ex vacuo dilatation of frontal horns. 
An associated diffuse cerebral cortical Atrophy.  

Imaging findings and history is consistent with Huntington's Disease.

Syn: Huntington Chorea.
An autosomal dominant neuro degenerative disorder with loss of GABAergic neurons of basal ganglia.
Clinically characterized by triad of Dementia, Choro athetosis and Psychosis.
Imaging wise diagnostic clue is caudate nuclei atrophy.
Age: Adult onset : 35 - 45years, Juvenile onset : < 20 years; M=F

Alzheimer's Disease MRI

A 60 yo female came for follow up MRI imaging. 

Now with new C/o recent onset slow progressive memory loss.  No family history.

This present MRI show marked diffuse cerebral atrophy compared to previous 2 years old MRI.

The 2 years old MRI

Imaging findings, comparison with previous MRI and history is consistent with Alzheimer's Disease.

Syn: Alzheimer Dementia.
A progressive neuro degenerative disorder of brain.
Clinically characterised by early onset dementia.
Parietal and temporal cortical atrophy, marked atrophy of hippocampi are the imaging diagnostic clue.
Most cases are spontaneous, ~5 to 10 % are familial and Autosomal Dominant.
Etiology:
Development of neurofibrillary tangles (NTs) and Senile plaques along cortical Memory pathways is the precursor of pathology. In neurofibrillary tangles there is deposition of tau protein and in Senile plaques there is deposition of beta Amyloid protein.
NTs impair Glucose transport and Senile plaques promotes inflammatory cascade.
These abnormal protein accumulation along cortical Memory pathways result in neuronal loss and impairs memory and cognition.

Corticobasal Ganglionic Degeneration

A 75 yo male ataxia. On neurological examination marked apraxia and cortical sensory loss like astereognosis). Increased tone in lower limbs.

MRI Axial T1 image show atrophy with marked widening of cortical sulci in parietal region. No signal abnormality in brain parenchyma on T2w images suggestive of cerebral cortical atrophy confined to parietal lobes.

Imaging finding of bilateral parietal lobe atrophy with history is consistent with a clinical diagnosis of Corticobasal Ganglionic Degeneration.


Corticobasal ganglionic degeneration (CBGD)
A rare Neurodegenerative disorder.
Imaging wise cerebral cortical atrophy prominently involving parietal lobes along with basal ganglia.
Clinically characterised by prominent cortical sensory loss and Apraxia. Alien hand syndrome, whereby pt complaints that he feels that his hands are disconnected from the rest of their body.
Dysfunction of the basal ganglia results in features of Parkinsonism, including increased tone, bradykinesia and gait disturbance. However, in contrast to Parkinson's Disease, Levodopa and other similar drugs are ineffective in this condition.
CBGD has significant overlap with other rare neurodegenerative disorders, including frontotemporal dementia, primary progressive aphasia (PPA), Pick's disease and progressive supranuclear palsy (PSP).