====== Cerebellar Cognitive Affective Syndrome ======

===== Cerebellum’s Cognitive Role =====

The cerebellum is traditionally associated with motor coordination, but modern neuroscience has revealed its key role in **cognition** and **emotion**.

==== Cerebellar Cognitive Affective Syndrome (CCAS) ====
Coined by Schmahmann and Sherman (1998), this syndrome includes:
  * **Executive dysfunction**: impaired planning, working memory, abstract reasoning.
  * **Spatial disorganization**: visuospatial deficits.
  * **Language impairments**: dysprosody, anomia, agrammatism.
  * **Personality changes**: apathy, disinhibition, emotional flattening.

This constellation is described as ''dysmetria of thought''—a cognitive equivalent to motor dysmetria.

==== Anatomical and Functional Basis ====
  * **Cerebro-cerebellar loops**: The dentate nucleus communicates with prefrontal, parietal, and limbic cortices via thalamic relays.
  * **Neuroimaging evidence**:
    * fMRI and PET show cerebellar activation during:
      * Language tasks (especially right cerebellar hemisphere).
      * Working memory tasks.
      * Emotion processing.
      * Social cognition.

==== Domains of Cognitive Involvement ====

^ Domain              ^ Manifestation of Cerebellar Dysfunction ^
| Executive function  | Disorganized thought, impaired reasoning |
| Language            | Poor verbal fluency, word-finding issues |
| Visuospatial skills | Constructional apraxia, disorientation   |
| Emotion and affect  | Apathy, irritability, emotional blunting |
| Social cognition    | Difficulty interpreting emotions/intentions |

==== Clinical Implications ====
  * **Neurodevelopment**: Implicated in Autism Spectrum Disorder (ASD), ADHD.
  * **Psychiatry**: Functional abnormalities linked to schizophrenia, depression, bipolar disorder.
  * **Surgical relevance**: Post-operative CCAS may occur after posterior fossa surgery, especially in children (e.g. cerebellar mutism syndrome).

==== Summary ====
The cerebellum plays a critical modulatory role across **motor, cognitive, and affective** domains. It acts as a ''universal calibrator''—coordinating not just movement, but also **thought** and **emotion**.