Cerebellum Dysfunction Flashcards
Describe the Cerebellum
- Little brain
- recieves input from almost all sensory systems (except SMELL AND TASTE)
- sensory input into the cerebellum is citical in the cerebllums fucntion in motor control
- COMPARES INTERNAL FEEDBACK WITH EXTERNAL FEEDBACK AND GENERATES CORRECTIVE SIGNALS FOR SUBSEQUENT MOVEEMNTS IN ORDER TO REDUCE ERRORS (FEEDFORWARD MECHANISM)
- mostly uncrossed. Therefore damage to the cerebellum will lead to Unilateral and IPSILATERAL motor impairment - some bilateral
Etiology for cerebellum
- Stroke (hemorrhagic>ischemic)
- TBI
- Hypoxic brain injury
- Nutritional disorder
- Exogenous Substances (alc, meds (anti-coagulants, anti-epileptics)
- Idiopathic disorders (oliviopontocerebellar atrophy)
- Congenital disorders (Arnold-Chiari malformation) (deformity where cerebellum descends down through Foramen magnum - compression)
- Hereditary (Friedreichs ataxia) - cerebellar ataxia and sensory
- Hypothyroidism
- MS
Functional regions of cerebellum and S+S for lesions to them
- Midline: Truncal ataxia, titubation (oscillatory moveemnts at head or trunk), orthostatic tremmor (when standing b/l legs shaking) gait imbalance
- Hemispheres: Limb ataxia, Dysarthria, hypotonia
- Posterior: eye movement disorders (nystagmus, VOR disruption), posture and gait imbalance
Define Asthenia
- Generalized mm weakness found in cerebellar lesions
What are the 13 Motor Impairments
- Astenia
- Ataxic gait
- Dysarthria
- Dysdidokinesia
- Dysmetria
- Dysrhythmia
- Dyssynergia
- Hypotonia
- Motor leanirng problems
- Nystagmus
- Rebound Phenomonen
- tremor
Define Ataxic Gait
- Ambulatory patterns in Cerebellum lesions include:
–> high BOS, high guard position, stepping pattern is irregular in direction and distance
–> unsteady, irregular, and staggering with deviations from LINE OF PROGRESSION
–> high falls risj
Walk like a baby - hands up in the air, wide BOS, staggering, varied length of steps and directions
Define Delayed reaction time
icnreased time to initiate voluntary movement in response to stimuli
Define dysarthria
Motor speech disorder affecting muscles to produce speech (lips, tongue, vocal cords)
- cerebellar or ataxic dysarthria is characterized by scanning speech (one syllable at a time)
-speech slow and slurred
Define Dysdiadokinesia
impaired ability to performing RAPID alternating movement
Define Dysmetria
Inability to judge length or distance of moevemnts
- Hypermetria: pverestimating distance of moevemnt
- Hypometria: underestimating distance (undershooting target)
Define Dysrhythmia
Abnormal rhythma nd timing of movement
Define Dyssenergia
inability to perform movements as SINGLE, SMOOTH activity.
Movement performed in sequence of parts
- AKA movement decomposition
Define Hypotonia
- decreased mm tone (decreased resistance to passive moevements)
- dissapears WITHIN A FEW WEEKS following acute lesion
Define Motor learning problems in cerebellum
- cerebellum compares internal feedback with external feedback
- feedforward control imapired
Define Nystagmus
- Rhythmic oscillatory movements of the eye back and forth
- affects accurate fixation of vision
- Believed to be due to cerebellum’s influence on the extra-occular muscle’s
synergy and tone
Define Rebound Phenomenon
Ability to stope forceful active moevemnt when resistance is removed –> AKA check reflex
“isometric resistance of flexed shoulder - when we let go of the force - their arm shouldn’t fly up”
Define Tremor and the 2 types
- Intention tremor
- Kinetic tremor: oscillatory movement during voluntary moevemnt
- increases as speed is increased - or when approaching atrget - Postural tremor (static tremor)
- oscillatory movements during static position
- back and forth oscillatory movements of the body is seen in upright static position (Titubations) is a type of postural tremor
What are the 14 Nonequilibrium Coordination tests for Crebellum
- Finger to nose
- Finger to therapist finger
- Finger to finger
- alternative nose-to-finger
- finger opposition
- Mass grasp
- Pronation/suppination
- Rebound test
- tapping
- Alternate heel to knee: heel to-toe
- Toe to examiners finger
- Heel on shin
- Drawing a circl
- Position holding
Define Finger-to-nose
- shoulder abducted to 90 with elbow extended
- pt instructed to bring tip of finger to his or her nose
- Dysdidokinesia
- Dysynergia
- Dysmetria
Define finger-to-therapist finger
- patient instructed to touch therapists index finger with their index finger
–> intention tremmor
Define Define finger to finger
both shoulders abducted to 90 with elbows extended
- touch index fingers of opposing hands in midline
Alternate nose-tofinger
alternativley touch their nose and the therapists finger
Finger opposition
touch tip of thumb to each finger in sequence
- speed icnreased
Mass grasp
alternate between opening and closing fist
