Coordination of movemnts - anatomy, physiology, examinaiton, corordination syndromes.
Definition
Coordination is the ability to perform smooth, accurate, purposeful, and well-timed movements. It requires the integration of sensory input with motor activity.
Anatomy and Physiology of Coordination
Normal coordination depends on the integrity of:
1. Cerebellum
- Main center for coordination
- Regulates force, speed, and accuracy of movement
- Maintains posture and balance
2. Vestibular System
- Maintains equilibrium and body position
- Coordinates eye and head movements
3. Proprioceptive Pathways
- Carry information about position and movement of limbs
- Posterior columns are essential
4. Motor System: Pyramidal and extrapyramidal systems execute movement
5. Sensory Cortex and Frontal Lobes: Planning and control of voluntary movements
Any lesion affecting these structures may cause incoordination (ataxia).
Examination of Coordination
The patient should be relaxed and cooperative. Compare both sides.
Upper Limb Tests
1.Finger-to-Nose Test: Patient touches their nose and then the examiner’s finger.
- Abnormal: Dysmetria, intention tremor.
2.Finger-to-Finger Test: Patient alternately touches examiner's fingers.
- Assesses accuracy of movement.
3.Rapid Alternating Movements:Rapid pronation and supination of hands.
- Abnormal: Dysdiadochokinesia.
Lower Limb Tests
1.Heel-to-Shin Test: Patient slides heel down the opposite shin.
- Abnormal: Irregular or wavering movement.
2.Gait and Balance Tests:
- Normal Gait Assessment:Observe walking pattern.
3.Tandem Gait: Heel-to-toe walking in a straight line.
- Abnormal: Swaying or inability to maintain balance.
4.Romberg Test: Patient stands with feet together, eyes open then closed.
- Positive Romberg: Loss of balance when eyes are closed.
- Suggests: Posterior column disease. Sensory ataxia
Romberg is usually negative in pure cerebellar ataxia.
Coordination Syndromes
1. Cerebellar Ataxia: Due to cerebellar lesions.
- Features: Wide-based gait. Dysmetria. Intention tremor. Dysdiadochokinesia. Nystagmus. Scanning speech. Hypotonia
Balance is impaired even with eyes open.
2. Sensory Ataxia: Due to lesions of the posterior columns or peripheral nerves causing loss of proprioception.
- Features: Stamping gait. Worse in darkness. Positive Romberg sign. Loss of vibration and position sense
3. Vestibular Ataxia: Due to vestibular system disorders.
- Features: Vertigo. Nausea and vomiting. Nystagmus. Tendency to fall toward the affected side