Cerebellar disorders may result in symptoms such as incoordination, clumsiness and tremors in limbs, posture and gait.
Cerebellar diseases cause incoordination, clumsiness and tremors because the cerebellum is responsible for smoothing out and refining voluntary movements. The cerebellum is the region of the brain responsible for controlling stance, gait and balance, as well as the coordination of complex and goal-directed movements.
The acute onset of cerebellar symptoms is considered a medical emergency and requires immediate medical attention. When the cerebellum is damaged, the nerve signals become disjointed and fail to flow smoothly, making usual, daily tasks difficult.
Common signs and symptoms of cerebellar disorders
Head
- Nystagmus
- A vision condition in which the eyes make repetitive, uncontrolled movements.
- These movements typically result in reduced vision and depth perception, often affecting balance and coordination.
- These involuntary eye movements can occur from side to side, up and down or in a circular pattern.
- Titubation
- Resting tremor of the head (rotatory, rocking or bobbing movement).
- Staccato speech
- Patients may have explosive, monosyllabic speech.
- Skew deviation of the eyes
- Vertical misalignment of the eyes.
- One points up and the other points down, resulting in diplopia of vertical gaze.
- The head ends up being tilted toward the side of the lower eye.
- Ocular dysmetria
- A constant under- or over-shooting of the eyes when attempting to focus the gaze on something.
- Others
- In some cases of cerebellar disorders, patients may have head deviation and or inaccurate finger–nose or finger–finger coordination.
Upper limb
- Tremor
- Coarse, rapid, side-to-side oscillations on the affected side.
- Drift
- When outstretched, the arm will drift aimlessly.
- When the arm’s position is changed with a sharp tap, the arm position may overcorrect and won’t be able to achieve its original position.
- Dysdiadochokinesis
- The patient will be unable to perform rapid alternating movements, such as repeated pronation-supination.
Trunk
- Truncal ataxia
- The patient will not be able to sit up straight with their eyes closed and may even fall over.
- A person will be unable to sit on the bed without steadying themselves.
Lower limb
- Gait disturbance
- The classical sign of a cerebellar disorder is a wide-based stance at rest.
- The person will also walk with their legs far apart to balance themselves.
- Tandem gait
- The cerebellar patient may not be able to walk heel-to-toe without losing balance.
- In some cases, patients may not be able to smoothly run their heel along their shin (performed under heel-shin test).
- Stagger
- The cerebellar patient may stagger like a drunk person to the side of the lesion.
The main clinical features of cerebellar disorders include incoordination, imbalance, tremors and troubles with eye movements.
What are the two distinguishable cerebellar syndromes?
There are two distinguishable cerebellar syndromes:
- Midline cerebellar syndromes
- These syndromes are characterized by an imbalance
- Patients are unsteady and are unable to stand and maintain balance with their eyes open or closed
- Severe midline disturbance causes truncal ataxia (dyscoordination)
- Some persons have bobbing motions of the head or trunk (titubation)
- Also often affect eye movements, and there may be nystagmus, ocular dysmetria and poor pursuit
- Hemispheric cerebellar syndromes
- They are characterized by incoordination of the limbs.
- There may be the decomposition of movement, dysmetria and rebound.
- Dysdiadochokinesis (the irregular performance with rapid alternating movements) is often seen in this syndrome.
- Tremors may be present when attempting to touch an object (intention tremors).
- A kinetic tremor may be present (tremor prominent when the digit is in motion).
- The finger-to-nose and heel-to-knee tests are classic tests of hemispheric cerebellar dysfunction.
- While reflexes may be depressed initially with hemispheric cerebellar syndromes, this cannot be counted on.
- Speech may be dysarthric, scanning or have an irregular emphasis on syllables.
There is no single specific treatment for cerebellar disorders. Instead, treatment is used to improve or relieve specific symptoms, and the goal is to improve the quality of life for the patients. Treatment often includes both pharmacological and nonpharmacological interventions. Early intervention with physical and occupational therapy, as well as neuropsychology for associated learning disorders, are required to ensure that patients with cerebellar disorders reach their potential.
What is cerebellar degeneration?
Cerebellar degeneration is a process in which neurons (nerve cells) in the cerebellum (the area of the brain that controls coordination and balance) deteriorate and die. Causes of the syndromes may be classified as either:
- Hereditary
- (Friedreich’s ataxia, cerebellar cortical atrophy, multisystem atrophy and olivopontocerebellar degeneration)
- Acquired
- (multiple sclerosis, stroke, chronic alcohol abuse or paraneoplastic syndromes)
Diseases that cause cerebellar degeneration can also involve other areas of the central nervous system, including the spinal cord, cerebral cortex and brainstem. Cerebellar degeneration may be the result of changes that alter the normal production of specific proteins that are necessary for the survival of neurons.
The signs and symptoms of cerebellar degeneration are:
- Wide-based, unsteady, lurching walk, which is often accompanied by a back-and-forth tremor in the trunk of the body
- Slow, unsteady and jerky movement of the arms or legs
- Slowed or slurred speech
- Nystagmus
There is no cure for hereditary forms of cerebellar degeneration. Treatment is usually supportive and is based on the person's symptoms. For example, drugs may be prescribed to ease gait abnormalities, while physical therapy can strengthen muscles. Other disorders that may contribute to cerebellar degeneration can use treatment to ease symptoms.