Disorders of the cerebellum and its inflow or outflow pathways produce deficits in the rate, range, and force of movement. Anatomically, the cerebellum has three subdivisions. The archicerebellum (vestibulocerebellum) comprises the flocculonodular lobe, helps maintain equilibrium and coordinate eyehead-neck movements, and is closely interconnected with the vestibular nuclei. The midline vermis (paleocerebellum) helps coordinate movement of the trunk and legs. Vermis lesions result in abnormalities of stance and gait. The lateral hemispheres, which make up the neocerebellum, control ballistic and finely coordinated limb movements, predominantly of the arms. Signs of cerebellar disease are listed below.
Ataxia - it’s unstady, wide-based gait; decomposition of movement; it’s inability to correctly sequence fine, coordinated acts; Static ataxia develops at vermix lesion and means standing and walking disorders. Dinamic ataxia develops at lesion of hemispheres. The patient is asked to touch the tip of his nose with the tip of his index finger slowly with his eyes open (the finger nose test). Then this is repeated with the eyes closed. To test the lower extremities the patient is asked to touch the knee by the opposite knee and slide it down the shin bone (the heel knee test) with the opened and closed eyes. Incoordination, not of sensory origin (cerebellar), is present with both the eyes open and closed. These tests recognize dinamic ataxia.
The Romberg test recognizes static ataxia. Your patient stand with heels and toes together with open eyes and then with closed eyes. The tendency to unstable position with the eyes close provides a positive Romberg probe.
An intentional tremor which is brought on by action and ceases at rest is also characteristic.
Dysdiadochokinesia - inability to perform rapid alternating movements. The normal individual is able to perform successive movements rapidly, as alternate pronation and supination of the forearm, or extension and flexion of the fingers. In cerebellar lesions the patient's successive movements are increasingly clumsy and irregular in time.
Dysmetria - inability to control range of movement;
Hypotonia - decreased muscle tone. Weakness may interfere with the testing procedure. The hypotonicity or atonicity can be tested by forcible swinging and flopping of the extremities.
Nystagmus - involuntary, rapid oscillation of the eyeballs in a horizontal, vertical, or rotary direction, with the fast component maximal toward the side of the cerebellar lesion;
Scanning speech-slow enunciation with a tendency to hesitate at the beginning of a word or syllable. Dysarthria - inability to articulate words correctly, with slurring and inappropriate phrasing. Dysarthria should be carefully described, as these are often present in cerebellar diseases. Speech is usually tested while the history is taken. In cerebellar disturbances speech is slow, monotonous and interrupted by breath-taking pauses not at punctuation points.
Tremor - rhythmic, alternating, oscillatory movement of a limb as it approaches a target (intention tremor) or of proximal musculature when fixed posture or weight bearing is attempted (postural tremor);