Ataxia is uncoordinated movement while a gait disorder is an abnormal pattern or style of walking. Both of these are findings that can be associated with many different disease processes, and thus clinicians evaluating patients with these abnormalities should view them in the context of individual clinical circumstances.
When initially evaluating a patient with ataxia or a gait distubance, consider whether the observed abonormalities are secondary manifestations of systemic disease rather than primary neurologic processes. Key symptoms that may suggest systemic disease include headache, nausea, fever, and decreased level of alertness. The physical examination may also show abnormalities outside of the nervous system, such as orthostatic vital sign changes that can point to hypovolemia or other systemic illness. Some forms of nystagmus may be suggestive of a central nervous system (CNS) disease process.
When evaluating ataxia that is suspected as a primary problem, differentiate between motor and sensory causes. One finding that suggests a cerebellar motor lesion is dysmetria, which can be elicited by finger to nose testing where patients may undershoot or overshoot their movements. Dysdiadochokinesia may be elicited by having the patient alternately flip their palms and backs of their hands on their thighs where clumsy rapid alternating movements can be observed. Heel to shin testing by having the patient slide one heel down the opposite shin can be useful for distinguishing between primary cerebellar disease and other sensory processing abnormalities. Overshoot of the knee or ankle signifies cerebellar disease, while a wavering course down the shin suggests a deficit of proprioception.
The Romberg test is primarily a test of sensation and can help to distinguish sensory ataxia from motor disease. Unsteadiness with the eyes open suggests a cerebellar motor ataxia, whereas worsening symptoms with eyes closed suggests a sensory ataxia that is unmasked with the removal of visual input. Test the posterior columns of the spinal cord by evaluating vibration and position sense in the lower extremities. Abnormalities attributed to posterior column degeneration can occur in tabes dorsalis (neurosyphilis) and vitamin B12 deficiency.
Observe patient ambulation in the emergency department to fully evaluate potential ataxia or gait disturbances. Subtle proximal or distal weakness can be identified by observing the patient rise from a chair and walk on heels and toes. Tandem heel-to-toe walking may elicit subtle ataxia. Broad-based, unsteady steps are characteristic of a motor ataxic gait, while a sensory ataxia with loss of proprioception may be notable for abrupt movements and slapping of the feet with each impact. A senile gait that is slow, broad based, and with a shortened stride may be seen with aging, but also with neurodegenerative disease such as Parkinson's disease and normal pressure hydrocephalus. Patients with Parkinson's disease often develop a narrow-based festinating gait with small shuffling steps that become more rapid. Weakness of the peroneal muscle weakness can manifest as foot drop, and ...