Final answer:
Decreased muscle strength in an 84-year-old individual's bilateral upper extremities is an abnormal finding, likely indicative of Upper Motor Neuron (UMN) lesions. Evaluating such motor function involves resistance tests and the pronator drift test. Signs of UMN lesions include strong deep tendon reflexes, decreased control of movement, and spasticity, amongst others.
Step-by-step explanation:
An 84-year-old with decreased muscle strength in his bilateral upper extremities indicates an abnormal finding. A potential cause for this condition could be Upper Motor Neuron (UMN) lesions, which can originate from several diseases, such as cerebral palsy, multiple sclerosis (MS), or a stroke. When assessing muscle strength, an examiner provides resistance to the arms. The absence of lateral differences in strength suggests a global issue rather than a unilateral corticospinal tract deficit. The pronator drift test is an example where if a patient, with closed eyes, cannot maintain the arms extended with palms facing up, it indicates a failure in the motor system. Other symptoms that may arise with UMN lesions include muscle weakness, problems with coordination, and difficulty maintaining balance.UMN damage is characterized by specific signs such as strong deep tendon reflexes, decreased control of movement, pronator drift, a positive Babinski sign, spasticity, and the clasp-knife response. In contrast, Lower Motor Neuron (LMN) lesions typically present with flaccid paralysis, muscle atrophy, fasciculations, and diminished reflexes.The referenced case of the patient Leborgne shows the progression of paralysis and the associated UMN damage, exemplifying the gradual decline in motor function. This case also highlights other important neurological findings, such as assessing sensory systems with pinprick tests and visual acuity tests. The comprehensive evaluation of patients with suspected motor neuron damage is crucial to establish an accurate diagnosis and appropriate management plan.