Final answer:
The assessment finding best associated with neonatal abstinence syndrome is a negative startle reflex. This condition typically exhibits an exaggerated startle reaction, which is a hyperactive response to stimuli and indicative of withdrawal symptoms in neonates.
Step-by-step explanation:
The neonate exhibiting abstinence syndrome is likely to present with a set of clinical manifestations due to withdrawal from substances to which they were exposed in utero. Among the choices given, increased drowsiness, diminished tendon reflexes, and hypothermia are not commonly associated with neonatal abstinence syndrome (NAS). Instead, the common assessment findings are hyperactivity of reflexes, tremors, irritability, and poor feeding, among others.
Therefore, the assessment finding that is best associated with neonatal abstinence syndrome is a negative startle reflex. This condition is characterized by a hyperactive response to stimuli, such as an exaggerated startle reaction. Since neonates usually have a well-developed sense of touch and respond to gentle touch and comfort, the lack of a normal startle reflex or an exaggerated startle reflex can be an indicator of NAS.
It's important to note that specialized scales are used to evaluate withdrawal symptoms in neonates, and management of the condition requires a healthcare professional's involvement.