Can medical conditions affect the results of the HGN test?

Medical conditions can indeed affect the results of the HGN test, particularly those that involve neurological disorders. HGN is a test used by law enforcement to assess whether a person is under the influence of alcohol or drugs, focusing on involuntary eye movements. Conditions such as multiple sclerosis, stroke, or even certain inner ear issues can cause abnormal eye movements that may mimic or obscure the signs typically associated with impairment due to substance use.

Individuals with neurological issues might display nystagmus or other eye movement irregularities that are unrelated to alcohol consumption, leading to a false positive during the HGN assessment. Understanding the medical context is crucial for accurately interpreting the results of this test. This recognition of how various health issues can influence the test results underscores the importance of a comprehensive evaluation beyond just the HGN findings alone.