A 62-year-old man comes to the office with his wife due to behavioral changes. The patient has become increasingly impulsive and irritable over the past 1-2 years. He recently lost his job after making inappropriate comments and touching female coworkers. The patient has also lost interest in his hobbies and appears withdrawn during social gatherings. His other medical problems are hypertension and hyperlipidemia. A thorough neuropsychological assessment is conducted. Inability to perform which of the following tasks would be most indicative of frontal lobe dysfunction?

Question

A 62-year-old man comes to the office with his wife due to behavioral changes.  The patient has become increasingly impulsive and irritable over the past 1-2 years.  He recently lost his job after making inappropriate comments and touching female coworkers.  The patient has also lost interest in his hobbies and appears withdrawn during social gatherings.  His other medical problems are hypertension and hyperlipidemia.  A thorough neuropsychological assessment is conducted.  Inability to perform which of the following tasks would be most indicative of frontal lobe dysfunction?

Quizplus · Accepted Answer

The frontal lobes are involved in a wide array of functions, including personality, language, motor functions, and executive functions. Executive functions include abstraction, planning, impulse inhibition, attention, and working memory. Abstraction may be tested by asking a patient to describe the similarities between two objects (eg, a watch and ruler both measure things). Patients with frontal lobe damage may be unable to provide an answer or may provide concrete answers such as "they both have numbers." Because of its role in personality and impulse inhibition, processes that damage the frontal lobe (eg, traumatic brain injury, frontotemporal dementia) may lead to significant changes in behavior. Behavior change is more likely with bilateral, rather than unilateral, injury. Patients with frontal lobe injury may be disinhibited, socially inappropriate, irritable, and impulsive. (Choice A) Impaired language comprehension (ie, Wernicke aphasia) results from lesions in the dominant superior temporal gyrus. (Choices C and D) Patients with lesions in the dominant angular and supramarginal gyri (located in the parietal lobe) may have right-left disorientation and finger agnosia (ie, inability to recognize fingers). When these symptoms are accompanied by agraphia (ie, inability to write) and acalculia (ie, inability to perform arithmetic), it is known as Gerstmann syndrome. (Choice E) The inability to recognize a familiar face (ie, prosopagnosia) may result from lesions in the fusiform gyrus (located in the temporal and occipital lobes). Educational objective: The frontal lobes are involved in personality, language, motor functions, and executive functions (eg, abstraction). Frontal lobe function may be diagnosed by testing abstraction ability (eg, asking about the similarities between two related objects) on the mental status examination. __________ References: Why do patients with neurodegenerative frontal syndrome fail to answer: 'In what way are an orange and a banana alike?' (http://www.ncbi.nlm.nih.gov/pubmed/25518957)

A 62-Year-Old Man Comes to the Office with His Wife