CLINICAL CASE | Anterior Temporal Lobe Degeneration
A 67-year-old woman was dining with her family when she was not able to recognize a food she commonly ate. She had been an empathetic person but recently has begun to be self-centered and unconcerned about others' feelings, including those of her daughter, with whom she was close. She had been socially dominant and extraverted, but recently lost that dominance, and has become neurotic and introverted. She had been a successful travel agent and had visited many countries worldwide, but she was now unable to recall the names of many of the places she had visited multiple times.
Over the next 2 years, her condition progressed, so that she was unable to recognize familiar people, words, and objects. Despite having normal calculation abilities, she stopped controlling her own finances. Around this time, her eating behavior changed. She also expressed socially inappropriate behaviors. For example, she developed a preference for sweets and condiments, and sometimes she ate condiments as food. She also tried to eat nonfood items. Her sensory and motor functions were unaffected, as were her visuospatial functions and episodic memory. Her speech and language were grammatically correct and fluent.
Figure 16–1A is from the patient, showing clear and marked degeneration of the right anterior temporal lobe; Figure 16–1B is an MRI from a healthy person at a similar placement within the anterior temporal lobe. Degeneration is manifested both as a reduction in the gray and white matter of the anterior temporal lobe and insular region, as well as a corresponding expansion of the lateral sulcus and other temporal lobe sulci (eg, rostral superior temporal sulcus). Notice that other brain regions (eg, head of caudate nucleus) appear normal.
Answer the following question based on your reading of this chapter.
1. Degeneration in which part of the temporal lobe accounts for the patient's impairments? Key neurological signs and corresponding damaged brain structures Frontotemporal dementia
The patient is suffering from frontotemporal dementia, a progressive degenerative disease characterized by loss of parts of the frontal and/or anterior temporal lobe; it can be lateralized. In this patient, it is primarily right-sided. Brodmann's area 38, amygdala, and corticocortical connections
Brodmann's area 38, the cortex of the temporal pole (see Figure 2–19), has corticocortical interconnections with other limbic cortical areas, including orbitofrontal cortex; it is interconnected with the amygdala, as well. These areas form a network, so that the personality changes, oral tendencies, and semantic impairments are difficult to attribute to a single structure. References
Gainotti G, Barbier A, Marra C. Slowly progressive defect in recognition of familiar people in a patient with right anterior temporal atrophy. Brain. 2003;126:792-803.
Gorno-Tempini ML, Rankin KP, Woolley JD, Rosen HJ, Phengrasamy L, Miller BL. Cognitive and behavioral profile in a case of right anterior temporal lobe neurodegeneration. Cortex. 2004;40(4-5):631-644.
Mummery CJ, Patterson K, Price CJ, Ashburner J, Frackowiak RSJ, Hodges JR. A voxel-based morphometry study of semantic dementia: relationship between ...