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 basic 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 an MRI 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. Where in the temporal lobe is there degeneration and why is there a regional reduction in gray matter?
2. Why is the space of the lateral sulcus expanded?
3. What are the general classes of function of the anterior temporal lobe?
4. Degeneration also encompasses the insular cortex. What are some functions of the insular cortex? Key neurological signs and corresponding damaged brain structures Frontotemporal dementia
Considering the constellation of behavioral signs, the progressive nature of the signs, and the radiological pattern of neural degeneration, the patient is suffering from a form of 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 2–18), 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. ...