This 68-year-old right-handed woman was evaluated for parkinsonism. Over the prior nine months, she had progressively become more withdrawn from her husband, whom she had been married to for 45 years. Initially, she would intermittently startle when her husband came into the room. Later, she started to sleep in a separate bed and avoided changing her clothes in front of him. When her husband asked her if there was anything wrong, she avoided him without any explanation. She progressively became verbally and physically aggressive toward him, which led to an intervention by her children. When they asked her if there were interpersonal issues between her and their father, she reported that he was not her husband. She acknowledged the resemblance but insisted that he was actually an impostor. Her children’s attempts to prove her wrong only made her more agitated. She was taken to the emergency room, where, after ruling out infections, toxic exposures, and stroke, she was given diagnosis of a psychotic disorder and was started on an antipsychotic, risperidone 2 mg daily. While this helped with her agitation, she became slower in her thinking. Her level of attention would fluctuate, and sometimes it appeared as if she were in a daze. In addition, a bilateral hand tremor emerged, and she started to shuffle.

Within the ever-evolving field of cognitive and behavioral neurology, management remains the most challenging aspect in clinical practice. These cases are a testament to changing paradigms of care and the importance of understanding the impact of certain treatments.

Brain imaging can be a very helpful tool in the diagnosis of cognitive and behavioral neurology. As with the clinical examination, it must be carefully interpreted. We present cases where subtle clues affected diagnosis.

This 65-year-old right-handed woman presented with a 2-year history of worsening gait and short-term memory impairment. She first noticed slowness in her movements and impaired balance resulting in falls, mostly backward. She tried levodopa titrated to 1200 mg a day with no benefit. Over the previous year, she developed difficulties multitasking and was easily distracted. She endorsed difficulty swallowing and, more recently, urinary incontinence. Her husband noted that she was withdrawn and seemed to have lost interest in hobbies and in social interactions with the family. She denied depression, anxiety, cognitive fluctuations, or hallucinations. She endorsed decreased sense of smell and a history of dream enactment behaviors. On neurological exam, she was easily distractible and tangential. Her speech was hypophonic. Her extraocular eye movements were normal. There was symmetric bradykinesia and distal hand myoclonus when the arms were held outstretched. She was unable to walk unaided (Video 23.1). The Montreal Cognitive Assessment (MoCA) score was 18/30, with impairments in trail making, cube copying, and clock drawing, backward digit span, serial sevens, sentence repetition and delayed recall (she recalled one word freely and recognized the other four when multiple choices were given).

This 51-year-old right-handed woman requested further care for her previously diagnosed Alzheimer disease. Over the previous year, her coworkers observed that she would frequently forget instructions and conversations and increasingly relied on written reminders. She would ask the same question repeatedly and cueing helped inconsistently. Her symptoms had not worsened since. There were no language or visuospatial impairments. Her past medical history included lumpectomy and tamoxifen for breast cancer five years ago, and a 30-year history of alcohol abuse (daily beer and vodka, unknown volume). Indeed, family members reported finding empty bottles of vodka in the garbage. She had no family history of cognitive impairment or other neurologic condition. Previous work up included a normal blood work, brain MRI with contrast, normal cell count, protein, glucose, and cytology in cerebrospinal fluid, but bilateral temporoparietal hypometabolism on FDG-PET (Figure 35.1). With a presumed diagnosis of Alzheimer disease, she was started on donepezil 5 mg daily.

This 69-year-old right-handed woman presented with 3-year history of progressive memory problems. Her husband described her initial difficulty was recalling recent events along with repeating stories. Within a year, she struggled with reading and with recognizing people, which she attributed to a change in vision. An ophthalmologic evaluation revealed bilateral cataracts, which were surgically corrected. However, her visual abilities continued to decline after surgery. She started having difficulties identifying objects and judging distances, which led her to stop driving. She denied any issues with her memory and attributed all of her problems to her vision, although she could not elaborate further. Her exam was remarkable for a circumlocutory discourse. Her Montreal Cognitive Assessment (MoCA) score was 12/30 due to impairments in trail making, cube copying, clock drawing, naming, serial sevens, phonemic fluency, delayed recall (she could not recall any words freely and recognized only one when multiple choices were given), and orientation to month and date.

This 60-year-old woman presented with a 6-year history of bilateral hand tremor and progressive gait impairment. She first noticed bilateral hand tremor when holding objects, followed by balance impairment, slow walking with foot dragging, and a tendency to fall forward. Within four years, she required a wheelchair for ambulation. She endorsed initial short-term memory affecting her ability to process information, which accelerated in the last year. Two years prior to the onset of her symptoms she had received chemotherapy (carboplatin and etoposide) with prophylactic whole-brain radiation as treatment for lung cancer.

This 65-year-old right-handed man presented with worsening “memory” problems for the past 5 years. He first noticed increasing difficulties with performing previously well-known and simple repairs at home, such as changing a light switch. A neuropsychological evaluation was reportedly normal. More recently, his family noticed declining skills in driving and use of appliances. In addition, performance of other tasks, such as preparing coffee, was affected by pauses and unnecessary steps. More recently, he was forgetful about recent events and unintentionally repetitive. There were no word-finding or navigation difficulties. On exam, he did not appear to be concerned about his impairments and inappropriately joked about them. His speech was fluent with occasional word-finding difficulties. He displayed optic ataxia and oculomotor apraxia, as well as simultanagnosia.

This 57-year-old right-handed woman presented to the clinic after four episodes of amnesia. The first one occurred six months previously while at her daughter’s house. Abruptly, she became disoriented to location and situation. She knew who she was and could recognize her daughter. She was reoriented by her daughter multiple times but still repeatedly asked where she was. She was taken to the emergency room, and after 45 minutes, she returned to her baseline and could recall the episode of disorientation. Her neurological exam was unremarkable, as well as her laboratory investigations, brain MRI, and EEG. She was discharged back home with the diagnosis of transient global amnesia (TGA). She had three additional episodes of similar characteristics since then, all within the last two months. She was on treatment with amlodipine for hypertension. Her repeat exam in the office setting was unremarkable.

This 76-year-old right-handed man with an amnestic presentation, suspicious for Alzheimer disease and diagnosed 5 years earlier, returned to the clinic for follow-up. Although he initially experienced improvement with donepezil, his cognition progressively declined over the following three years. In the last six months, his wife, who was his primary caregiver, noted that he was more forgetful and repetitive. However, now when he misplaced objects (e.g., wallet, books), he became convinced that the lost objects were stolen, even when the missing items were found and shown to him. Her repeated attempts to reassure him that the objects were merely misplaced triggered agitation and confusion. No threatened or real physical aggression ensued. In the office, he had no recollection of the events. He was oriented to place and person. His speech was fluent and his discourse was circumlocutory. The remainder of the exam was unremarkable.

This 70-year-old right-handed woman presented with a 2-year history of slowly worsening cognition, then with more recent abrupt decline. She noted increasing difficulty recalling recent events and coming up with words. Over the last month, her family reported that she became slow in her thinking and easily confused. About a week prior to this assessment, she had been found on the floor unresponsive and taken to the emergency room, where she had a witnessed seizure. Metabolic abnormalities and infections were ruled out. A lumbar puncture showed elevated protein (80 mg/dl) but no other abnormalities. Her brain MRI without contrast showed asymmetric subcortical and periventricular T2 hyperintensities (Figure 45.1). She was started on levetiracetam 500 mg BID. Since then, she continued to decline but did not have further seizures. On examination, she exhibited bradyphrenia and fluctuating alertness.

This 60-year-old woman presented with a 2-year history of cognitive changes and hallucinations concerning for dementia with Lewy bodies (DLB). She first reported seeing a bright moving circle out of her right visual field. The image was always the same and the episodes lasted 20 seconds. Their frequency increased to five times a day over the course of six months. After each episode, she experienced a headache lasting up to an hour with no associated nausea or photophobia. She had been initially diagnosed with migraine with aura and tried propranolol, verapamil and amitryptline, to no avail. Since starting topiramate six months prior to her evaluation the frequency had reduced to about once a day. However, she felt forgetful, slower in her thinking and had difficulty finding words since initiating topiramate treatment. The development of cognitive impairment in the background of hallucinations had raised the concern for early stages of DLB. However, she denied any motor changes (i.e., parkinsonism) or sleep disturbances (i.e., symptoms of REM sleep behavior disorder).

This 52-year-old man presented to the emergency room with aggressive behavior and emotional lability progressing over the previous three days. He had completed a three-week course of acyclovir for the treatment of herpes simplex encephalitis (HSE) two weeks prior. Other than residual mild memory difficulties, he was fully functional until his more recent behavioral changes. He was afebrile and his vitals were within normal limits. He was irritable and his attention fluctuated. His exam otherwise unremarkable. MRI of the brain with and without contrast was unremarkable. Laboratory results were significant only for mildly increased CSF protein (100 mg/dl normal range: 15–45 mg/dl). Given the concern of HSE relapse, he was placed on acyclovir again.

This 76-year-old man returned to the clinic, brought by his daughter for monitoring of his progressive memory impairment. Five years previously, neuropsychological evaluation revealed memory encoding deficits and brain MRI showed asymmetric hippocampal atrophy. With a diagnosis of probable Alzheimer disease, he was started on rivastigmine, gradually increased to a dose of 6 mg BID. The family noticed better thinking and less forgetfulness for six months, but he continued to decline thereafter. He went on to have difficulty dressing and bathing and experienced delusions of theft. After five years of treatment with rivastigmine, his daughter wondered if it should be discontinued.

This 44-year-old right-handed woman with 12 years of education presented to the clinic with behavioral changes in the context of abnormal movements. Her husband noticed she became emotionally distant and withdrawn three years prior. Around the same time, she exhibited restlessness and continual movements in her hands, which later spread to her whole body. She was initially thought to be depressed and treated with sertraline (titrated up to 200 mg a day) with no benefit. Within a year of symptom onset, impulsive, inappropriate behaviors emerged (e.g., making comments about other people in public and eating from her husband’s plate), accompanied by some delusional thoughts (e.g., thinking her family was trying to hurt her and the government was spying on her).