13.1 Clinical History – Main Complaint

JX is a 60-year-old man who presented to his general practitioner in mid-June of 2015 complaining that he was finding his spreadsheets at work harder to manage. He had taken a month of leave to seek medical attention. He had no difficulties describing the content of the spreadsheets to his colleagues, but found he had to zoom in on the specific pieces of data to be able to see them. He noted if he intently stared at the screen things would move around or change. He initially saw an opthalmologist, and there were no issues with his fields or acuity. He stated straight lines appeared crooked or had “knuckles” on them.

His wife noticed the occasional difficulty grasping new mental concepts or interpretating what an object in front of him was. Number recognition could be difficult. She noted the issues first started 4 years ago, had been slowly progressive, but was not affecting his work until recently.

He described accompanying lethargy and some weight loss despite not changing his lifestyle.

13.2 General History

JX has a year 10 education and works in a very demanding position involving the electronic statewide logistic coordination of fire service assets in a highly fire-prone state. His medical history is only significant for obstructive sleep apnea (which responded to a jaw splint). He lives with his wife and has two healthy children.

He has no regular medications. He drinks 10–20 g of alcohol a day.

He has never smoked and has no history of hypertension, diabetes, or hypercholesterolemia.

13.3 Family History

His mother is currently alive with a diagnosis of probable Alzheimer’s disease. No other significant family history.

13.4 Examination

BP 130/80, pulse 70 regular, chest was clear, and there was no significant adenopathy or organomegaly.

Cranial nerve examination was normal, as was peripheral nerve testing. There was no evidence of cerebellar dysfunction, nor signs of parkinsonism. There were no clinical frontal release signs. His gait was unremarkable.

Foldstein’s Mini-Mental State Examination (MMSE): 27/30 (lost one point in orientation, one with recall and significant difficulty with construction, failing to copy one pentagram). Clock face drawing was significantly impaired. Frontal Assessment Battery score: 17/18 (one point lost in mental flexibility). The score was 3/15 on the Geriatric Depression Scale (indicating low probability of depression).

13.5 Special Studies

MRI head – moderate bilateral parietal lobe atrophy. No temporal or hippocampal atrophy. No significant small vessel disease.

Blood results – vasculitis screen, TSH, B12, folate, HIV, syphilis serology all negative.

EEG – no abnormalities detected.

Neuropsychological testing – extremely severe visuoperceptual and visuoconstructional impairment. He was unable to put down more than a few isolated features from a complex figure (see Figure 13.1). Color identification was accurate. There may have been some mild left-sided visual neglect. There was no optic ataxia. There were several visual misperceptions (a dog’s head was seen as a guitar, still struggling even when his mistake was pointed out). Reading was accurate with slight hesitancy. Writing to dictation was accurate but messy. There was some subtle bilateral finger agnosia. He described mild difficulty with dressing. There were no issues with working memory or mental arithmetic. There was no evidence of a receptive dysphasia. His executive mental flexibility was in the superior range when corrected for his poor visual tracking. Semantic and verbal fluencies were in the high average range.

Figure 13.1 SPECT scan image demonstrating particularly right posterior parietal issues taken at JX’s initial presentation.

SPECT scan – moderate hypoperfusion of the posterior parietal lobes, more marked on the right. Patchy hypoperfusion of the temporal lobes posterolaterally and anteromedially. Preservation of frontal, occipital, and subcortical regions (see Figure 13.2).

Figure 13.2 Rey diagram and that constructed by JX at initial presentation in mid-2015. .

A lumbar puncture was not felt to be necessary.

13.6 Diagnosis

Atypical Alzheimer’s disease – posterior cortical atrophy (PCA) (Benson’s syndrome).