Clinical Reasoning: Progressive visuospatial problems in a 71-year-old man

Abstract

A 71-year-old right-handed man presented with a 3-month history of progressive cognitive impairment. Six weeks before presentation, he became unable to use his mobile phone, with difficulties pressing the digits in the correct order. He had developed problems reading, describing a jumbledup appearance of words on the page. He omitted single letters when writing, and had difficulty in using cutlery and accurately judging portion sizes. He had ceased driving due to navigational problems and because of repeatedly hitting the curb. In the last 4 weeks, he had developed difficulty dressing. Notably, he had good insight, being able to give a detailed description of symptoms.Four years earlier, the patient had been diagnosed with rheumatoid arthritis (RA) and commenced immunomodulatory therapy with methotrexate (15 mg/wk plus folic acid 5 mg/wk) and hydroxychloroquine (200 mg/d). One year later, following an exacerbation of joint symptoms and the development of interstitial lung disease thought to be a systemic complication of RA, his methotrexate dose was increased to 25 mg/wk (subcutaneously) and leflunomide (10 mg/d) was added. At presentation, he remained on methotrexate and hydroxychloroquine at the same doses, but leflunomide had been discontinued and sulfasalazine (3 g daily) commenced. The only other history of note was an episode of obstructive cholestasis. He was otherwise well, and the main carer for his wife.Examination revealed marked visuospatial dysfunction and simultanagnosia. The patient was able to read when presented with one line of text, but unable to read a paragraph. Object recognition was preserved; however, he was unable to describe a picture of a scene. He could not recognize interrupted figures or letters. He had an ideomotor limb apraxia, with impaired gesture copying (e.g., extending the 1st and 2nd digits at right angles). He scored 16/30 on the Montreal Cognitive Examination (MoCA), with severe constructional apraxia, being unable to draw a cube or clock, performing poorly on the Trail-Making Test (figure, A), and additional impairments on vigilance testing and serial 7s, reduced verbal fluency, and impaired delayed recall. There was no dysgraphesthesia or neglect. Speech was intact, and he could understand and follow written commands. There were no parkinsonian features and the remainder of the neurologic examination was normal. Systemic examination revealed bibasal lung crepitations. His admission blood pressure was 128/75 mm Hg. There was no clinical evidence of active joint inflammation.