TY - JOUR T1 - A cause of encephalopathy not to be missed JF - Practical Neurology JO - Pract Neurol SP - 524 LP - 527 DO - 10.1136/practneurol-2022-003389 VL - 22 IS - 6 AU - Tarig Abkur AU - Jonathan Cleaver AU - Kanchan Sharma Y1 - 2022/12/01 UR - http://pn.bmj.com/content/22/6/524.abstract N2 - A 56-year-old right-handed man was admitted to the hospital with a 7-day history of gradual-onset holocephalic headache. Two days after headache onset, he had developed dysarthria, musical hallucinations and progressive confusion. He had become non-verbal on the day of admission.He had a 10-year history of type 2 diabetes mellitus and bilateral sensorineural hearing impairment, requiring hearing aids. Close family members had noted further hearing deterioration two weeks before admission, which was later confirmed by audiometry; this affected both sides symmetrically particularly at higher frequencies. His maternal grandmother also had hearing impairment. He did not smoke or drink alcohol and had not used illicit drugs.His vital signs were stable but detailed physical examination was precluded by extreme agitation and aggressive behaviour. His attention was drawn only by standing directly in front of him, suggesting a bilateral peripheral vision loss. He moved all his limbs symmetrically without obvious ataxia and was ambulant. He could follow simple commands. Speech was limited to unintelligible sounds, but he could communicate by writing.Questions for considerationWhere do you localise the symptoms?What is the most likely differential diagnosis at this point?This man had new-onset headache, auditory hallucinations, worsening encephalopathy and seemed to have developed a new visual impairment affecting the peripheral vision bilaterally. Encephalopathy is often caused by a widespread multifocal process but can also result from a single lesion involving the frontal lobe or any part of the Papez circuit.The dissociation between poor verbal expression with intact writing suggested speech apraxia, which would localise to the inferior frontal and superior temporal cortex.Although difficult to characterise precisely here, his visual impairment suggested a bilateral peripheral visual field defect with central sparing. This pattern may occur with diffuse retinal disease or bilateral posterior cortical involvement, which further supports the multifocal nature of the disease. … ER -