In the third of our monthly series, Dr Roger Henderson asked readers to suggest what the cause of this patient’s confusion and change of mood was. Did you get the answer? Check below! (If you want to look at the case without spoilers, have a look at the original case here)
The case
A 38 year old man had been experiencing anxiety, anger outbursts and some hallucinations over the previous nine months, sufficient to warrant a referral for a psychiatric opinion. He had no pre-existing medical conditions, smoked both conventional tobacco and cannabis daily, was unemployed and had a past history of homelessness fifteen years earlier. He admitted to working as a sex worker during this time. There was no family history of significant illness – including dementia – and he did not drink alcohol excessively. His psychiatrist commenced him on antipsychotics but these appeared to have had little effect and his symptoms progressively worsened, including a loss of appetite and deteriorating cognitive impairment. He was kept under psychiatric review.
He then presented acutely with urinary incontinence, difficulty in speaking and confusion. Examination showed him to be alert but slow in movement, thin, tattooed, unkempt, malnourished and wary of interacting with any healthcare professional. He was obviously disorientated in both time and place, occasionally verbally aggressive, and with a degree of dysarthria and some mild bradykinesia. He had a negative Romberg test. Although examination was difficult, it appeared that his light reflexes were slightly reduced. He was admitted to hospital immediately for further investigations.
A number of blood tests were performed, including a full blood count, liver function tests, blood glucose, urea and electrolytes, inflammatory markers, thyroid function tests, HIV and hepatitis screen. These were all found to be negative. A chest X-ray and ECG were normal, and he had no obvious cardiac abnormalities on examination. His cognitive impairment rapidly worsened and further investigations were arranged including a brain MRI scan, lumbar puncture and serological testing.
Answer
His brain MRI showed some diffuse cerebral and cerebellar atrophy, and no space-occupying lesion. Analysis of his cerebrospinal fluid showed it to be positive for syphilis, as did his serological assay. Clinical findings and serological assessment were therefore compatible with neurosyphilis, particularly in the form of general paresis. He was treated with high-dose intravenous crystallized penicillin and his antipsychotic regimen was changed.
Unfortunately there was little demonstrable change in his symptoms due to the advanced stage of his neurosyphilis. Although tertiary stage syphilis is rare, early stage syphilis may be overlooked and so left untreated leading to irreversible neuronal damage.
Well done if you got this diagnosis right! Tertiary syphilis is often overlooked as a diagnosis due to its increasing rarity but should be considered as a differential diagnosis in cases of unexplained personality changes, psychosis and confusion. It should also be remembered that it can present one to thirty years after the initial untreated primary infection.
Dr Roger Henderson is a GP in south-west Scotland
