According to researchers who conducted and released several small case studies, a need for a "high index of suspicion for possible fungal meningitis" when ischemic stroke takes place in the subsequent circulation and patients have a history of epidural spinal injections is curial.
Of these three cases, one patient suffered a stroke a whole month following an epidural injection of tainted methylprednisolone. While the remaining two experienced stroke just after 2 weeks of injection, said senior author and neurologist at Vanderbilt University in Nashville, Daniel O. Claassen.
In the previous year, a compounding pharmacy in Massachusetts distributed contaminated methylprednisolone, which resulted in many deaths from fungal meningitis.
"We are finding all sorts of new presentations of fungal infections of the central nervous system. This particular fungus is angiotropic, which means it likes blood vessels. We think it is traveling and creating an inflammatory reaction in blood vessels. That's why we are seeing presentations of stroke,” said professor in the division of infectious diseases at the University of Texas Health Science Center at Houston, Luis Ostrosky, MD.
Two patients had small-vessel infarcts, while one had a large-vessel infarct. The infarcts were fueled by basilar, superior cerebellar, and posterior cerebral artery branches.
The infection can fester over a period of 1 to 4 weeks between the last spinal injection and when a patient seeks medical help.
Early MRI scans exhibited signs of a standard ischemic stroke. All three patients had at least one or more potential stroke risk factors.
“Presenting with stroke is not completely atypical for this disease, but the rate is not abnormally high,” said Claassen.
Furthermore, in possible cases of infection, a screening MRI may provide early warning of spinal or paraspinal meningitis.
For the first case study, a 78-year-old man experienced acute onset of left-sided weakness and speech disorder, yet exhibited no meningeal symptoms at the time.
Following the third day, MRI scans showed infarct expansion, and the patient's left-sided weakness increased. He died on the sixth day. An autopsy revealed fungal cerebral vasculitis and Exserohilum species were discovered microscopically.
The second case involved a 78-year-old woman who complained of headache, vertigo, and nausea. She had mild ataxia and MRI scans showed ischemic infarcts in the posterior circulation, one indicator of a large-vessel infarct, but stenosis was omitted on CT angiography.
She became feverish on the fourth day and neurologists noted mild encephalopathy. MRI revealed a new infarct as her health continued to decline. Because of her history of epidural injections and, at the time, recent reports of fungal meningitis, researchers performed a lumbar puncture and results called for antibiotics.
She died 50 days later. An autopsy showed hyphal fungal forms in the arterial wall that researchers assumed signified Exserohilum species based on CDC studies.
For case 3, a 70-year-old woman, exhibited headaches, fever, and was off-balance. She had been administered an epidural spinal injection 1 month prior. MRI revealed small-vessel ischemic strokes, but MR angiography did not point to any major stenoses.
Again, concerned for meningitis led to a lumbar puncture and according to results, antibiotics were started. She was released 37 days later.
"These cases highlight a diagnostic dilemma for neurologists. Patients with fungal meningitis who present with ischemic strokes may be afebrile, lack signs of meningeal irritation, and have traditional stroke risk factors," Claassen and fellow researchers said.
"An awareness of the presentation and vascular sequelae of fungal meningitis in immunocompetent patients should lead to earlier treatment and improved outcomes prior to a definitive diagnosis," they concluded.